Articles in scientific journals

TítuloAutoresLínea de InvestigaciónAñoDOIAbstractRevistaISSNAccesoPáginasVolumenIndexKey Words
Overcoming energy poverty through micro-grids: An integrated framework for resilient, participatory sociotechnical transitionsValencia, Felipe; Billi, Marco; Urquiza, AnahíCiudades Resilientes; Gobernanza e Interfaz Ciencia y Política2021.010.1016/j.erss.2021.102030Nowadays, the sustainability of micro-grids has received much attention in the research community since micro-grids are becoming an appealing alternative to provide clean energy access to rural communities, and by this token, contribute to overcome energy poverty. The aim of this paper was to investigate the sustainability of micro-grids through the analysis of their resilience. In this regard, an integrated framework was developed combining socio-technical transitions with socio-ecological resilience concepts. This allows to pay attention at once to two dimensions of micro-grid sustainability: (i) the ability of the micro-grid to effectively transform the relationship between community, energy, and territory to make it more sustainable in economic, social and environmental terms; (ii) the sustainability of the micro-grid itself, namely, its ability to endure, adapt to and recover from changes in contextual factors which may limit its operativity over time. Methodological guidelines are offered for the participatory co-construction and monitoring of the micro-grid and its monitoring, supporting both dimensions. To illustrate our proposal, the micro-grid installed in Huatacondo, north of Chile, was used as test-bed.Energy Research & Social Science22146296 Reuters ISIchile, energy poverty, micro-grids, participatory co-construction, socio-ecological resilience, socio-technical transitions, sustainability
The role of climate and disturbance regimes upon temperate rainforests during the Holocene: A stratigraphic perspective from Lago Fonk (∼40°S), northwestern PatagoniaHenríquez, Carla A.; Moreno, Patricio I.; Lambert, Fabrice; Alloway, Brent V.Ciudades Resilientes; Agua y Extremos2021.010.1016/j.quascirev.2021.106890Quaternary Science Reviews02773791 Reuters ISIcharcoal, explosives, fires, forestry, stratigraphy, volcanoes, centennial/millennial-scale variability, climate regime, disturbance regime, explosive volcanism, fire disturbance, holocenes, lake sediment cores, patagonia, pollen analysis, temperate rainforest, lakes, charcoal, climate variation, disturbance, explosive volcanism, fossil record, holocene, rainforest, stratigraphy, temperate forest, vegetation dynamics, chile, cumbria, england, lake district, longitudinal valley, patagonia, taiwan, united kingdom, eucryphia
Hydrological droughts in the southern Andes (40–45°S) from an ensemble experiment using CMIP5 and CMIP6 modelsAguayo, Rodrigo; León-Muñoz, Jorge; Garreaud, René; Montecinos, AldoAgua y Extremos2021.010.1038/s41598-021-84807-4Abstract The decrease in freshwater input to the coastal system of the Southern Andes (40–45°S) during the last decades has altered the physicochemical characteristics of the coastal water column, causing significant environmental, social and economic consequences. Considering these impacts, the objectives were to analyze historical severe droughts and their climate drivers, and to evaluate the hydrological impacts of climate change in the intermediate future (2040–2070). Hydrological modelling was performed in the Puelo River basin (41°S) using the Water Evaluation and Planning (WEAP) model. The hydrological response and its uncertainty were compared using different combinations of CMIP projects (n = 2), climate models (n = 5), scenarios (n = 3) and univariate statistical downscaling methods (n = 3). The 90 scenarios projected increases in the duration, hydrological deficit and frequency of severe droughts of varying duration (1 to 6 months). The three downscaling methodologies converged to similar results, with no significant differences between them. In contrast, the hydroclimatic projections obtained with the CMIP6 and CMIP5 models found significant climatic (greater trends in summer and autumn) and hydrological (longer droughts) differences. It is recommended that future climate impact assessments adapt the new simulations as more CMIP6 models become available.Scientific Reports2045-2322 Reuters ISI
A source of isotopically light organic carbon in a low-pH anoxic marine zoneVargas, Cristian A.; Cantarero, Sebastian I.; Sepúlveda, Julio; Galán, Alexander; De Pol-Holz, Ricardo; Walker, Brett; Schneider, Wolfgang; Farías, Laura; D’Ottone, Marcela Cornejo; Walker, Jennifer; Xu, Xiaomei; Salisbury, JoeZonas Costeras2021.010.1038/s41467-021-21871-4Abstract Geochemical and stable isotope measurements in the anoxic marine zone (AMZ) off northern Chile during periods of contrasting oceanographic conditions indicate that microbial processes mediating sulfur and nitrogen cycling exert a significant control on the carbonate chemistry (pH, A T , DIC and p CO 2 ) of this region. Here we show that in 2015, a large isotopic fractionation between DIC and POC, a DIC and N deficit in AMZ waters indicate the predominance of in situ dark carbon fixation by sulfur-driven autotrophic denitrification in addition to anammox. In 2018, however, the fractionation between DIC and POC was significantly lower, while the total alkalinity increased in the low-pH AMZ core, suggesting a predominance of heterotrophic processes. An isotope mass-balance model demonstrates that variations in the rates of sulfur- and nitrogen-mediated carbon fixation in AMZ waters contribute ~7–35% of the POC exported to deeper waters. Thus, dark carbon fixation should be included in assessments of future changes in carbon cycling and carbonate chemistry due to AMZ expansion.Nature Communications2041-1723 Reuters ISIcarbon, carbonic acid, nitrogen, organic carbon, oxygen, sulfur, water, anoxic conditions, carbon fixation, carbonate system, denitrification, isotopic fractionation, organic carbon, particulate organic carbon, stable isotope, alkalinity, anaerobic ammonium oxidation, article, carbon cycling, carbon dioxide tension, carbon fixation, denitrification, fractionation, heterotrophy, inorganic nutrient, light, microbial community, ph, salinity, temperature, chile
A review of the observed air temperature in the Antarctic Peninsula. Did the warming trend come back after the early 21st hiatus?Carrasco, Jorge F.; Bozkurt, Deniz; Cordero, Raul R.Zonas Costeras; Agua y Extremos2021.010.1016/j.polar.2021.100653Recent changes in the near-surface air temperature (nSAT) in the Antarctic Peninsula (AP) suggests that the absence of 21st century warming on Antarctic Peninsula may be coming to end. To examine this, the long-term annual and seasonal variability of the nSAT at eight Antarctic stations located in the AP are analyzed using available data from the SCAR Reader database, complemented with data from the Chilean Weather Service (Frei and O’Higgins). An exponential lter was applied to the original annual and seasonal mean series to obtain a decadal-like variation of the nSAT. A stacked and the standardized anomaly of the nSAT record was constructed to examine the average regional behavior in the AP. Cumulative sum (CUSUM) and changepoint analysis were applied through the stacked nSAT series to highlight signi cant changes caused by variation in weather and climate. The CUSUM and bootstrapping analysis revealed two statistically signi cant breaking points during the 1978–2020 period. The rst one occurred in the late nineties ending a warming period and making the beginning of a cooling period; the second one may have taken place in the mid-2010s and could mark the end of the warming pause. These trends appear to be consistent with the changes observed in the large-scale climate modes (i.e., the Antarctic Annular Mode – AAO).Polar Science18739652 Reuters ISIair temperature, antarctic peninsula, change point, reader database, warming and cooling trends
Air pollution and COVID-19 lockdown in a large South American city: Santiago Metropolitan Area, ChileToro A., Richard; Catalán, Francisco; Urdanivia, Francesco R.; Rojas, Jhojan P.; Manzano, Carlos A.; Seguel, Rodrigo; Gallardo, Laura; Osses, Mauricio; Pantoja, Nicolás; Leiva-Guzman, Manuel A.Ciudades Resilientes2021.010.1016/j.uclim.2021.100803The implementation of confinement and physical distancing measures to restrict people's activities and transit in the midst of the COVID-19 pandemic allowed us to study how these measures affect the air quality in urban areas with high pollution rates, such as Santiago, Chile. A comparative study between the concentrations of PM10, PM2.5, NOx, CO, and O3 during the months of March to May 2020 and the corresponding concentrations during the same period in 2017–2019 is presented. A combination of surface measurements from the air quality monitoring network of the city, remote satellite measurements, and simulations of traffic activity and road transport emissions allowed us to quantify the change in the average concentrations of each pollutant. Average relative changes of traffic emissions (between 61% and 68%) implied statistically significant concentrations reductions of 54%, 13%, and 11% for NOx, CO, and PM2.5, respectively, during the pandemic period compared to historical period. In contrast, the average concentration of O3 increased by 63% during 2020 compared to 2017–2019. The nonlinear response observed in the pollution levels can be attributed to the changes in the vehicular emission patterns during the pandemic and to the role of other sources such as residential emissions or secondary PM.Urban Climate22120955 Reuters ISIcovid-19 lockdown, traffic emission rates, urban air quality
Disentangling the effect of future land use strategies and climate change on streamflow in a Mediterranean catchment dominated by tree plantationsGalleguillos, Mauricio; Gimeno, Fernando; Puelma, Cristóbal; Zambrano-Bigiarini, Mauricio; Lara, Antonio; Rojas, MaisaCambio de Uso de Suelo; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2021.010.1016/j.jhydrol.2021.126047Climate change (CC) along with Land Use and Land Cover Change (LULCC) have a strong influence in water availability in already fragile Mediterranean ecosystems. In this work the Soil and Water Assessment Tool (SWAT) was implemented for the 2006–2018 period in a rainfed catchment of central Chile (36°) to test the hypothesis that adaptive plantation strategies could mitigate the impacts of climate change and increase streamflow. We also hypothesize that afforestation with exotic tree plantations will reduce water availability in Mediterranean catchments, acting in synergy with climate change. Five LULCC scenarios are analyzed: i) current long-term national Forest Policy (FP), ii) extreme scenario (EX) with large afforestation surfaces, both including the replacement of native shrublands with Pinus radiata; iii) adaptive plantation management scenario (FM), with lower planting density, iv) forced land displacement scenario (FLD), where plantations at the headwaters are moved to lowland areas and replaced with native shrublands, and v) pristine scenario (PR), with only native vegetation. Each LULCC scenario was run with present climate and with projections of different CMIP5 climate models under the RCP 8.5 scenario for the period 2037–2050, and then compared against simulations based on the present land cover and climate. Simulations with the five LULCC scenarios (FP, EX, FM, FLD and PR) with present climate resulted in variations of −2.5, −17.3, 0, 2.3 and 10.9% on mean annual streamflow (Q), while simulations with the current land cover and CC projections produced a 32.1% decrease in mean annual Q. The joint impact of CC and LULCC leads to changes in mean annual Q ranging from −46.2% (EX) to –23.3% (PR). Afforestation with exotic pines will intensify the reduction in water yield, while conservative scenarios focused on native forests protection and restoration could partially mitigate the effect of CC. We make a strong call to rethink current and future land management strategies to cope with lower water availability in a drier future.Journal of Hydrology00221694 Reuters ISIcatchments, climate models, conservation, land use, reforestation, runoff, stream flow, land use and land cover change, land-use strategies, mediterranean catchment, mediterranean ecosystem, plantation managements, protection and restoration, soil and water assessment tool, water availability, climate change, afforestation, catchment, climate change, coniferous forest, coniferous tree, land cover, land use, land use change, shrubland, soil and water assessment tool, streamflow, tree planting, mediterranean region, pinus radiata
Radiocarbon bomb-peak signal in tree-rings from the tropical Andes register low latitude atmospheric dynamics in the Southern HemisphereAncapichún, Santiago; De Pol-Holz, Ricardo; Christie, Duncan A.; Santos, Guaciara M.; Collado-Fabbri, Silvana; Garreaud, René; Lambert, Fabrice; Orfanoz-Cheuquelaf, Andrea; Rojas, Maisa; Southon, John; Turnbull, Jocelyn C.; Creasman, Pearce PaulCiudades Resilientes; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2021.010.1016/j.scitotenv.2021.145126South American tropical climate is strongly related to the tropical low-pressure belt associated with the South American monsoon system. Despite its central societal role as a modulating agent of rainfall in tropical South America, its long-term dynamical variability is still poorly understood. Here we combine a new (and world's highest) tree-ring 14C record from the Altiplano plateau in the central Andes with other 14C records from the Southern Hemisphere during the second half of the 20th century in order to elucidate the latitudinal gradients associated with the dissemination of the bomb 14C signal. Our tree-ring 14C record faithfully captured the bomb signal of the 1960's with an excellent match to atmospheric 14C measured in New Zealand but with significant differences with a recent record from Southeast Brazil located at almost equal latitude. These results imply that the spreading of the bomb signal throughout the Southern Hemisphere was a complex process that depended on atmospheric dynamics and surface topography generating reversals on the expected north-south gradient in certain years. We applied air-parcel modeling based on climate data to disentangle their different geographical provenances and their preformed (reservoir affected) radiocarbon content. We found that air parcel trajectories arriving at the Altiplano during the bomb period were sourced i) from the boundary layer in contact with the Pacific Ocean (41%), ii) from the upper troposphere (air above the boundary layer, with no contact with oceanic or continental carbon reservoirs) (38%) and iii) from the Amazon basin (21%). Based on these results we estimated the ∆14C endmember values for the different carbon reservoirs affecting our record which suggest that the Amazon basin biospheric 14C isoflux could have been reversed from negative to positive as early as the beginning of the 1970's. This would imply a much faster carbon turnover rate in the Amazon than previously modelled.Science of The Total Environment00489697 Reuters ISIboundary layers, carbon, forestry, topography, tropics, atmospheric dynamics, carbon reservoirs, continental carbons, geographical provenances, latitudinal gradients, southern hemisphere, tropical climates, upper troposphere, bombs (ordnance), carbon 14, atmospheric circulation, atmospheric dynamics, atmospheric modeling, carbon isotope, latitudinal gradient, paleoclimate, radiocarbon dating, southern hemisphere, tree ring, amazonas (brazil), araucaria, araucaria angustifolia, article, atmosphere, atmospheric circulation, bomb, bomb signal, carbon reservoir effect, chile, controlled study, environmental impact, environmental parameters, geographic distribution, latitude, new zealand, nonhuman, pacific ocean, plant structures, polylepis tarapacana, priority journal, rosaceae, southern hemisphere, surface topography, topography, tree ring, troposphere, turnover rate, bomb, brazil, sea, tree, amazon basin, andes, brazil, new zealand, pacific ocean, bombs, brazil, oceans and seas, pacific ocean, trees
Temperature and precipitation projections for the Antarctic Peninsula over the next two decades: contrasting global and regional climate model simulationsBozkurt, Deniz; Bromwich, David H.; Carrasco, Jorge; Rondanelli, RobertoZonas Costeras; Agua y Extremos2021.010.1007/s00382-021-05667-2This study presents near future (2020–2044) temperature and precipitation changes over the Antarctic Peninsula under the high-emission scenario (RCP8.5). We make use of historical and projected simulations from 19 global climate models (GCMs) participating in Coupled Model Intercomparison Project phase 5 (CMIP5). We compare and contrast GCMs projections with two groups of regional climate model simulations (RCMs): (1) high resolution (15-km) simulations performed with Polar-WRF model forced with bias-corrected NCAR-CESM1 (NC-CORR) over the Antarctic Peninsula, (2) medium resolution (50-km) simulations of KNMI-RACMO21P forced with EC-EARTH (EC) obtained from the CORDEX-Antarctica. A further comparison of historical simulations (1981–2005) with respect to ERA5 reanalysis is also included for circulation patterns and near-surface temperature climatology. In general, both RCM boundary conditions represent well the main circulation patterns of the historical period. Nonetheless, there are important differences in projections such as a notable deepening and weakening of the Amundsen Sea Low in EC and NC-CORR, respectively. Mean annual near-surface temperatures are projected to increase by about 0.5–1.5 ∘C across the entire peninsula. Temperature increase is more substantial in autumn and winter (∼ 2 ∘C). Following opposite circulation pattern changes, both EC and NC-CORR exhibit different warming rates, indicating a possible continuation of natural decadal variability. Although generally showing similar temperature changes, RCM projections show less warming and a smaller increase in melt days in the Larsen Ice Shelf compared to their respective driving fields. Regarding precipitation, there is a broad agreement among the simulations, indicating an increase in mean annual precipitation (∼ 5 to 10%). However, RCMs show some notable differences over the Larsen Ice Shelf where total precipitation decreases (for RACMO) and shows a small increase in rain frequency. We conclude that it seems still difficult to get consistent projections from GCMs for the Antarctic Peninsula as depicted in both RCM boundary conditions. In addition, dominant and common changes from the boundary conditions are largely evident in the RCM simulations. We argue that added value of RCM projections is driven by processes shaped by finer local details and different physics schemes that are introduced by RCMs, particularly over the Larsen Ice Shelf.Climate Dynamics0930-7575, 1432-0894 Reuters ISIair temperature, climate change, climate modeling, cmip, downscaling, extreme event, global climate, precipitation assessment, regional climate, antarctic peninsula, antarctica, larsen ice shelf, west antarctica
Mapping water ecosystem services: Evaluating InVEST model predictions in data scarce regionsBenra, F.; De Frutos, A.; Gaglio, M.; Álvarez-Garretón, C.; Felipe-Lucia, M.; Bonn, A.Agua y Extremos2021.010.1016/j.envsoft.2021.104982Sustainable management of water ecosystem services requires reliable information to support decision making. We evaluate the performance of the InVEST Seasonal Water Yield Model (SWYM) against water monitoring records in 224 catchments in southern Chile. We run the SWYM in three years (1998, 2007 and 2013) to account for recent land-use change and climatic variations. We computed squared Pearson correlations between SWYM monthly quickflow predictions and streamflow observations and applied a generalized mixed‐effects model to evaluate annual estimations. Results show relatively low monthly correlations with marked latitudinal and temporal variations while annual estimates show a good match between observed and modeled values, especially for values under 1000 mm/year. Better predictions were observed in regions with high rainfall and in dry years while poorer predictions were found in snow dominated and drier regions. Our results improve SWYM performance and contribute to water supply and regulation decision-making, particularly in data scarce regions.Environmental Modelling & Software13648152 Reuters ISIecosystems, forecasting, hydrogeology, land use, water management, water supply, climatic variation, land-use change, model prediction, pearson correlation, sustainable management, temporal variation, water ecosystems, water monitoring, decision making, decision support system, ecosystem service, estimation method, least squares method, performance assessment, prediction, streamflow, sustainable development, water supply, chile
Multiscale physical background to an exceptional harmful algal bloom of Dinophysis acuta in a fjord systemDíaz, Patricio A.; Peréz-Santos, Iván; Álvarez, Gonzalo; Garreaud, René; Pinilla, Elías; Díaz, Manuel; Sandoval, Alondra; Araya, Michael; Álvarez, Francisco; Rengel, José; Montero, Paulina; Pizarro, Gemita; López, Loreto; Iriarte, Luis; Igor, Gabriela; Reguera, BeatrizAgua y Extremos2021.010.1016/j.scitotenv.2021.145621Dinophysis acuta produces diarrhetic shellfish poisoning (DSP) toxins and pectenotoxins (PTX). It blooms in thermally-stratified shelf waters in late summer in temperate to cold temperate latitudes. Despite its major contribution to shellfish harvesting bans, little effort has been devoted to study its population dynamics in Chilean Patagonia. In 2017–2018, mesoscale distribution of harmful algal species (75 monitoring stations) revealed the initiation (late spring) and seasonal growth of a dense D. acuta population in the Aysén region, with maximal values at Puyuhuapi Fjord (PF). Vertical phytoplankton distribution and fine-resolution measurements of physical parameters along a 25-km transect in February 16th identified a 15-km (horizontal extension) subsurface thin layer of D. acuta from 4 to 8 m depth. This layer, disrupted at the confluence of PF with the Magdalena Sound, peaked at the top of the pycnocline (6 m, 15.9 °C, 23.4 psu) where static stability was maximal. By February 22nd, it deepened (8 m, 15.5 °C; 23.62 psu) following the excursions of the pycnocline and reached the highest density ever recorded (664 × 103 cells L−1) for this species. Dinophysis acuta was the dominant Dinophysis species in all microplankton net-tows/bottle samples; they all contained DSP toxins (OA, DTX-1) and PTX-2. Modeled flushing rates showed that Puyuhuapi, the only fjord in the area with 2 connections with the open sea, had the highest water residence time. Long term climate variability in the Southern hemisphere showed the effects of a Southern Annular Mode (SAM) in positive mode (+1.1 hPa) overwhelming a moderate La Niña. These effects included positive spring precipitation anomalies with enhanced salinity gradients and summer drought with positive anomalies in air (+1 °C) and sea surface (+2 °C) temperature. Locally, persistent thermal stratification in PF seemed to provide an optimal physical habitat for initiation and bloom development of D. acuta. Thus, in summer 2018, a favourable combination of meteorological and hydrographic processes of multiple scales created conditions that promoted the development of a widespread bloom of D. acuta with its epicentre at the head of Puyuhuapi fjord.Science of The Total Environment00489697 Reuters ISIalgae control, oceanography, plankton, plants (botany), population statistics, residence time distribution, shellfish, surface waters, diarrhetic shellfish poisoning, harmful algal blooms, long-term climate variability, mesoscale distribution, phytoplankton distributions, southern annular mode, thermally stratified, water residence time, protozoa, alga, algal bloom, climate effect, climate variation, flagellate, geographical distribution, growth rate, poisoning, population dynamics, southern hemisphere, toxin, alga, algal bloom, algal growth, article, chile, climate change, dinophysis acuta, environmental monitoring, hydrography, meteorological phenomena, microplankton, nonhuman, physical parameters, priority journal, salinity, sea surface temperature, seasonal variation, southern hemisphere, species distribution, thermoregulation, water residence time, algal bloom, dinoflagellate, estuary, human, chile, patagonia, dinophysis acuta, shellfish poisoning, chile, dinoflagellida, estuaries, harmful algal bloom, humans, shellfish poisoning
Climate response and drought resilience of Nothofagus obliqua secondary forests across a latitudinal gradient in south-central ChileUrrutia-Jalabert, R.; Barichivich, J.; Rozas, V.; Lara, A.; Rojas, Y.; Bahamondez, C.; Rojas-Badilla, M.; Gipoulou-Zuñiga, T.; Cuq, E.Cambio de Uso de Suelo2021.010.1016/j.foreco.2021.118962The climate response and resilience of tree growth to drought events have been widely reported for forests from the Northern Hemisphere. However, studies are much scarcer in the extra-tropical forests of southern South America. Mediterranean and Temperate forests of Chile are suffering from a moderate warming and a sustained precipitation decrease, occurring on top of an unprecedented megadrought since 2010. This study evaluated tree-growth patterns, the climate response and drought resilience of nine secondary Nothofagus obliqua forests across a latitudinal gradient from Mediterranean to Temperate climate in the Andes of Chile (35.7° to 40.3° S). Moreover, to improve the understanding of the spatial variation in productivity patterns, this research assessed trends in the maximum Normalized Difference Vegetation Index (peak in the NDVI) across the gradient for 2001–2018. Tree-growth patterns were highly influenced by stand dynamics, with steep decreasing trends in most of the stands related to a gradual canopy closure. Productivity trends had a flat pattern north of 38oS, but positive trends south of this latitude, which were mostly attributed to stand development. Tree growth was positively related to precipitation in all the sites, with annual and summer rainfall being more important in the north (Mediterranean climate) and south (Temperate climate), respectively. Conversely, maximum temperature had a negative effect on growth in most of the studied forests. This implies that projected warmer and drier conditions may have a detrimental effect on N. obliqua growth during coming decades. The two northern stands, located at the species dry range edge, were among the most resilient to drought and have not been strongly affected by the current megadrought in the area. Overall climate conditions, however, do not define the tolerance of stands to droughts, likely because local environmental and forests conditions play a key role. Although droughts have not strongly impacted the growth of N. obliqua across its distribution so far, future studies should assess the effects of the current long-term megadrought on growth resilience, and physiological studies should address the impacts of droughts and heat waves on forest function beyond what growth can unveil.Forest Ecology and Management0378-1127 Reuters ISIclimatology, drought, productivity, rain, climate condition, latitudinal gradients, maximum temperature, mediterranean climates, normalized difference vegetation index, northern hemispheres, southern south america, spatial variations, forestry, climate effect, drought resistance, heat wave, latitudinal gradient, ndvi, northern hemisphere, rainfall, secondary forest, spatial variation, drought, forestry, forests, growth, meteorology, productivity, rain, trees, andes, chile, nothofagus obliqua
Progressive water deficits during multiyear droughts in basins with long hydrological memory in ChileAlvarez-Garreton, Camila; Boisier, Juan Pablo; Garreaud, René; Seibert, Jan; Vis, MarcAgua y Extremos2021.010.5194/hess-25-429-2021Abstract. A decade-long (2010–2020) period with precipitation deficits in central–south Chile (30–41∘ S), the so-called megadrought (MD), has led to streamflow depletions of larger amplitude than expected from precipitation anomalies, indicating an intensification in drought propagation. We analysed the catchment characteristics and runoff mechanisms modulating such intensification by using the CAMELS-CL dataset and simulations from the HBV hydrological model. We compared annual precipitation–runoff (P–R) relationships before and during the MD across 106 basins with varying snow-/rainfall regimes and identified those catchments where drought propagation was intensified. Our results show that catchments' hydrological memory – modulated by snow and groundwater – is a key control of drought propagation. Snow-dominated catchments (30–35∘ S) feature larger groundwater contribution to streamflow than pluvial basins, which we relate to the infiltration of snowmelt over the Western Andean Front. This leads to longer memory in these basins, represented by a significative correlation between autumn streamflow (when snow has already melted) and the precipitation from the preceding year. Hence, under persistent drought conditions, snow-dominated catchments accumulate the effects of precipitation deficits and progressively generate less water, compared with their historical behaviour, notably affecting central Chile, a region with limited water supply and which concentrates most of the country's population and water demands. Finally, we addressed a general question: what is worse – an extreme single-year drought or a persistent moderate drought? In snow-dominated basins, where water provision strongly depends on both the current and previous precipitation seasons, an extreme drought induces larger absolute streamflow deficits; however persistent deficits induce a more intensified propagation of the meteorological drought. Hence, the worst scenario would be an extreme meteorological drought following consecutive years of precipitation below average, as occurred in 2019. In pluvial basins of southern Chile (35–41∘ S), hydrologic memory is still an important factor, but water supply is more strongly dependant on the meteorological conditions of the current year, and therefore an extreme drought would have a higher impact on water supply than a persistent but moderate drought.Hydrology and Earth System Sciences1607-7938 Reuters ISIcatchments, groundwater, runoff, snow, stream flow, water supply, annual precipitation, catchment characteristics, hydrological modeling, limited water supplies, meteorological condition, meteorological drought, precipitation anomalies, precipitation deficits, drought, catchment, drought, groundwater-surface water interaction, hydrological modeling, meteorology, precipitation (climatology), rainfall, runoff, snowmelt, streamflow, chile
Water management or megadrought: what caused the Chilean Aculeo Lake drying?Barría, Pilar; Chadwick, Cristián; Ocampo-Melgar, Anahí; Galleguillos, Mauricio; Garreaud, Rene; Díaz-Vasconcellos, Raúl; Poblete, David; Rubio-Álvarez, Eduardo; Poblete-Caballero, DagobertoCambio de Uso de Suelo; Agua y Extremos2021.010.1007/s10113-021-01750-wThe Aculeo Lake is an important natural reservoir of Central Chile, which provides valuable ecosystem services. This lake has suffered a rapid shrinkage of the water levels from year 2010 to 2018, and since October 2018, it is completely dry. This natural disaster is concurrent with a number of severe and uninterrupted drought years, along with sustained increases in water consumption associated to land use/land cover (LULC) changes. Severe water shortages and socio-environmental impacts were triggered by these changes, emphasizing the need to understand the causes of the lake desiccation to contribute in the design of future adaptation strategies. Thereby, the Water Evaluation and Planning (WEAP) hydrological model was used as a tool to quantify the water balance in the catchment. The model was run under a combination of three land use/land cover and two different climate scenarios that sample the cases with and without megadrought and with or without changes in land use. According to the results, the main triggering factor of the lake shrinkage is the severe megadrought, with annual rainfall deficits of about 38%, which resulted in amplified reductions in river flows (44%) and aquifer recharges (24%). The results indicate that the relative impact of the climate factor is more than 10 times larger than the impact of the observed LULC changes in the lake balance, highlighting the urgent need for adaptation strategies to deal with the projected drier futures.Regional Environmental Change1436-3798, 1436-378X Reuters ISIanthropogenic, attribution, decision making, drought, land use/land cover, water budget
Assessment of GPM IMERG satellite precipitation estimation and its dependence on microphysical rain regimes over the mountains of south-central ChileRojas, Yazmina; Minder, Justin R.; Campbell, Leah S.; Massmann, Adam; Garreaud, ReneAgua y Extremos2021.010.1016/j.atmosres.2021.105454Satellite data provide crucial information for those places lacking precipitation observations from ground-based sensors, especially over oceans, mountain regions, or developing countries. This is the case over much of South America, including Chile, a country with complex topography that has limited long-term precipitation records and high-elevation data, and no operational weather radars. This study focuses on investigating the skill of the Global Precipitation Measurement (GPM) Integrated Multi-Satellite Retrieval for GPM (IMERG: version 6) quantitative precipitation estimation (QPE). IMERG is assessed against ground-based observations from two field campaigns that took place near 36°S: The Chilean Coastal Orographic Precipitation Experiment (CCOPE; winter 2015), which collected data over the coastal mountain range, and The Chilean Orographic and Mesoscale Precipitation Study (ChOMPS; winter 2016), which collected observations in a transect from the coast to the Andes. To characterize how IMERG performance depends on microphysical regime, we used data from profiling radars and rain gauge measurements to classify rainfall into regimes including “ice-initiated rain” and “warm rain”, characterized by the presence or absence of a well-defined melting layer respectively. Rain gauge data was used to evaluate performance of IMERG QPE overall and for these two regimes. IMERG depicts the general spatial pattern of observed orographic enhancement but highly underestimates the magnitude of this enhancement. At higher elevations during CCOPE, IMERG underestimated the total amount of rainfall by 50%, while during ChOMPS the underestimation was by 16%. For CCOPE, at higher elevation sites, IMERG underestimated ice-initiated rain by 30% and underestimated warm rain by 70%. For ChOMPS, the underestimation at the Andes site was 33% for ice-initiated rain and 50% for warm rain. IMERG QPE for both field campaigns showed larger underestimations for warm rain periods and at higher elevations than for ice-initiated rain periods. Documenting how IMERG performance varies with terrain and microphysical regime may help guide improvements to satellite-based QPE.Atmospheric Research0169-8095 Reuters ISIdeveloping countries, ice, landforms, meteorological radar, radar measurement, rain gages, satellites, space-based radar, topography, complex topographies, global precipitation measurements, ground based sensors, ground-based observations, orographic enhancement, orographic precipitation, quantitative precipitation estimation, satellite precipitation, rain, assessment method, cloud microphysics, estimation method, precipitation assessment, satellite data, satellite imagery, spatiotemporal analysis, chile
Tree growth decline as a response to projected climate change in the 21st century in Mediterranean mountain forests of ChileMatskovsky, V.; Venegas-González, A.; Garreaud, R.; Roig, Fidel A.; Gutiérrez, Alvaro G.; Muñoz, Ariel A; Le Quesne, C.; Klock, K.; Canales, C.Agua y Extremos2021.010.1016/j.gloplacha.2020.103406Global Climate Models project that observed climate trends are likely to be preserved and the number of extreme events will be increasing during the rest of the 21st century, which may have a detrimental impact on forest ecosystems. These impacts may include forest decline and widespread dieback of the most vulnerable biomes, such as the Mediterranean Forest of Central Chile (MFCC). Nothofagus macrocarpa and Austrocedrus chilensis are two canopy-dominant, endangered tree species in the mountains of MFCC. Here, we project tree growth of these species based on tree-ring width chronologies, a simplified version of a process-based model, and climate change projections. We used the tree ring information derived from ~400 trees from 12 sites distributed across MFCC in combination with the simplified version of process-based Vaganov-Shashkin tree-growth model (VS-Lite) to forecast changes in tree growth for the next four decades. Tree growth projections were made on the basis of monthly values of temperature and precipitation from the output of 35 climate models based on two ensembles of CO2 emission scenarios of the IPCC AR5 (RCP 8.5: higher-emission scenario, and RCP 2.6: lower-emission scenario). For the MFCC region these scenarios result in temperature rise ranging between 0.5 ◦C and 2.0 ◦C, and a precipitation decrease between 5% and 20% by the year 2065, as related to historical conditions. Our results showed that the VS-Lite model is capable of reproducing tree growth decline during the recent extreme dry period, i.e. 2010–2018, which supports its use for tree growth projections in the MFCC region. According to the modeling results, we find that tree growth in both N. macrocarpa and A. chilensis forests distributed in the MFCC region will be adversely affected by future climate changes, mainly starting from the year 2035, under both scenarios. Our work provides evidence of the degree of vulnerability of Mediterranean mountain forests in central Chile according to current climate change projections. The projected decline in tree growth indicates serious risks in the dynamics and survival of these forests relatively soon, so alerts are given about this situation which may require to counteract the deleterious effects of global change on vegetation in this region.Global and Planetary Change0921-8181 Reuters ISIclimate models, ecosystems, forestry, landforms, climate change projections, deleterious effects, endangered tree species, global climate model, mediterranean forest, mediterranean mountains, process-based modeling, tree growth modeling, climate change, biome, chronology, climate change, climate modeling, deciduous tree, dieback, extreme event, forest ecosystem, global change, global climate, growth, mediterranean environment, montane forest, tree, tree ring, twenty first century, chile, austrocedrus chilensis, nothofagus macrocarpa
Coastal Bacterial Community Response to Glacier Melting in the Western Antarctic PeninsulaAlcamán-Arias, María Estrella; Fuentes-Alburquenque, Sebastián; Vergara-Barros, Pablo; Cifuentes-Anticevic, Jerónimo; Verdugo, Josefa; Polz, Martin; Farías, Laura; Pedrós-Alió, Carlos; Díez, BeatrizZonas Costeras2021.010.3390/microorganisms9010088Current warming in the Western Antarctic Peninsula (WAP) has multiple effects on the marine ecosystem, modifying the trophic web and the nutrient regime. In this study, the effect of decreased surface salinity on the marine microbial community as a consequence of freshening from nearby glaciers was investigated in Chile Bay, Greenwich Island, WAP. In the summer of 2016, samples were collected from glacier ice and transects along the bay for 16S rRNA gene sequencing, while in situ dilution experiments were conducted and analyzed using 16S rRNA gene sequencing and metatranscriptomic analysis. The results reveal that certain common seawater genera, such as Polaribacter, Pseudoalteromonas and HTCC2207, responded positively to decreased salinity in both the bay transect and experiments. The relative abundance of these bacteria slightly decreased, but their functional activity was maintained and increased the over time in the dilution experiments. However, while ice bacteria, such as Flavobacterium and Polaromonas, tolerated the increased salinity after mixing with seawater, their gene expression decreased considerably. We suggest that these bacterial taxa could be defined as sentinels of freshening events in the Antarctic coastal system. Furthermore, these results suggest that a significant portion of the microbial community is resilient and can adapt to disturbances, such as freshening due to the warming effect of climate change in Antarctica.Microorganisms2076-2607 Reuters ISIbacterial microbial community, coastal antarctic zone, glacial melting
Permafrost evolution in a mountain catchment near Santiago de ChileRuiz Pereira, S.; Marquardt, C.; Beriain, E.; Lambert, F.Ciudades Resilientes2021.010.1016/j.jsames.2021.103293The Chilean Central Andes near Santiago are a semi-arid region with substantial frozen water reserves in their high altitude cryosphere. Millions of people depend on the Andean cryosphere for freshwater supply. Over the last sixty years, global warming has altered the mountains’ water balance, as the temperature rose, precipitation decreased, and deglacierization exposed hundreds of square kilometers. The distribution of solid water stored in soil permafrost and the potential effects of climate change on it are unknown. Here, we map favorable spots for permafrost occurrence at the “Monos de Agua” catchment, Aconcagua basin at 33°S, between 3600 and 5100 m a.s.l.. We identify these “cold spots” based on ground surface temperature and incoming solar radiation between 2017 and 2019. We suggest that these locations currently present permafrost and frozen water might actually be there. We confirmed a body of frozen water at one of these cold spots using an electrical resistivity survey. Our mapping suggests that at least 15 ± 7% of the catchment's surface is underlain by permafrost. Permafrost occurrence begins around 3600 m a.s.l. with low probability and only at locations with favorable conditions of low exposure and isolation. Permafrost occurrence probability increases with altitude, with the largest fraction present above 4200 m a.s.l. Our results suggest that the permafrost area in this region will decrease between 13 and 87% by the end of the century under the future global warming RCP scenarios. This event represents new challenges for the hydrological memory and water security planning in the Chilean Central Andes.Journal of South American Earth Sciences08959811 Reuters ISIaggradation, catchment, environmental degradation, mountain environment, permafrost, solar radiation, surface temperature, aconcagua, andes, argentina, chile, cordillera principal, metropolitana, santiago [metropolitana]
Vegetation, disturbance, and climate history since the onset of ice-free conditions in the Lago Rosselot sector of Chiloé continental (44°S), northwestern PatagoniaMoreno, Patricio I.; Videla, Javiera; Kaffman, María José; Henríquez, Carla A.; Sagredo, Esteban A.; Jara-Arancio, Paola; Alloway, Brent V.Agua y Extremos2021.010.1016/j.quascirev.2021.106924We present results from Lago Negro, a small closed-basin lake adjacent to Lago Rosselot, to examine the vegetation and environmental history of an insufficiently studied sector of Chiloé Continental (41°30′-44°S) in northwestern Patagonia. Lake sediment cores from Lago Negro reveal 27 tephra deposited since ∼12.7 ka, including two prominent rhyodacite tephra marker beds erupted from Volcán Melimoyu, and a stratified basal clastic unit we attribute to meltwater discharge from an ice tongue that originated from Monte Queulat and covered Lago Rosselot during its expanded position, presumably Antarctic Cold Reversal in age. The pollen record shows closed-canopy North Patagonian rainforests since ∼12.7 ka, with variations in species composition and structure that suggest dynamic responses of the vegetation to past environmental changes. Vegetation responses to climate in the Lago Negro record were modulated, sometimes interrupted, by high magnitude and frequent disturbance regimes, most notably during maxima in explosive volcanic activity (∼9.5–7.2 ka and ∼3.6–1.6 ka) and heightened fire activity. Since Lago Negro is the southernmost palynological site so far investigated in the region and is located within a volcanically active sector, it provides a valuable perspective for assessing past vegetation responses along environmental gradients since the last glaciation. When compared with other sites throughout northwestern Patagonia, our record reveals a distinct north-to-south gradient in temperature and precipitation, with peak temperature and rainfall seasonality in the north, and a west-to-east gradient in disturbance regimes, with maximum frequency and magnitude of explosive volcanic events in the east. These gradients have modulated the response of rainforest vegetation to climate forcing at regional scale since ∼12.7 ka. We identify negligible differences in timing for the majority of key vegetation signals during the initial phase of the Lago Negro record, and propose that plant colonization and expansion along the ∼360 km long corridor through the Pacific slope of the northwestern Patagonian Andes was a rapid process during the Last Glacial Termination.Quaternary Science Reviews02773791 Reuters ISIclimate change, explosives, glacial geology, lakes, volcanoes, chiloe continental, disturbance paleoecology, glacier advance during the antarctic cold reversal, northwestern patagonium, patagonia, postglacial explosive volcanism, recession and stabilization during young dryas, vegetation and fire history, vegetation history, vegetation response, vegetation, climate forcing, disturbance, environmental change, environmental history, lacustrine deposit, sediment core, tephra, vegetation history, andes, chile, chiloe island, los lagos, patagonia
Recent Changes in the Low-Level Jet along the Subtropical West Coast of South AmericaAguirre, Catalina; Flores-Aqueveque, Valentina; Vilches, Pablo; Vásquez, Alicia; Rutllant, José A.; Garreaud, RenéZonas Costeras; Agua y Extremos2021.010.3390/atmos12040465Surface winds along the subtropical west coast of South America are characterized by the quasi-weekly occurrences of low-level jet events. These short lived but intense wind events impact the coastal ocean environment. Hence, identifying long-term trends in the coastal low-level jet (CLLJ) is essential for understanding changes in marine ecosystems. Here we use ERA5 reanalysis (1979–2019) and an objective algorithm to track anticyclones to investigate recent changes in CLLJ events off central Chile (25–43 °S). Results present evidence that the number of days with intense wind (≥10 ms−1), and the number and duration of CLLJ events have significantly changed off central Chile in recent decades. There is an increase in the number of CLLJ events in the whole study area during winter (June-July-August; JJA), while during summer (December–January–February; DJF) a decrease is observed at lower latitudes (29–34 °S), and an increase is found at the southern boundary of the Humboldt system. We suggest that changes in the central pressures and frequency of extratropical, migratory anticyclones that reach the coast of South America, which force CLLJs, have played an important role in the recent CLLJ changes observed in this region.Atmosphere2073-4433 Reuters ISIatmospheric pressure, tropics, central chile, coastal ocean environment, extratropical, long-term trend, low level jet, south america, surface winds, wind events, ecosystems, algorithm, anticyclone, climate modeling, coastal zone, jet, long-term change, surface wind, upwelling, chile
Temperature differently affected methanogenic pathways and microbial communities in sub-Antarctic freshwater ecosystemsLavergne, Céline; Aguilar-Muñoz, Polette; Calle, Natalia; Thalasso, Frédéric; Astorga-España, Maria Soledad; Sepulveda-Jauregui, Armando; Martinez-Cruz, Karla; Gandois, Laure; Mansilla, Andrés; Chamy, Rolando; Barret, Maialen; Cabrol, LéaCambio de Uso de Suelo2021.010.1016/j.envint.2021.106575Freshwater ecosystems are responsible for an important part of the methane (CH4) emissions which are likely to change with global warming. This study aims to evaluate temperature-induced (from 5 to 20 °C) changes on microbial community structure and methanogenic pathways in five sub-Antarctic lake sediments from Magallanes strait to Cape Horn, Chile. We combined in situ CH4 flux measurements, CH4 production rates (MPRs), gene abundance quantification and microbial community structure analysis (metabarcoding of the 16S rRNA gene). Under unamended conditions, a temperature increase of 5 °C doubled MPR while microbial community structure was not affected. Stimulation of methanogenesis by methanogenic precursors as acetate and H2/CO2, resulted in an increase of MPRs up to 127-fold and 19-fold, respectively, as well as an enrichment of mcrA-carriers strikingly stronger under acetate amendment. At low temperatures, H2/CO2-derived MPRs were considerably lower (down to 160-fold lower) than the acetate-derived MPRs, but the contribution of hydrogenotrophic methanogenesis increased with temperature. Temperature dependence of MPRs was significantly higher in incubations spiked with H2/CO2 (c. 1.9 eV) compared to incubations spiked with acetate or unamended (c. 0.8 eV). Temperature was not found to shape the total microbial community structure, that rather exhibited a site-specific variability among the studied lakes. However, the methanogenic archaeal community structure was driven by amended methanogenic precursors with a dominance of Methanobacterium in H2/CO2-based incubations and Methanosarcina in acetate-based incubations. We also suggested the importance of acetogenic H2-production outcompeting hydrogenotrohic methanogenesis especially at low temperatures, further supported by homoacetogen proportion in the microcosm communities. The combination of in situ-, and laboratory-based measurements and molecular approaches indicates that the hydrogenotrophic pathway may become more important with increasing temperatures than the acetoclastic pathway. In a continuously warming environment driven by climate change, such issues are crucial and may receive more attention.Environment International01604120 Reuters ISIbacteria, ecosystems, genes, hydrogen production, lakes, methane, rna, temperature distribution, water, 16s rrna amplicon, archaeon, ch$-4$, freshwater ecosystem, lows-temperatures, methanogenesis, methanogenic pathways, microbial communities, microbial community structures, production rates, global warming, climate change, climate effect, community structure, environmental disturbance, freshwater ecosystem, global warming, lacustrine deposit, limnology, methanogenesis, methanogenic bacterium, microbial community, rna, subantarctic region, temperature effect, cape horn, chile, horn island [wollaston islands], magallanes, magellan strait, tierra del fuego [(isg) south america], wollaston islands, archaea, methanobacterium, methanosarcina, fresh water, rna 16s, antarctica, chile, genetics, microflora, temperature, antarctic regions, chile, fresh water, microbiota, rna, ribosomal, 16s, temperature
Evaluating adaptation to drought in a changing climate: experience at the local scale in the Aconcagua ValleyAldunce, Paulina; Lillo-Ortega, Gloria; Araya-Valenzuela, Dámare; Maldonado-Portilla, Pamela; Gallardo, LauraCiudades Resilientes; Agua y Extremos2021.010.1080/17565529.2021.1893150Since 2010, a severe drought has affected central Chile, resulting in losses that prompt the need to evaluate and improve adaptation responses. The evaluation process requires the engagement of multiple actors in order to collect knowledge of their experiences and to inform future design and implementation of adaptation responses. A case study was conducted in four counties of the Aconcagua Valley, Chile, to evaluate the usefulness of existing drought response measures, and to identify strengths and weaknesses, and relevant actors’ recommendations for overcoming them. We applied the Index for the Usefulness of Adaptation Practices (IUPA), a multi-criteria tool that systematically identifies the perceived usefulness of measures. The most salient strengths of the evaluated measures were: replicability, pertinence, and efficacy; representing key factors that could facilitate the implementation of drought responses in similar contexts. The most salient weaknesses were: lack of integration with other policy domains and projects, low environmental protection, diminished autonomy in decision-making, and inequity. Proposed recommendations to overcome these weaknesses have real potential for implementation because they emerged from local actors. Results present empirical evidence of the utility of participatory approaches for a context-specific evaluation of measures, contributing to enhance adaptation to climate variability and change.Climate and Development1756-5529, 1756-5537 Reuters ISIchile, climate change, drought, evaluation of adaptation, index for the usefulness of adaptation practices (iupa)
Niche differentiation of Dinophysis acuta and D. acuminata in a stratified fjordBaldrich, Ángela M.; Pérez-Santos, Iván; Álvarez, Gonzalo; Reguera, Beatriz; Fernández-Pena, Concepción; Rodríguez-Villegas, Camilo; Araya, Michael; Álvarez, Francisco; Barrera, Facundo; Karasiewicz, Stéphane; Díaz, Patricio A.Zonas Costeras2021.010.1016/j.hal.2021.102010Dinophysis acuta and D. acuminata are associated with lipophilic toxins in Southern Chile. Blooms of the two species coincided during summer 2019 in a highly stratified fjord system (Puyuhuapi, Chilean Patagonia). High vertical resolution measurements of physical parameters were carried out during 48 h sampling to i) explore physiological status (e.g., division rates, toxin content) and ii) illustrate the fine scale distribution of D. acuta and D. acuminata populations with a focus on water column structure and co-occurring plastid-bearing ciliates. The species-specific resources and regulators defining the realized niches (sensu Hutchinson) of the two species were identified. Differences in vertical distribution, daily vertical migration and in situ division rates (with record values, 0.76 d−1, in D. acuta), in response to the environmental conditions and potential prey availability, revealed their niche differences. The Outlying Mean Index (OMI) analysis showed that the realized niche of D. acuta (cell maximum 7 × 103 cells L−1 within the pycnocline) was characterized by sub-surface estuarine waters (salinity 23 – 25), lower values of turbulence and PAR, and a narrow niche breath. In contrast, the realized niche of D. acuminata (cell maximum 6.8 × 103 cells L−1 just above the pycnocline) was characterized by fresher (salinity 17 – 20) outflowing surface waters, with higher turbulence and light intensity and a wider niche breadth. Results from OMI and PERMANOVA analyses of co-occurring microplanktonic ciliates were compatible with the hypothesis of species such as those from genera Pseudotontonia and Strombidium constituting an alternative ciliate prey to Mesodinium. The D. acuta cell maximum was associated with DSP (OA and DTX-1) toxins and pectenotoxins; that of D. acuminata only with pectenotoxins. Results presented here contribute to a better understanding of the environmental drivers of species-specific blooms of Dinophysis and management of their distinct effects in Southern Chile.Harmful Algae15689883 Reuters ISIcell differentiation, chile, ciliate, dinoflagellate, estuary, cell differentiation, chile, ciliophora, dinoflagellida, estuaries
Drivers of dinoflagellate benthic cyst assemblages in the NW Patagonian Fjords System and its adjacent oceanic shelf, with a focus on harmful speciesRodríguez-Villegas, Camilo; Lee, Matthew R.; Salgado, Pablo; Figueroa, Rosa I.; Baldrich, Ángela; Pérez-Santos, Iván; Tomasetti, Stephen J.; Niklitschek, Edwin; Díaz, Manuel; Álvarez, Gonzalo; Marín, Sandra L.; Seguel, Miriam; Farías, Laura; Díaz, Patricio A.Zonas Costeras2021.010.1016/j.scitotenv.2021.147378In recent decades, the alteration of coastal food webs (via aquaculture, fishing, and leisure activities), nutrient loading, and an expansion of monitoring programs have prompted an apparent worldwide rise in Harmful Algae Blooms (HABs). Over this time, a parallel increase in HABs has also been observed in the Chilean southern austral region (Patagonia fjords). HAB species like Alexandrium catenella—responsible for Paralytic Shellfish Poisoning (PSP)—are of great public concern due to their negative socioeconomic impacts and significant northward geographical range expansion. Many toxic dinoflagellate species (like A. catenella) produce benthic resting cysts, yet a holistic understanding of the physical-chemical and biological conditions influencing the distributions of cysts in this region is lacking. In this study, we measured a combination of hydrographic (temperature, salinity, and dissolved oxygen) and sediment physical-chemical properties (temperature, pH and redox potential), in addition to meiofaunal abundances –as sediment bioturbators and potential cyst predators– to determine the factors influencing dinoflagellate cyst distribution, with emphasis on A. catenella in and around a “hotspot” area of southern Chile. An analysis of similarities (ANOSIM) test revealed significant differences (p < 0.011) in cyst assemblages between the fjords and oceanic environments. Permutational Analysis of Variance (PERMANOVA) showed significant effects of sediment temperature and silt proportion in explaining differences in the cyst assemblages. A generalized linear model (GLM) indicated that sediment temperature, silt/sand, anoxic conditions, and low abundances of Harpacticoida —a meiofauna herbivore group and potential bioturbator— are associated with the higher resting cyst abundances of the harmful species A. catenella. The implications for A. catenella resting cysts dynamics are discussed, highlighting physical-chemical and biological interactions and their potential for PSP outbreak initiation.Science of The Total Environment0048-9697 Reuters ISIdissolved oxygen, expansion, leisure, ph, sediments, silt, alexandrium catenellum, algae blooms, chemical and biologicals, chilean patagonium, dinoflagellate resting cyst, harmful algae, meiofauna, paralytic shellfish poisoning, redox potentials, redoxpotential, redox reactions, ammonia, nitrite, river water, algal bloom, benthic foraminifera, dinoflagellate, meiofauna, physicochemical property, redox conditions, species diversity, species richness, alexandrium catenella, analysis of variance, article, dinoflagellate, harmful organism, hydrography, meiofauna, nonhuman, paralytic shellfish poisoning, ph, physical chemistry, population abundance, priority journal, salinity, sea, sea surface temperature, sediment, species composition, species distribution, chile, patagonia, alexandrium, alexandrium catenella, catenella, dinophyceae, harpacticoida
Temporal methane variability in the water column of an area of seasonal coastal upwelling: A study based on a 12 year time seriesFarías, L.; Tenorio, S.; Sanzana, K.; Faundez, J.Zonas Costeras2021.010.1016/j.pocean.2021.102589Temporal distribution of dissolved CH4 was analysed in a zone of strong seasonal coastal upwelling off central Chile (36.5°S,73°W). Observations were taken from a twelve-year time series that included monthly sampling of the water at eight depths. CH4 concentration fluctuated between 1.75 and 100.9 nmol L-1 (or 67.11% and 3965% of saturation), with the highest levels at bottom waters, which increase as upwelling evolved. Three kind of CH4 profiles were identified; a classical diffusion–advection distribution, with bottom/surface CH4 concentration ratio > 2, was predominantly observed in ~ 54% of the all profiles and attributed to high CH4 production in the sediments during coastal upwelling season (austral spring-summer); a period of higher biological productivity, as well as in hypoxic/anoxic condition. In contrast, relatively homogeneous profiles (CH4 level ratio between bottom and surface depth < 2) was observed about ~ 46% of all profiles during periods of extreme vertical mixing (such as winter storms). Furthermore, irregular CH4 profile with superficial peaks occurring between the surface and 15–30 m depth was likely observed. These peaks indicated that local production rates exceed turbulent mixing rates, suggesting a rapid CH4 cycling due to microbial processes on the surface. Despite the fact that strong seasonality was observed in most oceanographic variables, according to favourable and non-favourable upwelling periods, only a weak seasonality was observed in CH4 content and its air-sea flux, the latter ranged from 1.27 to 47.02 µmol m−2 d-1 (mean ± SD: 10.94 ± 7.48). The annual weighted mean CH4 effluxes during upwelling (64%) and non-upwelling (36%) periods fluctuated from 1.66 to 6.22 mmol m−2 (mean ± SD: 3.40 ± 1.43), highlighting the importance of the continental shelf under the influence of coastal upwelling as a significant CH4 source toward the atmosphere.Progress in Oceanography0079-6611 Reuters ISImixing, storms, time series, biological productivity, coastal upwelling, concentration ratio, continental shelves, local production, microbial process, temporal distribution, turbulent mixing, coastal engineering, bottom water, continental shelf, methane, microbial activity, pollutant source, seasonality, temporal variation, time series, upwelling, water column, chile
Electrochemical enrichment of marine denitrifying bacteria to enhance nitrate metabolization in seawaterDe La Fuente, María José; De la Iglesia, Rodrigo; Farias, Laura; Daims, Holger; Lukumbuzya, Michael; Vargas, Ignacio T.Zonas Costeras2021.010.1016/j.jece.2021.105604High concentrations of nitrate from industrial discharges to coastal marine environments are a matter of concern owing to their ecological consequences. In the last years, Bioelectrochemical Denitrification Systems (BEDS) have emerged as a promising nitrate removal technology. However, they still have limitations, such as the enrichment strategy for specific microbial communities in the electrodes under natural conditions. In this study, three-electrode electrochemical cells were used to test microbial enrichment from natural seawater by applying three reported potentials associated with the dissimilatory denitrification process (−130, −260, and −570 mV vs. Ag/AgCl). The microbial community analysis showed that by applying −260 mV (vs. Ag/AgCl) to the working electrode, it was possible to significantly enrich denitrifying microorganisms, specifically Marinobacter, in comparison with the control. Furthermore, −260 mV (vs. Ag/AgCl) led to a significantly higher nitrate removal than other conditions, which, combined with cyclic voltammetry analysis, suggested that the polarized electrodes worked as external electron donors for nitrate reduction. Hence, this work demonstrates for the first time that it is possible to enrich marine denitrifying microorganisms by applying an overpotential of −260 mV (vs. Ag/AgCl) without the need for a culture medium, the addition of an exogenous electron donor (i.e., organic matter) or a previously enriched inoculum.Journal of Environmental Chemical Engineering2213-3437 Reuters ISIcyclic voltammetry, denitrification, ecology, electric discharges, electrochemical electrodes, nitrates, seawater, ag/agcl, bioelectrochemical denitrification system, denitrifying bacteria, denitrifying microorganisms, electrochemicals, electron donors, industrial discharges, metabolization, microbial enrichment, nitrates removal, bacteria
Identifying key driving mechanisms of heat waves in central ChileDemortier, Alan; Bozkurt, Deniz; Jacques-Coper, MartínZonas Costeras; Agua y Extremos2021.010.1007/s00382-021-05810-zThis study explores the main drivers of heat wave (HW) events in central Chile using state-of-the-art reanalysis data (ERA5) and observations during the extended austral summer season (November to March) for the period 1979–2018. Frequency and intensity aspects of the HW events are considered using the total number of the HW events per season and the amplitude. We first contrast ERA5 with several surface meteorological stations in central Chile to evaluate its ability to capture daily maximum temperature variability and the HW events. We then use synoptic- and large-scale fields and teleconnection patterns to address the most favorable conditions of the HW events from a climatological perspective as well as from the extreme January 2017 HW event that swept central Chile with temperature records and wildfires. ERA5 tends to capture temperature extremes and the HW events at the inland stations; on the contrary, it has difficulties in capturing the maximum temperature variability at the coastal stations, which is plausible given the complex terrain features and confined coastal climate zone (only ∼7% of all grid boxes within central Chile). The composite HW days based on ERA5 reveals a mid-level trough-ridge dipole pattern exhibiting a blocking anticyclone on the surface over a large part of southwest South America. Relatively dry and warm easterly flow appears to accompany the anomalous warming in a large part of central Chile. The temporal evolution of the HW events yields a wave-like propagation pattern and enhancement of trough-ridge pattern along the South Pacific. This meridional dipole pattern is found to be largely associated with the Pacific South American pattern. In addition, the Madden–Julian Oscillation (MJO) appears to be a key component of the HW events in central Chile. In particular, while active MJO phases 2 and 7 promote sub-seasonal patterns that favor the South Pacific dipole mode, synoptic anomalies can superimpose on them and favor the formation of a migrating anticyclone over central-southern Chile and coastal lows over central Chile. Agreeing with the climatological findings, the extreme January 2017 HW analysis suggests that an eastward migratory mid-latitude trough-ridge pattern associated with MJO phase 2 was at work. We highlight that in addition to large- and synoptic-scale features, sub-synoptic processes such as coastal lows can have an important role in shaping the HW events and can lead to amplification of temperature extremes during the HW events.Climate Dynamics0930-7575, 1432-0894 Reuters ISIatmospheric teleconnections, blocking pattern, central chile, heat waves, mjo, temperature extremes
Development and resilience of deciduous Nothofagus forests since the Last Glacial Termination and deglaciation of the central Patagonian AndesVilla-Martínez, Rodrigo; Moreno, Patricio I.Agua y Extremos2021.010.1016/j.palaeo.2021.110459Resolving the history of vegetation, fire, and glaciation on the eastern slope of the central Patagonian Andes (44°-49°S) since the Last Glacial Termination (T1) has proved difficult. This is due to the steep environmental gradients, vegetation heterogeneity, and scarcity of dated glacial deposits and geomorphic features. Unsurprisingly, published records show important heterogeneities which limit our understanding of the timing and magnitude of climate and vegetation changes, and their driving mechanisms since T1. In this paper, we describe sediment cores from small closed-basin lakes located in the deciduous Nothofagus forest zone near Coyhaique, Chile. Our results indicate that the Coyhaique glacier lobe abandoned its final Last Glacial Maximum position just before ~17.9 cal kyr BP and underwent a step-wise recession that included a halt/readvance that culminated at ~16.8 cal kyr BP, contemporaneous with the formation of an ice-dammed proglacial lake in the Coyhaique/Balmaceda sector. This glacial lake stood at its highest level between ~17.9–17.2 cal kyr BP (<726 and > 650 m.a.s.l.), lowered between ~17.2–16.2 cal kyr BP (<650 and > 570 m.a.s.l.), and disappeared thereafter. Herbs and shrubs, currently dominant in high Andean and Patagonian steppe environments, colonized the ice-free terrains distal to the glacier margins and proglacial lakes under cold and dry conditions. This was followed by a steady increase in Nothofagus between ~16.6–14.8 cal kyr BP that led to the establishment of forests starting at ~14.8 cal kyr BP. The Holocene started with a sudden increase in Nothofagus and disappearance of conifers in the context of increase fire activity between ~11.7–9.4 cal kyr BP. Closed-canopy Nothofagus forests persisted virtually unaltered from ~9.4 cal kyr BP to the present day, despite frequent explosive volcanism and millennial-scale variations in fire regimes, attesting to their extraordinary postglacial resilience which contrasts with their behavior during T1. Recent large-scale deforestation by fire, livestock grazing, and the spread of non-native invasive plant species drove the fastest and largest-magnitude shifts seen during the last ~16,500 years.Palaeogeography, Palaeoclimatology, Palaeoecology00310182 Reuters ISIdeciduous forest, deglaciation, ecosystem resilience, forest canopy, glacial lake, holocene, last glacial maximum, proglacial environment, sediment core, andes, coihaique, patagonia, coniferophyta, nothofagus
Spatial Distribution of Dissolved Methane Over Extreme Oceanographic Gradients in the Subtropical Eastern South Pacific (17° to 37°S)Farías, L.; Troncoso, M.; Sanzana, K.; Verdugo, J.; Masotti, I.Zonas Costeras2021.010.1029/2020JC016925Methane (CH4) is one of the most powerful greenhouse gases with the capacity to influence the Earth's radiative budget as well as contribute to atmospheric chemistry. Natural oceanic production makes up to ∼4% of the overall global CH4 emissions, however, there is uncertainty around the accuracy of this value due to a lack of accurate measurements. Such is the case in the Subtropical Eastern South Pacific Ocean (SESP), a region with pronounced chlorophyll-a and oxygen gradients, which in turn affect the microbial CH4 cycling. This study was conducted during spring-summer (2014–2016) in the SESP. The region (∼17°–37°S/71°–110°W) is separated into (i) eutrophic, (ii) mesotrophic, and (iii) oligotrophic areas, according to oceanographic and biogeochemical criteria. The SESP presents high CH4 zonal variability with levels ranging from 0.63 to 33.4 nmol L−1, corresponding to 29% and 1,423% saturation, respectively. High CH4 concentrations (>1,000% saturation) are observed in the narrow eutrophic area subjected to coastal upwelling. These conditions clearly differ to those observed in the extended oligotrophic subtropical gyre (∼100% saturation). Furthermore, CH4 also tends to accumulate in the mesotrophic area (with upto 1,423% saturation), where oceanographic conditions as stratification, mesoscale eddies and island mass effect could trigger the presence of a microbial biomass that may be able to induce CH4 regeneration. The CH4 efflux is estimated to be between 0.13 and 19.1 µmol m−2 d−1 (mean ± SD = 4.72 ± 4.67) and the SESP has an emission rate of ∼87.9 Gg CH4 yr−1.Journal of Geophysical Research: Oceans2169-9275, 2169-9291 Reuters ISIaccuracy assessment, atmospheric chemistry, biogeochemistry, biomass, chlorophyll a, concentration (composition), greenhouse gas, gyre, mesoscale eddy, methane, nutrient cycling, radiative transfer, saturation, spatial distribution, upwelling, pacific ocean, pacific ocean (south)
Estimating discount rates for environmental goods: Are People’s responses inadequate to frequency of payments?Vásquez-Lavín, Felipe; Carrasco, Moisés; Barrientos, Manuel; Gelcich, Stefan; Ponce Oliva, Roberto D.Cambio de Uso de Suelo2021.010.1016/j.jeem.2021.102446Most stated preference studies estimate discount rates using a split-sample approach. Each sample faces a different payment frequency (for instance, 1, 5, 10) together with a randomly assigned bid vector; both the frequency of payments and the bid are fixed for a specific individual. This paper evaluates whether allowing respondents to choose their preferred payment frequency affects the estimated discount rate. We use data from a contingent valuation survey of a network of marine reserves and estimate discount rates using both an exogenous and endogenous approach. The former calculates the mean of the willingness to pay (WTP) for each sample and then finds the discount rate that makes the present value of each payment frequency equivalent. The latter estimates the WTP and the discount rate jointly. Results show that allowing people to choose the payment schedule significantly reduces the implicit discount rate. We observed the highest reductions in discount rates when we used all the information available from the valuation questions to bound the WTP distribution. Our analysis suggests that the exogenous approach would not be recommended for testing the adequacy of people's responses to the frequency of payments.Journal of Environmental Economics and Management00950696 Reuters ISIeconomic analysis, contingent valuations, discount rates, endogenous approaches, environmental goods, marine reserve, present value, stated-preference studies, willingness to pay, behavioral research, contingent valuation, discount rate, environmental economics, estimation method, marine park, willingness to pay
The state of science on severe air pollution episodes: Quantitative and qualitative analysisMorawska, Lidia; Zhu, Tong; Liu, Nairui; Amouei Torkmahalleh, Mehdi; de Fatima Andrade, Maria; Barratt, Benjamin; Broomandi, Parya; Buonanno, Giorgio; Carlos Belalcazar Ceron, Luis; Chen, Jianmin; Cheng, Yan; Evans, Greg; Gavidia, Mario; Guo, Hai; Hanigan, Ivan; Hu, Min; Jeong, Cheol H.; Kelly, Frank; Gallardo, Laura; Kumar, Prashant; Lyu, Xiaopu; Mullins, Benjamin J.; Nordstrøm, Claus; Pereira, Gavin; Querol, Xavier; Yezid Rojas Roa, Nestor; Russell, Armistead; Thompson, Helen; Wang, Hao; Wang, Lina; Wang, Tao; Wierzbicka, Aneta; Xue, Tao; Ye, CelineCiudades Resilientes2021.010.1016/j.envint.2021.106732Severe episodic air pollution blankets entire cities and regions and have a profound impact on humans and their activities. We compiled daily fine particle (PM2.5) data from 100 cities in five continents, investigated the trends of number, frequency, and duration of pollution episodes, and compared these with the baseline trend in air pollution. We showed that the factors contributing to these events are complex; however, long-term measures to abate emissions from all anthropogenic sources at all times is also the most efficient way to reduce the occurrence of severe air pollution events. In the short term, accurate forecasting systems of such events based on the meteorological conditions favouring their occurrence, together with effective emergency mitigation of anthropogenic sources, may lessen their magnitude and/or duration. However, there is no clear way of preventing events caused by natural sources affected by climate change, such as wildfires and desert dust outbreaks.Environment International01604120 Reuters ISIclimate change, air pollution episodes, anthropogenic sources, fine particles (pm$-2.5$/), formation of secondary pollutant, mitigating air pollutant, pollution emissions, pollution episodes, quantitative and qualitative analysis, severe air pollution event, urban air pollution, air pollution, accuracy assessment, atmospheric pollution, emission, episodic event, forecasting method, human activity, qualitative analysis, quantitative analysis, trend analysis, urban pollution, air pollutant, article, climate change, desert, forecasting, human, meteorology, qualitative analysis, quantitative analysis, wildfire
Influence of African Atmospheric Rivers on Precipitation and Snowmelt in the Near East's HighlandsBozkurt, D.; Sen, O. L.; Ezber, Y.; Guan, B.; Viale, M.; Caglar, F.Agua y Extremos2021.010.1029/2020JD033646Atmospheric rivers (ARs) traveling thousands of kilometers over arid North Africa could interact with the highlands of the Near East (NE), and thus affect the region's hydrometeorology and water resources. Here, we use a state-of-the-art AR tracking database, and reanalysis and observational datasets to investigate the climatology (1979–2017) and influences of these ARs in snowmelt season (March–April). The Red Sea and northeast Africa are found to be the major source regions of these ARs, which are typically associated with the eastern Mediterranean trough positioned over the Balkan Peninsula and a blocking anticyclone over the NE-Caspian region, triggering southwesterly air flow toward the NE's highlands. Approximately 8% of the ARs are relatively strong (integrated water vapor transport>275kg m1 s1). AR days exhibit enhanced precipitation over the crescent-shaped orography of the NE region. Mean AR days indicate wetter (up to+2mm day1) and warmer (up to+1.5°C) conditions than all-day climatology. On AR days, while snowpack tends to decrease (up to 30%) in the Zagros Mountains, it can show decreases or increases in the Taurus Mountains depending largely on elevation. A further analysis with the observations and reanalysis indicates that extreme ARs coinciding with large scale sensible heat transport can significantly increase the daily discharges. These results suggest that ARs can have notable impacts on the hydrometeorology and water resources of the region, particularly of lowland Mesopotamia, a region that is famous with great floods in the ancient narratives.Journal of Geophysical Research: Atmospheres2169-897X, 2169-8996 Reuters ISIairflow, anticyclone, atmospheric moisture, hydrometeorology, orography, precipitation assessment, snowmelt, trough, water vapor, balkans, indian ocean, mesopotamia, north africa, red sea [indian ocean], taurides, turkey, zagros
Forecasting PM2.5 levels in Santiago de Chile using deep learning neural networksMenares, Camilo; Perez, Patricio; Parraguez, Santiago; Fleming, Zoë L.Ciudades Resilientes2021.010.1016/j.uclim.2021.100906Air pollution has been shown to have a direct effect on human health. In particular, PM2.5 has been proven to be related to cardiovascular and respiratory problems. Therefore, it is important to have accurate models to predict high pollution events for this and other pollutants. We present different models that forecast PM2.5 maximum concentrations using a Long Short-Term Memory (LSTM) based neural network and a Deep Feedforward Neural Network (DFFNN). Ten years of air pollution and meteorological measurements from the network of monitoring stations in the city of Santiago, Chile were used, focusing on the behaviour of three zones of the city. All missing values were rebuilt using a method based on discrete cosine transforms and photochemical predictors selected through unsupervised clustering. Deep learning techniques provide significant improvements compared to a traditional multi-layer neural networks, particularly the LSTM model configured with a 7-day memory window (synoptic scale of pollution patterns) can capture critical pollution events at sites with both primary and secondary air pollution problems. Furthermore, the LSTM model consistently outperform deterministic models currently used in Santiago, Chile.Urban Climate22120955 Reuters ISIair quality forecasting, deep neural networks, fine particulate matter, lstm, machine learning, meteorology forecast
Leaf Thermal and Chemical Properties as Natural Drivers of Plant Flammability of Native and Exotic Tree Species of the Valparaíso Region, ChileGuerrero, Fabián; Hernández, Carla; Toledo, Mario; Espinoza, Lorena; Carrasco, Yulian; Arriagada, Andrés; Muñoz, Ariel; Taborga, Lautaro; Bergmann, Jan; Carmona, CamiloAgua y Extremos2021.010.3390/ijerph18137191Forest fires are one of the main environmental threats in Chile. Fires in this Mediterranean climate region frequently affect native forests and exotic plantations, including in several cases urban and rural settlements. Considering the scarcity of information regarding the fire response dynamics of tree species that are frequently affected by fires, this study aims to establish a flammability classification according to the evolution of the fire initiation risk presented by the most affected forest species in the Valparaíso region. Three exotic species, Eucalyptus globulus, Pinus radiata, and Acacia dealbata, and two native species, Cryptocarya alba and Quillaja saponaria, were studied. Flammability assays indicate that E. globulus, A. dealbata, and C. alba are extremely flammable, whereas P. radiata and Q. saponaria are flammable. Furthermore, E. globulus and A. dealbata have the highest heating values while Q. saponaria has the lowest values. The extreme flammability of E. globulus, A. dealbata, and C. alba indicates a high susceptibility to ignite. Furthermore, the high heat of combustion of E. globulus and A. dealbata can be associated with a high energy release, increasing the risk of fires spreading. In contrast, Q. saponaria has the lowest predisposition to ignite and capacity to release heat. Accordingly, this work shows that all studied tree species contain organic metabolites that are potentially flammable (sesquiterpenes, aliphatic hydrocarbons, alcohol esters, ketones, diterpenes, and triterpenes) and can be considered as drivers of flammability in vegetation. Finally, these preliminary results will aid in the construction of more resilient landscapes in the near future.International Journal of Environmental Research and Public Health1660-4601 Reuters ISIaliphatic hydrocarbon, fire behavior, fire management, forest fire, leaf, mediterranean environment, metabolite, physicochemical property, risk assessment, vegetation classification, chile, valparaiso [chile], acacia dealbata, cryptocarya alba, eucalyptus globulus, pinus radiata, quillaja saponaria, radiata, saponaria, chile, fire, forest, plant leaf, southern europe, tree, chile, fires, forests, mediterranean region, plant leaves, trees
Long-Term Exposure to Fine and Coarse Particulate Matter and COVID-19 Incidence and Mortality Rate in Chile during 2020Valdés Salgado, Macarena; Smith, Pamela; Opazo, Mariel A.; Huneeus, NicolásCiudades Resilientes2021.010.3390/ijerph18147409Background: Several countries have documented the relationship between long-term exposure to air pollutants and epidemiological indicators of the COVID-19 pandemic, such as incidence and mortality. This study aims to explore the association between air pollutants, such as PM2.5 and PM10, and the incidence and mortality rates of COVID-19 during 2020. Methods: The incidence and mortality rates were estimated using the COVID-19 cases and deaths from the Chilean Ministry of Science, and the population size was obtained from the Chilean Institute of Statistics. A chemistry transport model was used to estimate the annual mean surface concentration of PM2.5 and PM10 in a period before the current pandemic. Negative binomial regressions were used to associate the epidemiological information with pollutant concentrations while considering demographic and social confounders. Results: For each microgram per cubic meter, the incidence rate increased by 1.3% regarding PM2.5 and 0.9% regarding PM10. There was no statistically significant relationship between the COVID-19 mortality rate and PM2.5 or PM10. Conclusions: The adjusted regression models showed that the COVID-19 incidence rate was significantly associated with chronic exposure to PM2.5 and PM10, even after adjusting for other variables.International Journal of Environmental Research and Public Health1660-4601 Reuters ISIcovid-19, environmental risk, health impact, health risk, mortality, particulate matter, public health, air pollution, article, chile, climate, concentration (parameter), controlled study, coronavirus disease 2019, demography, environmental indicator, epidemiological data, human, incidence, long term exposure, major clinical study, mortality rate, pandemic, pm10 exposure, pm2.5 exposure, population size, severe acute respiratory syndrome coronavirus 2, social aspect, south america, adverse event, air pollutant, air pollution, environmental exposure, epidemiology, incidence, mortality, particulate matter, south america, sars coronavirus, air pollutants, air pollution, chile, covid-19, environmental exposure, humans, incidence, mortality, pandemics, particulate matter, sars-cov-2
Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern AndesPizarro, Jaime; Vergara, Pablo M.; Cerda, Sergio; Cordero, Raúl R.; Castillo, Ximena; Rowe, Penny M.; Casassa, Gino; Carrasco, Jorge; Damiani, Alessandro; Llanillo, Pedro J.; Lambert, Fabrice; Rondanelli, Roberto; Huneeus, Nicolas; Fernandoy, Francisco; Alfonso, Juan; Neshyba, StevenZonas Costeras2021.010.1038/s41598-021-93895-1Abstract The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 μm and 10 μm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.Scientific Reports2045-2322 Reuters ISI
Oceanography time series reveals annual asynchrony input between oceanic and estuarine waters in Patagonian fjordsPérez-Santos, Iván; Díaz, Patricio A.; Silva, Nelson; Garreaud, René; Montero, Paulina; Henríquez-Castillo, Carlos; Barrera, Facundo; Linford, Pamela; Amaya, Constanza; Contreras, Sergio; Aracena, Claudia; Pinilla, Elías; Altamirano, Robinson; Vallejos, Luis; Pavez, Javiera; Maulen, JuanAgua y Extremos2021.010.1016/j.scitotenv.2021.149241The postglacial Patagonian fjord system along the west coast of southern South America is one of the largest stretches of the southern hemisphere (SH) fjord belt, influenced by the SH westerly wind belt and continental freshwater input. This study reports a 3-year monthly time series (2017–2020) of physical and biogeochemical parameters obtained from the Reloncaví Marine Observatory (OMARE, Spanish acronym) at the northernmost embayment and fjord system of Patagonia. The main objective of this work was to understand the land–atmosphere–ocean interactions and to identify the mechanisms that modulate the density of phytoplankton. A key finding of this study was the seasonally varying asynchronous input of oceanic and estuarine water. Surface lower salinity and warmer estuarine water arrived in late winter to summer, contributing to water column stability, followed by subsurface higher salinity and less warmer oceanic water during fall–winter. In late winter 2019, an interannual change above the picnocline due to the record-high polarity of the Indian Ocean Dipole inhibited water column stability. The biogeochemical parameters (NO3−, NO2−, PO43−, Si(OH)4, pH, and dissolved oxygen) responded to the surface annual salinity variations, and oceanic water mass contributed greatly to the subsurface inorganic nutrient input. The water column N/P ratio indicated that no eutrophication occurred, even under intense aquaculture activity, likely because of the high ventilation dynamics of the Reloncaví Sound. Finally, a shift in phytoplankton composition, characterized by surface chlorophyll-a maxima in late winter and deepening of spring–summer blooms related to the physicochemical conditions of the water column, was observed. Our results support the ecosystem services provided by local oceanography processes in the north Patagonian fjords. Here, the anthropogenic impact caused by economic activities could be, in part, chemically reduced by the annual ventilation cycle mediated by the exchange of oceanic water masses into Patagonian fjords.Science of The Total Environment00489697 Reuters ISIbiochemical oxygen demand, dissolved oxygen, economics, ecosystems, estuaries, eutrophication, observatories, oceanography, phytoplankton, time series, atmospheric mode, biogeochemicals, column stability, estuarine waters, marine observatories, oceanic waters, patagonian fjord, southern hemisphere, times series, water columns, biogeochemistry, oxygen, picnocline, unclassified drug, water, annual variation, biogeochemistry, estuarine dynamics, estuarine environment, eutrophication, fjord, land-atmosphere interaction, land-sea interaction, nearshore dynamics, physical oceanography, southern hemisphere, time series, water column, water mass, westerly, air conditioning, aquaculture, aquatic environment, article, atmosphere, biogeochemical cycle, cell polarity, controlled study, estuary, falling, inorganic nutrient, nonhuman, oceanography, ph, physical chemistry, phytoplankton, salinity, subsurface runoff, summer, time series analysis, water column stability, winter, south america
Scientific warnings could help to reduce farmed salmon mortality due to harmful algal bloomsSoto, Doris; León-Muñoz, Jorge; Garreaud, René; Quiñones, Renato A.; Morey, FranciscoAgua y Extremos2021.010.1016/j.marpol.2021.104705The increasing occurrence of harmful algal blooms (HABs) affecting mariculture has been related to climatic factors but also to increasing eutrophication of coastal zones, to which aquaculture may also contribute. The role of climate change on HABs may be increasingly relevant but scientific efforts to separate this from other causal factors are to date inconclusive. HABs have been a permanent threat to the aquaculture industry in southern Chile, yet government and farmers may have not paid enough attention to scientific information and advice, even when risk-based predictions and warnings have been provided. Here we describe eutrophication risk assessments for water bodies hosting salmon farms and climate change risk maps for the salmon industry in Chilean Patagonia, including the increase of HABs as a main threat. Assessments and maps were delivered in 2020 both to producers and to government. We show that such risk information and mapping could have lessened recent salmon mortality due to HABs (March-April 2021) if government and farmers had followed explicit recommendations to reduce salmon farming production in water bodies with higher risk. This measure would reduce Exposure and Sensitivity under the climate change risk framework used. We provide policy recommendations, including reviewing maximum salmon production in relevant water bodies such as fjords according to eutrophication risks, while paying attention to additional stress from climate change variability and trends.Marine Policy0308597X Reuters ISIalgal bloom, aquaculture industry, aquaculture production, climate effect, coastal zone, eutrophication, governance approach, mariculture, mortality, risk assessment, salmonid culture, chile
Ensuring access to water in an emergency context: Towards an overexploitation and contamination of water resources?Nicolas-Artero, ChloéTransversal2021.010.1177/09646639211031626This article shows how geo-legal devices created to deal with environmental crisis situations make access to drinking water precarious and contribute to the overexploitation and contamination of water resources. It relies on qualitative methods (interviews, observations, archive work) to identify and analyse two geo-legal devices applied in the case study of the Elqui Valley in Chile. The first device, generated by the Declaration of Water Scarcity, allows private sanitation companies to concentrate water rights and extend their supply network, thus producing an overexploitation of water resources. In the context of mining pollution, the second device is structured around the implementation of the Rural Drinking Water Programme and the distribution of water by tankers, which has made access to drinking water more precarious for the population and does nothing to prevent pollution.Social & Legal Studies0964-6639, 1461-7390 Reuters ISIchile, emergency, environmental crisis, geo-legal devices, legal geography, water
Climate and Land Cover Trends Affecting Freshwater Inputs to a Fjord in Northwestern PatagoniaLeón-Muñoz, Jorge; Aguayo, Rodrigo; Marcé, Rafael; Catalán, Núria; Woelfl, Stefan; Nimptsch, Jorge; Arismendi, Ivan; Contreras, Camila; Soto, Doris; Miranda, AlejandroCambio de Uso de Suelo2021.010.3389/fmars.2021.628454Freshwater inputs strongly influence oceanographic conditions in coastal systems of northwestern Patagonia (41–45°S). Nevertheless, the influence of freshwater on these systems has weakened in recent decades due to a marked decrease in precipitation. Here we evaluate potential influences of climate and land cover trends on the Puelo River (640 m 3 s –1 ), the main source of freshwater input of the Reloncaví Fjord (41.5°S). Water quality was analyzed along the Puelo River basin (six sampling points) and at the discharge site in the Reloncaví Fjord (1, 8, and 25 m depth), through six field campaigns carried out under contrasting streamflow scenarios. We also used several indicators of hydrological alteration, and cross-wavelet transform and coherence analyses to evaluate the association between the Puelo River streamflow and precipitation (1950–2019). Lastly, using the WEAP hydrological model, land cover maps (2001–2016) and burned area reconstructions (1985–2019), we simulated future land cover impacts (2030) on the hydrological processes of the Puelo River. Total Nitrogen and total phosphorus, dissolved carbon, and dissolved iron concentrations measured in the river were 3–15 times lower than those in the fjord. Multivariate analyses showed that streamflow drives the carbon composition in the river. High streamflow conditions contribute with humic and colored materials, while low streamflow conditions corresponded to higher arrival of protein-like materials from the basin. The Puelo River streamflow showed significant trends in magnitude (lower streamflow in summer and autumn), duration (minimum annual streamflow), timing (more floods in spring), and frequency (fewer prolonged floods). The land cover change (LCC) analysis indicated that more than 90% of the basin area maintained its land cover, and that the main changes were attributed to recent large wildfires. Considering these land cover trends, the hydrological simulations project a slight increase in the Puelo River streamflow mainly due to a decrease in evapotranspiration. According to previous simulations, these projections present a direction opposite to the trends forced by climate change. The combined effect of reduction in freshwater input to fiords and potential decline in water quality highlights the need for more robust data and robust analysis of the influence of climate and LCC on this river-fjord complex of northwestern Patagonia.Frontiers in Marine Science2296-7745 Reuters ISIclimate change, hydrological modeling, land cover change, land-ocean interface, patagonia, water quality
Exploring the multidimensional effects of human activity and land cover on fire occurrence for territorial planningCarrasco, Jaime; Acuna, Mauricio; Miranda, Alejandro; Alfaro, Gabriela; Pais, Cristobal; Weintraub, AndrésCambio de Uso de Suelo2021.010.1016/j.jenvman.2021.113428The strong link between climate change and increased wildfire risk suggests a paradigm change on how humans must co-exist with fire and the environment. Different studies have demonstrated that human-induced fire ignitions can account for more than 90 % of forest fires, so human co-existence with wildfires requires informed decision making via preventive policies in order to minimize risk and adapt to new conditions. In this paper, we address the multidimensional effects of three groups of drivers (human activity, geographic and topographic, and land cover) that can be managed to assist in territorial planning under fire risk. We found critical factors of strong interactions with the potential to increase the likelihood of starting a fire. Our solution approach included the application of a Machine Learning method called Random Undersampling and Boosting (RUSBoost) to assess risk (fire occurrence probability), which was subsequently accompanied by a sensitivity analysis that revealed interactions of various levels of risk. The prediction performance of the proposed model was assessed using several statistical measures such as the Receiver Operating Characteristic curve (ROC) and the Area Under the Curve (AUC). The results confirmed the high accuracy of our model, with an AUC of 0.967 and an overall accuracy over test data of 93.01 % after applying a Bayesian approach for hyper-parameter optimization. The study area to test our solution approach comprised the entire geographical territory of central Chile.Journal of Environmental Management03014797 Reuters ISIaccuracy assessment, climate change, decision making, environmental effect, environmental management, exploration, fire, human activity, land cover, optimization, risk assessment, territorial planning, wildfire, area under the curve, article, chile, human, land use, machine learning, prediction, probability, receiver operating characteristic, risk assessment, sensitivity analysis, bayes theorem, climate change, human activities, probability, wildfire, chile, bayes theorem, climate change, human activities, humans, probability, wildfires
Road Traffic Noise on the Santa Marta City Tourist RouteJiménez-Uribe, Dámaris A.; Daniels, Darwin; Fleming, Zoë L.; Vélez-Pereira, Andrés M.Ciudades Resilientes2021.010.3390/app11167196The objective of this study was to determine the influence of vehicular traffic on the environmental noise levels of the Santa Marta City tourist route on the Colombian coast. An analysis of vehicle types and frequencies at various times of the day over nearly a year helped to track the main sources of environmental noise pollution. Five sampling points were selected, which were distributed over 12 km, with three classified as peripheral urban and two as suburban. The average traffic flow was 966 vehicles/h and was mainly composed of automobiles, with higher values in the peripheral urban area. The noise level was 103.3 dBA, with background and peak levels of 87.2 and 107.3 dBA, respectively. The noise level was higher during the day; however, there were no differences between weekdays and weekends. The results from the analysis of variance showed that the number of vehicles and the noise levels varied greatly according to the time of day and sampling point location. The peak and mean noise levels were correlated with the number of automobiles, buses and heavy vehicles. The mean noise levels were similar at all sample points despite the traffic flow varying, and the background noise was only correlated for automobiles (which varied much more than the heavy vehicles between day and night).Applied Sciences2076-3417 Reuters ISIacoustic pollution, analysis of variance, field measurements, freeway, traffic flow dynamics
The 21st-century fate of the Mocho-Choshuenco ice cap in southern ChileScheiter, Matthias; Schaefer, Marius; Flández, Eduardo; Bozkurt, Deniz; Greve, RalfZonas Costeras; Agua y Extremos2021.010.5194/tc-15-3637-2021Abstract. Glaciers and ice caps are thinning and retreating along the entire Andes ridge, and drivers of this mass loss vary between the different climate zones. The southern part of the Andes (Wet Andes) has the highest abundance of glaciers in number and size, and a proper understanding of ice dynamics is important to assess their evolution. In this contribution, we apply the ice-sheet model SICOPOLIS (SImulation COde for POLythermal Ice Sheets) to the Mocho-Choshuenco ice cap in the Chilean Lake District (40∘ S, 72∘ W; Wet Andes) to reproduce its current state and to project its evolution until the end of the 21st century under different global warming scenarios. First, we create a model spin-up using observed surface mass balance data on the south-eastern catchment, extrapolating them to the whole ice cap using an aspect-dependent parameterization. This spin-up is able to reproduce the most important present-day glacier features. Based on the spin-up, we then run the model 80 years into the future, forced by projected surface temperature anomalies from different global climate models under different radiative pathway scenarios to obtain estimates of the ice cap's state by the end of the 21st century. The mean projected ice volume losses are 56±16 % (RCP2.6), 81±6 % (RCP4.5), and 97±2 % (RCP8.5) with respect to the ice volume estimated by radio-echo sounding data from 2013. We estimate the uncertainty of our projections based on the spread of the results when forcing with different global climate models and on the uncertainty associated with the variation of the equilibrium line altitude with temperature change. Considering our results, we project a considerable deglaciation of the Chilean Lake District by the end of the 21st century.The Cryosphere1994-0424 Reuters ISIclimate modeling, deglaciation, equilibrium line, glacier dynamics, ice cap, ice sheet, surface temperature, twenty first century, andes, los rios [chile], mocho-choshuenco, southern volcanic zone
Ecogenomics and Adaptation Strategies of Southern Ocean Viral CommunitiesAlarcón-Schumacher, Tomás; Guajardo-Leiva, Sergio; Martinez-Garcia, Manuel; Díez, BeatrizZonas Costeras2021.010.1128/mSystems.00396-21Viruses are the most abundant biologic entities in marine systems and strongly influence the microbial community composition and diversity. However, little is known about viral communities’ adaptation and diversification in the ocean. , ABSTRACT The Southern Ocean (SO) represents up to one-fifth of the total carbon drawdown worldwide. Intense selective pressures (low temperature, high UV radiation, and strong seasonality) and physical isolation characterize the SO, serving as a “natural” laboratory for the study of ecogenomics and unique adaptations of endemic viral populations. Here, we report 2,416 novel viral genomes from the SO, obtained from newly sequenced viral metagenomes in combination with mining of publicly available data sets, which represents a 25% increase in the SO viral genomes reported to date. They comprised 567 viral clusters (defined as approximately genus-level groups), with 186 genera endemic to the SO, demonstrating that the SO viral community is predominantly constituted by a large pool of genetically divergent viral species from widespread viral families. The predicted proteome from SO viruses revealed that several protein clusters related to cold-shock-event responses and quorum-sensing mechanisms involved in the lysogenic-lytic cycle shift decision were under positive selection, which is ultimately important for fine adaptation of viral populations in response to the strong selective pressures of the SO. Finally, changes in the hydrophobicity patterns and amino acid frequencies suggested marked temperature-driven genetic selection of the SO viral proteome. Our data provide valuable insights into how viruses adapt and remain successful in this extreme polar marine environment. IMPORTANCE Viruses are the most abundant biologic entities in marine systems and strongly influence the microbial community composition and diversity. However, little is known about viral communities’ adaptation and diversification in the ocean. In this work, we take advantage of the geographical isolation and the intense selective pressures of the SO, to which viruses are exposed, to identify potential viral adaptations due to positive environmental selection and dispersal limitation. To that end, we recovered more than two thousand novel viral genomes, revealing a high degree of divergence in these SO endemic communities. Furthermore, we describe remarkable viral adaptations in amino acid frequencies and accessory proteins related to cold shock response and quorum sensing that allow them to thrive at lower temperatures. Consequently, our work greatly expands the understanding of the diversification of the viral communities of the SO and their particular adaptations to low temperatures.mSystems2379-5077 Reuters ISImolecular and physiological adaptations, southern ocean, stress adaptation, viral diversity
How well do gridded precipitation and actual evapotranspiration products represent the key water balance components in the Nile Basin?McNamara, Ian; Baez-Villanueva, Oscar M.; Zomorodian, Ali; Ayyad, Saher; Zambrano-Bigiarini, Mauricio; Zaroug, Modathir; Mersha, Azeb; Nauditt, Alexandra; Mbuliro, Milly; Wamala, Sowed; Ribbe, LarsAgua y Extremos2021.010.1016/j.ejrh.2021.100884Study region: Nile Basin, Africa. Study focus: The accurate representation of precipitation (P) and actual evapotranspiration (ETa) patterns is crucial for water resources management, yet there remains a high spatial and temporal variability among gridded products, particularly over data-scarce regions. We evaluated the performance of eleven state-of-the-art P products and seven ETa products over the Nile Basin using a four-step procedure: (i) P products were evaluated at the monthly scale through a point-to-pixel approach; (ii) streamflow was modelled using the Random Forest machine learning technique, and simulated for well-performing catchments for 2009–2018 (to correspond with ETa product availability); (iii) ETa products were evaluated at the multiannual scale using the water balance method; and (iv) the ability of the best-performing P and ETa products to represent monthly variations in terrestrial water storage (ΔTWS) was assessed through a comparison with GRACE Level-3 data. New hydrological insights for the region: CHIRPSv2 was the best-performing P product (median monthly KGE’ of 0.80) and PMLv2 and WaPORv2.1 the best-performing ETa products over the majority of the evaluated catchments. The application of the water balance using these best-performing products captures the seasonality of ΔTWS well over the White Nile Basin, but overestimates seasonality over the Blue Nile Basin. Our study demonstrates how gridded P and ETa products can be evaluated over extremely data-scarce conditions using an easily transferable methodology.Journal of Hydrology: Regional Studies22145818 Reuters ISIevapotranspiration, grace, precipitation, random forest, remote sensing, water balance
Fire-induced loss of the world’s most biodiverse forests in Latin AmericaArmenteras, Dolors; Dávalos, Liliana M.; Barreto, Joan S.; Miranda, Alejandro; Hernández-Moreno, Angela; Zamorano-Elgueta, Carlos; González-Delgado, Tania M.; Meza-Elizalde, María C.; Retana, JavierCambio de Uso de Suelo2021.010.1126/sciadv.abd3357Fire plays a dominant role in deforestation, particularly in the tropics, but the relative extent of transformations and influence of fire frequency on eventual forest loss remain unclear. Here, we analyze the frequency of fire and its influence on postfire forest trajectories between 2001 and 2018. We account for ~1.1% of Latin American forests burnt in 2002–2003 (8,465,850 ha). Although 40.1% of forests (3,393,250 ha) burned only once, by 2018, ~48% of the evergreen forests converted to other, primarily grass-dominated uses. While greater fire frequency yielded more transformation, our results reveal the staggering impact of even a single fire. Increasing fire frequency imposes greater risks of irreversible forest loss, transforming forests into ecosystems increasingly vulnerable to degradation. Reversing this trend is indispensable to both mitigate and adapt to climate change globally. As climate change transforms fire regimes across the region, key actions are needed to conserve Latin American forests.Science Advances2375-2548 Reuters ISIdeforestation, fires, evergreen forests, fire frequencies, fire regimes, forest loss, induced loss, key actions, latin america, latin americans, climate change, article, climate change, evergreen, forest, grass, nonhuman, south and central america
Influence of Estuarine Water on the Microbial Community Structure of Patagonian FjordsTamayo-Leiva, Javier; Cifuentes-Anticevic, Jerónimo; Aparicio-Rizzo, Pilar; Arroyo, José Ignacio; Masotti, Italo; Díez, BeatrizZonas Costeras2021.010.3389/fmars.2021.611981Fjords are sensitive areas affected by climate change and can act as a natural laboratory to study microbial ecological processes. The Chilean Patagonian fjords (41–56°S), belonging to the Subantarctic ecosystem (46–60°S), make up one of the world’s largest fjord systems. In this region, Estuarine Water (EW) strongly influences oceanographic conditions, generating sharp gradients of oxygen, salinity and nutrients, the effects of which on the microbial community structure are poorly understood. During the spring of 2017 we studied the ecological patterns (dispersal and oceanographic factors) underlying the microbial community distribution in a linear span of 450 km along the estuarine-influenced Chilean Patagonian fjords. Our results show that widespread microbial dispersion existed along the fjords where bacterioplankton exhibited dependence on the eukaryotic phytoplankton community composition. This dependence was particularly observed under the low chlorophyll- a conditions of the Baker Channel area, in which a significant relationship was revealed between SAR11 Clade III and the eukaryotic families Pyrenomonadaceae (Cryptophyte) and Coccomyxaceae (Chlorophyta). Furthermore, dissolved oxygen and salinity were revealed as the main drivers influencing the surface marine microbial communities in these fjords. A strong salinity gradient resulted in the segregation of the Baker Channel prokaryotic communities from the rest of the Patagonian fjords. Likewise, Microbacteriaceae, Burkholderiaceae and SAR11 Clade III, commonly found in freshwater, were strongly associated with EW conditions in these fjords. The direct effect of EW on the microbial community structure and diversity of the fjords exemplifies the significance that climate change and, in particular, deglaciation have on this marine region and its productivity.Frontiers in Marine Science2296-7745 Reuters ISIbacterioplankton, estuarine water, eukaryotic phytoplankton, microbial indicator, patagonian fjords, subantarctic
Ecologies of Repair: A Post-human Approach to Other-Than-Human NaturesBlanco-Wells, GustavoGobernanza e Interfaz Ciencia y Política2021.010.3389/fpsyg.2021.633737This conceptual paper explores the theoretical possibilities of posthumanism and presents ecologies of repair as a heuristic device to explore the association modes of different entities, which, when confronted with the effects of human-induced destructive events, seek to repair the damage and transform the conditions of coexistence of various life forms. The central idea is that severe socio-environmental crisis caused by an intensification of industrial activity are conducive to observing new sociomaterial configurations and affective dispositions that, through the reorganization of practices of resistance, remediation, and mutual care, are oriented to generating reparative and/or transformative processes from damaged ecologies and communities. Crises constitute true ontological experimentation processes where the presence of other-than-human natures, and of artifacts or devices that participate in reparative actions, become visible. A post-human approach to nature allows us to use languages and methodologies that do not restrict the emergence of assemblages under the assumption of their a priori ontological separation, but rather examine their reparative potential based on the efficacy of situated relationships. Methodologically, transdisciplinarity is relevant, with ethnography and other engaged methods applied over units of observation and experience called socio-geo-ecologies. The relevant attributes of these socio-geo-ecologies, beyond the individual, community, or institutional aspects, are the specific geological characteristics that make possible an entanglement of interdependent relationships between human and non-human agents. The conceptual analysis is illustrated with empirical examples stemming from socio-geo-ecologies researched in Southern Chile.Frontiers in Psychology1664-1078 Reuters ISIenvironmental crises, non-human, posthumanism, relational ontology, transdiscipline
Assessment of Cardiovascular Risk in Women with Periodontal Diseases According to C-reactive Protein LevelsDa Venezia, Claudia; Hussein, Nayib; Hernández, Marcela; Contreras, Johanna; Morales, Alicia; Valdés, Macarena; Rojas, Francisca; Matamala, Loreto; Hernández-Ríos, PatriciaCiudades Resilientes2021.010.3390/biom11081238Cardiovascular diseases (CVD) are highly prevalent non-communicable diseases worldwide. Periodontitis may act as a non-traditional cardiovascular risk (CVR) factor, linked by a low-grade systemic inflammation mediated by C-reactive protein (CRP). Patients with periodontitis reported higher serum CRP levels; however, a CRP systemic and periodontal correlation in gingival crevicular fluid (GCF) and its CVR impact have been barely studied. We aimed to assess the association between periodontal diseases and CVR in a group of adult women, based on serum high-sensitivity CRP (hs-CRP) levels; and secondly, to determine the association between serum and GCF CRP levels. Gingival crevicular fluid and blood samples were obtained from women with periodontitis, gingivitis, and healthy controls. Serum and GCF CRP were determined by turbidimetric method and Luminex technology, respectively. Data were analyzed and adjusted by CVR factors. All women presented moderate CVR, without an evident association between serum hs-CRP levels and periodontal diseases. While serum hs-CRP concentrations did not significantly differ between groups, patients with gingivitis and periodontitis showed higher CRP levels in GCF, which positively correlated to CRP detection in serum.Biomolecules2218-273X Reuters ISIc reactive protein, cholesterol, hemoglobin a1c, high density lipoprotein cholesterol, lipid, low density lipoprotein cholesterol, triacylglycerol, adult, article, blood sampling, body mass, cardiovascular risk factor, cephalic vein, cholesterol blood level, confidence interval, controlled study, data analysis, diabetes mellitus, diagnostic test accuracy study, diastolic blood pressure, dyslipidemia, educational status, fasting, female, gingival index, gingivitis, high density lipoprotein cholesterol level, human, hypertension, immunoassay, low density lipoprotein cholesterol level, major clinical study, obesity, periodontal disease, periodontitis, physical examination, protein blood level, retrospective study, smoking, systolic blood pressure, triacylglycerol blood level
Projected increases in surface melt and ice loss for the Northern and Southern Patagonian IcefieldsBravo, Claudio; Bozkurt, Deniz; Ross, Andrew N.; Quincey, Duncan J.Zonas Costeras2021.010.1038/s41598-021-95725-wAbstract The Northern Patagonian Icefield (NPI) and the Southern Patagonian Icefield (SPI) have increased their ice mass loss in recent decades. In view of the impacts of glacier shrinkage in Patagonia, an assessment of the potential future surface mass balance (SMB) of the icefields is critical. We seek to provide this assessment by modelling the SMB between 1976 and 2050 for both icefields, using regional climate model data (RegCM4.6) and a range of emission scenarios. For the NPI, reductions between 1.5 m w.e. (RCP2.6) and 1.9 m w.e. (RCP8.5) were estimated in the mean SMB during the period 2005–2050 compared to the historical period (1976–2005). For the SPI, the estimated reductions were between 1.1 m w.e. (RCP2.6) and 1.5 m w.e. (RCP8.5). Recently frontal ablation estimates suggest that mean SMB in the SPI is positively biased by 1.5 m w.e., probably due to accumulation overestimation. If it is assumed that frontal ablation rates of the recent past will continue, ice loss and sea-level rise contribution will increase. The trend towards lower SMB is mostly explained by an increase in surface melt. Positive ice loss feedbacks linked to increasing in meltwater availability are expected for calving glaciers.Scientific Reports2045-2322 Reuters ISIarticle, body weight, climate, glacier, sea level rise
Validation of 4D Flow based relative pressure maps in aortic flowsNolte, David; Urbina, Jesús; Sotelo, Julio; Sok, Leo; Montalba, Cristian; Valverde, Israel; Osses, Axel; Uribe, Sergio; Bertoglio, CristóbalCiudades Resilientes2021.010.1016/ the clinical gold standard for pressure difference measurements is invasive catheterization, 4D Flow MRI is a promising tool for enabling a non-invasive quantification, by linking highly spatially resolved velocity measurements with pressure differences via the incompressible Navier–Stokes equations. In this work we provide a validation and comparison with phantom and clinical patient data of pressure difference maps estimators. We compare the classical Pressure Poisson Estimator (PPE) and the new Stokes Estimator (STE) against catheter pressure measurements under a variety of stenosis severities and flow intensities. Specifically, we use several 4D Flow data sets of realistic aortic phantoms with different anatomic and hemodynamic severities and two patients with aortic coarctation. The phantom data sets are enriched by subsampling to lower resolutions, modification of the segmentation and addition of synthetic noise, in order to study the sensitivity of the pressure difference estimators to these factors. Overall, the STE method yields more accurate results than the PPE method compared to catheterization data. The superiority of the STE becomes more evident at increasing Reynolds numbers with a better capacity of capturing pressure gradients in strongly convective flow regimes. The results indicate an improved robustness of the STE method with respect to variation in lumen segmentation. However, with heuristic removal of the wall-voxels, the PPE can reach a comparable accuracy for lower Reynolds’ numbers.Medical Image Analysis13618415 Reuters ISIdiagnosis, hospital data processing, navier stokes equations, phantoms, reynolds number, aortic coarctation, convective flow, lower resolution, lumen segmentations, pressure differences, spatially resolved, stokes equations, synthetic noise, blood vessels, adult, aortic coarctation, aortic flow, article, case report, catheterization, clinical article, female, flow measurement, four-dimensional imaging, hemodynamic parameters, human, image analysis, male, nuclear magnetic resonance imaging, patient coding, pressure gradient, pressure measurement
Present‐Day Patagonian Dust Emissions: Combining Surface Visibility, Mass Flux, and Reanalysis DataCosentino, N. J.; Gaiero, D. M.; Lambert, F.Ciudades Resilientes2021.010.1029/2020JD034459The magnitude of the climatic forcing associated with mineral dust aerosols remains uncertain due in part to a lack of observations on dust sources. While modeling and satellite studies provide spatially extensive constraints, they must be supported by surface-validating dust monitoring. Southern South America is the main dust source to the southern oceans (>45°S), a region of low biological productivity potentially susceptible to increased micronutrient fertilization through dust deposition, as well as one of the main dust sources to Antarctica, implying long-range transport of dust from Patagonia and potentially affecting snow cover albedo. We present multiyear time series of dust-related visibility reduction (DRVR) and dust mass flux in Patagonia. We find that local DRVR is partly controlled by long-term (i.e., months) water deficit, while same-day conditions play a smaller role, reflective of water retention properties of fine-grained dust-emitting soils in low-moisture conditions. This is supported independently by reanalysis data showing that large-scale dust outbreaks are usually associated with anomalously high long-term water deficit. By combining visibility data, surface dust sampling, and particle dispersion modeling, we derive regional dust emission rates. Our results suggest that the inclusion of long-term soil hydrologic balance parameterizations under low-moisture conditions may improve the performance of dust emission schemes in Earth system models.Journal of Geophysical Research: Atmospheres2169-897X, 2169-8996 Reuters ISIatmospheric pollution, long range transport, mass transfer, mineral dust, pollutant source, pollution monitoring, visibility, antarctica, patagonia, south america
Streamflow response to native forest restoration in former Eucalyptus plantations in south central ChileLara, Antonio; Jones, Julia; Little, Christian; Vergara, NicolásCambio de Uso de Suelo2021.010.1002/hyp.14270Global increases in intensive forestry have raised concerns about forest plantation effects on water, but few studies have tested the effects of plantation forest removal and native forest restoration on catchment hydrology. We describe results of a 14-year paired watershed experiment on ecological restoration in south central Chile which documents streamflow response to the early stages of native forest restoration, after clearcutting of plantations of exotic fast-growing Eucalyptus, planting of native trees, and fostering natural regeneration of native temperate rainforest species. Precipitation, streamflow, and vegetation were measured starting in 2006 in four small (3 to 5 ha) catchments with Eucalyptus globulus plantations and native riparian buffers in the Valdivian Coastal Reserve. Mean annual precipitation is 2500 mm, of which 11% occurs in summer. Streamflow increased, and increases persisted, throughout the first 9 years of vigorous native forest regeneration (2011 to 2019). Annual streamflow increased by 40% to >100% in most years and >150% in fall and summer of some years. Streamflow was 50% to 100% lower than before treatment in two dry summers. Base flow increased by 28% to 87% during the restoration period compared to pre-treatment, and remained elevated in later years despite low summer precipitation. Overall, these findings indicate that removal of Eucalyptus plantations immediately increased streamflow, and native forest restoration gradually restored deep soil moisture reservoirs that sustain base flow during dry periods, increasing water ecosystem services. To our knowledge this is the first study to assess catchment streamflow response to native forest restoration in former forest plantations. Therefore, the results of this study are relevant to global efforts to restore native forest ecosystems on land currently intensively managed with fast-growing forest plantations and may inform policy and decision-making in areas experiencing a drying trend associated with climate change.Hydrological Processes0885-6087, 1099-1085 Reuters ISIaerodynamics, climate change, decision making, ecosystems, hydrogeology, reforestation, reservoirs (water), restoration, runoff, soil moisture, stream flow, ecological restoration, eucalyptus globulus, eucalyptus plantations, fast growing forests, mean annual precipitation, natural regeneration, summer precipitation, temperate rainforest, conservation
A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditionsSokhi, Ranjeet S.; Singh, Vikas; Querol, Xavier; Finardi, Sandro; Targino, Admir Créso; Andrade, Maria de Fatima; Pavlovic, Radenko; Garland, Rebecca M.; Massagué, Jordi; Kong, Shaofei; Baklanov, Alexander; Ren, Lu; Tarasova, Oksana; Carmichael, Greg; Peuch, Vincent-Henri; Anand, Vrinda; Arbilla, Graciela; Badali, Kaitlin; Beig, Gufran; Belalcazar, Luis Carlos; Bolignano, Andrea; Brimblecombe, Peter; Camacho, Patricia; Casallas, Alejandro; Charland, Jean-Pierre; Choi, Jason; Chourdakis, Eleftherios; Coll, Isabelle; Collins, Marty; Cyrys, Josef; da Silva, Cleyton Martins; Di Giosa, Alessandro Domenico; Di Leo, Anna; Ferro, Camilo; Gavidia-Calderon, Mario; Gayen, Amiya; Ginzburg, Alexander; Godefroy, Fabrice; Gonzalez, Yuri Alexandra; Guevara-Luna, Marco; Haque, Sk. Mafizul; Havenga, Henno; Herod, Dennis; Hõrrak, Urmas; Hussein, Tareq; Ibarra, Sergio; Jaimes, Monica; Kaasik, Marko; Khaiwal, Ravindra; Kim, Jhoon; Kousa, Anu; Kukkonen, Jaakko; Kulmala, Markku; Kuula, Joel; La Violette, Nathalie; Lanzani, Guido; Liu, Xi; MacDougall, Stephanie; Manseau, Patrick M.; Marchegiani, Giada; McDonald, Brian; Mishra, Swasti Vardhan; Molina, Luisa T.; Mooibroek, Dennis; Mor, Suman; Moussiopoulos, Nicolas; Murena, Fabio; Niemi, Jarkko V.; Noe, Steffen; Nogueira, Thiago; Norman, Michael; Pérez-Camaño, Juan Luis; Petäjä, Tuukka; Piketh, Stuart; Rathod, Aditi; Reid, Ken; Retama, Armando; Rivera, Olivia; Rojas, Néstor Y.; Rojas-Quincho, Jhojan P.; San José, Roberto; Sánchez, Odón; Seguel, Rodrigo J.; Sillanpää, Salla; Su, Yushan; Tapper, Nigel; Terrazas, Antonio; Timonen, Hilkka; Toscano, Domenico; Tsegas, George; Velders, Guus J.M.; Vlachokostas, Christos; von Schneidemesser, Erika; Vpm, Rajasree; Yadav, Ravi; Zalakeviciute, Rasa; Zavala, MiguelCiudades Resilientes2021.010.1016/j.envint.2021.106818This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.Environment International01604120 Reuters ISIatmospheric movements, carbon monoxide, geographical regions, nitrogen oxides, ozone, particles (particulate matter), quality control, sulfur dioxide, % reductions, air pollutants, biomass-burning, covid-19, nitrogen dioxides, no $-2$, observational analysis, particulate matter, pm$-2.5$, sulphur dioxide, air quality, air quality, atmospheric pollution, carbon monoxide, concentration (composition), covid-19, nitrogen dioxide, ozone, particulate matter, sulfur dioxide
Water Use and Climate Stressors in a Multiuser River Basin Setting: Who Benefits from Adaptation?Ponce Oliva, Roberto D.; Montevechio, Esteban Arias; Jorquera, Francisco Fernández; Vásquez-Lavin, Felipe; Stehr, AlejandraCambio de Uso de Suelo2021.010.1007/s11269-020-02753-8Adapting to new climate conditions will require an intricate mix of knowledge, planning, coordination, and foresight. There is increasing sectoral evidence on the implementation of successful adaptation actions. However, the success of these actions when we consider the interdependencies among sectors remains debatable. This paper aims to assess who benefits from implementing adaptation options in a multiuser river basin to both climate-induced and demographic stress on water use. Our analysis relies on a hydro-economic model that considers two sets of water users: agriculture and urban households. We innovate in our modelling approach by analyzing and explicitly integrating the household-level economic behavior through its water demand. We assess the cross-user consequences of autonomous and planned adaptation actions. We provide insights into the different trade-offs at the basin level, demonstrating the compatibilities and divergences between agriculture and household-level water demand. We found different consequences of implementing either autonomous or planned adaptation measures. For instance, a decentralized scheme would drive negative implications for the entire basin, although the less water-intensive sector will be better off. On the other hand, different policy interventions would drive positive consequences for the entire basin, with the most water-intensive sector benefiting the most. These results highlight the distributional consequences across users of different adaptation measures.Water Resources Management0920-4741, 1573-1650 Reuters ISIagricultural robots, agriculture, economic and social effects, watersheds, climate condition, climate stressors, distributional consequences, economic modeling, household level, policy intervention, river basins, urban-household, water resources, adaptive management, climate change, policy implementation, river basin, river management, trade-off, water demand, water management, water planning, water use
Diversifying Chile’s climate action away from industrial plantationsHoyos-Santillan, Jorge; Miranda, Alejandro; Lara, Antonio; Sepulveda-Jauregui, Armando; Zamorano-Elgueta, Carlos; Gómez-González, Susana; Vásquez-Lavín, Felipe; Garreaud, Rene D.; Rojas, MaisaCambio de Uso de Suelo; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2021.010.1016/j.envsci.2021.06.013As president of the Climate Change Conference of the Parties, Chile has advocated for developing ambitious commitments to mitigate greenhouse gas emissions to achieve carbon-neutrality by 2050. However, Chile’s motivations and ambitious push to reach carbon-neutrality are complicated by a backdrop of severe drought, climate change impacts (i.e., wildfires, tree mortality), and the use of industrial plantations as a mitigation strategy. This has become more evident as widespread and severe wildfires have impacted large areas of industrial plantations, transforming the land-use, land-use change, and forestry sector from a carbon sink to a net carbon source. Consequently, Chile must diversify its climate actions to achieve carbon-neutrality. Nature-based solutions, including wetlands-peatlands and oceans, represent alternative climate actions that can be implemented to tackle greenhouse gas emissions at a national level. Diversification, however, must guarantee Chile’s long-term carbon sequestration capacity without compromising the ecological functionality of biodiverse treeless habitats and native forest ecosystems.Environmental Science & Policy14629011 Reuters ISIcarbon, biodiversity, building, carbon footprint, carbon sequestration, carbon sink, carbon source, chile, climate, climate change, drought, electric power plant, energy yield, forest, forestry, housing, land use, note, peatland, plantation, sea, tree, wetland, wildfire
Sensitivity of Water Price Elasticity Estimates to Different Data Aggregation LevelsFlores Arévalo, Yarela; Ponce Oliva, Roberto D.; Fernández, Francisco J.; Vásquez-Lavin, FelipeCambio de Uso de Suelo2021.010.1007/s11269-021-02833-3The empirical literature on residential water demand employs various data aggregation methods, which depend on whether the aggregation is over consumption, sociodemographic variables, or both. In this study, we distinguish three dataset types—aggregated data, disaggregated data, and semi-aggregated data—to compare the consequences of using a large sample of semi-aggregated data vis-à-vis a small sample of fully disaggregated data on the water price elasticity estimates. We also analyze whether different aggregation levels in the sociodemographic variables affect the water price elasticity estimates when the number of observations is fixed. We employ a discrete-continuous choice model that considers that consumers face an increasing block price structure. Our results demonstrate that the water price elasticities depend upon the level of aggregation of the data used and the sample size. We also find that the water price elasticities are statistically different when comparing a large semi-aggregated sample with a small disaggregated sample.Water Resources Management0920-4741, 1573-1650 Reuters ISIelasticity, large dataset, aggregated datum, aggregation level, data aggregation, empirical literature, price structure, residential water demand, small samples, socio-demographic variables, cost estimating, data processing, demand elasticity, discrete choice analysis, estimation method, sensitivity analysis, water demand, water economics
Nexus Thinking at River Basin Scale: Food, Water and WelfarePonce Oliva, Roberto D.; Fernández, Francisco J.; Vasquez-Lavín, Felipe; Arias Montevechio, Esteban; Julio, Natalia; Stehr, AlejandraCambio de Uso de Suelo2021.010.3390/w13071000Water resources face an unparalleled confluence of pressures, with agriculture and urban growth as the most relevant human-related stressors. In this context, methodologies using a Nexus framework seem to be suitable to address these challenges. However, the urban sector has been commonly ignored in the Nexus literature. We propose a Nexus framework approach, considering the economic dimensions of the interdependencies and interconnections among agriculture (food production) and the urban sector as water users within a common basin. Then, we assess the responses of both sectors to climatic and demographic stressors. In this setting, the urban sector is represented through an economic water demand at the household level, from which economic welfare is derived. Our results show that the Nexus components here considered (food, water, and welfare) will be negatively affected under the simulated scenarios. However, when these components are decomposed to their particular elements, we found that the less water-intensive sector—the urban sector—will be better off since food production will leave significant amounts of water available. Moreover, when addressing uncertainty related to climate-induced shocks, we could identify the basin resilience threshold. Our approach shows the compatibilities and divergences between food production and the urban sector under the Nexus framework.Water2073-4441 Reuters ISIagricultural robots, agriculture, urban growth, economic welfare, food production, household level, river basins, water demand, water users, water resources
Landscape Engineering Impacts the Long-Term Stability of Agricultural PopulationsFreeman, Jacob; Anderies, John M.; Beckman, Noelle G.; Robinson, Erick; Baggio, Jacopo A.; Bird, Darcy; Nicholson, Christopher; Finley, Judson Byrd; Capriles, José M.; Gil, Adolfo F.; Byers, David; Gayo, Eugenia; Latorre, ClaudioCiudades Resilientes2021.010.1007/s10745-021-00242-zExplaining the stability of human populations provides knowledge for understanding the resilience of human societies to environmental change. Here, we use archaeological radiocarbon records to evaluate a hypothesis drawn from resilience thinking that may explain the stability of human populations: Faced with long-term increases in population density, greater variability in the production of food leads to less stable populations, while lower variability leads to more stable populations. However, increased population stability may come with the cost of larger collapses in response to rare, large-scale environmental perturbations. Our results partially support this hypothesis. Agricultural societies that relied on extensive landscape engineering to intensify production and tightly control variability in the production of food experienced the most stability. Contrary to the hypothesis, these societies also experienced the least severe population declines. We propose that the interrelationship between landscape engineering and increased political-economic complexity reduces the magnitude of population collapses in a region.Human Ecology0300-7839, 1572-9915 Reuters ISIhuman population ecology, intensification, population stability, radiocarbon, resilience
High-Frequency Variability of the Surface Ocean Properties Off Central Chile During the Upwelling SeasonAguirre, Catalina; Garreaud, René; Belmar, Lucy; Farías, Laura; Ramajo, Laura; Barrera, FacundoZonas Costeras; Agua y Extremos2021.010.3389/fmars.2021.702051The ocean off south-central Chile is subject to seasonal upwelling whose intensity is mainly controlled by the latitudinal migration of the southeast Pacific subtropical anticyclone. During austral spring and summer, the mean flow is equatorward favoring coastal upwelling, but periods of strong southerly winds are intermixed with periods of relaxed southerlies or weak northerly winds (downwelling favorable). This sub-seasonal, high-frequency variability of the coastal winds results in pronounced changes in oceanographic conditions and air-sea heat and gas exchanges, whose quantitative description has been limited by the lack of in-situ monitoring. In this study, high frequency fluctuations of meteorological, oceanographic and biogeochemical near surface variables were analyzed during two consecutive upwelling seasons (2016–17 and 2017–18) using observations from a coastal buoy located in the continental shelf off south-central Chile (36.4°S, 73°W), ∼10 km off the coast. The radiative-driven diel cycle is noticeable in meteorological variables but less pronounced for oceanographic and biogeochemical variables [ocean temperature, nitrate (NO 3 −), partial pressure of carbon dioxide ( p CO 2 sea ), pH, dissolved oxygen (DO)]. Fluorescence, as a proxy of chlorophyll- a , showed diel variations more controlled by biological processes. In the synoptic scale, 23 active upwelling events (strong southerlies, lasting between 2 and 15 days, 6 days in average) were identified, alternated with periods of relaxed southerlies of shorter duration (4.5 days in average). Upwelling events were related to the development of an atmospheric low-level coastal jet in response to an intense along-shore pressure gradient. Physical and biogeochemical surface seawater properties responded to upwelling favorable wind stress with approximately a 12-h lag. During upwelling events, SST, DO and pH decrease, while NO 3 −, p CO 2 sea , and air-sea fluxes increases. During the relaxed southerly wind periods, opposite tendencies were observed. The fluorescence response to wind variations is complex and diverse, but in many cases there was a reduction in the phytoplankton biomass during the upwelling events followed by higher values during wind relaxations. The sub-seasonal variability of the coastal ocean characterized here is important for biogeochemical and productivity studies.Frontiers in Marine Science2296-7745 Reuters ISIair-sea exchanges, biogeochemical properties, coastal buoy observations, coastal upwelling, coastal winds, eastern boundary conditions, sub-seasonal variability
Tree-Holes as Alternative Reproductive Sites of Batrachyla antartandica Barrio, 1967 (Anura: Batrachylidae)Rabanal, Felipe E.; Úbeda, Carmen; Tejo, Camila F.; Lavilla, Esteban O.Cambio de Uso de Suelo2021.010.2994/SAJH-D-18-00064.1Although the original description of Batrachyla antartandica categorically states that the species should not be considered as arboreal, our field observations show that it has excellent climbing abilities. Associated with this fact, B. antartandica shows an alternative mode of reproduction that involves the use of tree-trunk cavities filled with water as a site for calling, reproduction, development, and metamorphosis. As far as we know, B. antartandica is the only anuran species in the Valdivian temperate rainforests of Chile and Argentina with a completely arboreal life cycle.South American Journal of Herpetology1808-9798 Reuters ISIamphibia, arboreality, microhabitats, phytotelmata, reproductive modes, temperate rainforests
Water dynamics over a Western Patagonian watershed: Land surface changes and human factorsOlivera-Guerra, L.; Quintanilla, M.; Moletto-Lobos, I.; Pichuante, E.; Zamorano-Elgueta, C.; Mattar, C.Cambio de Uso de Suelo2022.010.1016/j.scitotenv.2021.150221Warming trends in Patagonia and severe droughts in recent decades are still poorly understood in terms of their hydrological effects. The effects of climate change on water dynamics in addition to human water management could generate a future water scarcity scenario in one of the regions with the most abundant water resources of Chile. The aim of this work is to focus on assessing the impacts of warming trends on water dynamics in the Patagonian Simpson River watershed during the last two decades. We estimated anomalies in the main components of water balance such as precipitation (P), snow cover (SC), evapotranspiration (ET) and streamflows (Q) as well as surface variables and meteorological forcing (i.e. air temperature - Ta, solar radiation - RS, land surface temperature - LST). The processed data were obtained from remote sensing, reanalysis and in-situ data. We implemented a trend analysis for each variable in the period 2000-2019 at monthly, seasonal and annual scale. Results showed a warming trend in Ta and LST of about 1.2 °C and 2.1 °C, respectively, concentrated mainly in the autumn and winter seasons. Although P showed non-significant trends, Q diminished significantly at rates of more than 9.1 m3/s/decade, representing 36% of its historical mean. However, the decreases in Q are seen only in the maximum (spring) and minimum (summer) seasonal flows. These decreases are explained by significant increases in ET, led by a positive feedback of its drivers (LST, Ta and RS), which is directly linked to the impact of warming and an associated vegetation greenness in the watershed, as well as a decrease in SC during winter that feeds the Simpson River during spring and summer. The decrease in Q is reinforced by the intensification of water withdrawals in recent decades, as shown by an accelerated increase in water rights for agricultural and drinking uses. In a context of water scarcity and increasing and extreme droughts, this work contributes to further understanding water dynamics in western Patagonia, providing support for policy and decision-making when defining sustainable productive practices at watershed scale.Science of The Total Environment00489697 Reuters ISIatmospheric temperature, climate change, drought, dynamics, potable water, remote sensing, snow, surface measurement, vegetation, water management, water supply, watersheds, patagonia, reanalysis, reanalysis data, remote-sensing, simpson, trend analysis, vegetation greenness, warming effect, water dynamics, water scarcity, decision making
Precipitation declines influence the understory patterns in Nothofagus pumilio old-growth forests in northwestern PatagoniaSoto, Daniel P.; Donoso, Pablo J.; Zamorano-Elgueta, Carlos; Ríos, Andrea I.; Promis, ÁlvaroCambio de Uso de Suelo2021.010.1016/j.foreco.2021.119169Forest understories are essential to plant diversity and ecosystem functioning. However, studies about changes in understory patterns as affected by varying precipitation are scarce. Pure Nothofagus pumilio (common name: lenga) forests dominate the eastern side of the Andes mountains in Patagonia across an ample range of precipitation (~1500–500 mm). By studying the same forest type, in the same developmental stage (old-growth), we aimed to isolate the effects of precipitation upon these N. pumilio ecosystems, particularly for the understory. Three sites were selected with annual average precipitations of ~1000 mm (humid), ~800 mm (mesic), and 600 mm (dry), with a distance of 30 km between the humid and the dry sites, and only 18 km between the mesic and the dry sites. In each site, we established three 40 × 40 m plots in 4 blocks, and 30 1 m2 regeneration subplots within each plot. In each subplot we measured vascular plant cover, richness and diversity (alpha and beta), litter cover and coarse woody debris, plus several abiotic variables. We analyzed the data with mixed analysis of variance, differences of understory plant communities through blocked distance-based multivariate analysis of variance, and visualized the groups (sites) with non-metric multidimensional scaling. Indicator species at each site were identified through blocked species indicator analysis. The dry site differed significantly compared to the humid and mesic sites, with the lowest understory cover (4 vs. 82–78%), plant richness (15 vs. 25–26 species), and Simpson diversity index (0.05 vs. 0.66–0.64). Beta turnover diversity was higher between the dry site with either the humid and the mesic sites (βt = 0.613 and 0.561, respectively), which in turn had more species in common (βt = 0.115). An increase in exposed mineral soil, soil water content, and leaf area index occurred from dry to humid sites, and vice versa for transmitted radiation and litter cover. All sites had different indicator species, but with indicator values increasing from dry to humid sites. The dramatic impoverishment of the plant community once precipitation drops within the range of 800 and 600 mm per year in Northern Patagonia sets a warning to the potential effects of climate change upon N. pumilio-dominated forest ecosystems and their plant diversity. Some forest management and potential adaptation strategies are proposed.Forest Ecology and Management03781127 Reuters ISIecosystems, multivariant analysis, reforestation, soil moisture, 'dry' [, biotic/abiotic interactions, indicator species, litter cover, nothofagus, patagonia, plant communities, plant diversity, site quality, transitional forest, climate change, adaptation, climate change, developmental stage, diversity index, forest management, leaf area index, litter, multivariate analysis, coverings, ecosystems, nothofagus, patagonia, plants, reforestation, site index, sites, andes, patagonia, indicator indicator, nothofagus pumilio, tracheophyta
How Much Can We See from a UAV-Mounted Regular Camera? Remote Sensing-Based Estimation of Forest Attributes in South American Native ForestsMiranda, Alejandro; Catalán, Germán; Altamirano, Adison; Zamorano-Elgueta, Carlos; Cavieres, Manuel; Guerra, Javier; Mola-Yudego, BlasCambio de Uso de Suelo2021.010.3390/rs13112151Data collection from large areas of native forests poses a challenge. The present study aims at assessing the use of UAV for forest inventory on native forests in Southern Chile, and seeks to retrieve both stand and tree level attributes from forest canopy data. Data were collected from 14 plots (45 × 45 m) established at four locations representing unmanaged Chilean temperate forests: seven plots on secondary forests and seven plots on old-growth forests, including a total of 17 different native species. The imagery was captured using a fixed-wing airframe equipped with a regular RGB camera. We used the structure from motion and digital aerial photogrammetry techniques for data processing and combined machine learning methods based on boosted regression trees and mixed models. In total, 2136 trees were measured on the ground, from which 858 trees were visualized from the UAV imagery of the canopy, ranging from 26% to 88% of the measured trees in the field (mean = 45.7%, SD = 17.3), which represented between 70.6% and 96% of the total basal area of the plots (mean = 80.28%, SD = 7.7). Individual-tree diameter models based on remote sensing data were constructed with R2 = 0.85 and R2 = 0.66 based on BRT and mixed models, respectively. We found a strong relationship between canopy and ground data; however, we suggest that the best alternative was combining the use of both field-based and remotely sensed methods to achieve high accuracy estimations, particularly in complex structure forests (e.g., old-growth forests). Field inventories and UAV surveys provide accurate information at local scales and allow validation of large-scale applications of satellite imagery. Finally, in the future, increasing the accuracy of aerial surveys and monitoring is necessary to advance the development of local and regional allometric crown and DBH equations at the species level.Remote Sensing2072-4292 Reuters ISIantennas, cameras, data handling, fixed wings, learning systems, photogrammetry, remote sensing, satellite imagery, surveys, unmanned aerial vehicles (uav), aerial photogrammetry, boosted regression trees, field inventories, large-scale applications, machine learning methods, remote sensing data, secondary forests, structure from motion, forestry
Deep fire topology: Understanding the role of landscape spatial patterns in wildfire occurrence using artificial intelligencePais, Cristobal; Miranda, Alejandro; Carrasco, Jaime; Shen, Zuo-Jun MaxCambio de Uso de Suelo; Transversal2021.010.1016/j.envsoft.2021.105122Increasing wildfire activity globally has become an urgent issue with enormous ecological and social impacts. In this work, we focus on analyzing and quantifying the influence of landscape topology, understood as the spatial structure and interaction of multiple land-covers in an area, on fire ignition. We propose a deep learning framework, Deep Fire Topology, to estimate and predict wildfire ignition risk. We focus on understanding the impact of these topological attributes and the rationale behind the results to provide interpretable knowledge for territorial planning considering wildfire ignition uncertainty. We demonstrate the high performance and interpretability of the framework in a case study, accurately detecting risky areas by exploiting spatial patterns. This work reveals the strong potential of landscape topology in wildfire occurrence prediction and its implications to develop robust landscape management plans. We discuss potential extensions and applications of the proposed method, available as an open-source software.Environmental Modelling & Software13648152 Reuters ISIapplication programs, deep learning, open source software, open systems, risk perception, deep learning, ecological impacts, landscape topology, machine-learning, social impact, spatial patterns, territorial planning, wildfire ignition, wildfire ignition risk, wildfire management, topology, artificial intelligence, estimation method, land cover, performance assessment, risk assessment, territorial planning, topology, uncertainty analysis, wildfire
Spatiotemporal Peatland Productivity and Climate Relationships Across the Western South American AltiplanoAnderson, Talia G.; Christie, Duncan A.; Chávez, Roberto O.; Olea, Matias; Anchukaitis, Kevin J.Agua y Extremos2021.010.1029/2020JG005994The South American Altiplano is one of the largest semiarid high-altitude plateaus in the world. Within the Altiplano, peatlands known as “bofedales” are important components of regional hydrology and provide key water resources and ecosystem services to Andean communities. Warming temperatures, changes in hydroclimate, and shifting atmospheric circulation patterns all affect peatland dynamics and hydrology. It is therefore urgent to better understand the relationships between climate variability and the spatiotemporal variations in peatland productivity across the Altiplano. Here, we explore climate influences on peatland vegetation using 31 years of Landsat data. We focus specifically on the bofedal network in the western Altiplano, the driest sector of the plateau, and use the satellite-derived Normalized Difference Vegetation Index (NDVI) as an indicator of productivity. We develop temporally and spatially continuous NDVI products at multiple scales in order to evaluate relationships with climate variables over the past three decades. We demonstrate that cumulative precipitation and snow persistence over the prior 2 years are strongly associated with growing season productivity. A step change in peatland productivity between 2013–2015 drives an increasing trend in NDVI and is likely a response to consecutive years of anomalously high snow accumulation and rainfall. Early summer minimum temperatures emerge as a secondary influence on productivity. Understanding large-scale productivity dynamics and characterizing the response of bofedales to climate variability over the last three decades provides a baseline to monitor the responses of Andean peatlands to climate change.Journal of Geophysical Research: Biogeosciences2169-8953, 2169-8961 Reuters ISIatmospheric circulation, climate change, growing season, ndvi, peatland, precipitation (chemistry), precipitation (climatology), rainfall, snow accumulation, spatiotemporal analysis, altiplano, indicator indicator, varanidae
Chemical Signals in Tree Rings from Northern Patagonia as Indicators of Calbuco Volcano Eruptions since the 16th CenturyBertin, Lizette J.; Christie, Duncan A.; Sheppard, Paul R.; Muñoz, Ariel A.; Lara, Antonio; Alvarez, ClaudioCambio de Uso de Suelo; Agua y Extremos2021.010.3390/f12101305The Calbuco volcano ranks third in the specific risk classification of volcanoes in Chile and has a detailed eruption record since 1853. During 2015, Calbuco had a sub-Plinian eruption with negative impacts in Chile and Argentina, highlighting the need to determine the long-term history of its activity at a high-resolution time scale to obtain a better understanding of its eruptive frequency. We developed a continuous eruptive record of Calbuco for the 1514–2016 period by dendrochemical analysis of Fitzroya cupressoides tree rings at a biennium resolution using inductively coupled plasma–mass spectrometry. After comparing the chemical record of 20 elements contained in tree rings with historical eruptions, one group exhibited positive anomalies during (Pb/Sn) and immediately after (Mo/P/Zn/Cu) eruptions, with a Volcanic Explosivity Index (VEI) ≥ 3, and so were classified as chemical tracers of past eruptions (TPE). The tree-ring width chronology also exhibited significant decreases in tree growth associated with eruptions of VEI ≥ 3. According to these records, we identified 11 new eruptive events of Calbuco, extending its eruptive chronology back to the 16th century and determining a mean eruptive frequency of ~23 years. Our results show the potential to use dendrochemical analysis to infer past volcanic eruptions in Northern Patagonia. This information provides a long-term perspective for assessing eruptive history in Northern Patagonia, with implications for territorial planning.Forests1999-4907 Reuters ISIforestry, indicators (chemical), inductively coupled plasma, mass spectrometry, chemical signals, fitzroya cupressoides, inductively coupled plasma-mass spectrometry, northern patagonia, risk classification, sub-plinian eruption, tree rings, volcanic eruptions, volcanic explosivity indices, volcano eruptions, volcanoes
High competitive ability of Centaurea melitensis L. (Asteraceae) does not increase in the invaded rangeSotes, Gastón J.; Cavieres, Lohengrin A.; Gómez-González, SusanaCambio de Uso de Suelo2021.010.1007/s10530-020-02396-1Understanding why alien species become dominant in recipient communities requires a biogeographical perspective comparing the ecology of native and introduced populations. The genus Centaurea (Asteraceae) is well-known in invasion ecology because several aggressive invaders, including Centaurea melitensis L., belong to this genus. We compared the competitive ability of C. melitensis individuals from Spain (native range) and Chile (invaded range) when competing against Helenium aromaticum (Hook.) L.H. Bailey, a native relative from Chile. We performed germination bioassays and common garden competition experiments to compare: (1) the germination capacities of C. melitensis (Spain and Chile) and H. aromaticum (2) the potential allelopathic effect of leaf lixiviates of C. melitensis (Spain and Chile) on the seed germination of H. aromaticum, (3) the ability of C. melitensis from both origins to reduce the growth of H. aromaticum. No significant differences in the capacity of seed germination were found among C. melitensis from Chile and Spain and the native H. aromaticum. However, the seed germination of H. aromaticum was inhibited by the presence of C. melitensis leaves from Chile and Spain. Also, the biomass of H. aromaticum was reduced in the presence of C. melitensis, regardless of their origin. Our results demonstrate the competitive superiority of the invasive C. melitensis over H. aromaticum, but we found no evidence of an evolutionary increase in the competitive ability of the invader populations. Therefore, at least part of the invasive potential of C. melitensis seems to be acquired by selective processes in their original range.Biological Invasions1387-3547, 1573-1464 Reuters ISIangiosperm, bioassay, biogeography, biological invasion, biomass, community dynamics, competitive ability, garden, germination, introduced species, native species, range expansion, chile, spain, asteraceae, centaurea, centaurea melitensis, helenium aromaticum
Trace elements in Antarctic penguins and the potential role of guano as source of recycled metals in the Southern OceanSparaventi, Erica; Rodríguez-Romero, Araceli; Barbosa, Andrés; Ramajo, Laura; Tovar-Sánchez, AntonioZonas Costeras; Agua y Extremos2021.010.1016/j.chemosphere.2021.131423Penguins dominate the Antarctic avifauna. As key animals in the Antarctic ecosystem, they are monitored to evaluate the ecological status of this pristine and remote region and specifically, they have been used as effective bioindicators suitable for long-term monitoring of metals in the Antarctic environment. However, studies about the role of this emblematic organism could play in the recycling of trace metals (TMs) in the Antarctic ecosystem are very limited. In this study we evaluate, using the peer review research articles already published and our own findings, the distribution of metals (i.e., Ca, Fe, Al, Na, Zn, Mg, Cu, K, Cd, Mn, Sr, Cr, Ni, Pb, Hg, V, Ba, Co, La, Ag, Rb, Hf, Sc, Au and Cs) and metalloids (As and Sb), measured in different biotic matrices, with emphasis on guano, of the Chinstrap (Pygoscelis antarcticus), Adélie (Pygoscelis adeliae) and Gentoo (Pygoscelis papua) penguins. Regarding bioactive metals, the high concentrations (μg g−1 dry weight) of Cu (2.0 ± 1.4) x 102, Fe (4.1 ± 2.9) x 102, Mn (30 ± 34) and Zn (210 ± 90) reported in the guano from all the penguin species studied including our data, are of the same order of magnitude as those reported for whale feces (μg g−1 dry weight): Cu (2.9 ± 2.4) x 102, Fe (1.5 ± 1.4) x 102, Mn (28 ± 17) and Zn (6.2 ± 4.3) x 102, and one order of magnitude higher than the metal contents in krill (μg g−1 dry weight) of Cu (10.2 ± 5.5), Fe (24 ± 29) and Zn (13.5 ± 1.7). This suggest that penguin's excretion products could be an important source of these essential elements in the surface water, with an estimated annual release on a breeding season for Cu, Fe, Mn, Zn respectively of 28, 56, 4 and 29 tons, for the Chinstrap, Adélie and Gentoo penguins. The results provide evidence on the potential influence of penguins recycling TMs in the surface layer of the water column.Chemosphere00456535 Reuters ISIecosystems, recycling, surface waters, trace elements, antarctica, dropping, dry weight, ecological status, metal concentrations, orders of magnitude, remote regions, southern ocean, trace metal, traces elements, metals, avifauna, bioindicator, breeding season, concentration (composition), excretion, feces, guano, metalloid, recycling, seabird, trace element, whale, southern ocean, pygoscelis antarcticus, spheniscidae
Energy and Water Policies in Chile, Two Different Endings with Implications in the Water-Energy NexusBórquez, Roxana; Fuster, RodrigoGobernanza e Interfaz Ciencia y Política2021.010.3390/en14113286Energy and water have faced important levels of conflicts in the last 20–25 years in Chile. However, the way that they have been politically addressed in the last decade differs. These differences emerge from how these fields have been historically configurated, impacting on how the policy problems and policy options have been framed. Using thematic analysis of 93 interviews and documentary analysis, this article analyzes by contrasting two participatory processes which nourish the formulation of the energy and water policies in Chile in 2014–2015. It seeks to understand the factors that may influence why the development, impact and inclusion of new voices in public policies related to water and energy have been different, and how that can impact the water–energy nexus. Five factors emerge as determinants in this difference: structure of use, number of actors, governance and institutional framework, elite conformation, and legal framework. These factors impacted the policy processes and the scope of the policy outcomes, generating two different results: a long-term energy policy, and a water policy that did not survive the presidential period. Thus, the water–energy nexus is under pressure as a result of the tension between power structures, social responses to environmental issues and decision-making, environmental limitations, and climate change stressors, creating greater vulnerability and conflicts.Energies1996-1073 Reuters ISIclimate change, decision making, energy and water policy, environmental issues, environmental limitations, institutional framework, legal frameworks, participatory process, thematic analysis, water and energies, water management
La construcción social de los mercados de agua en Chile: Un enfoque desde la geografía legalArtero, Chloé NicolasTransversal2021.010.4067/S0718-34022021000200163El artículo propone un enfoque desde la geografía legal para entender la construcción social de los mercados de agua en la cuenca semiárida del río Elqui, desde la segundad mitad del siglo XX. A partir de metodologías cualitativas (etnografía, entrevistas, archivos) revela la dimensión conjuntamente espacial y jurídica de la formación de los mercados de agua. Los objetos técnicos hídricos instalados desde la segunda mitad del siglo XX atraen nuevos inversionistas y transforman la economía política del valle. Desde entonces, los usuarios usan los objetos técnicos hídricos e instrumentalizan o producen derecho a escala local para comprar, vender o alquilar derechos de agua, formando cinco mercados de agua.Revista de geografía Norte Grande0718-3402 Reuters ISIchile, legal geography, semiarid, technical objects, water markets
An Integrated Framework to Streamline Resilience in the Context of Urban Climate Risk AssessmentUrquiza, A.; Amigo, C.; Billi, M.; Calvo, R.; Gallardo, L.; Neira, C. I.; Rojas, M.Ciudades Resilientes; Gobernanza2021.010.1029/2020EF001508Cities are increasingly acknowledged as crucial when facing climate change—and the environmental crisis more in general—, offering challenges and opportunities in terms of both mitigation and adaptation. Climate change-sensitive urban governance requires proactive, integrated, and contextualized approaches, making room for the complex, multilayered, multiscalar, and dynamic processes constituting a city. The notion of “resilience” has been acquiring growing recognition as a flexible and powerful concept to respond to these challenges. Resilience itself, however, is also a polysemic notion, often treated as little more than a catchword or a wishful aim or superimposed with other climate-related terms, such as risk, vulnerability, or adaptation. To promote a stronger integration among different problem-settings and epistemic communities, this paper advances six analytical distinctions aiming to provide structure and articulation to existing definitions of the concept of “resilience.” Likewise, it offers an integrated analytical framework and methodological pipeline to streamline resilience analysis in the context of urban climate risk assessment. The framework is specially defined to link up with the definition of climate risk provided by the Intergovernmental Panel on Climate Change (IPCC) latest Assessment Reports and is illustrated through examples derived from the recent experience of the Chilean Climate Risk Atlas.Earth's Future2328-4277, 2328-4277 Reuters ISIclimate risk, ecosystem services, polycentric governance, socio-ecological systems, systems-of-systems, urban resilience
High- and low-latitude forcings drive Atacama Desert rainfall variations over the past 16,000 yearsGonzález-Pinilla, Francisco J.; Latorre, Claudio; Rojas, Maisa; Houston, John; Rocuant, M. Ignacia; Maldonado, Antonio; Santoro, Calogero M.; Quade, Jay; Betancourt, Julio L.Gobernanza2021.010.1126/sciadv.abg1333Late Quaternary precipitation dynamics in the central Andes have been linked to both high- and low-latitude atmospheric teleconnections. We use present-day relationships between fecal pellet diameters from ashy chinchilla rats (Abrocoma cinerea) and mean annual rainfall to reconstruct the timing and magnitude of pluvials (wet episodes) spanning the past 16,000 years in the Atacama Desert based on 81 14C-dated A. cinerea paleomiddens. A transient climate simulation shows that pluvials identified at 15.9 to 14.8, 13.0 to 8.6, and 8.1 to 7.6 ka B.P. can be linked to North Atlantic (high-latitude) forcing (e.g., Heinrich Stadial 1, Younger Dryas, and Bond cold events). Holocene pluvials at 5.0 to 4.6, 3.2 to 2.1, and 1.4 to 0.7 ka B.P. are not simulated, implying low-latitude internal variability forcing (i.e., ENSO regime shifts). These results help constrain future central Andean hydroclimatic variability and hold promise for reconstructing past climates from rodent middens in desert ecosystems worldwide.Science Advances2375-2548 Reuters ISIclimatology, rain, atacama desert, atmospheric teleconnections, central andes, forcings, high latitudes, high-low, late quaternary, low latitudes, pluvials, rainfall variation, landforms
The last glacial termination in northwestern Patagonia viewed from the Lago Fonk (∼40°S) recordHenríquez, Carla A.; Moreno, Patricio I.; Dunbar, Robert B.; Mucciarone, David A.Agua y Extremos2021.010.1016/j.quascirev.2021.107197The anatomy of the Last Glacial Termination (T1) in the southern mid-latitudes, and its relationship with changes in the Southern Westerly Winds (SWW), offers empirical constraints for understanding the mechanisms involved in the transition from the Last Glacial Maximum into the current interglacial. Northwestern Patagonia (40°-44°S) is a sensitive region for monitoring past changes in the SWW, the Patagonian Ice Sheet, terrestrial ecosystems, and fire regimes through T1. Here we present results from Lago Fonk (∼40°S) to examine the structure of T1 based on the palynological, macroscopic charcoal, elemental, and isotopic composition of organic lake sediments. We observe an instantaneous establishment of Nothofagus-dominated forests at the onset of T1, followed by a diversification and densification trend that culminated with the establishment of thermophilous, Myrtaceae-dominated North Patagonian rainforests between ∼15.6–14.7 cal ka BP. The expansion of the conifer Podocarpus nubigena marks a shift to cool-temperate and hyperhumid conditions, coeval with high lake levels and enhanced algal productivity between ∼14.7–11.9 cal ka BP. Stand-replacing fires, driven by enhanced seasonality or high-frequency rainfall variability, started at ∼12.4 cal ka BP and catalyzed the rapid spread of Weinmannia trichosperma. Subsequent warming and a decline in precipitation at ∼11.4 cal ka BP led to intense fire activity, lake-level lowering, and establishment of the Valdivian rainforest trees Eucryphia/Caldcluvia. Our results suggest a coherent linkage between changes documented in the amphi south Pacific region and Antarctic ice cores during T1. This implies a zonal and hemispheric response to changes in the position/intensity of the SWW that emphasizes their central role as a key driver of the hemispheric and global climate evolution through T1.Quaternary Science Reviews02773791 Reuters ISIfires, forestry, glacial geology, lakes, 'current, lake levels, lake sediment cores, last glacial maximum, last glacial terminations, midlatitudes, multi proxies, multi-proxy index, patagonia, southern westerly winds, charcoal, coniferophyta, eucryphia, myrtaceae, nothofagus, podocarpus nubigenus, weinmannia trichosperma
Intraseasonal teleconnections leading to heat waves in central ChileJacques‐Coper, Martín; Veloso‐Aguila, Daniel; Segura, Christian; Valencia, AmandaZonas Costeras2021.010.1002/joc.7096The ability to anticipate meteorological extreme events beyond the synoptic range of ~1 week offers direct applications, for example, to limit their ecological and socioeconomical impacts. This study focuses on precursors of summer (December–February, DJF) warm events, particularly heat waves, in central Chile (CCh), which are typically induced by low-level anticyclonic anomalies located to the south of this region. Considering that such atmospheric configuration can be part of a large-scale wave-train circulation pattern located upstream of CCh, we investigate signals that might provide guidance concerning the genesis of warm events in CCh. For a historical period (DJF 1872–2010) based on the 20th century reanalysis version 2 (20CR), our results present teleconnections that indicate higher probabilities of occurrence of such warm events with respect to expected climatological values. These signals can be monitored at least ~2 weeks in advance. Specifically, we explore the relationship between warm events in CCh and (a) the Madden-Julian Oscillation (MJO) as a tropical source of variability, and (b) an extra-tropical index (ETI), representative of the internal dynamics of the Southern Hemipshere mid-latitudes, presented as an original contribution from this study following a novel approach. Both signals, and apparently their constructive superposition, seem to contribute to the organization of the large-scale circulation anomalies leading ultimately to heat waves in CCh. We confirm these results for recent decades (DJF 1981–2020) using temperature observations and further data sets, namely the NCEP-NCAR Reanalysis (NNR) and the Climate Forecast System Reanalysis versions 1 and 2 (CFSR and CFSv2, respectively). Finally, we describe three recent heat wave events in CCh (DJF 2019–2020) to illustrate the suitability of this conceptualization.International Journal of Climatology0899-8418, 1097-0088 Reuters ISItropics, anticyclonic anomalies, circulation patterns, historical periods, large-scale circulation, madden-julian oscillation, meteorological extremes, provide guidances, temperature observations, climatology, atmospheric circulation, extreme event, heat wave, seasonal variation, teleconnection, temperature effect, weather forecasting, chile
Paving the road for electric vehicles: Lessons from a randomized experiment in an introduction stage marketGuevara, C. Angelo; Figueroa, Esteban; Munizaga, Marcela A.Ciudades Resilientes2021.010.1016/j.tra.2021.09.011We study attitudes, perceptions, and valuations of a convenience sample of Chilean employees from an electric distribution company who applied for a subsidized electric vehicle (EV) acquisition program. The subsidy was randomly assigned among the interested applicants. We use this data in an experiment to assess the impact that being a user, or a non-user of an EV has on the factors under study, using focus groups and a stated preference (SP) experiment. In the focus groups, users mentioned relatively more benefits and barriers of EVs, while non-users spontaneously stated that a limited charging network at the urban level could be an issue. The SP survey suggested that being a user did not trigger a change in environmental attitudes; on the other hand, it significantly boosted perceptions of maintenance costs and driving range. Additionally, discrete choice models estimated from the SP data suggested a possibly null willingness to pay for urban charging infrastructure, expressed as a percentage of current gas stations, among the user group. We discuss possible policy implications that can be inferred from this analysis, considering the size and source limitations of the available sample.Transportation Research Part A: Policy and Practice09658564 Reuters ISIpublic policy, acquisition programmes, driving range, electric distribution company, environmental attitudes, focus groups, group users, maintenance cost, randomized experiments, stated preference surveys, stated preferences, electric vehicles
Fire-induced loss of the world’s most biodiverse forests in Latin AmericaArmenteras, Dolors; Dávalos, Liliana M.; Barreto, Joan S.; Miranda, Alejandro; Hernández-Moreno, Angela; Zamorano-Elgueta, Carlos; González-Delgado, Tania M.; Meza-Elizalde, María C.; Retana, JavierCambio de Uso de Suelo2021.010.1126/sciadv.abd3357Fire plays a dominant role in deforestation, particularly in the tropics, but the relative extent of transformations and influence of fire frequency on eventual forest loss remain unclear. Here, we analyze the frequency of fire and its influence on postfire forest trajectories between 2001 and 2018. We account for ~1.1% of Latin American forests burnt in 2002–2003 (8,465,850 ha). Although 40.1% of forests (3,393,250 ha) burned only once, by 2018, ~48% of the evergreen forests converted to other, primarily grass-dominated uses. While greater fire frequency yielded more transformation, our results reveal the staggering impact of even a single fire. Increasing fire frequency imposes greater risks of irreversible forest loss, transforming forests into ecosystems increasingly vulnerable to degradation. Reversing this trend is indispensable to both mitigate and adapt to climate change globally. As climate change transforms fire regimes across the region, key actions are needed to conserve Latin American forests.Science Advances2375-2548 Reuters ISIdeforestation, fires, evergreen forests, fire frequencies, fire regimes, forest loss, induced loss, key actions, latin america, latin americans, climate change, article, climate change, evergreen, forest, grass, nonhuman, south and central america
Global resilience models and territories of the South. A critical reviewMarin, JulietteCiudades Resilientes2021.010.1016/j.ijdrr.2021.102541The resilience of cities, regions and other territorial scales is defined by various conceptual frameworks and has since the 2000s constituted a growing scientific and technical field. Although literature points out the difficulty of implementing such a vague and ambiguous concept, a range of metrics, methodological frameworks and principles have emerged, using tools like composite indicators, qualitative assessment or stochastic modelling. Among these models some have been applied globally over the last ten years, for e.g. the City Resilience Framework developed for the 100 Resilient Cities network. This article proposes a discussion of these global resilience models in order to contribute to our understanding of how they are constructed, how they function, and their potential to transform territories. By using literature review and qualitative content analysis, four axes of inquiry are developed: translations and adaptations of the notion of resilience within hegemonic networks; socio-technical markers of resilience models; resilience as a device of neoliberal governmentality; the position of Latin America within the production of knowledge concerning resilience. This manuscript main contribution is to put into question some gaps or biases in our scientific outputs and models that we might be reproducing or legitimating, and that are worth cross-examine. Three key findings are: Evidenced biases in disciplinary associations of resilience; Evidenced gaps in using closed-form of modelling resilience that invisibilize important assumptions of territories and despolitize the concept; The North-South divide resilience knowledge production is not only quantitative but also expressed in the core of models and tools.International Journal of Disaster Risk Reduction22124209 Reuters ISIglobal south, literature review, sustainability, urban resilience
Study of the urban microclimate using thermal UAV. The case of the mid-sized cities of Arica (arid) and Curicó (Mediterranean), ChileSmith, Pamela; Sarricolea, Pablo; Peralta, Orlando; Aguila, Juan Pablo; Thomas, FelipeCiudades Resilientes2021.010.1016/j.buildenv.2021.108372The study of the urban microclimate requires detailed information that is not available in most cities. The monitoring of climate parameters is reduced to a limited number of stations that are useful for urban climate studies at local or zonal scales. Detailed information is generally obtained through field work and fixed sensors. There are some climate parameters that can be obtained from remote sensors, such as the surface emission temperature, however, this information is only available in medium or low-resolution images from satellite images. Currently, it is possible to generate detailed information with Unmanned Aerial Vehicles (UAV). There are not many UAVs that can capture information on the surface emission temperature and those that can are, in general, prohibitively expensive. Only a few years ago a low-cost drone became available, the Mavic 2 dual, equipped with a thermal sensor, which qualitatively captures information from the thermal field. This article proposes the study of the urban microclimate of two mid-size Chilean cities using thermal images captured with the Mavic 2 dual drone, for which it was first necessary to process the images and convert their values to degrees Celsius. The values obtained are compared with those derived from Modis and Landsat satellite images, evaluating the correlation of the information.Building and Environment03601323 Reuters ISIcosts, drones, remote sensing, satellite imagery, climate parameters, climate studies, field works, mid-sized city, surface emissions, surface temperatures, thermal, unmanned aerial vehicle, urban climates, urban microclimate, antennas
Overcoming energy poverty through micro-grids: An integrated framework for resilient, participatory sociotechnical transitionsValencia, Felipe; Billi, Marco; Urquiza, AnahíCiudades Resilientes; Gobernanza e Interfaz Ciencia y Política2021.010.1016/j.erss.2021.102030Nowadays, the sustainability of micro-grids has received much attention in the research community since micro-grids are becoming an appealing alternative to provide clean energy access to rural communities, and by this token, contribute to overcome energy poverty. The aim of this paper was to investigate the sustainability of micro-grids through the analysis of their resilience. In this regard, an integrated framework was developed combining socio-technical transitions with socio-ecological resilience concepts. This allows to pay attention at once to two dimensions of micro-grid sustainability: (i) the ability of the micro-grid to effectively transform the relationship between community, energy, and territory to make it more sustainable in economic, social and environmental terms; (ii) the sustainability of the micro-grid itself, namely, its ability to endure, adapt to and recover from changes in contextual factors which may limit its operativity over time. Methodological guidelines are offered for the participatory co-construction and monitoring of the micro-grid and its monitoring, supporting both dimensions. To illustrate our proposal, the micro-grid installed in Huatacondo, north of Chile, was used as test-bed.Energy Research & Social Science22146296 Reuters ISIchile, energy poverty, micro-grids, participatory co-construction, socio-ecological resilience, socio-technical transitions, sustainability
Biotic and abiotic drivers of carbon, nitrogen and phosphorus stocks in a temperate rainforestPerez-Quezada, Jorge F.; Pérez, Cecilia A.; Brito, Carla E.; Fuentes, Juan P.; Gaxiola, Aurora; Aguilera-Riquelme, David; Lopatin, JavierCambio de Uso de Suelo2021.010.1016/j.foreco.2021.119341Forest Ecology and Management03781127 Reuters ISIbiomass, carbon, ecosystems, forestry, lakes, magnesium, nitrogen, nutrients, phosphorus, biotics, deadwood, evergreen broadleaf forest, n:p ratio, nitrogen and phosphorus, patagonia, property, southern south america, temperate rainforest, vine, soils, abiotic factor, belowground biomass, environmental factor, forest ecosystem, geodiversity, land use, land use change, old-growth forest, rainforest, soil nutrient, species diversity, biomass, carbon, ecosystems, forestry, lakes, magnesium, south america, matthiola
Procurement of camelid fiber in the hyperarid Atacama Desert coast: Insights from stable isotopesGayo, E. M.; Martens, T.; Stuart-Williams, H.; Fenner, J.; Santoro, C.; Carter, C.; Cameron, J.Ciudades Resilientes10.1016/j.quaint.2019.12.008Pastoralism and camelid management are traditionally attributed to the sociopolitical, economic and cosmovision of Andean populations, rather than to lowland hunter gatherer societies, living on the Pacific coast where camelid hunting is considered a marginal activity, and husbandry is a difficult enterprise given the hyper-arid conditions of lowland terrestrial ecosystems. Contrary to this interpretative historical view, our stable isotope analyses applied to 48 camelid fiber samples, suggests this highly valued camelid byproduct was obtained from camelids sustained on lomas vegetation formations during the Archaic (ca. 6500-4000 cal yr BP), Formative (ca. 4000-1500 cal yr BP) and Late periods (ca. 660-480 cal yr BP).Quaternary International10406182 Reuters ISIanimal husbandry, archaeology, arid environment, byproduct, hunter-gatherer, pastoralism, prehistoric, stable isotope, ungulate, atacama desert, chile, animalia, camelidae
RF-MEP: A novel Random Forest method for merging gridded precipitation products and ground-based measurementsBaez-Villanueva, Oscar M.; Zambrano-Bigiarini, Mauricio; Beck, Hylke E.; McNamara, Ian; Ribbe, Lars; Nauditt, Alexandra; Birkel, Christian; Verbist, Koen; Giraldo-Osorio, Juan Diego; Xuan Thinh, NguyenAgua y Extremos2020.010.1016/j.rse.2019.111606The accurate representation of spatio-temporal patterns of precipitation is an essential input for numerous environmental applications. However, the estimation of precipitation patterns derived solely from rain gauges is subject to large uncertainties. We present the Random Forest based MErging Procedure (RF-MEP), which combines information from ground-based measurements, state-of-the-art precipitation products, and topography-related features to improve the representation of the spatio-temporal distribution of precipitation, especially in data-scarce regions. RF-MEP is applied over Chile for 2000—2016, using daily measurements from 258 rain gauges for model training and 111 stations for validation. Two merged datasets were computed: RF-MEP3P (based on PERSIANN-CDR, ERA-Interim, and CHIRPSv2) and RF-MEP5P (which additionally includes CMORPHv1 and TRMM 3B42v7). The performances of the two merged products and those used in their computation were compared against MSWEPv2.2, which is a state-of-the-art global merged product. A validation using ground-based measurements was applied at different temporal scales using both continuous and categorical indices of performance. RF-MEP3P and RF-MEP5P outperformed all the precipitation datasets used in their computation, the products derived using other merging techniques, and generally outperformed MSWEPv2.2. The merged P products showed improvements in the linear correlation, bias, and variability of precipitation at different temporal scales, as well as in the probability of detection, the false alarm ratio, the frequency bias, and the critical success index for different precipitation intensities. RF-MEP performed well even when the training dataset was reduced to 10% of the available rain gauges. Our results suggest that RF-MEP could be successfully applied to any other region and to correct other climatological variables, assuming that ground-based data are available. An R package to implement RF-MEP is freely available online at Sensing of Environment00344257 Reuters ISIdecision trees, merging, precipitation (chemical), rain gages, topography, bias correction, environmental applications, ground based measurement, precipitation products, probability of detection, random forests, rf-mep, spatiotemporal distributions, rain, algorithm, correction, data set, ground-based measurement, measurement method, model validation, numerical method, precipitation (climatology), raingauge, topography, trmm, uncertainty analysis, chile
Assessment of ECMWF SEAS5 seasonal forecast performance over South AmericaGubler, S.; Sedlmeier, K.; Bhend, J.; Avalos, G.; Coelho, C. A. S.; Escajadillo, Y.; Jacques-Coper, M.; Martinez, R.; Schwierz, C.; de Skansi, M.; Spirig, Ch.Zonas Costeras2020.010.1175/WAF-D-19-0106.1Seasonal predictions have a great socio-economic potential if they are reliable and skillful. In this study, we assess the prediction performance of SEAS5, version 5 of the seasonal prediction system of the European Centre for Medium-Range Weather Forecasts (ECMWF), over South America against homogenized station data. For temperature, we find highest prediction performances in the tropics during austral summer, where the probability that the predictions correctly discriminate different observed outcomes is 70%. In regions lying to the east of the Andes, the predictions of maximum and minimum temperature still exhibit considerable performance, while further to the south in Chile and Argentina the temperature prediction performance is low. Generally, the prediction performance of minimum temperature is slightly lower than for maximum temperature. The prediction performance of precipitation is generally lower and spatially and temporally more variable than for temperature. The highest prediction performance is observed at the coast and over the highlands of Colombia and Ecuador, over north-eastern part of Brazil, and over an isolated region to the north of Uruguay during DJF. In general, Nino3.4 has a strong influence on both air temperature and precipitation in the regions where ECMWF SEAS5 shows high performance, in some regions through teleconnections (e.g., to the north of Uruguay). However, we show that SEAS5 outperforms a simple empirical prediction based on Nino3.4 in most regions where the prediction performance of the dynamical model is high, thereby supporting the potential benefit of using a dynamical model instead of statistical relationships for predictions at the seasonal scale.Weather and Forecasting0882-8156, 1520-0434 Reuters ISIclimatology, empirical predictions, european centre for medium-range weather forecasts, maximum and minimum temperatures, minimum temperatures, prediction performance, seasonal prediction, statistical relationship, temperature prediction, weather forecasting, air temperature, climate prediction, performance assessment, precipitation (climatology), summer, teleconnection, weather forecasting, argentina, brazil, chile, colombia, ecuador, uruguay
Definiciones tecno-políticas en la configuración de la matriz energética chilena durante el siglo xxFolchi, Mauricio; Blanco-Wells, Gustavo; Meier, StefanGobernanza e Interfaz Ciencia y Política2019.010.4067/S0717-71942019000200373Nuestro artículo examina la configuración histórica de la matriz energética chilena a lo largo del siglo xx y la comprende como el resultado de la expansión y declive relativo de tres regímenes socio-técnicos interdependientes: el carbón, el petróleo y la electricidad. Para cada uno de estos regímenes se estudian las definiciones tecno-políticas que orientaron su desarrollo, las cuales fueron representadas por las élites como “problemas” de carácter ideológico, social o económico, que debían ser resueltos tanto por el Estado como los privados.Historia (Santiago)0717-7194 Reuters ISIA
Recent changes in the precipitation-driving processes over the southern tropical Andes/western AmazonSegura, Hans; Espinoza, Jhan Carlo; Junquas, Clementine; Lebel, Thierry; Vuille, Mathias; Garreaud, ReneAgua y Extremos2020.010.1007/s00382-020-05132-6Analyzing December–February (DJF) precipitation in the southern tropical Andes—STA (12∘S–20∘S; > 3000 m.a.s.l) allows revisiting regional atmospheric circulation features accounting for its interannual variability over the past 35 years (1982–2018). In a region where in-situ rainfall stations are sparse, the CHIRPS precipitation product is used to identify the first mode of interannual DJF precipitation variability (PC1-Andes). A network of 98 rain-gauge stations further allows verifying that PC1-Andes properly represents the spatio-temporal rainfall distribution over the region; in particular a significant increase in DJF precipitation over the period of study is evident in both in-situ data and PC1-Andes. Using the ERA-Interim data set, we found that aside from the well-known relationship between precipitation and upper-level easterlies over the STA, PC1-Andes is also associated with upward motion over the western Amazon (WA), a link that has not been reported before. The ascent over the WA is a component of the meridional circulation between the tropical North Atlantic and western tropical South America—WTSA (80∘W–60∘W; 35∘S–10∘N). Indeed, the precipitation increase over the last 2 decades is concomitant with the strengthening of this meridional circulation. An intensified upward motion over the WA has moistened the mid-troposphere over WTSA, and as a consequence, a decreased atmospheric stability between the mid- and the upper troposphere is observed over this region, including the STA. We further show that, over the last 15 years or so, the year-to-year variability of STA precipitation (periodicity < 8 years) has been significantly associated with upward motion over the WA, while upper-level easterlies are no longer significantly correlated with precipitation. These observations suggests that the STA have experienced a transition from a dry to a wet state in association with a change in the dominant mode of atmospheric circulation. In the former dominant state, zonal advection of momentum and moisture from the central Amazon, associated with upper-level easterlies, is necessary to develop convection over the STA. Since the beginning of the 21st century, DJF precipitation over the STA seems to respond directly and primarily to upward motion over the WA. Beyond improving our understanding of the factors influencing STA precipitation nowadays, these results point to the need of exploring their possible implications for the long-term evolution of precipitation in a context of global warming.Climate Dynamics0930-7575, 1432-0894 Reuters ISIannual variation, atmospheric circulation, atmospheric convection, precipitation (climatology), rainfall, troposphere, altiplano, amazonia, andes
The deglaciation of the Americas during the Last Glacial TerminationPalacios, David; Stokes, Chris R.; Phillips, Fred M.; Clague, John J.; Alcalá-Reygosa, Jesus; Andrés, Nuria; Angel, Isandra; Blard, Pierre-Henri; Briner, Jason P.; Hall, Brenda L.; Dahms, Dennis; Hein, Andrew S.; Jomelli, Vincent; Mark, Bryan G.; Martini, Mateo A.; Moreno, Patricio; Riedel, Jon; Sagredo, Esteban; Stansell, Nathan D.; Vázquez-Selem, Lorenzo; Vuille, Mathias; Ward, Dylan J.Agua y Extremos2020.010.1016/j.earscirev.2020.103113This paper reviews current understanding of deglaciation in North, Central and South America from the Last Glacial Maximum to the beginning of the Holocene. Together with paleoclimatic and paleoceanographic data, we compare and contrast the pace of deglaciation and the response of glaciers to major climate events. During the Global Last Glacial Maximum (GLGM, 26.5-19 ka), average temperatures decreased 4° to 8°C in the Americas, but precipitation varied strongly throughout this large region. Many glaciers in North and Central America achieved their maximum extent during the GLGM, whereas others advanced even farther during the subsequent Heinrich Stadial 1 (HS-1). Glaciers in the Andes also expanded during the GLGM, but that advance was not the largest, except on Tierra del Fuego. HS-1 (17.5-14.6 ka) was a time of general glacier thickening and advance throughout most of North and Central America, and in the tropical Andes; however, glaciers in the temperate and subpolar Andes thinned and retreated during this period. During the Bølling-Allerød interstadial (B-A, 14.6-12.9 ka), glaciers retreated throughout North and Central America and, in some cases, completely disappeared. Many glaciers advanced during the Antarctic Cold Reversal (ACR, 14.6-12.9 ka) in the tropical Andes and Patagonia. There were small advances of glaciers in North America, Central America and in northern South America (Venezuela) during the Younger Dryas (12.9-11.7 ka), but glaciers in central and southern South America retreated during this period, except on the Altiplano where advances were driven by an increase in precipitation. Taken together, we suggest that there was a climate compensation effect, or ‘seesaw’, between the hemispheres, which affected not only marine currents and atmospheric circulation, but also the behavior of glaciers. This seesaw is consistent with the opposing behavior of many glaciers in the Northern and Southern Hemispheres.Earth-Science Reviews0012-8252 Reuters ISIchronology, deglaciation, glacier, last glacial maximum, paleoceanography, paleoclimate, paleotemperature, precipitation (climatology), central america, north america, south america
Initial response of understorey vegetation and tree regeneration to a mixed‐severity fire in old‐growth Araucaria–Nothofagus forestsFuentes‐Ramirez, Andres; Salas‐Eljatib, Christian; González, Mauro E; Urrutia‐Estrada, Jonathan; Arroyo‐Vargas, Paola; Santibañez, PabloCambio de Uso de Suelo2020.010.1111/avsc.12479Questions: Fire is a key factor influencing Araucaria araucana forests, but the impact of fire severity on the understorey vegetation is not well understood. In this study we seek to answer the following questions: (a) how do initial plant diversity, composition and spatial distribution of the understorey vegetation change in response to different levels of fire severity; and (b) does the abundance of dominant tree species exhibit different patterns across a fire severity gradient shortly after fire?. Location: Old-growth Araucaria araucana–Nothofagus pumilio forests in the Andes of south-central Chile (38° S, 71° W) burned in 2015. Methods: We evaluated the post-fire plant regeneration across a fire severity gradient ranging from unburned forests to areas of high fire severity. One year after fire (in February 2016), we measured woody and herbaceous species richness, abundance, height, origin (native vs exotic species), life forms and the spatial pattern of plant recovery. Results: Plant species richness and abundance were significantly higher within the unburned forest and low fire severity areas one year after fire, compared to areas of high and moderate fire severity. Overall, nearly 50% of the species present in the unburned forest were not found in areas of high severity, including the tree Nothofagus pumilio. Rapid vegetative resprouting of pioneer species such as Chusquea culeou resulted in an aggregated spatial distribution of plants after fire. Conclusions: Plant diversity and the abundance of Araucaria araucana and Nothofagus pumilio were reduced in areas of high fire severity one year after fire. Exotic species were more abundant within areas of low severity, being likely mediated by cattle browsing. Our research makes clear the potential changes in forest composition and structure if dominant tree species are not capable of recovering after fire. We recommend the exclusion of cattle within fire-affected areas and planting Nothofagus pumilio in areas of high fire severity. © 2020 International Association for Vegetation ScienceApplied Vegetation Science1402-2001, 1654-109X Reuters ISIabundance, araucaria araucana, nothofagus pumilio, plant diversity, post-fire vegetation recovery, severity gradient, spatial distribution, species richness
Water Crisis in Petorca Basin, Chile: The Combined Effects of a Mega-Drought and Water ManagementMuñoz A.; Klock-Barría, Karin; Alvarez-Garreton, Camila; Aguilera-Betti, Isabella; González-Reyes, Álvaro; Lastra, José A.; Chávez, Roberto O.; Barría, Pilar; Christie, Duncan; Rojas-Badilla, Moises; Quesne, Carlos LeAgua y Extremos2020.010.3390/w12030648Since 2010, Chile has experienced one of the most severe droughts over the last century, the so-called mega-drought (MD). The MD conditions, combined with intensive agricultural activities and the current water management system, have led to water scarcity problems in Mediterranean and Semi-arid regions of Chile. An emblematic case is the Petorca basin, where a water crisis is undergone. To characterize this crisis, we analyzed water provision by using tree-ring records, remote sensing, instrumental data, and allocated water rights within the basin. Results indicate that the MD is the most severe dry period over the last 700-years of streamflow reconstruction. During the MD, streamflow and water bodies of the upper parts of the basin have been less affected than mid and low areas of this valley, where consumptive withdrawals reach up to 18% of the mean annual precipitation. This extracted volume is similar to the MD mean annual precipitation deficits. The impacts of the current drought, along with the drier climate projections for Central Chile, emphasize the urgency for faster policy changes related to water provision. Climate change adaptation plans and policies should enhance the current monitoring network and the public control of water use to secure the water access for inhabitants and productive activities.Water2073-4441 Reuters ISIagricultural robots, drought, forestry, remote sensing, stream flow, trees (mathematics), water management, agricultural activities, climate change adaptation, climate projection, current monitoring, instrumental data, mean annual precipitation, water management systems, water scarcity, climate change, drought, reconstruction, streamflow, water management, water use, chile
Water demand in the Chilean manufacturing industry: Analysis of the economic value of water and demand elasticitiesVásquez-Lavín, Felipe; Vargas O, Leonardo; Hernández, José I.; Ponce Oliva, Roberto D.Cambio de Uso de Suelo10.1016/j.wre.2020.100159In this article, we estimate both the economic value of water and own-price and cross-price elasticities of water for the Chilean manufacturing industry using the production function approach. Estimating the production function allows us to estimate the marginal productivity of water which corresponds to its economic value. Our estimations are based on panel data obtained from the National Industrial Survey for the period 1995–2014, accounting for more than 10,000 industrial plants. We use a translog specification for the production function, considering water, capital, labor, energy, and intermediate material as explanatory variables. We find substitution patterns among most inputs, except for energy and water, which are found to be complements. Our results suggest that the manufacturing sector is characterized by an elastic water demand, with an average economic value of water of 8.071 [USD/m3]. Based on our findings, there is room to increase water prices in most sectors without affecting the competitiveness of firms. Knowing the economic value of water and its price elasticity could help policymakers to design water policies that promote more efficient use of this scarce resource.Water Resources and Economics22124284 Reuters ISIcapital, competitiveness, economic analysis, manufacturing, panel data, substitution, water demand, water industry, water resource
Investigating the regional contributions to air pollution in Beijing: a&#160;dispersion modelling study using CO as a&#160;tracerPanagi, Marios; Fleming, Zoë L.; Monks, Paul S.; Ashfold, Matthew J.; Wild, Oliver; Hollaway, Michael; Zhang, Qiang; Squires, Freya A.; Vande Hey, Joshua D.Ciudades Resilientes2020.010.5194/acp-20-2825-2020Abstract. The rapid urbanization and industrialization of northern China in recent decades has resulted in poor air quality in major cities like Beijing. Transport of air pollution plays a key role in determining the relative influence of local emissions and regional contributions to observed air pollution. In this paper, dispersion modelling (Numerical Atmospheric Modelling Environment, NAME model) is used with emission inventories and in situ ground measurement data to track the pathways of air masses arriving in Beijing. The percentage of time the air masses spent over specific regions during their travel to Beijing is used to assess the effects of regional meteorology on carbon monoxide (CO), a good tracer of anthropogenic emissions. The NAME model is used with the MEIC (Multi-resolution Emission Inventory for China) emission inventories to determine the amount of pollution that is transported to Beijing from the immediate surrounding areas and regions further away. This approach captures the magnitude and variability of CO over Beijing and reveals that CO is strongly driven by transport processes. This study provides a more detailed understanding of relative contributions to air pollution in Beijing under different regional airflow conditions. Approximately 45 % over a 4-year average (2013–2016) of the total CO pollution that affects Beijing is transported from other regions, and about half of this contribution comes from beyond the Hebei and Tianjin regions that immediately surround Beijing. The industrial sector is the dominant emission source from the surrounding regions and contributes over 20 % of the total CO in Beijing. Finally, using PM2.5 to determine high-pollution days, three pollution classification types of pollution were identified and used to analyse the APHH winter campaign and the 4-year period. The results can inform targeted control measures to be implemented by Beijing and the surrounding provinces to tackle air quality problems that affect Beijing and China.Atmospheric Chemistry and Physics1680-7324 Reuters ISIair mass, air quality, atmospheric modeling, atmospheric pollution, carbon monoxide, emission inventory, meteorology, tracer, beijing [beijing (ads)], beijing [china], china, hebei, tianjin
Observed Emergence of the Climate Change Signal: From the Familiar to the UnknownHawkins, E.; Frame, D.; Harrington, L.; Joshi, M.; King, A.; Rojas, M.; Sutton, R.Gobernanza e Interfaz Ciencia y Política2020.010.1029/2019GL086259Changes in climate are usually considered in terms of trends or differences over time. However, for many impacts requiring adaptation, it is the amplitude of the change relative to the local amplitude of climate variability which is more relevant. Here, we develop the concept of “signal‐to‐noise” in observations of local temperature, highlighting that many regions are already experiencing a climate which would be “unknown” by late 19th century standards. The emergence of observed temperature changes over both land and ocean is clearest in tropical regions, in contrast to the regions of largest change which are in the northern extratropics—broadly consistent with climate model simulations. Significant increases and decreases in rainfall have also already emerged in different regions with the United Kingdom experiencing a shift toward more extreme rainfall events, a signal which is emerging more clearly in some places than the changes in mean rainfall.Geophysical Research Letters0094-8276, 1944-8007 Reuters ISIclimate models, rain, signal to noise ratio, temperature, climate model simulations, climate variability, emergence, extremes, local temperature, observations, signal to noise, temperature changes, climate change, climate change, climate modeling, climate variation, land-sea interaction, observational method, rainfall, temperature gradient, united kingdom
Soccer games and record-breaking PM2.5 pollution events in Santiago, ChileLapere, Rémy; Menut, Laurent; Mailler, Sylvain; Huneeus, NicolásCiudades Resilientes2020.010.5194/acp-20-4681-2020Abstract. In wintertime, high concentrations of atmospheric fine particulate matter (PM2.5) are commonly observed in the metropolitan area of Santiago, Chile. Hourly peaks can be very strong, up to 10 times above average levels, but have barely been studied so far. Based on atmospheric composition measurements and chemistry-transport modeling (WRF-CHIMERE), the chemical signature of sporadic skyrocketing wintertime PM2.5 peaks is analyzed. This signature and the timing of such extreme events trace their origin back to massive barbecue cooking by Santiago's inhabitants during international soccer games. The peaks end up evacuated outside Santiago after a few hours but trigger emergency plans for the next day. Decontamination plans in Santiago focus on decreasing emissions from traffic, industry, and residential heating. Thanks to the air quality network of Santiago, this study shows that cultural habits such as barbecue cooking also need to be taken into account. For short-term forecast and emergency management, cultural events such as soccer games seem a good proxy to prognose possible PM2.5 peak events. Not only can this result have an informative value for the Chilean authorities but also a similar methodology could be reproduced for other cases throughout the world in order to estimate the burden on air quality of cultural habits.Atmospheric Chemistry and Physics1680-7324 Reuters ISIair quality, atmospheric chemistry, atmospheric pollution, concentration (composition), emission inventory, metropolitan area, particulate matter, pollutant source, pollution control, pollution incidence, sport, urban atmosphere, urban pollution, winter, chile, metropolitana
El Formativo en Tarapacá (3000-1000 aP): Arqueología, naturaleza y cultura en la Pampa del Tamarugal, Desierto de Atacama, norte de ChileUribe, Mauricio; Angelo, Dante; Capriles, José; Castro, Victoria; de Porras, María Eugenia; García, Magdalena; Gayo, Eugenia; González, Josefina; Herrera, María José; Izaurieta, Roberto; Maldonado, Antonio; Mandakovic, Valentina; McRostie, Virginia; Razeto, Jorge; Santana, Francisca; Santoro, Calogero; Valenzuela, Jimena; Vidal, AlejandraCiudades Resilientes2020.010.1017/laq.2019.92En este trabajo se describen las relaciones que las sociedades humanas establecieron con su entorno durante el período Formativo (3000-1000 aP) en la Pampa del Tamarugal, Desierto de Atacama, desde una perspectiva teórico-metodológica que pone el acento en el potencial del registro ecofactual. Éste, al mediar entre lo cultural y lo ambiental, proporciona información vital para una mejor comprensión de la relación entre naturaleza y cultura construida por estas sociedades. Queremos demostrar que este proceso forma parte de una larga historia de racionalización del desierto y de sus recursos silvestres, locales e introducidos, así como de la vivencia particular que tuvieron estas comunidades andinas. Por consiguiente, proponemos que la intervención humana en la Pampa del Tamarugal puede ser entendida como un cambio no sólo ecológico y económico, sino también cosmológico. , In this article, we illustrate the relationships that human societies established with their environment during the Formative period in the Pampa del Tamarugal (3000–1000 BP), Atacama Desert, Chile. We employed a theoretical-methodological perspective that emphasizes the explanatory potential of ecofacts. By mediating between humans and environment, this perspective provides a better understanding of how these societies constructed nature and culture. The purpose is to show that this process was part of a long history of rationalization of the desert, its resources, and the lived experience of the Formative communities that occupied that landscape. Therefore, we propose that this human intervention in Pampa del Tamarugal can be understood not only as an ecological and economic change but also a “cosmological” one.Latin American Antiquity1045-6635, 2325-5080 Reuters ISIarqueobotánica, arqueología simétrica, formativo, palabras claveandes centro-sur, tarapacá, zooarqueología
Mathematical Modeling for 2D Light--Sheet Fluorescence Microscopy image reconstructionCueva, Evelyn; Courdurier, Matias; Osses, Axel; Castañeda, Victor; Palacios, Benjamin; Härtel, SteffenCiudades Resilientes2020.010.1088/1361-6420/ab80d8Inverse Problems0266-5611, 1361-6420 Reuters ISIcameras, fluorescence, fluorescence microscopy, image reconstruction, iterative methods, light, linear systems, molecules, direct acquisition, excitation process, fluorescence microscopy images, fluorescent molecules, numerical experiments, regularized method, sparse linear systems, transport equation, inverse problems
Late Quaternary climatic variability in northern Patagonia, Argentina, based on δ18O of modern and fossil shells of Amiantis purpurata (Bivalvia, Veneridae)Bayer, Sol; Beierlein, Lars; Morán, Gisela A.; Doldán, María S.; Morsan, Enrique M.; Brey, Thomas; Mackensen, Andreas; Farias, Laura; García, Gerardo; Gordillo, SandraZonas Costeras2020.010.1016/j.palaeo.2020.110012Amiantis purpurata is a common warm-temperate water bivalve species distributed from southern Brazil to northern Patagonia, Argentina, which has a rich and well preserved fossil record in the San Matías Gulf (SMG) dating back to the late Quaternary. This study aims to establish A. purpurata shells as a new palaeoarchive of past marine conditions in South America. We compared the stable oxygen and carbon profiles (δ18Oshell; δ13Cshell) of eleven specimens of A. purpurata from different geological times (modern, Late Holocene and interglacial Late Pleistocene), and additionally present in situ oxygen isotope values of seawater within SMG (δ18Owater). Using both sets of information, we calculated and reconstructed palaeowater temperatures for the Late Holocene and compared them to modern water temperatures. Our findings indicate that A. purpurata records past environmental parameters such as water temperatures on a seasonal scale and can therefore be considered a suitable candidate for future palaeoenvironmental reconstructions in Northern Patagonia. This study is the first step towards further stable isotope analyses on fossil A. purpurata shells, which will show whether and if so, to what extent, important global climate events such as the Neoglacial (Early Holocene), the Hypsithermal (Middle Holocene) and the Little Ice Age (Late Holocene) occurred in South America.Palaeogeography, Palaeoclimatology, Palaeoecology00310182 Reuters ISIbivalve, climate variation, fossil record, global climate, hypsithermal, interglacial, little ice age, marine environment, neoglacial, oxygen isotope, pleistocene-holocene boundary, quaternary, shell, type specimen, argentina, atlantic ocean, brazil, san matias gulf, amiantis, bivalvia, veneridae
South Pacific Subtropical High from the late Holocene to the end of the 21st century: insights from climate proxies and general circulation modelsFlores-Aqueveque, Valentina; Rojas, Maisa; Aguirre, Catalina; Arias, Paola A.; González, CharlesZonas Costeras; Gobernanza e Interfaz Ciencia y Política2020.010.5194/cp-16-79-2020Abstract. The South Pacific Subtropical High (SPSH) is a predominant feature of the South American climate. The variability of this high-pressure center induces changes in the intensity of coastal alongshore winds and precipitation, among others, over southwestern South America. In recent decades, strengthening and expansion of the SPSH have been observed and attributed to the current global warming. These changes have led to an intensification of the southerly winds along the coast of northern to central Chile and a decrease in precipitation from central to southern Chile. Motivated by improving our understanding about the regional impacts of climate change in this part of the Southern Hemisphere, we analyzed SPSH changes during the two most extreme climate events of the last millennium, the Little Ice Age (LIA) and the Current Warm Period (CWP: 1970–2000), based on paleoclimate records and CMIP5/PMIP3 model simulations. In order to assess the level of agreement of general circulation models, we also compare them with ERA-Interim reanalysis data for the 1979–2009 period as a complementary analysis. Finally, with the aim of evaluating future SPSH behavior, we include 21st century projections under a Representative Concentration Pathway (RCP8.5) scenario in our analyses. Our results indicate that during the relative warm (cold) period, the SPSH expands (contracts). Together with this change, alongshore winds intensify (weaken) south (north) of ∼35∘ S; also, southern westerly winds become stronger (weaker) and shift southward (northward). Model results generally underestimate reanalysis data. These changes are in good agreement with paleoclimate records, which suggest that these variations could be related to tropical climate dynamics but also to extratropical phenomena. However, although models adequately represent most of the South American climate changes, they fail to represent the Intertropical Convergence Zone–Hadley cell system dynamics, emphasizing the importance of improving tropical system dynamics in simulations for a better understanding of its effects on South America. Climate model projections indicate that changes recently observed will continue during the next decades, highlighting the need to establish effective mitigation and adaptation strategies against their environmental and socioeconomic impacts.Climate of the Past1814-9332 Reuters ISIclimate change, general circulation model, holocene, little ice age, paleoclimate, proxy climate record, twenty first century, chile, pacific ocean, pacific ocean (south), south america
Physiological and morphological responses to permanent and intermittent waterlogging in seedlings of four evergreen trees of temperate swamp forestsZúñiga-Feest, Alejandra; Bustos-Salazar, Angela; Alves, Fernanda; Martinez, Vanessa; Smith-Ramírez, CeciliaCambio de Uso de Suelo2017.010.1093/treephys/tpx023Tree Physiology0829-318X, 1758-4469 Reuters ISIacclimation, adventitious root, carbon cycle, evergreen tree, gas exchange, growth, leaf area, metabolism, microhabitat, morphology, photosynthesis, physiological response, seedling, stomatal conductance, swamp forest, temperate environment, tolerance, transpiration, waterlogging, south america, blepharocalyx, drimys winteri, luma apiculata, myrceugenia exsucca, water, drimys, ecosystem, forest, growth, development and aging, myrtaceae, physiology, plant leaf, plant root, seedling, tree, wetland, drimys, ecosystem, forests, myrtaceae, plant leaves, plant roots, seedlings, trees, water, wetlands
The southern South American Proteaceae, Embothrium coccineum exhibits intraspecific variation in growth and cluster-root formation depending on climatic and edaphic originsZúñiga-Feest, Alejandra; Delgado, Mabel; Bustos-Salazar, Angela; Ochoa, ValeriaCambio de Uso de Suelo2015.010.1007/s11104-015-2574-6Background and aims Cluster root (CR) functioning has been studied mainly in Proteaceae species from (P)-deficient old soils. However, in southern South America, six species occur in young P rich soils. The aims were: i) to study the growth and CR formation of Embothrium coccineum seedlings from populations contrasting in edaphic and climatic conditions and, ii) to study the effect of P availability on CR formation. Methods Seedlings were grown from seeds collected from nine Chilean populations of E. coccineum (36° to 45° S). After 9 months in a nursery, CR formation and growth were determined. Additionally, seedlings from the two populations at the extreme ends of the distribution were maintained on sand and watered with nutrient solutions including or excluding P. Results All seedlings showed CR formation at 4 months old; however, CR allocation differed in that it was lower in plants from the north versus from the south. CR in seedlings from Curacautín (38°) were suppressed when P supply increased, though this was not seen in seedlings from Coyhaique (45°). Conclusions Results suggest local root adaptation related to both climatic and edaphic conditions. We hypothesize that these features could favor Proteaceae persistence in southern South American ecosystems.Plant and Soil0032-079X, 1573-5036 Reuters ISIclimate conditions, cluster analysis, evergreen tree, growth rate, hypothesis testing, intraspecific variation, persistence, phosphorus, seedling, volcanic soil, aisen, chile, coihaique, embothrium coccineum, proteaceae
Carbon allocation to growth and storage in two evergreen species of contrasting successional statusPiper, Frida I.; Sepúlveda, Paulina; Bustos-Salazar, Angela; Zúñiga-Feest, AlejandraCambio de Uso de Suelo2017.010.3732/ajb.1700057Premise of the study: A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-growing tree species in the world (Eucalyptus globulus) and a shade-tolerant, slow-growing species (Luma apiculata). Methods: Seedlings were subjected to one out of four combinations of light (high vs. low) and initial defoliation (90% defoliated vs. nondefoliated) for four months. Growth, C storage concentration in different organs, leaf shedding, and lateral shoot formation were measured at the end of the experiment. Key results: Eucalyptus globulus grew faster than L. apiculata in high light, but not in low light. Both species had lower C storage concentration in low than in high light, but similar C storage concentrations in each light condition. Defoliation had no effect on C storage, except in the case of the old leaves of both species, which showed lower C storage levels in response to defoliation. Across treatments, leaf shedding was 96% higher in E. globulus than in L. apiculata while, in contrast, lateral shoot formation was 87% higher in L. apiculata. Conclusions: In low light, E. globulus prioritized C storage instead of growth, whereas L. apiculata prioritized growth and lateral branching. Our results suggest that shade tolerance depends on efficient light capture rather than C conservation traits. Keywords: C starvation; Eucalyptus globulus; Luma apiculata; Myrtaceae; defoliation; growth–survival tradeoff; leaf shedding; starch; succession; understory.American Journal of Botany0002-9122, 1537-2197 Reuters ISIbiomass allocation, carbon sequestration, defoliation, evergreen tree, growth, light availability, seedling, shade tolerance, shading, starch, succession, survival, trade-off, understory, eucalyptus globulus, luma apiculata, myrtaceae, carbon, carbon cycle, eucalyptus, forest, growth, development and aging, light, metabolism, myrtaceae, plant leaf, seedling, tree, carbon, carbon cycle, eucalyptus, forests, light, myrtaceae, plant leaves, seedlings, trees
Gene fusion of heterophyletic gamma-globin genes in platyrrhine primatesArroyo, José Ignacio; Nery, Mariana F.Zonas Costeras2018.010.1007/s12041-018-1039-0We performed phylogenetic analyses of HBG genes to assess its origin and interspecific variation among primates. Our analyses showed variation in HBG genes copy number ranging from one to three, some of them pseudogenes. For platyrrhines HBG genes, phylogenetic reconstructions of flanking regions recovered orthologous clades with distinct topologies for 5′ and 3′ flanking regions. The 5′ region originated in the common ancestor of platyrrhines but the 3′ region had an anthropoid origin. We hypothesize that the platyrrhine HBG genes of 5′ and 3′ heterophyletic origins arose from subsequent fusions of the (earlier) platyrrhine 5′ portion and the (later) anthropoid 3′ portion.Journal of Genetics0022-1333, 0973-7731 Reuters ISIhemoglobin gamma chain, animal, biological model, classification, gene duplication, gene fusion, genetic variation, genetics, molecular evolution, phylogeny, primate, pseudogene, animals, evolution, molecular, gamma-globins, gene duplication, gene fusion, genetic variation, models, genetic, phylogeny, primates, pseudogenes
Using probabilistic analysis to improve greenhouse gas baseline forecasts in developing country contexts: the case of ChileO’ Ryan, Raul; Benavides, Carlos; Díaz, Manuel; San Martín, Juan Pablo; Mallea, JavierGobernanza e Interfaz Ciencia y Política2019.010.1080/14693062.2018.1503153In this paper, initial steps are presented toward characterizing, quantifying, incorporating and communicating uncertainty applying a probabilistic analysis to countrywide emission baseline forecasts, using Chile as a case study. Most GHG emission forecasts used by regulators are based on bottom-up deterministic approaches. Uncertainty is usually incorporated through sensitivity analysis and/or use of different scenarios. However, much of the available information on uncertainty is not systematically included. The deterministic approach also gives a wide range of variation in values without a clear sense of probability of the expected emissions, making it difficult to establish both the mitigation contributions and the subsequent policy prescriptions for the future. To improve on this practice, we have systematically included uncertainty into a bottom-up approach, incorporating it in key variables that affect expected GHG emissions, using readily available information, and establishing expected baseline emissions trajectories rather than scenarios. The resulting emission trajectories make explicit the probability percentiles, reflecting uncertainties as well as possible using readily available information in a manner that is relevant to the decision making process. Additionally, for the case of Chile, contradictory deterministic results are eliminated, and it is shown that, whereas under a deterministic approach Chile’s mitigation ambition does not seem high, the probabilistic approach suggests this is not necessarily the case. It is concluded that using a probabilistic approach allows a better characterization of uncertainty using existing data and modelling capacities that are usually weak in developing country contexts.Climate Policy1469-3062, 1752-7457 Reuters ISIcarbon emission, climate change, developing world, environmental policy, forecasting method, greenhouse gas, probability, uncertainty analysis, chile
Governing nature-based tourism mobility in National Park Torres del Paine, Chilean Southern PatagoniaRuiz, José Barrena; Lamers, Machiel; Bush, Simon; Wells, Gustavo BlancoGobernanza e Interfaz Ciencia y Política2019.010.1080/17450101.2019.1614335Nature-based tourism is a mobile activity shaped by the capacity of tourists for displacement and the socio-material infrastructure allowing flows. However, the literature has scarcely addressed aspects of mobility in governing nature-based tourism. Taking the case of the National Park Torres del Paine we explore three aspects of mobility in nature-based tourism using the concepts of routes, frictions, and rhythms. Our findings show that the movement of tourists challenges spatially bounded forms of governance. Instead, we argue, new mobility-sensitive forms of nature-based tourism governance are needed that can complement the use of fixed-boundary conservation enclosures.Mobilities1745-0101, 1745-011X Reuters ISIecotourism, governance approach, mobility, protected area, tourist attraction, tourist destination, chile, chile, magallanes, patagonia, torres del paine national park
MMP-8, TRAP-5, and OPG Levels in GCF Diagnostic Potential to Discriminate between Healthy Patients’, Mild and Severe Periodontitis SitesHernández, Marcela; Baeza, Mauricio; Contreras, Johanna; Sorsa, Timo; Tervahartiala, Taina; Valdés, Macarena; Chaparro, Alejandra; Hernández-Ríos, PatriciaCiudades Resilientes2020.010.3390/biom10111500Biomarkers represent promising aids in periodontitis, host-mediate diseases of the tooth-supporting tissues. We assessed the diagnostic potential of matrix metalloproteinase-8 (MMP-8), tartrate-resistant acid phosphatase-5 (TRAP-5), and osteoprotegerin (OPG) to discriminate between healthy patients’, mild and severe periodontitis sites. Thirty-one otherwise healthy volunteers with and without periodontal disease were enrolled at the Faculty of Dentistry, University of Chile. Periodontal parameters were examined and gingival crevicular fluid was sampled from mild periodontitis sites (M; n = 42), severe periodontitis sites (S; n = 59), and healthy volunteer sites (H; n = 30). TRAP-5 and OPG were determined by commercial multiplex assay and MMP-8 by the immunofluorometric (IFMA) method. STATA software was used. All biomarkers showed a good discrimination performance. MMP-8 had the overall best performance in regression models and Receiver Operating Characteristic (ROC) curves, with high discrimination of healthy from periodontitis sites (area under the curve (AUC) = 0.901). OPG showed a very high diagnostic precision (AUC ≥ 0.95) to identify severe periodontitis sites (S versus H + M), while TRAP-5 identified both healthy and severe sites. As conclusions, MMP-8, TRAP-5, and OPG present a high precision potential in the identification of periodontal disease destruction, with MMP-8 as the most accurate diagnostic biomarker.Biomolecules2218-273X Reuters ISIacid phosphatase tartrate resistant isoenzyme, neutrophil collagenase, osteoprotegerin, tartrate resistant acid phosphatase 5, unclassified drug, acid phosphatase tartrate resistant isoenzyme, acp5 protein, human, biological marker, mmp8 protein, human, neutrophil collagenase, osteoprotegerin, tnfrsf11b protein, human, adult, area under the curve, article, clinical article, controlled study, cross-sectional study, diagnostic accuracy, diagnostic test accuracy study, disease severity, female, fluorometry, gingivitis, human, immunoassay, male, middle aged, periodontal disease, periodontal pocket depth, periodontitis, receiver operating characteristic, sensitivity and specificity, time resolved spectroscopy, blood, chronic periodontitis, differential diagnosis, genetics, gingivitis, metabolism, pathology, periodontitis, severity of illness index, adult, biomarkers, chronic periodontitis, diagnosis, differential, female, gingival crevicular fluid, humans, male, matrix metalloproteinase 8, middle aged, osteoprotegerin, periodontitis, severity of illness index, tartrate-resistant acid phosphatase
Validation of a 9-km WRF dynamical downscaling of temperature and precipitation for the period 1980–2005 over Central South ChileFernández, Alfonso; Schumacher, Vanúcia; Ciocca, Isabella; Rifo, Andreaw; Muñoz, Ariel A.; Justino, FlavioAgua y Extremos2020.010.1007/s00704-020-03416-9In this paper, we evaluated a dynamical downscaling produced for Central South Chile (32°S–38°S) relative to climatic conditions between 1980 and 2005. Assessing the skill of dynamical downscaling relative to the present climate is key to determine the degree of confidence on regional climatic projections. We used the Weather Research and Forecasting model to simulate that period at ~ 9 km grid-cell size, forced by the bias-corrected Community Earth System Model. Results indicated that the dynamical downscaling adequately reproduced spatio-temporal features of the climate within the region. Temperature showed a positive bias at the annual scale while the opposite occurred for precipitation. The bias varied when the comparison was performed relative to a gridded product or instrumental records from weather stations. At the monthly scale, the model failed to capture long-term trends relative to the gridded dataset while reproducing spatial patterns, especially for temperature. We found a generally statistically significant spatial clustering of the monthly mean bias that can support implementation and application of dynamical downscaling and bias-correction methods that account for the distinct climatic features of the study area. In particular, the strip 34°S–35°S presented features that are coincident with previous findings suggesting this latitude to be a boundary between different climate regimes north and south. According to our results, we assert that this dynamical downscaling is comparable with other available databases and thus can be utilized in future studies as an additional and independent source of analysis, contributing to a balanced appraisal of climate scenarios for policymaking within the region.Theoretical and Applied Climatology0177-798X, 1434-4483 Reuters ISIair temperature, climate conditions, climate prediction, computer simulation, downscaling, precipitation assessment, regional climate, weather forecasting, chile
Evaluation of multiple indices of the South American monsoonCorrea, Isabel C.; Arias, Paola A.; Rojas, MaisaGobernanza e Interfaz Ciencia y Política2020.010.1002/joc.6880In this article, multiple methods for estimating the onset and demise of the South American Monsoon System (SAMS) are evaluated during the period 1979–2018. The results obtained from indices based on precipitation, outgoing longwave radiation and combined empirical orthogonal functions (LISAM) show a delay in the SAMS onset while the demise dates do not show marked changes during the considered period. The latter indicates that the observed shortening of the SAMS (and the consistent lengthening of the southern Amazon dry season) mainly depend on variations at the onset stage of the SAMS, as identified in previous studies based on different databases and methodologies. This result is independent on the observational dataset considered. This allows resolving previously inconsistent results on the shortening of the SAMS. Furthermore, the climatological patterns of precipitation and atmospheric circulation at surface and upper levels associated with SAMS are best represented by the precipitation‐based index; however, all indices exhibit general difficulties in representing the evolution of the atmospheric circulation at 200 hPa. Finally, our analyses suggest that including northeastern (NE) Brazil in the domain considered to characterize the SAMS tends to alter the estimates of SAMS timing, primarily its onset. In particular, the trend towards late onsets of the SAMS is evidenced by all indices over spatial domains that do not include NE Brazil, while this trend is considerably weakened or not significant when this area is included. This denotes a strong sensitivity of the different indices to the spatial domain considered for SAMS characterization.International Journal of Climatology0899-8418, 1097-0088 Reuters ISIclimatology, orthogonal functions, atmospheric circulation, dry seasons, empirical orthogonal function, monsoon system, multiple index, multiple methods, outgoing longwave radiation, spatial domains, atmospheric thermodynamics
A Twitter-Lived Red Tide Crisis on Chiloé Island, Chile: What Can Be Obtained for Social-Ecological Research through Social Media Analysis?Mascareño, Aldo; Henríquez, Pablo A.; Billi, Marco; Ruz, Gonzalo A.Gobernanza e Interfaz Ciencia y Política2020.010.3390/su12208506Considering traditional research on social-ecological crises, new social media analysis, particularly Twitter data, contributes with supplementary exploration techniques. In this article, we argue that a social media approach to social-ecological crises can offer an actor-centered meaningful perspective on social facts, a depiction of the general dynamics of meaning making that takes place among actors, and a systemic view of actors’ communication before, during and after the crisis. On the basis of a multi-technique approach to Twitter data (TF-IDF, hierarchical clustering, egocentric networks and principal component analysis) applied to a red tide crisis on Chiloé Island, Chile, in 2016, the most significant red tide in South America ever, we offer a view on the boundaries and dynamics of meaning making in a social-ecological crisis. We conclude that this dynamics shows a permanent reflexive work on elucidating the causes and effects of the crisis that develops according to actors’ commitments, the sequence of events, and political conveniences. In this vein, social media analysis does not replace good qualitative research, it rather opens up supplementary possibilities for capturing meanings from the past that cannot be retrieved otherwise. This is particularly relevant for studying social-ecological crises and supporting collective learning processes that point towards increased resilience capacities and more sustainable trajectories in affected communities.Sustainability2071-1050 Reuters ISIcommunication, ecological approach, hierarchical system, literature review, principal component analysis, red tide, research work, social media, chile, chilo
A Network for Advancing Dendrochronology, Dendrochemistry and Dendrohydrology in South AmericaAguilera-Betti, Isabella; Lucas, Christine; Ferrero, María Eugenia; Muñoz, Ariel A.Agua y Extremos2020.010.3959/TRR2019-12Tree-ring research (TRR) in South America (SA) continues to make important contributions in multiple sub-disciplines, including dendrochemistry and dendrohydrology. 1 2 communicate recent advances in TRR within a network of laboratories in Argentina, Brazil, Chile, Peru, and Uruguay. Novel methodologies and results in dendrochemistry and wood anatomy were also presented by collaborating researchers from German institutions. The report describes some of the research within the subdisciplines of tree-ring science, including dendrochemistry, anatomy and dendrohydrology, and their application to understanding spatio-temporal variability in heavy metal contamination, climate, hydrology, fire regimes and other critical components of South American forest and woodland ecosystems. The meeting demonstrated a broadening and diversification in the research and applications of TRR in SA, whereby collaboration across research centers has been critical for the advances made in broad-scale comparative studies as well as multi-proxy approaches and the study of global and hemisphere-scale climate phenomena.Tree-Ring Research1536-1098 Reuters ISIchemical analysis, climate, pollution, stable isotopes, trace elements, tree rings, wood anatomy
Metagenomic Insights into the Sewage RNA Virosphere of a Large CityGuajardo-Leiva, Sergio; Chnaiderman, Jonás; Gaggero, Aldo; Díez, BeatrizZonas Costeras2020.010.3390/v12091050Sewage-associated viruses can cause several human and animal diseases, such as gastroenteritis, hepatitis, and respiratory infections. Therefore, their detection in wastewater can reflect current infections within the source population. To date, no viral study has been performed using the sewage of any large South American city. In this study, we used viral metagenomics to obtain a single sample snapshot of the RNA virosphere in the wastewater from Santiago de Chile, the seventh largest city in the Americas. Despite the overrepresentation of dsRNA viruses, our results show that Santiago’s sewage RNA virosphere was composed mostly of unknown sequences (88%), while known viral sequences were dominated by viruses that infect bacteria (60%), invertebrates (37%) and humans (2.4%). Interestingly, we discovered three novel genogroups within the Picobirnaviridae family that can fill major gaps in this taxa’s evolutionary history. We also demonstrated the dominance of emerging Rotavirus genotypes, such as G8 and G6, that have displaced other classical genotypes, which is consistent with recent clinical reports. This study supports the usefulness of sewage viral metagenomics for public health surveillance. Moreover, it demonstrates the need to monitor the viral component during the wastewater treatment and recycling process, where this virome can constitute a reservoir of human pathogens.Viruses1999-4915 Reuters ISIprotein e6, rna, rna 16s, rna directed rna polymerase, viral protein, acute gastroenteritis, aedes aegypti, amino acid substitution, animal disease, antibiotic resistance, article, bioinformatics, bromoviridae, caudovirales, chile, cystoviridae, dna extraction, escherichia coli, feces analysis, flocculation, gastroenteritis, genetic variability, genome analysis, genotype, greenhouse effect, health survey, high throughput sequencing, hospitalization, human, human rotavirus, illumina sequencing, intestine flora, metagenome, metagenomics, microbial community, microbial diversity, nonhuman, norovirus, nucleotide sequence, open reading frame, phage therapy, phylogenetic tree, phylogeny, picobirnaviridae, polyacrylamide gel electrophoresis, prevalence, public health, real time polymerase chain reaction, recycling, retroposon, rotavirus, rotavirus c, sequence analysis, sewage, taxonomy, ultracentrifugation, vaccination, viral gastroenteritis, virosphere, virus detection, virus genome, virus particle, wart virus, waste water management, water availability, animal, classification, genetics, invertebrate, metagenome, metagenomics, picobirnavirus, procedures, rna virus, sewage, virology, virus, wastewater, animals, chile, humans, invertebrates, metagenome, metagenomics, picobirnavirus, rna viruses, rotavirus, sewage, viral proteins, viruses, waste water
Two Centuries of Hydroclimatic Variability Reconstructed From Tree‐Ring Records Over the Amazonian Andes of PeruHumanes‐Fuente, V.; Ferrero, M. E.; Muñoz, A. A.; González‐Reyes, Á.; Requena‐Rojas, E. J.; Barichivich, J.; Inga, J. G.; Layme‐Huaman, E. T.Agua y Extremos2020.010.1029/2020JD032565Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high‐quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provide a complete record since 1979 and offer a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scales. We developed the first annually resolved precipitation reconstruction for the tropical Andes in Peru, based on tree‐ring chronologies of Cedrela and Juglans species. The annual (November–October) reconstruction extends the short instrumental records back to 1817, explaining 68% of the total variance of precipitation over the 1979–2007 calibration period. The reconstruction reveals the well‐documented influence of El Niño‐Southern Oscillation (ENSO) on Amazon Rainfall at interannual scales (~19% of total variance) and significant multidecadal variability with alternating periods of about 40 years (~13% of rainfall variability) related to the Atlantic Multidecadal Oscillation (AMO). Both oscillatory modes can explain dry and humid periods observed within the reconstruction and are likely associated with the negative trends of rainfall in the short instrumental records and the increased drought recurrence in recent decades. Our results show that montane tropical tree rings can be used to reconstruct precipitation with exceptionally high fidelity, characterize the interannual to multidecadal variability, and identify remote forcings in the hydroclimate over the Andean Amazon Basin of Peru.Journal of Geophysical Research: Atmospheres2169-897X, 2169-8996 Reuters ISIclimate variation, decadal variation, el nino-southern oscillation, humid environment, paleoclimate, rainfall, reconstruction, tree ring, amazonia, andes, peru, cedrela, juglans
Transforming knowledge systems for life on Earth: Visions of future systems and how to get thereFazey, Ioan; Schäpke, Niko; Caniglia, Guido; Hodgson, Anthony; Kendrick, Ian; Lyon, Christopher; Page, Glenn; Patterson, James; Riedy, Chris; Strasser, Tim; Verveen, Stephan; Adams, David; Goldstein, Bruce; Klaes, Matthias; Leicester, Graham; Linyard, Alison; McCurdy, Adrienne; Ryan, Paul; Sharpe, Bill; Silvestri, Giorgia; Abdurrahim, Ali Yansyah; Abson, David; Adetunji, Olufemi Samson; Aldunce, Paulina; Alvarez-Pereira, Carlos; Amparo, Jennifer Marie; Amundsen, Helene; Anderson, Lakin; Andersson, Lotta; Asquith, Michael; Augenstein, Karoline; Barrie, Jack; Bent, David; Bentz, Julia; Bergsten, Arvid; Berzonsky, Carol; Bina, Olivia; Blackstock, Kirsty; Boehnert, Joanna; Bradbury, Hilary; Brand, Christine; Böhme (born Sangmeister), Jessica; Bøjer, Marianne Mille; Carmen, Esther; Charli-Joseph, Lakshmi; Choudhury, Sarah; Chunhachoti-ananta, Supot; Cockburn, Jessica; Colvin, John; Connon, Irena L.C.; Cornforth, Rosalind; Cox, Robin S.; Cradock-Henry, Nicholas; Cramer, Laura; Cremaschi, Almendra; Dannevig, Halvor; Day, Catherine T.; de Lima Hutchison, Cathel; de Vrieze, Anke; Desai, Vikas; Dolley, Jonathan; Duckett, Dominic; Durrant, Rachael Amy; Egermann, Markus; Elsner (Adams), Emily; Fremantle, Chris; Fullwood-Thomas, Jessica; Galafassi, Diego; Gobby, Jen; Golland, Ami; González-Padrón, Shiara Kirana; Gram-Hanssen, Irmelin; Grandin, Jakob; Grenni, Sara; Lauren Gunnell, Jade; Gusmao, Felipe; Hamann, Maike; Harding, Brian; Harper, Gavin; Hesselgren, Mia; Hestad, Dina; Heykoop, Cheryl Anne; Holmén, Johan; Holstead, Kirsty; Hoolohan, Claire; Horcea-Milcu, Andra-Ioana; Horlings, Lummina Geertruida; Howden, Stuart Mark; Howell, Rachel Angharad; Huque, Sarah Insia; Inturias Canedo, Mirna Liz; Iro, Chidinma Yvonne; Ives, Christopher D.; John, Beatrice; Joshi, Rajiv; Juarez-Bourke, Sadhbh; Juma, Dauglas Wafula; Karlsen, Bea Cecilie; Kliem, Lea; Kläy, Andreas; Kuenkel, Petra; Kunze, Iris; Lam, David Patrick Michael; Lang, Daniel J.; Larkin, Alice; Light, Ann; Luederitz, Christopher; Luthe, Tobias; Maguire, Cathy; Mahecha-Groot, Ana-Maria; Malcolm, Jackie; Marshall, Fiona; Maru, Yiheyis; McLachlan, Carly; Mmbando, Peter; Mohapatra, Subhakanta; Moore, Michele-Lee; Moriggi, Angela; Morley-Fletcher, Mark; Moser, Susanne; Mueller, Konstanze Marion; Mukute, Mutizwa; Mühlemeier, Susan; Naess, Lars Otto; Nieto-Romero, Marta; Novo, Paula; O’Brien, Karen; O'Connell, Deborah Anne; O'Donnell, Kathleen; Olsson, Per; Pearson, Kelli Rose; Pereira, Laura; Petridis, Panos; Peukert, Daniela; Phear, Nicky; Pisters, Siri Renée; Polsky, Matt; Pound, Diana; Preiser, Rika; Rahman, Md. Sajidur; Reed, Mark S.; Revell, Philip; Rodriguez, Iokiñe; Rogers, Briony Cathryn; Rohr, Jascha; Nordbø Rosenberg, Milda; Ross, Helen; Russell, Shona; Ryan, Melanie; Saha, Probal; Schleicher, Katharina; Schneider, Flurina; Scoville-Simonds, Morgan; Searle, Beverley; Sebhatu, Samuel Petros; Sesana, Elena; Silverman, Howard; Singh, Chandni; Sterling, Eleanor; Stewart, Sarah-Jane; Tàbara, J. David; Taylor, Douglas; Thornton, Philip; Tribaldos, Theresa Margarete; Tschakert, Petra; Uribe-Calvo, Natalia; Waddell, Steve; Waddock, Sandra; van der Merwe, Liza; van Mierlo, Barbara; van Zwanenberg, Patrick; Velarde, Sandra Judith; Washbourne, Carla-Leanne; Waylen, Kerry; Weiser, Annika; Wight, Ian; Williams, Stephen; Woods, Mel; Wolstenholme, Ruth; Wright, Ness; Wunder, Stefanie; Wyllie, Alastair; Young, Hannah R.Agua y Extremos2020.010.1016/j.erss.2020.101724Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent.Energy Research & Social Science22146296 Reuters ISIclimate and energy research, epistemology, knowledge, social-technical transitions, sustainability science, transformation
Six hundred years of South American tree rings reveal an increase in severe hydroclimatic events since mid-20th centuryMorales, Mariano S.; Cook, Edward R.; Barichivich, Jonathan; Christie, Duncan A.; Villalba, Ricardo; LeQuesne, Carlos; Srur, Ana M.; Ferrero, M. Eugenia; González-Reyes, Álvaro; Couvreux, Fleur; Matskovsky, Vladimir; Aravena, Juan C.; Lara, Antonio; Mundo, Ignacio A.; Rojas, Facundo; Prieto, María R.; Smerdon, Jason E.; Bianchi, Lucas O.; Masiokas, Mariano H.; Urrutia-Jalabert, Rocio; Rodriguez-Catón, Milagros; Muñoz, Ariel A.; Rojas-Badilla, Moises; Alvarez, Claudio; Lopez, Lidio; Luckman, Brian H.; Lister, David; Harris, Ian; Jones, Philip D.; Williams, A. Park; Velazquez, Gonzalo; Aliste, Diego; Aguilera-Betti, Isabella; Marcotti, Eugenia; Flores, Felipe; Muñoz, Tomás; Cuq, Emilio; Boninsegna, José A.Agua y Extremos2020.010.1073/pnas.2002411117South American (SA) societies are highly vulnerable to droughts and pluvials, but lack of long-term climate observations severely limits our understanding of the global processes driving climatic variability in the region. The number and quality of SA climate-sensitive tree ring chronologies have significantly increased in recent decades, now providing a robust network of 286 records for characterizing hydroclimate variability since 1400 CE. We combine this network with a self-calibrated Palmer Drought Severity Index (scPDSI) dataset to derive the South American Drought Atlas (SADA) over the continent south of 12°S. The gridded annual reconstruction of austral summer scPDSI is the most spatially complete estimate of SA hydroclimate to date, and well matches past historical dry/wet events. Relating the SADA to the Australia–New Zealand Drought Atlas, sea surface temperatures and atmospheric pressure fields, we determine that the El Niño–Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) are strongly associated with spatially extended droughts and pluvials over the SADA domain during the past several centuries. SADA also exhibits more extended severe droughts and extreme pluvials since the mid-20th century. Extensive droughts are consistent with the observed 20th-century trend toward positive SAM anomalies concomitant with the weakening of midlatitude Westerlies, while low-level moisture transport intensified by global warming has favored extreme rainfall across the subtropics. The SADA thus provides a long-term context for observed hydroclimatic changes and for 21st-century Intergovernmental Panel on Climate Change (IPCC) projections that suggest SA will experience more frequent/severe droughts and rainfall events as a consequence of increasing greenhouse gas emissions.Proceedings of the National Academy of Sciences0027-8424, 1091-6490 Reuters ISIrain, atmospheric pressure, carbon footprint, controlled study, drought, environmental impact, experience, greenhouse effect, hydroclimate, moisture, nonhuman, priority journal, review, sea surface temperature, seasonal variation, soil moisture, south america, spatiotemporal analysis, tree, tree ring, climate, geographic mapping, greenhouse effect, growth, development and aging, statistical model, tree, climate, droughts, geographic mapping, global warming, models, statistical, rain, south america, trees
Landscape evolution and the environmental context of human occupation of the southern pampa del tamarugal, Atacama Desert, ChileWorkman, T. Race; Rech, Jason A.; Gayó, Eugenia M.; Santoro, Calogero M.; Ugalde, Paula C.; De Pol-Holz, Ricardo; Capriles, Jose M.; Latorre, ClaudioCiudades Resilientes2020.010.1016/j.quascirev.2020.106502As with most living organisms, human populations respond to climatic, environmental, and population pressures by transforming their range and subsistence strategies over space and time. An understanding of human ecology can be gained when the archaeological record is placed within the context of dynamic landscape changes and alterations in natural resource availability. We reconstructed the landscape evolution of the Quebrada Maní fan complex, situated along the west-facing slope of the Central Andes in the hyperarid core of the Atacama Desert, an area that contains an archaeological record that spans almost 13,000 years. Surficial geologic mapping and dating of three 2–12 km2 study sites, in conjunction with archaeological records and analysis of remotely sensed data for the ∼400 km2 fan complex, was conducted to reconstruct the landscape evolution and the way of life of Paleoindian (ca. 12.8–11.5 ka) and early/late Formative (ca 2.5 to 0.7 ka) social groups. Just prior to any known human occupation, a large pluvial event in the high Andes, regionally referred to as CAPE I, impacted the Quebrada Maní fan complex from ca.18–16.5 ka. During CAPE I, the Maní fan complex was dominated by perennial stream systems that deposited well-sorted conglomerates in the upper reaches of the fan (Unit T2) and perennial wetlands (Unit B1). This pluvial period was followed by the onset of an extreme drought sometime after 15 ka, but before 13 ka, when wetlands desiccated and the distal reaches of the fan deflated. Sand sheets and sand dunes were deposited across broad reaches of the landscape and Quebrada Maní incised 3–5 m into its floodplain. This drought had profound implications for the distribution of natural resources during the subsequent pluvial event (CAPE II) that ensued from ca. 12.5–9.5 ka. Incision along the upper reaches of the fan caused a more restricted floodplain and allowed the deposition of extensive wetlands along the more distal central reaches of the fan where groundwater emerged. Paleoindian residential open-air camps were placed in these areas. Wetlands were replaced by a tree-covered floodplain during the latter portion of this pluvial event (ca. 10.5–9 ka). We found no archaeological evidence for human occupations between ∼8–2.5 ka, suggesting a lack of natural resources and/or very low hunter-gatherer population densities. During this time, Quebrada Maní incised up to 8 m into the floodplain. Mudflow deposition – typical of the present-day fan complex – initiated around 2.5 ka, likely responding to an increase in precipitation. This triggered a re-population of the fan surface by Formative agricultural groups that irrigated and extensively farmed these floodplains. By the end of the Formative, these socio-cultural groups became increasingly vulnerable to climatic changes as cut-and-fill cycles in the drainage necessitated major infrastructure adjustments, until the technologies and social-cultural convention of the epoch could not cope with environmental change and investments were abandoned by ∼0.8 ka.Quaternary Science Reviews02773791 Reuters ISIagricultural robots, banks (bodies of water), deposition, drought, ecology, employment, environmental technology, floods, groundwater, investments, natural resources, population statistics, wetlands, atacama desert , chile, cultural conventions, environmental change, environmental contexts, landscape evolutions, population densities, remotely sensed data, resource availability, biology, archaeological evidence, climate change, drought, floodplain, hunter-gatherer, landscape change, landscape evolution, natural resource, occupation, population density, precipitation (climatology), reconstruction, satellite data, wetland, andes, atacama desert, chile
Association between coal and firewood combustion and hospital admissions and mortality in Chile 2015 – An ecological approachParedes, María; Muñoz, María; Valdés Salgado, Macarena; Maldonado, AnaCiudades Resilientes2020.010.26444/aaem/125010Introduction and objective: Burning coal and firewood generates toxic emissions that are associated with respiratory illness, cardiovascular disease, and even death. The aim of the study is to evaluate the association between county-level prevalence of household coal and firewood use and health outcomes, including total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates. Material and methods: The ecological study included data on the use of household coal and firewood in 139 counties obtained from the 2015 Chilean National Socio-economic Characterization Survey. Total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates, were obtained from the Department of Health Statistics. Poisson models with robust error variance, Pearson linear correlation coefficients, and scatterplots were used to explore associations between household coal and firewood use and morbidity-mortality, stratifying by geographic zone. Results: Total, respiratory, and cardiovascular mortality and total and respiratory hospitalization rates were 5.7 per 1,000, 552 per 100,000, 157 per 100,000, 92.5 per 1000, and 8.8 per 1000 inhabitants, respectively. The median prevalence of coal use for residential cooking, heating, or water heating was 3.64%, while the median prevalence of firewood combustion was 12%. In southern counties, age- and gender-adjusted respiratory mortality increased 2.02 (95% CI: 1.17–3.50), 1.5 (95% CI: 1.11–1.89), and 1.76-fold (95% CI: 1.19–2.60) for each percentage increase in household coal and firewood use for heating, cooking and heating water, respectively. Conclusions: The prevalence of household coal and firewood used for heating and cooking was positively correlated with respiratory mortality and hospitalization in southern zone counties.Annals of Agricultural and Environmental Medicine1232-1966, 1898-2263,125010,0,2.htmlThomson Reuters ISIcoal, coal, adult, all cause mortality, article, cardiovascular mortality, chile, combustion, cooking, female, firewood, heating, hospital admission, hospital mortality, hospitalization, household, human, male, morbidity, mortality rate, poverty, prevalence, trend study, wood, adverse event, cardiovascular disease, epidemiology, indoor air pollution, mortality, respiratory tract disease, wood, air pollution, indoor, cardiovascular diseases, chile, coal, cooking, female, heating, hospital mortality, hospitalization, humans, male, respiratory tract diseases, wood
Tree-growth at the rear edge of a Nothofagus pumilio Andean forest from Northern Patagonia show different patterns and a decline in the common signal during the last centurySerrano-León, Hernán; Christie, Duncan A.Agua y Extremos2020.010.1016/j.foreco.2020.118426Nothofagus pumilio is the dominant tree species at high elevations in the southern Andes between 35° and 55° S. Despite the number of tree-growth studies on this tree species, there is scarce information about the growth patterns and its relation with climatic variability at its lower elevation margin of distribution in the windward side of the Andes. In this study we focus on the altitudinal rear edge of a N. pumilio forest growing on the Pacific side of the northern Patagonian Andes to determine the main temporal patterns of tree radial growth, identify its relations with regional and large-scale climate and to assess the temporal variation of common signal in tree growth at centennial time-scales. A Principal Component Analysis (PCA) between trees for their common period 1850–2010 indicates the existence of more than one pattern of tree growth within this lower altitudinal margin, which exhibit contrasting relations with climate. The tree ring chronology and the PC1 amplitude of tree growth shows negative correlation with maximum temperature during spring-summer while the PC2 shows the contrary. Maps and correlation functions indicate that the PC1 and PC2 patterns of N. pumilio growth are significantly related with high latitude climate variability induced by the Antarctic Oscillation (AAO) during spring-summer in an opposite manner, with the PC1 (PC2) negatively (positively) correlated with the poleward displacement of the storm tracks driven by the mid- and high-latitude dipole pressure in the Southern Hemisphere. The running PCA between the standardized tree ring-width series shows a decreasing trend in the percentage of variance explained by the first mode of tree growth, indicating a centennial scale loss in the common signal of growth within the population, especially since mid-20th century when the behavior of the AAO was unprecedented within the context of the last millennium. Given that the future climatic scenario for northern Patagonia as predicted by models would led to more arid conditions forced by the positive trend of the AAO, we expect that the main pattern of N. pumilio growth at the rear edge of Choshuenco volcano will be negatively affected. Despite the present knowledge about N. pumilio radial growth in treeline environments, specific research is needed to gain insights about the complexity of the climate-growth relationship at its low elevation margin, in order to evaluate anomalies in tree growth patterns in the habitat where N. pumilio grows and competes with other low elevation species more tolerant to warmer conditions.Forest Ecology and Management03781127 Reuters ISIpopulation statistics, springs (components), antarctic oscillation, climate variability, climatic variability, correlation function, maximum temperature, negative correlation, southern hemisphere, tree-ring chronologies, forestry, antarctic oscillation, complexity, correlation, evergreen tree, principal component analysis, temporal variation, timescale, twentieth century, andes, patagonia, nothofagus pumilio
Ecology of the collapse of Rapa Nui societyLima, M.; Gayo, E. M.; Latorre, C.; Santoro, C. M.; Estay, S. A.; Cañellas-Boltà, N.; Margalef, O.; Giralt, S.; Sáez, A.; Pla-Rabes, S.; Chr. Stenseth, N.Ciudades Resilientes2020.010.1098/rspb.2020.0662Collapses of food producer societies are recurrent events in prehistory and have triggered a growing concern for identifying the underlying causes of convergences/divergences across cultures around the world. One of the most studied and used as a paradigmatic case is the population collapse of the Rapa Nui society. Here, we test different hypotheses about it by developing explicit population dynamic models that integrate feedbacks between climatic, demographic and ecological factors that underpinned the socio-cultural trajectory of these people. We evaluate our model outputs against a reconstruction of past population size based on archaeological radiocarbon dates from the island. The resulting estimated demographic declines of the Rapa Nui people are linked to the long-term effects of climate change on the island's carrying capacity and, in turn, on the ‘per-capita food supply’.Proceedings of the Royal Society B: Biological Sciences0962-8452, 1471-2954 Reuters ISIcarrying capacity, climate change, collapse, population decline, population dynamics, population modeling, prehistoric, radiocarbon dating, reconstruction, easter island
Anaerobic oxidation of methane and associated microbiome in anoxic water of Northwestern Siberian lakesCabrol, Léa; Thalasso, Frédéric; Gandois, Laure; Sepulveda-Jauregui, Armando; Martinez-Cruz, Karla; Teisserenc, Roman; Tananaev, Nikita; Tveit, Alexander; Svenning, Mette M.; Barret, MaialenCambio de Uso de Suelo2020.010.1016/j.scitotenv.2020.139588Science of The Total Environment00489697 Reuters ISIgenes, lakes, methane, oxidation, permafrost, polymerase chain reaction, rna, anaerobic oxidation of methanes, anoxic layers, ch4 oxidation, discontinuous permafrost, methane oxidation, methane oxidizing bacteria (mob), permafrost thaws, stratified lakes, anoxic water, lake water, methane, methane, rna 16s, water, anoxic conditions, arctic environment, lake water, methane, microbial activity, oxic conditions, oxidation, permafrost, water quality, 16s rrna gene, anaerobic metabolism, article, bacterial gene, bacterial microbiome, bacterial strain, chemical composition, concentration (parameter), dna barcoding, geobacter, geothrix, iron metabolism, lake ecosystem, mcra gene, methane oxidizing bacterium, methanotrophic bacterium, methylococcaceae, methylotenera, microbial interaction, nonhuman, permafrost, pmoa gene, priority journal, real time polymerase chain reaction, russian federation, taxonomy, anaerobic growth, arctic, lake, microflora, oxidation reduction reaction, igarka, krasnoyarsk [russian federation], russian federation, siberia, geobacter, geothrix, methylobacter, methylotenera, otus, anaerobiosis, arctic regions, lakes, methane, microbiota, oxidation-reduction, rna, ribosomal, 16s, russia, water
High Impact Weather Events in the AndesPoveda, Germán; Espinoza, Jhan Carlo; Zuluaga, Manuel D.; Solman, Silvina A.; Garreaud, René; van Oevelen, Peter J.Agua y Extremos2020.010.3389/feart.2020.00162Frontiers in Earth Science2296-6463 Reuters ISIdeforestation, economics, extreme weather, land use, precipitation (meteorology), storms, tropics, water pollution, weather information services, extratropical, extreme precipitation events, extreme weather events, high mountains, land-use change, mesoscale convective system, research gaps, weather events, climate change
Predicting spatial variability of selected soil properties using digital soil mapping in a rainfed vineyard of central ChileMashalaba, Lwando; Galleguillos, Mauricio; Seguel, Oscar; Poblete-Olivares, JavieraCambio de Uso de Suelo2020.010.1016/j.geodrs.2020.e00289Soil physical properties influence vineyard behavior, therefore the knowledge of their spatial variability is essential for making vineyard management decisions. This study aimed to model and map selected soil properties by means of knowledge-based digital soil mapping approach. We used a Random Forest (RF) algorithm to link environmental covariates derived from a LiDAR flight and satellite spectral information, describing soil forming factors and ten selected soil properties (particle size distribution, bulk density, dispersion ratio, Ksat, field capacity, permanent wilting point, fast drainage pores and slow drainage pores) at three depth intervals, namely 0–20, 20–40, and 40–60 cm at a systematic grid (60 × 60 m2). The descriptive statistics showed low to very high variability within the field. RF model of particle size distribution, and bulk density performed well, although the models could not reliably predict saturated hydraulic conductivity. There was a better prediction performance (based on 34% model validation) in the upper depth intervals than the lower depth intervals (e.g., R2 of 0.66; nRMSE of 27.5% for clay content at 0–20 cm and R2 of 0.51; nRMSE of 16% at 40–60 cm). There was a better prediction performance in the lower depth intervals than the upper depth intervals (e.g., R2 of 0.49; nRMSE of 23% for dispersion ratio at 0–20 cm and R2 of 0.81; nRMSE of 30% at 40–60 cm). RF model overestimated areas with low values and underestimated areas with high values. Further analysis suggested that Topographic position Index, Topographic Wetness Index, aspect, slope length factor, modified catchment area, catchment slope, and longitudinal curvature were the dominant environmental covariates influencing prediction of soil properties.Geoderma Regional23520094 Reuters ISIalfisols, digital soil mapping, environmental covariates, random forest model, remote sensing, soil properties, vineyard
Two decades of ozone standard exceedances in Santiago de ChileSeguel, Rodrigo J.; Gallardo, Laura; Fleming, Zoë L.; Landeros, SofíaCiudades Resilientes2020.010.1007/s11869-020-00822-wAir Quality, Atmosphere & Health1873-9318, 1873-9326 Reuters ISIatmospheric pollution, carbon monoxide, climate change, exhaust emission, nitric oxide, ozone, spatiotemporal analysis, urban pollution, urban sprawl, urbanization, volatile organic compound, santiago [metropolitana]
13,000 years of sociocultural plant use in the Atacama Desert of northern ChileUgalde, Paula C.; McRostie, Virginia; Gayo, Eugenia M.; García, Magdalena; Latorre, Claudio; Santoro, Calogero M.Ciudades Resilientes2020.010.1007/s00334-020-00783-1Throughout Earth’s most extreme environments, such as the Kalahari Desert or the Arctic, hunter–gatherers found ingenious ways to obtain proteins and sugars provided by plants for dietary requirements. In the hyperarid Atacama Desert, wild plant resources are scarce and unevenly distributed due to limited water availability. This study brings together all available archaeobotanical evidence gathered in the Atacama Desert from the Late Pleistocene (ca. 13,000 cal bp) until the Inka epoch (ca. 450 cal bp) to help us comprehend when these populations acquired and managed useful plants from the coastal zone, Intermediate Depression, High Andes, as well as tropical and subtropical ecosystems. Widespread introduction of farming crops, water control techniques and cultivation of diverse plants by 3,000 cal bp ended not only a chronic food shortage, but also led to the establishment of a set of staple foods for the Atacama Desert dwellers, a legacy that remains visible today. By contrasting these trends with major sociocultural changes, together with palaeodemographic and climatic fuctuations, we note that humans adapted to, and transformed this hyperarid landscape and oscillating climate, with plants being a key factor in their success. This long-term process, which we term the “Green Revolution”, coincided with an exponential increase in the number of social groups inhabiting the Atacama Desert during the Late Holocene.Vegetation History and Archaeobotany0939-6314, 1617-6278 Reuters ISIarchaeobotany, atacama desert, palaeoenvironments, plant management, socio-cultural change
Geo-climatic hazards in the eastern subtropical Andes: distribution, climate drivers and trendsVergara, Iván; Moreiras, Stella M.; Araneo, Diego; Garreaud, RenéAgua y Extremos2020.010.5194/nhess-20-1353-2020Abstract. Detecting and understanding historical changes in the frequency of geo-climatic hazards (G-CHs) is crucial for the quantification of current hazards and project them into the future. Here we focus in the eastern subtropical Andes (32–33∘ S), using meteorological data and a century-long inventory of 553 G-CHs triggered by rainfall or snowfall. We first analyse their spatio-temporal distributions and the role of climate variability in the year-to-year changes in the number of days per season with G-CHs. Precipitation is positively correlated with the number of G-CHs across the region and year-round; mean temperature is negatively correlated with snowfall-driven hazards in the western (higher) half of the study region during winter and with rainfall-driven hazards in the eastern zone during summer. The trends of the G-CH frequency since the mid-20th century were calculated, paying attention to their non-systematic monitoring. The G-CH series for the different triggers, zones and seasons were generally stationary. Nonetheless, there is a small positive trend in rainfall-driven G-CHs in the eastern zone during summer, congruent with a rainfall increase there. We also found a decrease in snowfall-driven G-CHs in the western zone from the late 1990s onwards, most likely due to a reduction in winter precipitation rather than to an increase in temperature.Natural Hazards and Earth System Sciences1684-9981 Reuters ISIclimate conditions, detection method, precipitation intensity, seasonal variation, snow, spatiotemporal analysis, subtropical region, trend analysis, andes
Thermo- and physicochemical properties of native and exotic forest species of Valparaíso, Chile, as essential information for fire risk managementGuerrero, Fabián; Toledo, Mario; Ripoll, Nicolás; Espinoza, Lorena; Morales, Rodrigo; Muñoz, Ariel; Taborga, Lautaro; Carrasco, YulianAgua y Extremos2020.010.1071/WF19086Wildfires in the Valparaı́so region (Chile) account for one of the main threats to local biodiversity, ecosystem services and infrastructure. This study focused on producing an initial record of thermo- and physicochemical properties of local forest species. For this purpose, leaf samples of species found in the Peñuelas Lake National Reserve, namely Pinus radiata, Eucalyptus globulus, Acacia dealbata, Quillaja saponaria and Cryptocarya alba, were collected and analysed. Higher and lower heating value, flash point, density and moisture content tests were performed for each sample. Overall results showed that lower heating values measured for both native and exotic species could indicate a high energy release source in wildfires. However, differences in the flash point between species indicated that C. alba and E. globulus had a lower ignition resistance than other species tested, possibly due to a lower flash point. In contrast, Q. saponaria and A. dealbata had the highest flash point for native and exotic species respectively. Finally, all presented data and procedures were aimed at establishing a foundation for a national database of critical forest species properties to be used in wildfire simulation tools. This database will enhance forest fire management effectiveness in Chile.International Journal of Wildland Fire1049-8001 Reuters ISIcalorific value, cryptocarya alba, flash point, forest fires, forest fuel, moisture content, quillaja saponaria, wildfires
Diversity loss and changes in saproxylic beetle assemblages following a high-severity fire in Araucaria–Nothofagus forestsTello, Francisco; González, Mauro E.; Valdivia, Nelson; Torres, Fernanda; Lara, Antonio; García-López, AlejandraCambio de Uso de Suelo2020.010.1007/s10841-020-00223-5Journal of Insect Conservation1366-638X, 1572-9753 Reuters ISIabundance, beetle, biodiversity, coniferous forest, dead wood, deciduous forest, saproxylic organism, specialist, species richness, wildfire, chile, coleoptera, hexapoda, nothofagus
Trends and emissions of six perfluorocarbons in the Northern Hemisphere and Southern HemisphereDroste, Elise S.; Adcock, Karina E.; Ashfold, Matthew J.; Chou, Charles; Fleming, Zoë; Fraser, Paul J.; Gooch, Lauren J.; Hind, Andrew J.; Langenfelds, Ray L.; Leedham Elvidge, Emma; Mohd Hanif, Norfazrin; O&apos;Doherty, Simon; Oram, David E.; Ou-Yang, Chang-Feng; Panagi, Marios; Reeves, Claire E.; Sturges, William T.; Laube, Johannes C.Ciudades Resilientes2020.010.5194/acp-20-4787-2020Abstract. Perfluorocarbons (PFCs) are potent greenhouse gases with global warming potentials up to several thousand times greater than CO2 on a 100-year time horizon. The lack of any significant sinks for PFCs means that they have long atmospheric lifetimes of the order of thousands of years. Anthropogenic production is thought to be the only source for most PFCs. Here we report an update on the global atmospheric abundances of the following PFCs, most of which have for the first time been analytically separated according to their isomers: c-octafluorobutane (c-C4F8), n-decafluorobutane (n-C4F10), n-dodecafluoropentane (n-C5F12), n-tetradecafluorohexane (n-C6F14), and n-hexadecafluoroheptane (n-C7F16). Additionally, we report the first data set on the atmospheric mixing ratios of perfluoro-2-methylpentane (i-C6F14). The existence and significance of PFC isomers have not been reported before, due to the analytical challenges of separating them. The time series spans a period from 1978 to the present. Several data sets are used to investigate temporal and spatial trends of these PFCs: time series of air samples collected at Cape Grim, Australia, from 1978 to the start of 2018; a time series of air samples collected between July 2015 and April 2017 at Tacolneston, UK; and intensive campaign-based sampling collections from Taiwan. Although the remote “background” Southern Hemispheric Cape Grim time series indicates that recent growth rates of most of these PFCs are lower than in the 1990s, we continue to see significantly increasing mixing ratios that are between 6 % and 27 % higher by the end of 2017 compared to abundances measured in 2010. Air samples from Tacolneston show a positive offset in PFC mixing ratios compared to the Southern Hemisphere baseline. The highest mixing ratios and variability are seen in air samples from Taiwan, which is therefore likely situated much closer to PFC sources, confirming predominantly Northern Hemispheric emissions for most PFCs. Even though these PFCs occur in the atmosphere at levels of parts per trillion molar or less, their total cumulative global emissions translate into 833 million metric tonnes of CO2 equivalent by the end of 2017, 23 % of which has been emitted since 2010. Almost two-thirds of the CO2 equivalent emissions within the last decade are attributable to c-C4F8, which currently also has the highest emission rates that continue to grow. Sources of all PFCs covered in this work remain poorly constrained and reported emissions in global databases do not account for the abundances found in the atmosphere.Atmospheric Chemistry and Physics1680-7324 Reuters ISIatmospheric chemistry, concentration (composition), emission control, global warming, greenhouse gas, northern hemisphere, organofluorine, source apportionment, trend analysis, australia, cape grim, tasmania, united kingdom
Environmental costs of water transfersVargas, Cristian A.; Garreaud, Rene; Barra, Ricardo; Vásquez-Lavin, Felipe; Saldías, Gonzalo S.; Parra, OscarAgua y Extremos2020.010.1038/s41893-020-0526-5Nature Sustainability2398-9629 Reuters ISI
Landscape Disturbance Gradients: The Importance of the Type of Scene When Evaluating Landscape Preferences and PerceptionsAltamirano, Adison; Gonzalez-Suhr, Carolina; Marien, Caroline; Catalán, Germán; Miranda, Alejandro; Prado, Marco; Tits, Laurent; Vieli, Lorena; Meli, PaulaCambio de Uso de Suelo10.3390/land9090306Understanding of people’s landscape preferences is important for decision-making about land planning, particularly in the disturbance patterns that usually occur in rural-urban gradients. However, the use of different types of images concerning the same landscape may influence social preferences and thus perceptions of landscape management and planning decisions. We evaluated landscape preferences and perceptions in four landscapes of southern Chile. We specifically: (1) compared people’s perceptions related to living in, visiting, the scenic beauty, well-being, risks, and level of landscape disturbance; and (2) evaluated the influence of the type of scene (i.e., eye-level or aerial images) in these preferences and perceptions. Preferences and perceptions resulted to be better when using eye-level (4.0 ± 1.1) than aerial (3.7 ± 0.6) images. In general, we observed a negative association between preferences and perceptions and the landscape disturbance; however, it was consistent when using aerial images but was masked when valuing landscape through eye-level images. Implications of these results are relevant because by far, most landscape preference studies use traditional eye-level images. Different types of scenes should be considered in order to embrace the landscape preferences and perceptions of all those involved and help decision-making in landscape planning.Land2073-445X Reuters ISIA
Natural forests loss and tree plantations: large-scale tree cover loss differentiation in a threatened biodiversity hotspotAltamirano, Adison; Miranda, Alejandro; Aplin, Paul; Carrasco, Jaime; Catalán, Germán; Cayuela, Luis; Fuentes-Castillo, Taryn; Hernández, Angela; Martínez-Harms, María J; Peluso, Franco; Prado, Marco; Reyes-Riveros, Rosa; Van Holt, Tracy; Vergara, Cristian; Zamorano-Elgueta, Carlos; Di Bella, CarlosCambio de Uso de Suelo10.1088/1748-9326/abca64Distinguishing between natural forests from exotic tree plantations is essential to get an accurate picture of the world’s state of forests. Most exotic tree plantations support lower levels of biodiversity and have less potential for ecosystem services supply than natural forests, and differencing them is still a challenge using standard tools. We use a novel approach in south-central of Chile to differentiate tree cover dynamics among natural forests and exotic tree plantations. Chile has one of the world’s most competitive forestry industry and the region is a global biodiversity hotspot. Our collaborative visual interpretation method combined a global database of tree cover change, remote sensing from high-resolution satellite images and expert knowledge. By distinguishing exotic tree plantation and natural forest loss, we fit spatially explicit models to estimate tree-cover loss across 40 millions of ha between 2000 and 2016. We were able to distinguish natural forests from exotic tree plantations with an overall accuracy of 99% and predicted forest loss. Total tree cover loss was continuous over time, and the disaggregation revealed that 1 549 909 ha of tree plantations were lost (mean = 96 869 ha year−1 ), while 206 142 ha corresponded to natural forest loss (mean = 12 884 ha year−1 ). Mostly of tree plantations lost returned to be plantation (51%). Natural forests were converted mainly (75%) to transitional land covers (e.g. shrubland, bare land, grassland), and an important proportion of these may finish as tree plantation. This replacement may undermine objectives of increased carbon storage and biodiversity. Tree planting as a solution has gained increased attention in recen years with ambitious commitments to mitigate the effects of climate change. However, negative outcomes for the environment could result if strategies incentivize the replacement of natural forests into other land covers. Initiatives to reduce carbon emissions should encourage differentiating natural forests from exotic tree plantations and pay more attention on protecting and managing sustainably the former.Environmental Research Letters1748-9326 Reuters ISIclimate change, ecosystems, reforestation, remote sensing, ecosystem services, expert knowledge, forestry industry, high resolution satellite images, loss differentiation, overall accuracies, spatially explicit models, visual interpretation, biodiversity, biodiversity, climate change, ecosystem service, forest cover, forest ecosystem, plantation forestry, remote sensing, satellite imagery, strategic approach, tree, chile
Firewood certification programs: Key attributes and policy implicationsVásquez-Lavin, Felipe; Barrientos, Manuel; Castillo, Álvaro; Herrera, Iván; Ponce Oliva, Roberto D.Cambio de Uso de Suelo10.1016/j.enpol.2019.111160Evidence from south-central Chile shows that the concentration limits for PM10 and PM2.5, defined by both the World Health Organization and national standards, are systematically exceeded, affecting approximately 10 million people. Among the sources of this pollution, firewood use accounts for the largest share. This study assesses whether consumers value environmental, social, and legal attributes associated with the firewood certification programs. We used a discrete choice model based on a sample of 500 households. According to our results, the price premium for certified firewood is about 10% in the most likely scenario, with those attributes closely related to private benefits having a higher value, compared to those of social benefits. We identify significant heterogeneity among respondents belonging to two different consumer classes: 1) those who are less price sensitive and are willing to pay for attributes related to certification; 2) those who are sensitive to prices and are not willing to pay for attributes related to certification. Since the second class includes about 46% of the sample, the implementation of certification programs could be jeopardized. Therefore, knowing this information helps us determine whether a certification system can foster the firewood industry transition to a more sustainable model.Energy Policy0301-4215 Reuters ISIbehavioral research, energy utilization, environmental regulations, public policy, certification, certification programs, certification systems, consumers' preferences, discrete choice models, firewood use, household energy consumption, world health organization, air quality, air quality, certification, consumption behavior, discrete choice analysis, environmental policy, fuelwood, household energy, willingness to pay, chile
Raco Wind at the Exit of the Maipo Canyon in Central Chile: Climatology, Special Observations, and Possible MechanismsMuñoz R.; Armi, Laurence; Rutllant, José A.; Falvey, Mark; Whiteman, C. David; Garreaud, René; Arriagada, Andrés; Flores, Federico; Donoso, NicolásAgua y Extremos2020.010.1175/JAMC-D-19-0188.1Raco is the local name given to a strong (gusts up to 17 m s −1 ), warm, and dry down-valley wind observed at the exit of the Maipo River Canyon in central Chile. Its climatology is documented based on eight years of surface measurements near the canyon exit together with a more complete characterization of its structure during an intensive observational period (IOP) carried out in July 2018. Raco winds occur in the cold season under well-defined synoptic conditions, beginning abruptly at any time during the night, reaching maximum hourly averages around 10 m s −1 , and terminating around noon with the onset of afternoon westerly up-valley winds. About 25% of the days in May–August have more than six raco hours between 0100 and 1200 LT, and raco episodes last typically 1–2 days. The sudden appearance of raco winds at the surface can be accompanied by conspicuous warming (up to 10°C) and drying (up to 3 g kg −1 ). Raco winds are associated with a strong along-canyon pressure gradient, a regional pressure fall, and clear skies. During the IOP, radiosondes launched from both extremes of the canyon exit corridor showed a nocturnal easterly jet at 700 m AGL that occasionally descended rapidly to the surface, producing the raco. Transects along the canyon performed with a mobile ceilometer revealed a sharp frontlike feature between the cold pool over the Santiago Valley and the raco-affected conditions in the Maipo Canyon. Possible factors producing the easterly jet aloft and its occasional descent toward the surface are discussed, and a gap-wind mechanism is postulated to be at work.Journal of Applied Meteorology and Climatology1558-8424, 1558-8432 Reuters ISIclimatology, landforms, meteorological instruments, surface measurement, central chile, clear sky, cold season, intensive observational periods, possible mechanisms, synoptic conditions, up-valley winds, valley winds, wind, canyon, climatology, gust, jet stream, pressure gradient, chile, maipo river
Embedding effect and the consequences of advanced disclosure: evidence from the valuation of cultural goodsCarrasco, Moisés; Vasquez-Lavin, Felipe; Ponce Oliva, Roberto D.; Bustamante Oporto, José Luis; Barrientos, Manuel; Cerda, Arcadio A.Cambio de Uso de Suelo2020.010.1007/s00181-020-01897-1This study revisits the embedding effect, a long-standing problem in the nonmarket valuation literature. The embedding effect was a popular research topic during the 1990s, especially following the Exxon Valdez oil spill in Alaska. It has resurfaced after a special issue of The Journal of Economic Perspectives in 2012 in which Jerry Hausmann asserts that among the three long-standing problems with contingent valuation, the embedding effect is the most challenging. In this study, we focus on how information disclosure regarding the nested structure of goods affects both the willingness to pay and the presence of the embedding effect. Our results suggest that the level of embedding can be reduced with a more complete description of the nested structure of the goods under valuation. Therefore, it is highly important for each valuation study to test whether sufficient information is provided on the goods’ nested structure to ensure that the relationships among the goods’ subsets are correctly understood by respondents. We show that by providing respondents with more high-quality information, it is possible to mitigate the embedding effect.Empirical Economics0377-7332, 1435-8921 Reuters ISIcontingent valuation, information, willingness to pay
Mediterranean Heathland as a Key Habitat for Fire Adaptations: Evidence from an Experimental ApproachGómez-González, Susana; Paniw, Maria; Durán, Mario; Picó, Sergio; Martín-Rodríguez, Irene; Ojeda, FernandoCambio de Uso de Suelo10.3390/f11070748Some fire ecology studies that have focused on garrigue-like vegetation suggest a weak selective pressure of fire in the Mediterranean Basin compared to other Mediterranean-type regions. However, fire-prone Mediterranean heathland from the western end of the Mediterranean Basin has been frequently ignored in the fire ecology literature despite its high proportion of pyrogenic species. Here, we explore the evolutionary ecology of seed traits in the generalist rockrose Cistus salviifolius L. (Cistaceae) aiming to ascertain the role of the Mediterranean heathland for fire adaptations in the Mediterranean Region. We performed a germination experiment to compare the relationship of seed size to (i) heat-stimulated germination, (ii) dormancy strength, and (iii) heat survival in plants from ‘high-fire’ heathland vs. ‘low-fire’ coastal shrubland. Germination after heat-shock treatment was higher in large seeds of both ‘high-fire’ and ‘low-fire’ habitats. However, dormancy was weaker in small seeds from ‘low-fire’ habitats. Finally, seed survival to heat shock was positively related to seed size. Our results support that seed size is an adaptive trait to fire in C. salviifolius, since larger seeds had stronger dormancy, higher heat-stimulated germination and were more resistant to heat shock. This seed size–fire relationship was tighter in ‘high-fire’ Mediterranean heathland than ‘low-fire’ coastal shrubland, indicating the existence of differential fire pressures and evolutionary trends at the landscape scale. These findings highlight the Mediterranean heathland as a relevant habitat for fire-driven evolution, thus contributing to better understand the role of fire in plant evolution within the Mediterranean region.Forests1999-4907 Reuters ISIafter-heat treatment, cultivation, ecosystems, plants (botany), seed, evolutionary ecology, evolutionary trend, experimental approaches, heat shock treatment, landscape scale, mediterranean basin, mediterranean region, selective pressure, fires, adaptation, angiosperm, dormancy, evolution, evolutionary biology, experimental study, fire management, generalist, germination, habitat structure, heathland, mediterranean environment, temperature effect, wildfire, cultivation, dormancy, ecosystems, fires, germination, heat, mediterranean, mediterranean region, cistaceae, cistus, cistus salviifolius
Afforestation falls short as a biodiversity strategyGómez-González, Susana; Ochoa-Hueso, Raúl; Pausas, Juli G.Cambio de Uso de Suelo10.1126/science.abd3064Science0036-8075, 1095-9203 Reuters ISIafforestation, biodiversity, carbon footprint, climate change, environmental economics, environmental policy, european union, human, landscape, letter, planting time, priority journal, wellbeing, environmental protection, tree, biodiversity, conservation of natural resources, european union, trees
First snow, glacier and groundwater contribution quantification in the upper Mendoza River basin using stable water isotopesCrespo, Sebastián; Fernandoy, Francisco; Cara, Leandro; Klarian, Sebastián; Lavergne, CélineAgua y Extremos10.1080/10256016.2020.1797713The Mendoza River streamflow, South America (∼32 °S), derives almost exclusively from winter snow precipitation falling in the Andes. Almost 70% of the water feeding the river originates in the Cordillera Principal geological province. In addition to the snow that precipitates in this area, there are 951 cryoforms providing meltwater to the upper catchment. Given the high inter-annual variability of snowfall and the megadrought affecting the region since 2010, it is crucial to quantify the contribution from different water sources buffering the Mendoza River runoff. Combining instrumental records of streamflow from glaciers and rivers, meteorological data, remote sensing of snow-covered areas and ionic and stable isotope analysis of different water sources, this study attempts to understand the hydrological contribution of different water sources to the basin. We demonstrated for the first time the relevance of different water sources in addition to snow in a dry period. During the melting season, 65% of the streamwaters originated from the glaciers (i.e. 50 and 15% from glaciers and rock glaciers, respectively), representing a higher proportion compared to snowmelt (17%). Groundwater input showed relatively large contributions, averaging 18%. This work offers information to develop adaptation strategies for future climate change scenarios in the region.Isotopes in Environmental and Health Studies1025-6016, 1477-2639 Reuters ISIclimate change, glacier dynamics, groundwater, hydrogen isotope, oxygen isotope, rock glacier, snow cover, stable isotope, streamflow, water quality, andes, argentina, mendoza, mendoza river, deuterium, ground water, isotope, oxygen, snow, altitude, chemistry, chile, climate change, environmental monitoring, hydrology, ice cover, procedures, river, season, water cycle, altitude, chile, climate change, deuterium, environmental monitoring, groundwater, hydrology, ice cover, isotopes, oxygen isotopes, rivers, seasons, snow, water cycle
Where Does the Chilean Aconcagua River Come from? Use of Natural Tracers for Water Genesis Characterization in Glacial and Periglacial EnvironmentsCrespo, Sebastián; Lavergne, Céline; Fernandoy, Francisco; Muñoz, Ariel; Cara, Leandro; Olfos-Vargas, SimónAgua y Extremos10.3390/w12092630The Aconcagua river basin (Chile, 32 °S) has suffered the effects of the megadrought over the last decade. The severe snowfall deficiency drastically modified the water supply to the catchment headwaters. Despite the recognized snowmelt contribution to the basin, an unknown streamflow buffering effect is produced by glacial, periglacial and groundwater inputs, especially in dry periods. Hence, each type of water source was characterized and quantified for each season, through the combination of stable isotope and ionic analyses as natural water tracers. The δ18O and electric conductivity were identified as the key parameters for the differentiation of each water source. The use of these parameters in the stable isotope mixing “simmr” model revealed that snowmelt input accounted 52% in spring and only 22–36% during the rest of the year in the headwaters. While glacial supply contributed up to 34%, both groundwater and periglacial exhibited a remarkable contribution around 20% with some seasonal variations. Downstream, glacial contribution averaged 15–20%, groundwater seasonally increased up to 46%, and periglacial input was surprisingly high (i.e., 14–21%). The different water sources contribution quantification over time for the Aconcagua River reported in this work provides key information for water security in this territory.Water2073-4441 Reuters ISIcatchments, glacial geology, groundwater, isotopes, rivers, snow melting systems, water supply, buffering effect, ionic analysis, natural tracers, natural waters, seasonal variation, stable isotopes, water genesis, water security, tracers, catchment, ionic composition, river basin, seasonal variation, snowmelt, stable isotope, streamflow, aconcagua river, chile, valparaiso [chile]
Exploring the contours of climate governance: An interdisciplinary systematic literature review from a southern perspectiveSapiains, Rodolfo; Ibarra, Cecilia; Jiménez, Guadalupe; O'Ryan, Raúl; Blanco, Gustavo; Moraga, Pilar; Rojas, MaisaGobernanza e Interfaz Ciencia y Política10.1002/eet.1912Dealing with climate change is one of this century's most difficult challenges demanding new strategies to steer societies towards common transformational goals. A growing literature involving “climate governance” is evolving and should advance the discussion on transformations and the involvement of different actors in climate action. However, it is unclear that the Global South's particularities are being integrated. This study has a three-fold goal: (a) identify the different approaches to climate governance found in the mainstream literature, (b) explore the degree of integration of the Global South in those approaches, and (c) contribute to the ongoing discussion on this issue from a southern perspective. A systematic literature review on “climate governance” was conducted, distinguishing different approaches and their significance for the Global South. Results clustered in six groups use the characterizations: multi-level, global, adaptive, transnational, polycentric, and experimental/transformative. These terms account for different levels of decision-making, emerging values, and the importance of non-State and sub-national actors. Approaches vary, in relation to change and participation, from an incremental improvement focus to a more transformative perspective and from the promotion of community influence to processes based on traditional institutions. In the Global South, multi-level, multi-actor climate governance occurs in a context of deep inequality and asymmetric power relations, rising environmental conflicts, and a lack of adequate mechanisms for community participation. Addressing climate change here will require, acknowledging the State alone cannot solve the issue, that different views must be considered and that contextualized perspectives from the Global South must be integrated.Environmental Policy and Governance1756-932X1-14Thomson Reuters ISIclimate change, climate modeling, decision making, governance approach, literature review, participatory approach
Hydroclimate of the Andes Part I: Main Climatic FeaturesEspinoza, Jhan Carlo; Garreaud, René; Poveda, Germán; Arias, Paola A.; Molina-Carpio, Jorge; Masiokas, Mariano; Viale, Maximiliano; Scaff, LuciaAgua y Extremos2020.010.3389/feart.2020.00064The Andes is the longest cordillera in the world and extends from northern South America (11°N) to the southern tip of the continent (53°S). The Andes runs through seven countries and is characterized by a wide variety of ecosystems strongly related to the contrasting climate over its eastern and western sides and along its latitudinal extension. In fact, the tropical Andes is the most biodiverse region on Earth. Currently, this region faces the highest potential impact of climate change, which could affect food security and water supplies for about 90 million people. From a scientific and societal view, the Andes present specific challenges because of its unique landscape and the fragile equilibrium between the growing population and its environment. In this manuscript, we provide an updated review of the most relevant scientific literature regarding the hydroclimate of the Andes. This review paper is presented in two parts. Part I is dedicated to summarize the scientific knowledge about the main climatic features of the Andes, with emphasis on mean large-scale atmospheric circulation, the Andes-Amazon hydroclimate interconnections, and the regular cycles of precipitation, including the most characteristic diurnal and annual cycles of precipitation. Part II, which is also included in the research topic “Connecting Mountain Hydroclimate Through the American Cordilleras”, focuses on hydroclimate variability of the Andes at a sub-continental scale.Frontiers in Earth Science2296-6463 Reuters ISIatmospheric pressure, biodiversity, earth (planet), atmospheric circulation, climatic features, continental scale, research topics, scientific knowledge, scientific literature, southern oscillation, water security, climate change
Extreme sea levels at Rapa Nui (Easter Island) during intense atmospheric riversCarvajal, Matías; Winckler, Patricio; Garreaud, René; Igualt, Felipe; Contreras-López, Manuel; Averil, Pamela; Cisternas, Marco; Gubler, Alejandra; Breuer, Wolfgang A.Agua y Extremos2021.010.1007/s11069-020-04462-2In addition to the tsunami hazard posed by distant great earthquakes, Rapa Nui (Easter Island), in the Southeast Pacific Ocean, is exposed to frequent and intense coastal storms. Here, we use sea-level records and field surveys guided by video and photographic footage to show that extreme sea levels at Rapa Nui occur much more frequent than previously thought and thus constitute an unrecognized hazard to the inland’s maritime supply chain. We found that extreme sea-level events, including the two most extreme (March 5th and May 5th, 2020) in our 17-month-long analyzed period (from January 1st, 2019, to May 31st, 2020), resulted from constructive superpositions of seiches on the shelf, storm surges and high tides. By further analyzing time series of atmospheric and wind-generated wave data, we conclude that these extreme sea levels are ultimately driven by the breaking of large waves near the coastline (i.e., wave setup), with lesser contribution of barometric setup and even less of wind setup. We also propose that these large waves were mainly generated from strong, long-lasting, NW winds associated with intense atmospheric rivers (long, narrow regions in the atmosphere that transport abundant water vapor) passing over Rapa Nui. Given that the intensity of atmospheric rivers and sea level are thought to increase as climate changes, a deeper understanding of the relation between meteorological and oceanographic processes at Rapa Nui is strongly needed.Natural Hazards0921-030X Reuters ISIatmospheric dynamics, extreme event, field survey, hazard assessment, photography, sea level, sea level change, seiche, storm surge, time series, tsunami, vulnerability, water vapor, wind wave, easter island, pacific ocean, pacific ocean (southeast)
Future Changes in the Free Tropospheric Freezing Level and Rain–Snow Limit: The Case of Central ChileMardones, Piero; Garreaud, René D.Agua y Extremos2020.010.3390/atmos11111259The freezing level in the free troposphere often intercepts the terrain of the world’s major mountain ranges, creating a rain–snow limit. In this work, we use the free tropospheric height of the 0 °C isotherm (H0) as a proxy of both levels and study its distribution along the western slope of the subtropical Andes (30°–38° S) in present climate and during the rest of the 21st century. This portion of the Andes corresponds to central Chile, a highly populated region where warm winter storms have produced devastating landslides and widespread flooding in the recent past. Our analysis is based on the frequency distribution of H0 derived from radiosonde and surface observations, atmospheric reanalysis and climate simulations. The future projections primarily employ a scenario of heavy greenhouse gasses emissions (RCP8.5), but we also examine the more benign RCP4.5 scenario. The current H0 distribution along the central Chile coast shows a gradual decrease southward, with mean heights close to 2600 m ASL (above sea level) at 30 °C S to 2000 m ASL at 38° S for days with precipitation, about 800 m lower than during dry days. The mean value under wet conditions toward the end of the century (under RCP8.5) is close to, or higher than, the upper quartile of the H0 distribution in the current climate. More worrisome, H0 values that currently occur only 5% of the time will be exceeded in about a quarter of the rainy days by the end of the century. Under RCP8.5, even moderate daily precipitation can increase river flow to levels that are considered hazardous for central Chile.Atmosphere2073-4433 Reuters ISIfreezing, rain, sea level, snow, storms, atmospheric reanalysis, climate simulation, daily precipitations, free troposphere, frequency distributions, future projections, mountain ranges, surface observation, troposphere, climate change, cmip, flooding, freezing, future prospect, troposphere, andes, chile
The Chilean Tornado Outbreak of May 2019: Synoptic, mesoscale, and historical contextsVicencio, José; Rondanelli, Roberto; Campos, Diego; Valenzuela, Raúl; Garreaud, René; Reyes, Alejandra; Padilla, Rodrigo; Abarca, Ricardo; Barahona, Camilo; Delgado, Rodrigo; Nicora, GabrielaZonas Costeras; Agua y Extremos2020.010.1175/BAMS-D-19-0218.1Capsule An unprecedented tornado outbreak occurred in Southern Chile, with at least seven tornadoes reported over a period of 24 hours, causing substantial damage, dozens of injuries, and one fatality.Bulletin of the American Meteorological Society0003-0007, 1520-0477 Reuters ISIpotential energy, storms, anecdotal evidences, convective available potential energies, lightning datum, low-level winds, mid-latitude storms, tornado outbreak, vorticity generation, western south america, tornadoes
High competitive ability of Centaurea melitensis L. (Asteraceae) does not increase in the invaded rangeSotes, Gastón J.; Cavieres, Lohengrin A.; Gómez-González, SusanaCambio de Uso de Suelo2020.010.1007/s10530-020-02396-1Understanding why alien species become dominant in recipient communities requires a biogeographical perspective comparing the ecology of native and introduced populations. The genus Centaurea (Asteraceae) is well-known in invasion ecology because several aggressive invaders, including Centaurea melitensis L., belong to this genus. We compared the competitive ability of C. melitensis individuals from Spain (native range) and Chile (invaded range) when competing against Helenium aromaticum (Hook.) L.H. Bailey, a native relative from Chile. We performed germination bioassays and common garden competition experiments to compare: (1) the germination capacities of C. melitensis (Spain and Chile) and H. aromaticum (2) the potential allelopathic effect of leaf lixiviates of C. melitensis (Spain and Chile) on the seed germination of H. aromaticum, (3) the ability of C. melitensis from both origins to reduce the growth of H. aromaticum. No significant differences in the capacity of seed germination were found among C. melitensis from Chile and Spain and the native H. aromaticum. However, the seed germination of H. aromaticum was inhibited by the presence of C. melitensis leaves from Chile and Spain. Also, the biomass of H. aromaticum was reduced in the presence of C. melitensis, regardless of their origin. Our results demonstrate the competitive superiority of the invasive C. melitensis over H. aromaticum, but we found no evidence of an evolutionary increase in the competitive ability of the invader populations. Therefore, at least part of the invasive potential of C. melitensis seems to be acquired by selective processes in their original range.Biological Invasions1387-3547, 1573-1464 Reuters ISIangiosperm, bioassay, biogeography, biological invasion, biomass, community dynamics, competitive ability, garden, germination, introduced species, native species, range expansion, chile, spain, asteraceae, centaurea, centaurea melitensis, helenium aromaticum
Regional patterns and temporal evolution of ocean iron fertilization and CO2 drawdown during the last glacial terminationLambert, Fabrice; Opazo, Natalia; Ridgwell, Andy; Winckler, Gisela; Lamy, Frank; Shaffer, Gary; Kohfeld, Karen; Ohgaito, Rumi; Albani, Samuel; Abe-Ouchi, AyakoCiudades Resilientes2021.010.1016/j.epsl.2020.116675The last time Earth's climate experienced geologically rapid global warming was associated with the last glacial termination, when atmospheric CO2 concentrations rose from 180 ppmv during the Last Glacial Maximum (LGM, 26-19 kaBP) to ∼260 ppmv by the early Holocene (12-8 kaBP). About one quarter of that difference is thought to be due to a stronger biological pump during glacial times, driven by increased aeolian dust deposition and hence greater iron availability in ocean surface waters. However, dust supply did not change uniformly or in synchrony over the deglacial transition and what is not known is the relative importance of different oceanic regions and how this may have changed in time. Using an Earth system model of intermediate complexity, we quantify the sensitivity of atmospheric CO2 to regional changes in iron supply, and test six different global dust reconstructions in order to explore uncertainty in past dust changes. We confirm the Southern Ocean (>34°S) as the region most sensitive to iron fertilization, with the Atlantic and Pacific sectors accounting for about % and %, respectively, of the total CO2 reduction from global iron fertilization. However, the North Pacific contributes % to the total implying an important role for Northern Hemisphere processes in driving deglacial CO2 rise. In addition, our analysis reveals an unexpected regional-temporal disparity, and while Southern Hemisphere iron fertilization influences atmospheric CO2 relatively constantly throughout the termination the impact of the Northern Hemisphere only occurs during the later stages of the termination.Earth and Planetary Science Letters0012821X Reuters ISIbiology, carbon dioxide, dust, earth (planet), glacial geology, global warming, surface waters, co2 concentration, earth system model of intermediate complexity, iron fertilization, last glacial maximum, last glacial terminations, northern hemispheres, southern hemisphere, temporal evolution, iron, carbon dioxide, dust, global warming, iron, last glacial maximum, northern hemisphere, paleoclimate, reconstruction, temporal evolution
Extreme Drought Affects Visitation and Seed Set in a Plant Species in the Central Chilean Andes Heavily Dependent on Hummingbird PollinationArroyo, Mary T. K.; Robles, Valeria; Tamburrino, Ítalo; Martínez-Harms, Jaime; Garreaud, René D.; Jara-Arancio, Paola; Pliscoff, Patricio; Copier, Ana; Arenas, Jonás; Keymer, Joaquín; Castro, KiaraAgua y Extremos2020.010.3390/plants9111553Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant–pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019–2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of Mutisia subulata (Asteraceae) is a specialised hummingbird-pollinated species. In a two-year study which included the severest drought year, we quantified visitation frequency, flower-head density, flower-head visitation rates, two measures of floral longevity, nectar characteristics and seed set and monitored climatic variables to detect direct and indirect climate-related effects on pollinator visitation. Flower-head density, nectar standing crop and seed set were significantly reduced in the severest drought year while nectar concentration increased. The best model to explain visitation frequency included flower-head density, relative humidity, temperature, and nectar standing crop with highly significant effects of the first three variables. Results for flower-head density suggest hummingbirds were able to associate visual signals with reduced resource availability and/or were less abundant. The negative effect of lower relative humidity suggests the birds were able to perceive differences in nectar concentration. Reduced seed set per flower-head together with the availability of far fewer ovules in the 2019–2020 austral summer would have resulted in a major reduction in seed set. Longer and more intense droughts in this century could threaten local population persistence in M. subulata.Plants2223-7747 Reuters ISIcentral chile, extreme drought, floral longevity, floral resources, hummingbird-pollination, mutisia subulata, oreotrochilus leucopleurus, seed set, visitation rates
Ideas and perspectives: A strategic assessment of methane and nitrous oxide measurements in the marine environmentWilson, Samuel T.; Al-Haj, Alia N.; Bourbonnais, Annie; Frey, Claudia; Fulweiler, Robinson W.; Kessler, John D.; Marchant, Hannah K.; Milucka, Jana; Ray, Nicholas E.; Suntharalingam, Parvadha; Thornton, Brett F.; Upstill-Goddard, Robert C.; Weber, Thomas S.; Arévalo-Martínez, Damian L.; Bange, Hermann W.; Benway, Heather M.; Bianchi, Daniele; Borges, Alberto V.; Chang, Bonnie X.; Crill, Patrick M.; del Valle, Daniela A.; Farías, Laura; Joye, Samantha B.; Kock, Annette; Labidi, Jabrane; Manning, Cara C.; Pohlman, John W.; Rehder, Gregor; Sparrow, Katy J.; Tortell, Philippe D.; Treude, Tina; Valentine, David L.; Ward, Bess B.; Yang, Simon; Yurganov, Leonid N.Zonas Costeras2020.010.5194/bg-17-5809-2020Abstract. In the current era of rapid climate change, accurate characterization of climate-relevant gas dynamics – namely production, consumption, and net emissions – is required for all biomes, especially those ecosystems most susceptible to the impact of change. Marine environments include regions that act as net sources or sinks for numerous climate-active trace gases including methane (CH4) and nitrous oxide (N2O). The temporal and spatial distributions of CH4 and N2O are controlled by the interaction of complex biogeochemical and physical processes. To evaluate and quantify how these mechanisms affect marine CH4 and N2O cycling requires a combination of traditional scientific disciplines including oceanography, microbiology, and numerical modeling. Fundamental to these efforts is ensuring that the datasets produced by independent scientists are comparable and interoperable. Equally critical is transparent communication within the research community about the technical improvements required to increase our collective understanding of marine CH4 and N2O. A workshop sponsored by Ocean Carbon and Biogeochemistry (OCB) was organized to enhance dialogue and collaborations pertaining to marine CH4 and N2O. Here, we summarize the outcomes from the workshop to describe the challenges and opportunities for near-future CH4 and N2O research in the marine environment.Biogeosciences1726-4189 Reuters ISIbiogeochemistry, gas exchange, marine ecosystem, methane, nitrous oxide, numerical model, strategic approach
Low-Cost Ka-Band Cloud Radar System for Distributed Measurements within the Atmospheric Boundary LayerAguirre, Roberto; Toledo, Felipe; Rodríguez, Rafael; Rondanelli, Roberto; Reyes, Nicolas; Díaz, MarcosZonas Costeras2020.010.3390/rs12233965Radars are used to retrieve physical parameters related to clouds and fog. With these measurements, models can be developed for several application fields such as climate, agriculture, aviation, energy, and astronomy. In Chile, coastal fog and low marine stratus intersect the coastal topography, forming a thick fog essential to sustain coastal ecosystems. This phenomenon motivates the development of cloud radars to boost scientific research. In this article, we present the design of a Ka-band cloud radar and the experiments that prove its operation. The radar uses a frequency-modulated continuous-wave with a carrier frequency of 38 GHz. By using a drone and a commercial Lidar, we were able to verify that the radar can measure reflectivities in the order of −60 dBZ at 500 m of distance, with a range resolution of 20 m. The lower needed range coverage imposed by our case of study enabled a significant reduction of the instrument cost compared to existent alternatives. The portability and low-cost of the designed instrument enable its implementation in a distributed manner along the coastal mountain range, as well as its use in medium-size aerial vehicles or balloons to study higher layers. The main features, limitations, and possible improvements to the current instrument are discussed.Remote Sensing2072-4292 Reuters ISIagricultural robots, antennas, atmospheric boundary layer, climate models, costs, ecosystems, fog, optical radar, topography, application fields, cloud radar systems, coastal ecosystems, coastal topography, distributed measurements, frequency-modulated continuous waves, physical parameters, scientific researches, radar measurement
Differences in the composition of organic aerosols between winter and summer in Beijing: a study by direct-infusion ultrahigh-resolution mass spectrometrySteimer, Sarah S.; Patton, Daniel J.; Vu, Tuan V.; Panagi, Marios; Monks, Paul S.; Harrison, Roy M.; Fleming, Zoë L.; Shi, Zongbo; Kalberer, MarkusCiudades Resilientes2020.010.5194/acp-20-13303-2020Abstract. This study investigates the chemical composition of PM2.5 collected at a central location in Beijing, China, during winter 2016 and summer 2017. The samples were characterised using direct-infusion negative-nano-electrospray-ionisation ultrahigh-resolution mass spectrometry to elucidate the composition and the potential primary and secondary sources of the organic fraction. The samples from the two seasons were compared with those from a road-tunnel site and an urban background site in Birmingham, UK, analysed in the course of an earlier study using the same method. There were strong differences in aerosol particle composition between the seasons, particularly regarding (poly-)aromatic compounds, which were strongly enhanced in winter, likely due to increased fossil fuel and biomass burning for heating. In addition to the seasonal differences, compositional differences between high- and low-pollution conditions were observed, with the contribution of sulfur-containing organic compounds strongly enhanced under high-pollution conditions. There was a correlation of the number of sulfur-containing molecular formulae with the concentration of particulate sulfate, consistent with a particle-phase formation process.Atmospheric Chemistry and Physics1680-7324 Reuters ISIaerosol composition, biomass burning, concentration (composition), fossil fuel, mass spectrometry, particulate matter, sulfate, summer, winter, beijing [beijing (ads)], beijing [china], birmingham [birmingham (dst)], birmingham [england], china, england, united kingdom
Influence of coastal upwelling on micro-phytoplankton variability at Valparaíso Bay (~33ºS), Central ChileAparicio-Rizzo, Pilar; Masotti, Italo; Landaeta, Mauricio F.Zonas Costeras2020.010.22370/rbmo.2020.55.1.2353In this work 10 years of data (1986-1996) from a fixed station located in the northern part of Valparaíso Bay (33º00’S; 71º35’W) were analysed to study the influence of coastal upwelling activity on the temporal variation of micro-phytoplankton (20-200 μm) and their relationship with oceanographic conditions. The upwelling activity at the bay was associated to semi-annual wind regime with an intensification of upwelling-favourable S-SW winds from September to March followed by a decrease and the occurrence of downwelling events from April to August. Oceanographic conditions showed the ascent of cold, nutrient-rich salty water in spring (September-November). However, during summertime under highest upwelling index, thermal stratification conditions were registered. This stratification might be associated to either the solar radiation or the presence of an upwelling shadow area in the bay. The upwelling period had the highest micro-phytoplankton abundance mainly dominated by diatoms. This period was associated with an increase in biomass and richness in the bay. Meanwhile during non-upwelling period —under homogenous conditions of temperature, salinity and nutrients— an increase in diversity (but low abundance and richness) associated to dinoflagellates and silicoflagellates was noted. Therefore, the results suggest the presence of a bi-modal regime of micro-phytoplankton in the bay in response to changes in oceanographic conditions related to local wind forcing and mixing/stratification.Revista de Biología Marina y Oceanografía0718-1957, 0717-3326 Reuters ISIcoastal zone, phytoplankton, stratification, temporal variation, upwelling, wind forcing, chile, valparaiso bay, valparaiso [chile], bacillariophyta, costera, dictyochophyceae, dinophyceae
A statistical physics approach to perform fast highly-resolved air quality simulations – A new step towards the meta-modelling of chemistry transport modelsBessagnet, Bertrand; Couvidat, Florian; Lemaire, VincentCiudades Resilientes2019.010.1016/j.envsoft.2019.02.017A methodology rested on model-based machine learning using simple linear regressions and the parameterizations of the main physics and chemistry processes has been developed to perform highly-resolved air quality simulations. The training of the methodology is (i) completed over a 6-month period using the outputs of the chemical transport model CHIMERE, and (ii) then applied over the subsequent 6 months. Despite rough assumptions, this new methodology performs as well as the raw CHIMERE simulation for daily mean concentrations of the main criteria air pollutants (NO2, Ozone, PM10 and PM2.5) with correlations ranging from 0.75 to 0.83 for the particulate matter and up to 0.86 for the maximum ozone concentrations. Some improvements are investigated to expand this methodology to several other uses, but at this stage the method can be used for air quality forecasting, analysis of pollution episodes and mapping. This study also confirms that including a minimum set of selected physical parameterizations brings a high added value on machine learning processes.Environmental Modelling & Software13648152 Reuters ISIair quality, linear regression, machine learning, optical resolving power, ozone, statistics, air quality forecasting, air quality modelling, chemical transport models, chemistry transport model, criteria air pollutants, increment, meta model, simple linear regression, statistical physics, air quality, atmospheric modeling, atmospheric pollution, machine learning, methodology, ozone, particulate matter, regression analysis, simulation, statistical analysis
Connection between Antarctic Ozone and Climate: Interannual Precipitation Changes in the Southern HemisphereDamiani, Alessandro; Cordero, Raul R.; Llanillo, Pedro J.; Feron, Sarah; Boisier, Juan P.; Garreaud, Rene; Rondanelli, Roberto; Irie, Hitoshi; Watanabe, ShingoZonas Costeras; Agua y Extremos2020.010.3390/atmos11060579In this study, we explored the connection between anomalies in springtime Antarctic ozone and all-year precipitation in the Southern Hemisphere by using observations from 1960–2018 and coupled simulations for 1960–2050. The observations showed that this correlation was enhanced during the last several decades, when a simultaneously increased coupling between ozone and Southern Annular Mode (SAM) anomalies became broader, covering most of the following summer and part of the previous winter. For eastern Australia, the ozone–precipitation connection shows a greater persistence toward the following summer than for other regions. On the other hand, for South America, the ozone–precipitation correlation seems more robust, especially in the early summer. There, the correlation also covers part of the previous winter, suggesting that winter planetary waves could affect both parameters. Further, we estimated the sensitivity of precipitation to changes in Antarctic ozone. In both observations and simulations, we found comparable sensitivity values during the spring–summer period. Overall, our results indicate that ozone anomalies can be understood as a tracer of stratospheric circulation. However, simulations indicate that stratospheric ozone chemistry still contributes to strengthening the interannual relationship between ozone and surface climate. Because simulations reproduced most of the observed connections, we suggest that including ozone variability in seasonal forecasting systems can potentially improve predictions.Atmosphere2073-4433 Reuters ISIozone layer, coupled simulation, precipitation change, seasonal forecasting, sensitivity values, southern annular mode, southern hemisphere, stratospheric circulations, stratospheric ozone chemistry, ozone, annual variation, anomaly, atmospheric chemistry, computer simulation, ozone, precipitation (climatology), regional climate, southern hemisphere, antarctica
Taxonomic Novelty and Distinctive Genomic Features of Hot Spring CyanobacteriaAlcorta, Jaime; Alarcón-Schumacher, Tomás; Salgado, Oscar; Díez, BeatrizZonas Costeras2020.010.3389/fgene.2020.568223Several cyanobacterial species are dominant primary producers in hot spring microbial mats. To date, hot spring cyanobacterial taxonomy, as well as the evolution of their genomic adaptations to high temperatures, are poorly understood, with genomic information currently available for only a few dominant genera, including Fischerella and Synechococcus. To address this knowledge gap, the present study expands the genomic landscape of hot spring cyanobacteria and traces the phylum-wide genomic consequences of evolution in high temperature environments. From 21 globally distributed hot spring metagenomes, with temperatures between 32 and 75°C, 57 medium- and high-quality cyanobacterial metagenome-assembled genomes were recovered, representing taxonomic novelty for 1 order, 3 families, 15 genera and 36 species. Comparative genomics of 93 hot spring genomes (including the 57 metagenome-assembled genomes) and 66 non-thermal genomes, showed that the former have smaller genomes and a higher GC content, as well as shorter proteins that are more hydrophilic and basic, when compared to the non-thermal genomes. Additionally, the core accessory orthogroups from the hot spring genomes of some genera had a greater abundance of functional categories, such as inorganic ion metabolism, translation and post-translational modifications. Moreover, hot spring genomes showed increased abundances of inorganic ion transport and amino acid metabolism, as well as less replication and transcription functions in the protein coding sequences. Furthermore, they showed a higher dependence on the CRISPR-Cas defense system against exogenous nucleic acids, and a reduction in secondary metabolism biosynthetic gene clusters. This suggests differences in the cyanobacterial response to environment-specific microbial communities. This phylum-wide study provides new insights into cyanobacterial genomic adaptations to a specific niche where they are dominant, which could be essential to trace bacterial evolution pathways in a warmer world, such as the current global warming scenario.Frontiers in Genetics1664-8021 Reuters ISIamino acid transporter, reduced nicotinamide adenine dinucleotide (phosphate) dehydrogenase (quinone), rna 16s, amino acid metabolism, article, bacterium isolation, bioinformatics, bioremediation, comparative genomics, crispr cas system, cyanobacterium, dna base composition, dna extraction, gene cluster, gene sequence, genetic transcription, genome size, genomics, geographic distribution, haplotype, heat shock, human, hydrophilicity, hydrophobicity, ion transport, metagenome, metagenomics, microbial community, microbial diversity, molecular genetics, nonhuman, phylogenomics, polyphyly, prevalence, protein function, protein processing, secondary metabolism, taxonomy, thermal spring
Fermentation and Anaerobic Oxidation of Organic Carbon in the Oxygen Minimum Zone of the Upwelling Ecosystem Off Concepción, in Central ChileSrain, Benjamín M.; Sobarzo, Marcus; Daneri, Giovanni; González, Humberto E.; Testa, Giovanni; Farías, Laura; Schwarz, Alex; Pérez, Norma; Pantoja-Gutiérrez, SilvioZonas Costeras2020.010.3389/fmars.2020.00533We studied the dynamics of fermentation and anaerobic degradation of organic matter at a fixed station in the Oxygen Minimum Zone (OMZ) within the Humboldt Current System off Concepción, central Chile. Products of the main anaerobic microbial reactions fermentation, denitrification, and reduction of Fe(OH)3 and SO42– were analyzed during laboratory incubations of OMZ waters. Fermentation of glucose and amino acids resulted in the production of volatile fatty acids, mainly acetate; these compounds were detected year-round in in situ water samples and were associated with high primary production rates and presence of O2-deficient waters at the sampling site. In contrast, whilst ethanol was produced from glucose fermentation by OMZ water microorganisms under laboratory conditions, it was not detected in the water column during the annual cycle. Evidence of acetate oxidation (which is thermodynamically feasible), with Fe(OH)3 as an electron acceptor, suggests that microbial activity could reduce solid-phase Fe carried by rivers using fermented metabolites in oxygen-depleted water, thus releasing dissolved bioavailable Fe. Here we present evidence for productivity-driven seasonality of biogeochemical cycles in the Humboldt system, supported by fermentation and anaerobic consumption of fermentation products oxidized by a variety of electron acceptors including NO3–, Fe(OH)3, and SO42–. Our results suggest that products of fermentation in the OMZ may provide a source of labile organics for advection to oxygenated waters of subantarctic origin during austral winter. Fermentation, anaerobic oxidation and associated advection of fermentation products are likely to be enhanced during the twenty-first century due both to temperature increase and decrease in dissolved O2 in the water column.Frontiers in Marine Science2296-7745 Reuters ISIacetate, anaerobic respiration, chile, fermentation, oxygen minimum zone, south east pacific, volatile fatty acids
Assessment of landscape transformation in protected areasPereira, Sebastian Ruiz; Fernández, José; Herrera, José; Olea, JorgeCiudades Resilientes2021.010.1016/j.eiar.2020.106472Mountain protected landscapes continuously endure conflicts of appropriation that bear inherent transformations. One type of direct intervention is by Commercial Concessions within these areas, affecting their landscape value. The aim is to determine conceptual gaps in Environmental Impact Studies regarding landscape assessment and propose a way to improve them in this sense. Shortcomings regarding landscape are checked in different normative frameworks and tensions are analyzed through the case of a Commercial Concession grant within a Mountain Protected area in the South-Central Andes of Chile (38°22′S;71°35′W). Weak or absent definitions of landscape are found in normative frames and Environmental Impact guidelines. A reductionism of landscape as mere viewshed units avoids a proper differentiation for several types of economic transformations and conservation management purposes therein. Hence, transformations affecting the inherent value of landscape are latent under monitoring and legislation abiding practices. Tensions between protected areas and commercial concessions depend on landscape management strategies which are associated to capital gain uncertainties by risking the nonuse-value of landscape. This uncertainty as a natural insurance value can be integrated to conceptual analyses assessing landscape transformations and report their depreciation. These transformations of landscape value are deemed necessary to be implemented in Environmental Impact Assessment without having to discretize bipartite purposes in protected areas by assessing landscape value through conceptual and economic analyses.Environmental Impact Assessment Review01959255 Reuters ISIconservation, economic analysis, environmental impact assessments, environmental protection, uncertainty analysis, conceptual analysis, conservation management, economic transformation, environmental impact study, landscape assessments, landscape management, landscape values, protected areas, environmental impact, conceptual framework, conservation management, economic analysis, environmental impact assessment, legislation, protected area, uncertainty analysis, andes, chile
Increasing trends (2001–2018) in photochemical activity and secondary aerosols in Santiago, ChileMenares, Camilo; Gallardo, Laura; Kanakidou, Maria; Seguel, Rodrigo; Huneeus, NicolásCiudades Resilientes2020.010.1080/16000889.2020.1821512Despite the decline in partially (PM10) and fully (PM2.5) inhalable particles observed in recent decades, Santiago in Chile shows high levels of particle and ozone pollution. Attainment plans have emphasized measures aimed at curbing primary and, to some extent, secondary particles, but little attention has been paid to photochemical pollution. Nevertheless, ozone hourly mixing ratios in Eastern Santiago regularly exceed 110 ppbv in summer, and in winter maximum mixing ratios often reach 90 ppbv. Moreover, the sum of ozone and nitrogen dioxide shows an increasing trend of more than 3.5 ppbv per decade at 5 out of 8 stations. This trend is driven by increasing NO2, possibly associated with increasing motorization but also with changes in photochemistry. To estimate the fraction of secondary particles in PM2.5 and due to the lack of long-term speciation data for particles, we use carbon monoxide as a proxy of primary particles and ozone daily maxima as a proxy for secondary particle formation. We find a growing fraction of secondary particles due to an increase in the oxidizing capacity of Santiago’s atmosphere. This stresses the need for new curbing measures to tackle photochemical pollution. This is particularly needed in the context of a changing climate.Tellus B: Chemical and Physical Meteorology1600-0889 Reuters ISIaerosol composition, aerosol formation, atmospheric chemistry, ozone, particulate matter, photochemistry, trend analysis, chile, metropolitana
Daily and seasonal variation of the surface temperature lapse rate and 0°C isotherm height in the western subtropical AndesIbañez, María; Gironás, Jorge; Oberli, Christian; Chadwick, Cristián; Garreaud, René D.Agua y Extremos2020.010.1002/joc.6743International Journal of Climatology0899-8418, 1097-0088 Reuters ISIcatchments, floods, isotherms, risk assessment, risk perception, runoff, surface properties, tropics, hydrological modelling, inter-day variations, mountainous basins, seasonal variation, surface air temperatures, surface temperatures, temperature inversions, temporal variation, atmospheric temperature, diurnal variation, mountain environment, mountain region, seasonal variation, sensor, surface temperature, warming, andes, chile
Seasonal precipitation in South Central Chile: trends in extreme events since 1900González-Reyes, Álvaro; Jacques-Coper, Martin; Muñoz, Ariel AndresZonas Costeras; Agua y Extremos2020.010.20937/ATM.52871We study a regional precipitation time series, built upon seven meteorological records from South Central Chile (SCC; 37° - 42°S), which together cover the period 1900 - 2019. As a first objective, we investigated changes in the return period (RP) of dry ( P80) seasonal extreme events of precipitation (SEE), for each season. We observed a reduction in the RP of wet SEE during 1900 - 1950 in all seasons. Contrarily, the dry SEE RP shows a reduction from 1950 to the present in all seasons. This phenomenon is noteworthy since 1900 for summer and winter, and since 1930 for autumn. Spring registers a constant RP value from 1990 onwards. As a second objective, we study possible relationships between seasonal precipitation variability and climate modes, such as the Southern Annular Mode (SAM) and the Tripolar Index (TPI) of sea surface temperature (SST) over the Pacific Ocean. Summer and autumn precipitation register a significant negative correlation with SAM activity at interannual and decadal scales, while winter and spring precipitation show a significant positive correlation with SST variability over multiple regions of the Pacific Ocean (including the tropics and New Zealand) and the Southern Ocean (Amundsen-Bellingshausen Sea). Finally, we confirm that SAM strongly modulates precipitation in SCC, especially in autumn, and that SEE variability in SCC is considerably characterized by climate modes of tropical and extra-tropical origin.Atmósfera Reuters ISIextreme seasonal precipitation events, south-central chile, southern annular mode (sam), tripole index of sea surface temperature of the pacific ocean (tpi)
Using Sentinel-2 and canopy height models to derive a landscape-level biomass map covering multiple vegetation typesFassnacht, Fabian Ewald; Poblete-Olivares, Javiera; Rivero, Lucas; Lopatin, Javier; Ceballos-Comisso, Andrés; Galleguillos, MauricioCambio de Uso de Suelo2021.010.1016/j.jag.2020.102236Vegetation biomass is a globally important climate-relevant terrestrial carbon pool and also drives local hydrological systems via evapotranspiration. Vegetation biomass of individual vegetation types has been successfully estimated from active and passive remote sensing data. However, for many tasks, landscape-level biomass maps across several vegetation types are more suitable than biomass maps of individual vegetation types. For example, the validation of ecohydrological models and carbon budgeting typically requires spatially continuous biomass estimates, independent from vegetation type. Studies that derive biomass estimates across multiple vegetation or land-cover types to merge them into a single landscape-level biomass map are still scarce, and corresponding workflows must be developed. Here, we present a workflow to derive biomass estimates on landscape-level for a large watershed in central Chile. Our workflow has three steps: First, we combine field plot based biomass estimates with spectral and structural information collected from Sentinel-2, TanDEM-X and airborne LiDAR data to map grassland, shrubland, native forests and pine plantation biomass using random forest regressions with an automatic feature selection. Second, we predict all models to the entire landscape. Third, we derive a land-cover map including the four considered vegetation types. We then use this land-cover map to assign the correct vegetation type-specific biomass estimate to each pixel according to one of the four considered vegetation types. Using a single repeatable workflow, we obtained biomass predictions comparable to earlier studies focusing on only one of the four vegetation types (Spearman correlation between 0.80 and 0.84; normalized-RMSE below 16 % for all vegetation types). For all woody vegetation types, height metrics were amongst the selected predictors, while for grasslands, only Sentinel-2 bands were selected. The land-cover was also mapped with high accuracy (OA = 83.1 %). The final landscape-level biomass map spatially agrees well with the known biomass distribution patterns in the watershed. Progressing from vegetation-type specific maps towards landscape-level biomass maps is an essential step towards integrating remote-sensing based biomass estimates into models for water and carbon management.International Journal of Applied Earth Observation and Geoinformation03032434 Reuters ISIA
Transformation of social capital during and after a disaster event: the cases Chañaral and Diego de Almagro, Atacama Region, ChileCastro-Correa, Carmen-Paz; Aldunce Ide, Paulina; Wyndham Vásquez, Katherine; Mena Maldonado, Dania; Pérez Tello, SoniaAgua y Extremos2020.010.1007/s11069-020-04091-9This article analyzes the impact of socio-natural disasters on social capital at a local level, studying the cases of the communities of Chañaral and Diego de Almagro after the flooding and mudflow disasters of 2015. Specifically, we explore different dynamics of social capital in the response to the emergency, recovery and reconstruction stages, exploring its role in strengthening adaptation and resilience capacities for disaster risk reduction. Through the qualitative analysis of semi-structured interviews with survivors of the disaster, we explore the nature and role of social trust and its influence on the formation and consolidation of bonding, bridging and linking social capital in the context of disaster is analyzed. The results unpack the role of social capital in the response, recovery and reconstruction processes after a disaster event, which directly influences the development and consolidation of capacities for community adaptation, highlighting the role of trust for the strengthening of resilience. Likewise, the article provides details about the role of institutions and authorities in the consolidation of bridging and linking social capital, which requires the generation of formal and fluid communication channels that allow for the creation of trust, not only among the members of the community, but between the community and the institutions and authorities.Natural Hazards0921-030X, 1573-0840 Reuters ISIadaptive management, consolidation, disaster management, flooding, local participation, mudflow, qualitative analysis, social capital, atacama, chanaral island, chile, diego de almagro island, magallanes
Evidence of climate-driven changes on atmospheric, hydrological, and oceanographic variables along the Chilean coastal zoneGrez, Patricio Winckler; Aguirre, Catalina; Farías, Laura; Contreras-López, Manuel; Masotti, ÍtaloZonas Costeras2020.010.1007/s10584-020-02805-3Abstract The Chilean coastal zone (CCZ) is subjected to a complex spectrum of anthropogenic, geophysical, biogeochemical, and climate-driven perturbations. Potentially affected variables including atmospheric sea level pressure ( Pa ), alongshore wind, sea surface temperature ( SST ), chlorophyll-a, rainfall, river discharge, relative mean sea level ( RMSL ), and wave climate are studied using in situ and satellite records, hindcasts, and reanalysis datasets. Linear temporal trends and correlations of anomalies are estimated between 18°S and 55°S along the CCZ. The comparison of some of the variables is achieved by means of a strict homogenization procedure on a monthly basis for 35 years. Our findings show that the poleward drift and strengthening of the Southeast Pacific Subtropical Anticyclone (SPSA) partially explains the increase in Pa and reduction in rainfall and river discharge. The enhancement of alongshore winds, also attributable to changes in the SPSA, increases coastal upwelling, which in turn could reduce SST and increase chlorophyll-a. Despite differential latitudinal responses, increasing wave heights and a southward rotation are evidenced. RMSL does not show significant variation as it is presumably affected by seafloor changes during the seismic cycle. Though some correlations are evidenced, the influence of climate variability at decadal scale (PDO, SAM) may be affecting the detected trends due to the short length of available data. Impacts on coastal communities, infrastructure, and ecosystems are discussed, aiming to highlight that coastal vulnerabilities and risk management should be based on the cumulative impacts of these variables.Climatic Change0165-0009, 1573-1480 Reuters ISIchlorophyll, coastal zones, ocean currents, rain, risk management, surface waters, climate variability, coastal communities, coastal upwelling, cumulative impacts, homogenization procedure, sea level pressure, sea surface temperature (sst), subtropical anticyclone, sea level, anthropogenic effect, biogeochemistry, climate change, coastal zone, complexity, geophysical method, mantle upwelling, perturbation, rainfall, river discharge, satellite data, sea level pressure, sea surface temperature, wave climate, pacific ocean, pacific ocean (southeast)
Climate change perception, vulnerability, and readiness: inter-country variability and emerging patterns in Latin AmericaAzócar, Gabriela; Billi, Marco; Calvo, Rubén; Huneeus, Nicolas; Lagos, Marta; Sapiains, Rodolfo; Urquiza, AnahíCiudades Resilientes; Gobernanza e Interfaz Ciencia y Política2020.010.1007/s13412-020-00639-0In Latin America, there is scarce comparative research on variables associated with the perception of climate change. This hinders the ability of governments to take mitigation and adaptation measures in the face of the phenomenon, as well as the ability of the population to cope with its effects. In order to fill that void, this research studies the relationship between climate change perception, vulnerability, and readiness in 17 countries of the region. To that end, perception indicators included in the Latinobarómetro 2017 survey are analyzed, contrasted with vulnerability and readiness indexes provided by the University of Notre Dame’s Global Adaptation Index. The analytical strategy includes the statistical description of the variables associated with the perception of climate change in countries of the region, clustering together those countries that display similar behavioral patterns in relation to their vulnerability and readiness indicators, as well as crosstabs with climate change indicators. The key findings indicate that it is possible to identify 3 patterns of behavior regarding the countries’ vulnerability and readiness, which account for high, intermediate, and low levels in those variables. These patterns indicate cross-cutting trends concerning variables such as the level of education and affinity for the market economy, as well as particularities differentiating each country from the rest. The main conclusion is the existence of a negative association between the affinity people express for the market economy and their acknowledgment of climate change as a relevant problem.Journal of Environmental Studies and Sciences2190-6483, 2190-6491 Reuters ISIadaptive management, climate change, perception, questionnaire survey, vulnerability, latin america
Fire history in Andean Araucaria–Nothofagus forests: coupled influences of past human land-use and climate on fire regimes in north-west PatagoniaGonzález, M. E.; Muñoz, A. A.; González-Reyes, A.; Christie, D. A.; Sibold, J.Cambio de Uso de Suelo; Agua y Extremos2020.010.1071/WF19174International Journal of Wildland Fire1049-8001 Reuters ISIclimate variability, dendroecology, el niño southern oscillation, native americans, southern annular mode, tree-rings
Hidden welfare effects of tree plantationsAnríquez, Gustavo; Toledo, Gabriela; Arriagada, RodrigoCambio de Uso de Suelo2020.010.1017/S1355770X20000303Abstract Subsidies to promote tree plantations have been questioned because of negative impacts of the forestry industry. Quantitative evidence on the socioeconomic impacts of afforestation subsidies or of tree plantations is elusive, mainly due to data scarcity. We assess the overall impact of a tree plantation subsidy in Chile, using our original 20-year panel dataset that includes small area estimates of poverty and the subsidy assignment at the census-district scale. We show that forestry subsidies – on average – in fact, do increase poverty. More specifically, using difference in difference with matching techniques, and instrumental variables approaches, we show that there is an increase of about 2 per cent in the poverty rate of treated localities. We identify employment as a causal mechanism explaining this finding, since we found a negative effect of tree plantations on employment, and therefore, on poverty. We suggest reassessment of the distributional effects of the forest subsidy and forestry industry.Environment and Development Economics1355-770X, 1469-4395 Reuters ISIafforestation subsidies, impact evaluation, poverty, tree plantations
Low Growth Sensitivity and Fast Replenishment of Non-structural Carbohydrates in a Long-Lived Endangered Conifer After DroughtUrrutia-Jalabert, R.; Lara, A.; Barichivich, J.; Vergara, N.; Rodriguez, C.; Piper, F.Cambio de Uso de Suelo2020.010.3389/fpls.2020.00905There is an ongoing debate on whether a drought induced carbohydrate limitation (source limitation) or a direct effect of water shortage (sink limitation) limit growth under drought. In this study, we investigated the effects of the two driest summers recorded in southern Chile in the last seven decades, on the growth and non-structural carbohydrates (NSC) concentrations of the slow-growing conifer Fitzroya cupressoides. Specifically, we studied the seasonal variation of NSC in saplings and adults one and two years after the occurrence of a 2 year-summer drought at two sites of contrasting precipitation and productivity (mesic-productive vs. rainy-less productive). We also evaluated radial growth before, during and after the drought, and predicted that drought could have reduced growth. If drought caused C source limitation, we expected that NSCs will be lower during the first than the second year after drought. Conversely, similar NSC concentrations between years or higher NSC concentrations in the first year would be supportive of sink limitation. Also, due to the lower biomass of saplings compared with adults, we expected that saplings should experience stronger seasonal NSC remobilization than adults. We confirmed this last expectation. Moreover, we found no significant growth reduction during drought in the rainy site and a slightly significant growth reduction at the mesic site for both saplings and adults. Across organs and in both sites and age classes, NSC, starch, and sugar concentrations were generally higher in the first than in the second year following drought, while NSC seasonal remobilization was generally lower. Higher NSC concentrations along with lower seasonal NSC remobilization during the first post-drought year are supportive of sink limitation. However, as these results were found at both sites while growth decreased slightly and just at the mesic site, limited growth only is unlikely to have caused NSC accumulation. Rather, these results suggest that the post-drought dynamics of carbohydrate storage are partly decoupled from the growth dynamics, and that the rebuild of C reserves after drought may be a priority in this species.Frontiers in Plant Science1664-462X Reuters ISIcarbon limitation, drought, fitzroya cupressoides, non-structural carbohydrates, remobilization, starch, sugars, tree-growth
Forest browning trends in response to drought in a highly threatened mediterranean landscape of South AmericaMiranda, A.; Lara, A.; Altamirano, A.; Di Bella, C.; González, M. E.; Julio Camarero, J.Cambio de Uso de Suelo10.1016/j.ecolind.2020.106401Deforestation is widely studied throughout the world. However, a less evident issue is the effect of climate change and drought on remnants of native forests. The objective of this work was to understand the geographic variations in resistance to drought of the Mediterranean sclerophyllous forests of central Chile. These forests have been historically reduced and fragmented and in recent years were subjected to the most prolonged drought occurred between 2010 and 2017. Using data from the MODIS satellite sensor, temporal trends in the NDVI (Normalized Difference Vegetation Index) were quantified. We related these trends with different environmental variables to understand the effects of geographical variation and forest type as indicators of resistance to drought. We observed a significant direct effect of drought, attributable to the reduced precipitation in central Chile, and a significantly reduced NDVI in near one-third of the region forests (browning). However, NDVI and therefore forest productivity were more stable in some mesic sites such as ravine bottoms, but not on south-facing slopes. This suggests that under a regime of reduced precipitations, a greater available soil humidity would be a more important factor than the fact of receiving less solar radiation. Finally, the highest degree of browning was observed in semi-arid sclerophyllous forest dominated by species tolerant to drought. Our findings emphasize the need to consider topographic site conditions to adequately assess forest productivity and vulnerability where local wet conditions could provide drought refuges. This recent drought may be analogous to forecasted warmer and drier climate conditions with more frequent and severe droughts, so our results may serve as a general framework for climate-smart decisions in highly threatened forest restoration and conservation.Ecological Indicators1470160X Reuters ISIclimate change, deforestation, drought, productivity, environmental variables, forest productivity, forest restoration, geographic variation, geographical variations, mediterranean landscapes, modis satellite sensors, normalized difference vegetation index, conservation, climate change, conservation status, deforestation, drought stress, endangered species, geographical variation, mediterranean environment, modis, ndvi, relative humidity, satellite sensor, vulnerability, wilting, chile
Evidence-based mapping of the wildland-urban interface to better identify human communities threatened by wildfiresMiranda, A.; Carrasco, J.; González, M. E.; Pais, C.; Lara, A.; Altamirano, A.; Weintraub, A.; Syphard, A.Cambio de Uso de Suelo10.1088/1748-9326/ab9be5The wildland-urban interface (WUI) is the spatial manifestation of human communities coupled with vegetated ecosystems. Spatial delineation of the WUI is important for wildfire policy and management, but is typically defined according to spatial relationships between housing development and wildland vegetation without explicit consideration of fire risk. A fire risk-based definition of WUI can enable a better distribution of management investment so as to maximize social return. We present a novel methodological approach to delineate the WUI based on a fire risk assessment. The approach establishes a geographical framework to model fire risk via machine learning and generate multi-scale, variable-specific spatial thresholds for translating fire probabilities into mapped output. To determine whether fire-based WUI mapping better captures the spatial congruence of houses and wildfires than conventional methods, we compared national and subnational fire-based WUI maps for Chile to WUI maps generated only with housing and vegetation thresholds. The two mapping approaches exhibited broadly similar spatial patterns, the WUI definitions covering almost the same area and containing similar proportions of the housing units in the area under study (17.1% vs. 17.9%), but the fire-based WUI accounted for 13.8% more spatial congruence of fires and people (47.1% vs. 33.2% of ignitions). Substantial regional variability was found in fire risk drivers and the corresponding spatial mapping thresholds, suggesting there are benefits to developing different WUI maps for different scales of application. We conclude that a dynamic, multi-scale, fire-based WUI mapping approach should provide more targeted and effective support for decision making than conventional approaches.Environmental Research Letters1748-9326 Reuters ISIbehavioral research, decision making, housing, mapping, risk assessment, vegetation, conventional approach, conventional methods, fire risk assessment, methodological approach, regional variability, spatial relationships, vegetated ecosystems, wildland urban interface, fires, decision making, machine learning, mapping, spatial analysis, threshold, wildfire, wildlife management, chile
Evaluation of anthropogenic air pollutant emission inventories for South America at national and city scaleHuneeus, N.; Gon, Hugo Denier van der; Castesana, Paula; Menares, Camilo; Granier, Claire; Granier, Louise; Alonso, Marcelo; de Fatima Andrade, Maria; Dawidowski, Laura; Gallardo, Laura; Gomez, Dario; Klimont, Zbigniew; Janssens-Maenhout, Greet; Osses, Mauricio; Puliafito, S. Enrique; Rojas, Nestor; Ccoyllo, Odón Sánchez-; Tolvett, Sebastián; Ynoue, Rita YuriCiudades Resilientes10.1016/j.atmosenv.2020.117606Atmospheric Environment13522310 Reuters ISIair quality, atmospheric composition, climate change, cost effectiveness, air pollutant emission, air quality modeling, anthropogenic climate changes, anthropogenic emissions, emission inventories, greenhouse gases (ghg), national emission inventories, sectoral contribution, greenhouse gases, anthropogenic source, atmospheric pollution, climate change, emission inventory, greenhouse gas, human activity, megacity, pollutant source, united nations framework convention on climate change, air quality, argentina, article, brazil, chile, colombia, greenhouse gas, human, peru, urban area, argentina, brazil, chile, colombia, peru
Local Perceptions of Fires Risk and Policy Implications in the Hills of Valparaíso, ChileSapiains, Rodolfo; Ugarte, Ana María; Aldunce, Paulina; Marchant, Germant; Romero, Javier Alberto; González, Mauro E.; Inostroza-Lazo, ValentinaCambio de Uso de Suelo; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política10.3390/su12104298Climate change is increasing the occurrence of natural disasters worldwide, and more frequent and intense fires represent one of the most destructive expressions of this trend. Chile is highly vulnerable to climate change, and fires are a recurrent phenomenon affecting many people each year. To reduce fire risk, the Intergovernmental Panel on Climate Change (IPCC) suggests reducing both exposure and vulnerability through multiple initiatives, which demand increased community engagement. In such a context, this study explores local perceptions of fire in a sample of inhabitants in a wildland-urban interface (WUI) in Valparaiso, a city that is affected by numerous fires each year. The ultimate goal was to identify psychological and community factors that should be taken into consideration to develop prevention plans and safer environments for people living in a context of poverty and social inequity. Using a qualitative approach, 28 interviews were conducted and analyzed following grounded theory principles. Results identified multiple causes, impacts, and characteristics of the problem perceived by people who permanently cohabit with fire risk, showing that for many of them, fire risk is not about the probability of occurrence of a disaster, but a question about when and how the next fire will happen. However, in such a complex scenario, psychological, community, and structural barriers deter people from implementing more effective actions. Conversely, in emergency situations, such barriers are irrelevant and cooperative actions prevail, suggesting the existence of resources and capacities within the community that could lessen exposure and vulnerability if activated on a day-to-day basis. Overall, reducing fire risk cannot be achieved by local communities alone nor without their support. To build, maintain, and consolidate fire prevention actions, it is critical to activate community strengths and cooperation and engage the resources and management capacity of local governments.Sustainability2071-1050 Reuters ISIfire management, intergovernmental panel on climate change, local government, local planning, natural disaster, policy implementation, probability, qualitative analysis, risk assessment, vulnerability, valparaiso
Producción de sueros y vacunas en Chile, la importancia del abastecimiento localIbarra, Cecilia; Parada, MirthaGobernanza e Interfaz Ciencia y Política2020.010.4067/S0716-10182020000400413En Chile, se produjeron vacunas desde fines del siglo XIX hasta inicios del siglo XXI de manera ininterrumpida. La producción se realizó en institutos del Estado, desde donde se abastecía al Servicio de Salud para los programas de vacunación. Además de fabricar, envasar y distribuir vacunas, los institutos del Estado, en particular el Instituto Bacteriológico (IB), exportaron vacunas a Latinoamérica y realizaron investigación y desarrollo, destacándose en este ámbito con la vacuna Fuenzalida-Palacios para el control de la rabia humana y canina. El presente estudio provee un listado de vacunas producidas en Chile en los institutos del Estado entre fines del siglo XIX y el año 2005, y una discusión sobre las visiones del rol de Estado que justificaron las acciones respecto de la producción de vacunas en Chile. El Estado desarrollista de mediados del siglo XX, dio paso al Estado neoliberal que se institucionalizó con la constitución de 1980 definiendo el rol subsidiario que ha guiado la discusión en materia de producción de vacunas locales en las últimas décadas.Revista chilena de infectología0716-1018 Reuters ISIrabies vaccine, animal, chile, dog, human, organization, preventive health service, rabies, academies and institutes, animals, chile, dogs, humans, immunization programs, rabies, rabies vaccines
Recent Near-surface Temperature Trends in the Antarctic Peninsula from Observed, Reanalysis and Regional Climate Model DataBozkurt, D.; Bromwich, D. H.; Carrasco, J; Hines, Keith M.; Maureira, J. C.; Rondanelli, R.Zonas Costeras; Agua y Extremos2020.010.1007/s00376-020-9183-xThis study investigates the recent near-surface temperature trends over the Antarctic Peninsula. We make use of available surface observations, ECMWF’s ERA5 and its predecessor ERA-Interim, as well as numerical simulations, allowing us to contrast different data sources. We use hindcast simulations performed with Polar-WRF over the Antarctic Peninsula on a nested domain configuration at 45 km (PWRF-45) and 15 km (PWRF-15) spatial resolutions for the period 1991-2015. In addition, we include hindcast simulations of KNMI-RACMO21P obtained from the CORDEX-Antarctica domain (~50 km) for further comparisons. Results show that there is a marked windward warming trend except during summer. This windward warming trend is particularly notable in the autumn season and likely to be associated with the recent deepening of the Amundsen/Bellingshausen Sea low and warm advection towards the Antarctic Peninsula. On the other hand, an overall summer cooling is characterized by the strengthening of the Weddell Sea low as well as an anticyclonic trend over the Amundsen Sea accompanied by northward winds. The persistent cooling trend observed at the Larsen Ice Shelf station is not captured by ERA-Interim, whereas hindcast simulations indicate that there is a clear pattern of windward warming and leeward cooling. Furthermore, larger temporal correlations and lower differences exhibited by PWRF-15 illustrate the existence of the added value in the higher spatial resolution simulation.Advances in Atmospheric Sciences0256-1530, 1861-9533 Reuters ISIadded value, amundsen/bellingshausen sea, cloud computing, dynamical downscaling, reanalysis, temperature trend, weddell sea, 宋米荣
An early Holocene westerly minimum in the southern mid-latitudesMoreno, P.I; Henríquez, W.I.; Pesce, O.H.; Henríquez, C.A.; Fletcher, M.S.; Garreaud, R.D.; Villa-Martínez, R.P.Agua y Extremos2021.010.1016/j.quascirev.2020.106730An important coupled ocean-atmospheric system in the mid- and high latitudes involves the Southern Westerly Winds (SWW) and the Southern Ocean (SO), which controls climate in the southernmost third of the world, deep water formation, and ventilation of CO2 from the deep ocean. Most studies have examined its role as a driver of atmospheric CO2 concentrations during glacial terminations, but very few have investigated its influence during the Holocene, i.e. the current interglacial. A fundamental problem, however, is resolving whether the SWW strength increased or declined during the early Holocene (∼11.5–7.5 ka, ka = 1000 cal yr BP) in sectors adjacent to the Drake Passage. Here we assess past changes in SWW influence over the last ∼17,000 years using terrestrial paleoclimate records from southwestern Patagonia (∼52°S). We detect a zonally symmetric Early Holocene Westerly Minimum which diminished wind stress and upwelling on the SO, contributing to a contemporary decline in atmospheric CO2 concentrations and enrichment in the stable carbon isotope ratio of atmospheric CO2 (δ13Catm). Our mid-latitude data also indicate a shift to strong SWW influence at ∼7.5 ka which correlates with a sustained increase in atmospheric CO2 and halt in the δ13Catm rise, suggesting enhancement of high-latitude ocean ventilation by an invigorated SWW-SO coupled system.Quaternary Science Reviews0277-3791 Reuters ISIoceanography, atmospheric systems, co2 concentration, deep-water formation, glacial terminations, ocean ventilations, paleoclimate records, southern westerly winds, stable carbon isotope ratio, carbon dioxide, atmosphere-ocean coupling, carbon isotope ratio, concentration (composition), historical record, holocene, midlatitude environment, paleoclimate, stable isotope, upwelling, westerly, drake passage, patagonia, southern ocean
Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 kaMoreno, Patricio I.; Vilanova, Isabel; Villa-Martínez, Rodrigo P.; Francois, Jean P.Agua y Extremos2018.010.3389/fevo.2018.00034The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S). We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.Frontiers in Ecology and Evolution2296-701X Reuters ISIfire regime, lake sediments, paleoclimate, patagonia, vegetation dynamics
Temporal Variability in Net Primary Production in an Upwelling Area off Central Chile (36°S)Testa, Giovanni; Masotti, Italo; Farías, LauraZonas Costeras2018.010.3389/fmars.2018.00179The temporal variability of Net Primary Production (NPP) off central Chile (36°S, 73°W), an area subjected to seasonal coastal upwelling, was analyzed using monthly in situ 13C incubations within the photic zone, along with bio-oceanographic variables from a fixed time series station; and satellite NPP estimations (NPPE) from the Vertically Generalized Production Model between 2006 and 2015. NPP and NPPE rates varied from 0.03 to 18.29 and from 0.45 to 9.07 g C m−2 d−1, respectively. Both rates were fairly well correlated with each other (r2 = 0.61), but when these data were separated into two periods, higher r2 value was found during winter (r2 = 0.70) with respect to the rest of the year (r2 = 0.24); the latter correlation was partially due to increased weekly NPPE variability during active and relaxed upwelling events. NPP rates along with other biophysical variables allowed for a division of the annual cycle into three distinct periods: September to January (high productivity, mean integrated NPP rates of 4.0 g C m−2 d−1), February to March (intermediate productivity, mean integrated NPP rates of 1.4 g C m−2 d−1), and May to August (basal level, mean integrated NPP rates of 0.5 g C m−2 d−1). NPP appeared to be partially controlled by nutrient inputs, either from upwelling (September-April) and river discharge (May-August), maintaining high NPP rates throughout the entire year, with an annual mean NPP rate of 1.1 kg C m−2 yr−1. In this region, El Niño Southern Oscillation events did not appear to impact the NPP interannual variability.Frontiers in Marine Science2296-7745 Reuters ISIcentral chile, coastal upwelling, el niño southern oscillation, primary production rates, river discharge
Toward High-Resolution Vertical Measurements of Dissolved Greenhouse Gases (Nitrous Oxide and Methane) and Nutrients in the Eastern South PacificTroncoso, Macarena; Garcia, Gerardo; Verdugo, Josefa; Farías, LauraZonas Costeras2018.010.3389/fmars.2018.00148In this study, in situ, real-time and high-resolution vertical measurements of dissolved greenhouse gases (GHGs) such as nitrous oxide (N2O) and methane (CH4) and nutrients are reported for the eastern South Pacific (ESP); a region with marked zonal gradients, ranging from highly productive and suboxic conditions in coastal upwelling systems to oligotrophic and oxygenated conditions in the subtropical gyre. Four high-resolution vertical profiles for gases (N2O and CH4) and nutrients (NO−3 and PO3−4) were measured using a Pumped Profiling System (PPS), connected with a liquid degassing membrane coupled with Cavity Ring-Down Spectroscopy (CRDS) and a nutrient auto-analyzer, respectively. The membrane-CRDS system maintains a linear response over a wide range of gas concentrations, detecting N2O and CH4 levels as low as 0.0774 ± 0.0004 and 0.1011 ± 0.001 ppm, respectively. Continuous profiles for gases and nutrients were similar to those reported throughout the ESP, with pronounced N2O and CH4 peaks at the upper oxycline and at the base of the euphotic zone and pycnocline, respectively, in the coastal zone; but almost constant depth profiles in the subtropical gyre. Additionally, other vertical gas and nutrient structures were observed using continuous sampling, which would not have been detected by discrete sampling. Our results demonstrate that continuous measurements can be a potentially useful methodology for future GHGs cycle studies.Frontiers in Marine Science2296-7745 Reuters ISIcontinuous profiles, eastern south pacific, methane, nitrous oxide, nutrients
The influence of river discharge on nutrient export and phytoplankton biomass off the Central Chile coast (33º-37ºS). Seasonal cycle and interannual variabilityMasotti, Italo; Aparicio-Rizzo, Pilar; Yevenes, Mariela A; Garreaud, Rene; Farias, LauraZonas Costeras2018.010.3389/fmars.2018.00423Using in situ hydro-chemical data and MODIS-SeaWiFS ocean color images as a proxy of river plumes and phytoplankton biomass from 2000 to 2014, this study documents the temporal co-variability of river discharge, plume area, nitrate and phosphate export and phytoplankton biomass in the coastal waters off Central Chile (33º-37ºS). Five major rivers (Maipo, Mataquito, Maule, Itata and Biobío) drain into this region with annual mean discharge ranging from 120 to 1000 m3 s-1. River discharge and coastal plume area present a marked seasonal cycle, reaching maximum values during the winter rainy season (June-September). Export of riverine nutrients also peaks in winter, leading to an increase in phytoplankton biomass within the plumes that can be twice larger than the background values in coastal areas away from the river mouths. Wintertime river discharge, plume area and nutrient export are also correlated at interannual time scales. During a recent extended dry period (2010-2014), river discharges, plume areas and nutrient export clearly decreased by about 50% compared to historical values, reducing significantly the size of the chlorophyll pool within plumes off Central Chile during winter. The potential impacts of droughts are discussed in terms of coastal ecology and primary production, a highly relevant issue considering the projections of a dry climate over Central Chile in the future. Systematic evidence of mega-drought effects upon coastal productivity still does not exist, but it remains a priority to further investigate and quantify these impacts.Frontier in Marine Science2296-774527Thomson Reuters ISIcentral chile, drought, nutrient export, phytoplankton biomass, river discharge, satellite remote sensing
Analysis of exposure to fine particulate matter using passive data from public transportTrewhela, Benjamín; Huneeus, Nicolás; Munizaga, Marcela; Mazzeo, Andrea; Menut, Laurent; Mailler, Sylvain; Valari, Myrto; Ordoñez, CesarCiudades Resilientes2019.010.1016/j.atmosenv.2019.116878The city of Santiago experiences extreme pollution events during winter due to particulate matter and the associated health impact depends on the exposure to this pollutant, particularly to PM2.5. We present and apply a method that estimates the exposure of users of the public transport system of Santiago by combining smart card mobility data with measured surface concentrations from the monitoring network of Santiago and simulated concentrations by the CHIMERE model. The method was applied between July 20th and 24th of 2015 to 105,588 users corresponding to 12% of the frequent users of the public transport system and approximately 2% of the total population of Santiago. During those five days, estimated exposure based on measured concentrations varied between 44 and 75 μg/m3 while exposure based on simulated concentrations varied between 45 and 89 μg/m3. Furthermore, including socioeconomic conditions suggests an inverse relationship between exposure and income when measured concentrations are used, i.e. the lower the income the higher the exposure, whereas no such relationship is observed when using simulated concentrations. Although only exposure to PM2.5 was considered in this study, the method can also be applied to estimate exposure to other urban pollutant such as ozone.Atmospheric Environment1352-2310 Reuters ISIair quality, carrier mobility, inverse problems, smart cards, exposure, extreme pollution events, fine particulate matter, pm2.5, public transport, public transport systems, socio-economic conditions, surface concentration, particles (particulate matter), ozone, air exposure, air quality, concentration (composition), health impact, ozone, particulate matter, public transport, socioeconomic conditions, air monitoring, air pollutant, air quality, article, chile, concentration (parameter), environmental exposure, income, model, particle size, particulate matter, population, priority journal, traffic and transport, urban area
Multidecadal environmental pollution in a mega-industrial area in central Chile registered by tree ringsMuñoz, Ariel A.; Klock-Barría, Karin; Sheppard, Paul R.; Aguilera-Betti, Isabella; Toledo-Guerrero, Isadora; Christie, Duncan A.; Gorena, Tamara; Gallardo, Laura; González-Reyes, Álvaro; Lara, Antonio; Lambert, Fabrice; Gayo, Eugenia; Barraza, Francisco; Chávez, Roberto O.Ciudades Resilientes; Agua y Extremos2019.010.1016/j.scitotenv.2019.133915Science of The Total Environment0048-9697 Reuters ISIair quality, aluminum alloys, pollution control, trace elements, trees (mathematics), baseline, dendrochemistry, industrial pollution, macrocarpa, trace metal, forestry, aluminum, arsenic, cadmium, chromium, cobalt, copper, iron, lead, molybdenum, silver, trace metal, vanadium, zinc, anthropogenic source, concentration (composition), decadal variation, dendrochronology, environmental change, soil pollution, soil quality, trace metal, tree ring, air monitoring, air pollution, air quality, article, biochemistry, chemical composition, chile, comparative study, controlled study, cupressus, cupressus macrocarpa, dendrochemistry, environmental impact, geographic distribution, human activities, industrial area, plant structures, priority journal, temporal analysis, tree ring, chemistry, environmental monitoring, industry, pollution, procedures, tree, chile, cupressus macrocarpa, chile, environmental monitoring, environmental pollution, industry, trees
Holocene glacier fluctuations in Patagonia are modulated by summer insolation intensity and paced by Southern Annular Mode-like variabilityReynhout, Scott A.; Sagredo, Esteban A.; Kaplan, Michael R.; Aravena, Juan Carlos; Martini, Mateo A.; Moreno, Patricio I.; Rojas, Maisa; Schwartz, Roseanne; Schaefer, Joerg M.Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2019.010.1016/j.quascirev.2019.05.029Alpine glaciers are sensitive indicators of changes in climate, and their ubiquity in mountainous regions make them valuable proxies for terrestrial climate reconstructions worldwide. However, the timing and extent of glacier change across the South American mid-latitudes through the Holocene are still poorly constrained relative to their counterparts in the Northern Hemisphere. Here we report a new 10Be surface exposure-based chronology of moraines recording a series of progressively less-extensive glacier advances of Glaciar Torre (Argentina, 49.3°S/73.0°W) since the Last Glacial Maximum, with expansions culminating at 17,600 ± 900, 13,500 ± 500, 9700 ± 400, 6900 ± 200, 6100 ± 300, 4500 ± 200, and 530 ± 60 yr BP. The declining magnitude of Holocene glacier expansions parallels a gradual rise in local summer insolation intensity during the Holocene, while individual advances occurred during inferred negative Southern Annular Mode (SAM)-like states at centennial to millennial timescales. These observations suggest that (i) summer insolation intensity modulated antiphased trends in glacier extent in the polar hemispheres during the Holocene, and that (ii) centennial-scale ‘SAM-like’ temperature and precipitation anomalies paced glacier fluctuations throughout Patagonia. Given the persistence of the inferred ’SAM-like’ anomalies throughout the Holocene, the modern measured trend towards positive SAM index conditions could mark the onset of a fundamental shift in the climate of the Southern Hemisphere midlatitudes that warrants consideration in projections of future climate.Quaternary Science Reviews0277-3791 Reuters ISIexpansion, geomorphology, glacial geology, cosmogenic isotopes, glacial, glaciation, holocenes, paleoclimatology, south america, southern annular mode, incident solar radiation, chronology, geomorphology, glacier advance, holocene, insolation, last glacial maximum, midlatitude environment, mountain region, paleoclimate, precipitation (climatology), reconstruction, southern hemisphere, summer, argentina, patagonia
Inter-annual variability of oceanographic conditions and phytoplankton in Valparaíso Bay (~33°S), central ChileAparicio-Rizzo, Pilar; Masotti, ItaloZonas Costeras2019.010.22370/rbmo.2019.54.1.1495The inter-annual variability of oceanographic conditions and phytoplankton abundance and biomass was studied using 10 years (1986-1996) of in situ observations at a fixed station in Valparaíso Bay (~33ºS). The time series analysis revealed that strong S-SW winds drive a quasi-permanent upwelling activity that maintain the nutrients availability in the water column to fuel the phytoplankton in the bay. The most important changes in bio-oceanographic conditions were observed during 1987 El Niño event, which was characterized by higher temperatures but lower values for salinity, nitrate, and phosphate concentrations, together with a decrease of phytoplankton biomass compared to 1988 La Niña event when colder, saltier, and nutrient-rich upwelled water were observed. High Aconcagua River discharges were observed during the El Niño conditions (1987-1988 and 1993), which led to a decrease in surface salinity and a high abundance of dinoflagellates. Two periods with differences in bio-oceanographic conditions were observed; 1988-1992 showed lower temperatures but higher nutrients (nitrate), phytoplankton biomass and abundance of diatoms than 1993-1996 period. Throughout the study period, positive trends in upwelling activity was registered accompanied by a fall in phytoplankton biomass and dinoflagellate abundance. This paper provides new evidences concerning the influence of El Niño Southern Oscillation (ENSO) in phytoplankton and oceanographic conditions in the coastal upwelling off central Chile.Revista de Biología Marina y Oceanografía0717-3326 Reuters ISIabundance, annual variation, biomass, dinoflagellate, el nino-southern oscillation, environmental factor, phytoplankton, surface temperature, time series analysis, upwelling, aconcagua river, chile, valparaiso bay, valparaiso [chile], bacillariophyta, dinophyceae
The Central Chile Mega Drought (2010–2018): A climate dynamics perspectiveGarreaud, R.; Boisier, J. P.; Rondanelli, R.; Montecinos, A.; Sepúlveda, H.; Veloso‐Aguila, D.Zonas Costeras; Agua y Extremos2020.010.1002/joc.6219Central Chile, home to more than 10 million inhabitants, has experienced an uninterrupted sequence of dry years since 2010 with mean rainfall deficits of 20–40%. The so‐called Mega Drought (MD) is the longest event on record and with few analogues in the last millennia. It encompasses a broad area, with detrimental effects on water availability, vegetation and forest fires that have scaled into social and economical impacts. Observations and reanalysis data reveal that the exceptional length of the MD results from the prevalence of a circulation dipole‐hindering the passage of extratropical storms over central Chile—characterized by deep tropospheric anticyclonic anomalies over the subtropical Pacific and cyclonic anomalies over the Amundsen–Bellingshausen Sea. El Niño Southern Oscillation (ENSO) is a major modulator of such dipole, but the MD has occurred mostly under ENSO‐neutral conditions, except for the winters of 2010 (La Niña) and 2015 (strong El Niño). Climate model simulations driven both with historical forcing (natural and anthropogenic) and observed global SST replicate the south Pacific dipole and capture part of the rainfall anomalies. Idealized numerical experiments suggest that most of the atmospheric anomalies emanate from the subtropical southwest Pacific, a region that has experienced a marked surface warming over the last decade. Such warming may excite atmospheric Rossby waves whose propagation intensifies the circulation pattern leading to dry conditions in central Chile. On the other hand, anthropogenic forcing (greenhouse gases concentration increase and stratospheric ozone depletion) and the associated positive trend of the Southern Annular Mode also contribute to the strength of the south Pacific dipole and hence to the intensity and longevity of the MD. Given the concomitance of the seemingly natural (ocean sourced) and anthropogenic forcing, we anticipate only a partial recovery of central Chile precipitation in the decades to come.International Journal of Climatology0899-8418 Reuters ISIatmospheric pressure, climate change, deforestation, drought, greenhouse gases, mechanical waves, oceanography, ozone layer, rain, tropics, anthropogenic forcing, anticyclonic anomalies, chile, climate model simulations, enso, numerical experiments, south america, stratospheric ozone depletion, climate models, antarctic oscillation, anthropogenic effect, atmospheric dynamics, climate change, climate forcing, drought, el nino-southern oscillation, pacific decadal oscillation, precipitation (climatology), rossby wave, amundsen sea, bellingshausen sea, chile, pacific ocean, pacific ocean (south), pacific ocean (subtropical), southern ocean
Operationalizing the IUCN Red List of Ecosystems in public policyAlaniz, Alberto J.; Pérez‐Quezada, Jorge F.; Galleguillos, Mauricio; Vásquez, Alexis E.; Keith, David A.Cambio de Uso de Suelo2019.010.1111/conl.12665Threats to ecosystems are closely linked to human development, whereas lack, insufficiency, and inefficiency of public policies are important drivers of environmental decline. Previous studies have discussed the contribution of IUCN's Red List of Ecosystems (RLE) in conservation issues; however, its applications in different policy fields and instruments for achieving biodiversity conservation have not been explored in detail. Here, we introduce a framework to operationalize the RLE in public policy, facilitating work of governments, practitioners, and decision makers. Our analysis identified 20 policy instruments that could reduce risks to ecosystems highlighted by different Red List criteria. We discuss how RLE could inform the policy process by analyzing different instruments that could be designed, implemented, and modified to achieve risk reduction. We also present practical examples from around the world showing how ecosystem conservation could be improved by operationalizing the RLE in policy instruments. The RLE criteria can inform the policy process by helping to shape objectives and identifying policy instruments that directly address the causes and severity of risks illuminated in Red List assessments. We conclude that RLE could be expanded into a broader holistic spectrum of policy instruments, which could be a key to achieving the ecosystem conservation.Conservation Letters1755-263X Reuters ISIassessment criteria, conservation planning, ecosystem conservation, land use planning, policy instruments, prioritization, threatened ecosystems
The glass half-empty: climate change drives lower freshwater input in the coastal system of the Chilean Northern PatagoniaAguayo, Rodrigo; León-Muñoz, Jorge; Vargas-Baecheler, José; Montecinos, Aldo; Garreaud, René; Urbina, Mauricio; Soto, Doris; Iriarte, José LuisAgua y Extremos2019.010.1007/s10584-019-02495-6Oceanographic conditions in coastal Chilean northern Patagonia (41–46°S) are strongly influenced by freshwater inputs. Precipitation and streamflow records have shown a marked decrease in this area during the last decades. Given this hydro-climatic scenario, we evaluated the hydrological sensitivity driven by climate change in the Puelo River (average annual streamflow = 640 m³ s⁻¹), one of the most important sources of freshwater in the fjords and inland seas of Chile’s Northern Patagonia. A lumped hydrological model was developed to evaluate the potential impacts of climate change under the Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 scenarios in the near future (2030–2060) using the delta change method based on 25 General Circulation Models. The model was fed by local hydro-meteorological data and remote sensors, simulating well the magnitude and seasonality of Puelo River streamflow. Considering the Refined Index of Agreement (RIA), the model achieved a high performance in the calibration (RIA = 0.79) and validation stages (RIA = 0.78). Under the RCP 8.5 scenario (multi-model mean), the projections suggest that the annual input of freshwater from the Puelo River to the Reloncaví Fjord would decrease by − 10% (1.6 km³ less freshwater); these decreases would mainly take place in summer (~ − 20%) and autumn (~ − 15%). The recurrence of extreme hydroclimatic events is also projected to increase in the future, with the probability of occurrence of droughts, such as the recent 2016 event with the lowest freshwater input in the last 70 years, doubling with respect to the historical records.Climatic Change0165-0009 Reuters ISIclimate models, digital storage, remote sensing, rivers, stream flow, water, general circulation model, historical records, hydrological modeling, index of agreements, meteorological data, oceanographic conditions, probability of occurrence, streamflow records, climate change, climate change, coastal zone, fjord, freshwater input, hydrological modeling, hydrometeorology, satellite sensor, streamflow, patagonia, puelo river
Traits of perch trees promote seed dispersal of endemic fleshy-fruit species in degraded areas of endangered Mediterranean ecosystemsMiranda, Alejandro; Vásquez, Inao A.; Becerra, Pablo; Smith-Ramírez, Cecilia; Delpiano, Cristian A.; Hernández-Moreno, Angela; Altamirano, AdisonCambio de Uso de Suelo2019.010.1016/j.jaridenv.2019.103995The presence and attributes of perch trees in degraded areas may promote seed dispersal. We evaluated the effect of the distance from remnant forest fragments on seed rain of different fleshy-fruit tree species and examined whether the seed rain is favoured by some traits of the perch trees (Acacia caven), such as canopy diameter and tree height. The study was carried out in two localities of central Chile with extensive “espinales” adjacent to remnant fragments of sclerophyllous forest. We installed 210 seed traps under the same number of A. caven trees along 10 transects in the two study areas. We set up the seed traps between 1 and 100 m away from forest fragments. We found a significant negative relationship between seed rain and distance. We also found a positive relationship between seed rain and the height and canopy diameter of the perch tree. Our results suggest that different woody species are able to disperse into the espinal, and that bigger A. caven trees are better perches than smaller individuals. We propose that at distances up to at least 100 m from forest fragments, seed availability does not limit natural regeneration into espinales.Journal of Arid Environments0140-1963 Reuters ISIconiferous tree, endangered species, endemic species, forest ecosystem, fruit, restoration ecology, seed dispersal, seed rain, chile, mediterranean region, acacia caven, aves
Role of the East Asian trough on the eastern Mediterranean temperature variability in early spring and the extreme case of 2004 warm spellBozkurt, Deniz; Ezber, Yasemin; Sen, Omer LutfiTransversal2019.010.1007/s00382-019-04847-5This study investigates the potential influence of the East Asian trough (EAT) on the eastern Mediterranean temperature variability in early spring. In connection with this, it also examines the extreme case of the year 2004 when anomalous warming of the eastern Anatolia resulted in unprecedented snowmelt runoff amounts in the Euphrates and Tigris basins in early March. In the analyses, we used reanalysis data, gridded products of surface temperature and snow cover, river discharge data and satellite imagery. We employed an intensity index for the EAT and a trough displacement index for the Mediterranean trough (MedT) to explore the relationship between the strength of the EAT and the displacement of the MedT at pentad resolution. Our analysis shows that there are statistically significant correlations (at 99% confidence level) between the strength of the EAT and the zonal shift of the MedT on some pentads (e.g., 3rd, 13th, 37th and 59th), but that the highest correlation occurs on the 13th pentad of the year corresponding to the early days of March. It seems that, on this pentad, when the EAT is strong, the MedT tends to be located in the west of its climatological position (about 30−35E ) which causes warmer conditions over the eastern Mediterranean. In 2004, which appears to be an extreme year for this phenomenon, the MedT is positioned and deepened in the central Mediterranean (about 10−15E), and extended towards central Africa during the early days of March. This synoptic pattern provided favorable conditions for the development of a tropical plume/atmospheric river with a southwest-northeast orientation, carrying warm tropical African air towards the eastern Mediterranean and Anatolian highlands resulting in rapid melting of the snowpack as well as severe precipitation, and thus flooding events, in the eastern Anatolia. A key finding in our analysis is that the strengthening of the EAT was instrumental to the increased amplitude of the ridge-trough system over the Euro-Mediterranean region in the early days of 2004 spring. We highlight that the response of surface and upper level meteorological conditions to the amplitude of the ridge-trough system enhanced by the strength of the EAT might be crucial in the understanding of some of the extreme hydrometeorological events in the eastern Mediterranean region.Climate Dynamics0930-7575 Reuters ISIconfidence interval, extreme event, hydrometeorology, river discharge, rossby wave, snowmelt, spring (season), teleconnection, temperature profile, trough, warming, euphrates river, far east, mediterranean sea, mediterranean sea (east), tigris river
Early arboreal colonization, postglacial resilience of deciduous Nothofagus forests, and the Southern Westerly Wind influence in central-east Andean PatagoniaMoreno, P.I.; Simi, E.; Villa-Martínez, R.P.; Vilanova, I.Agua y Extremos2019.010.1016/j.quascirev.2019.06.004The history and dynamics of deciduous Nothofagus forests along the eastern slopes of the central Patagonian Andes (44°-49°S) remain insufficiently studied and understood, particularly at timescales ranging from centuries to millennia. Available fossil pollen records point to time-transgressive responses of the arboreal vegetation to climatic changes during the Last Glacial Termination (T1) and early Holocene, and spatial heterogeneity since then along north-south, east-west, and elevation transects. The degree to which these results represent biogeographic and climatic trends, varying environmental gradients, or site-specific phenomena has not been assessed in detail. Here we present a fossil pollen and macroscopic charcoal record from Lago Churrasco (45°41′S, 71°49′W), a small closed-basin lake located in the deciduous Nothofagus forest zone of the central-east Andes of Chilean Patagonia. Our results suggest that Nothofagus trees colonized newly deglaciated terrains at ∼16,000 cal yr BP and formed scrublands/woodlands several millennia earlier than reported by previous studies east of the Andes. This suggests expansion and local densification of tree populations sourced from the eastern margin of the Patagonian Ice Sheet during the Last Glacial Maximum, with the additional implication that temperature and precipitation conditions favorable for tree survival and reproduction developed early during T1. We posit that the amount of moisture delivered by the Southern Westerly Winds was not a limiting factor for arboreal expansion during T1 in this sector of the central Patagonian Andes. Closed-canopy Nothofagus forests established at ∼10,000 cal yr BP and have remained essentially invariant despite climate change and natural disturbance regimes. This resilience was challenged and exceeded by human disturbance during the 20th century through the use of fire, leading to deforestation and spread of invasive exotic species in an extraordinarily rapid event. Our record suggests a permanent influence of the Southern Westerly Winds over the last 10,000 years, with relatively modest variations at centennial and millennial timescales.Quaternary Science Reviews0277-3791 Reuters ISIcharcoal, deforestation, expansion, glacial geology, environmental gradient, invasive exotic species, last glacial maximum, last glacial terminations, natural disturbance regime, nothofagus forests, southern westerly winds, spatial heterogeneity, climate change, biogeography, climate change, climate variation, colonization, deciduous forest, deforestation, deglaciation, disturbance, fossil record, heterogeneity, last glacial maximum, limiting factor, pollen, postglacial, precipitation (climatology), reproduction, vegetation type, andes, patagonia, nothofagus
The Impacts of Native Forests and Forest Plantation on Water Supply in ChileAlvarez-Garreton, Camila; Lara, Antonio; Boisier, Juan Pablo; Galleguillos, MauricioCambio de Uso de Suelo; Agua y Extremos2019.010.3390/f10060473Over the past 40 years, south-central Chile has experienced important land-use-induced land cover changes, with massive conversion from native forests (NF) to Pinus radiata D.Don and Eucalyptus spp. exotic forest plantations (FP). Several case studies have related this conversion to a reduction in water supply within small catchments (<100 ha). In this work, we explore the impacts of NF and FP on streamflow by using a large-sample catchment dataset recently developed for Chile. We select 25 large forested catchments (>20,000 ha) in south-central Chile (35° S–41° S), analyze their land cover and precipitation spatial distributions, and fit a regression model to quantify the influence of NF, FP, grassland (GRA) and shrubland (SHR) partitions on annual runoff. To assess potential effects of land cover changes on water supply, we use the fitted model (R2 = 0.84) in synthetic experiments where NF, GRA and SHR covers within the catchments are replaced by patches of FP. We show that annual runoff consistently decreases with increments of FP, although the magnitude of the change (ranging from 2.2% to 7.2% mean annual runoff decrease for 10,000 ha increment in FP) depends on several factors, including the initial land cover partition within the basin, the replaced land cover class, the area of the catchment, and the type of catchment (drier or humid). Finally, in the context of the mitigation strategies pledged in the Chilean NDC (Nationally Determined Contributions defined after the Paris Agreement), which include the afforestation of 100,000 ha (mainly native forest) by 2030, we quantify the impacts on water supply due to the afforestation of 100,000 ha with different combinations of NF and FP. We show that annual runoff is highly sensitive to the relative area of FP to NF: ratios of FP to NF areas of 10%, 50% and 90% would lead to 3%, −18% and −40% changes in mean annual runoff, respectively. Our results can be used in the discussion of public policies and decision-making involving forests and land cover changes, as they provide scientifically-based tools to quantify expected impacts on water resources. In particular, this knowledge is relevant for decision making regarding mitigation strategies pledged in the Chilean NDC.Forests1999-4907 Reuters ISIcatchments, decision making, land use, large dataset, reforestation, regression analysis, runoff, chile, forest plantation, grassland, land use and land cover change, native forests, shrublands, water provision, water supply, grassland, land cover, land use change, plantation forestry, runoff, shrubland, streamflow, water supply, chile, decision making, land use, reforestation, regression analysis, runoff, chile, eucalyptus, pinus radiata
A perched, high-elevation wetland complex in the Atacama Desert (northern Chile) and its implications for past human settlementSitzia, Luca; Gayo, Eugenia M.; Sepulveda, Marcela; González, Juan S.; Ibañez, Lucia; Queffelec, Alain; De Pol-Holz, RicardoCiudades Resilientes2019.010.1017/qua.2018.144A previously undocumented type of wetland is described from the Atacama Desert in northern Chile (3000 m above sea level), sustained exclusively by direct precipitation and perched above the regional water table. Geomorphological mapping, pedostratigraphy, geochemistry, and analysis of contemporary vegetation is used to understand wetland formation and dynamics during historical and present time periods. The paleowetland deposits overlie a Miocene tuff that acts as an impermeable barrier to water transfer and creates conditions for local shallow ground water. These deposits include several paleosols that were formed during periods when precipitation increased regionally at 7755–7300, 1270, 545, and 400–300 cal yr BP. The similarity in timing with other palaeohydrological records for the Atacama implies that paleosols from this wetland are proxies for reconstructing past changes in local and regional hydrological cycle. Archaeological investigations have revealed the presence of two small farms from the Late Intermediate period, i.e., during the earliest wetter phase represented by the paleosols. Both farms are located near the paleowetland deposits, which suggests that local inhabitants exploited these water sources during late pre-Hispanic times. Results of this study improve knowledge of settlement patterns during this and earlier cultural periods.Quaternary Research0033-5894 Reuters ISIdeposits, groundwater, sea level, volcanoes, atacama desert, central andes, holocenes, intermediate periods, tuff, volcanic ash, wetlands, formation mechanism, holocene, paleohydrology, paleosol, prehistoric, settlement pattern, tuff, volcanic ash, wetland, andes, atacama desert, chile
Using aboveground vegetation attributes as proxies for mapping peatland belowground carbon stocksLopatin, Javier; Kattenborn, Teja; Galleguillos, Mauricio; Perez-Quezada, Jorge F.; Schmidtlein, SebastianCambio de Uso de Suelo2019.010.1016/j.rse.2019.111217Peatlands are key reservoirs of belowground carbon (C) and their monitoring is important to assess the rapid changes in the C cycle caused by climate change and direct anthropogenic impacts. Frequently, information of peatland area and vegetation type estimated by remote sensing has been used along with soil measurements and allometric functions to estimate belowground C stocks. Despite the accuracy of such approaches, there is still the need to find mappable proxies that enhance predictions with remote sensing data while reducing field and laboratory efforts. Therefore, we assessed the use of aboveground vegetation attributes as proxies to predict peatland belowground C stocks. First, the ecological relations between remotely detectable vegetation attributes (i.e. vegetation height, aboveground biomass, species richness and floristic composition of vascular plants) and belowground C stocks were obtained using structural equation modeling (SEM). SEM was formulated using expert knowledge and trained and validated using in-situ information. Second, the SEM latent vectors were spatially mapped using random forests regressions with UAV-based hyperspectral and structural information. Finally, this enabled us to map belowground C stocks using the SEM functions parameterized with the random forests derived maps. This SEM approach resulted in higher accuracies than a direct application of a purely data-driven random forests approach with UAV data, with improvements of r2 from 0.39 to 0.54, normalized RMSE from 31.33% to 20.24% and bias from −0.73 to 0.05. Our case study showed that: (1) vegetation height, species richness and aboveground biomass are good proxies to map peatland belowground C stocks, as they can be estimated using remote sensing data and hold strong relationships with the belowground C gradient; and (2) SEM is facilitates to incorporate theoretical knowledge in empirical modeling approaches.Remote Sensing of Environment0034-4257 Reuters ISIcarbon, climate change, decision trees, remote sensing, scanning electron microscopy, unmanned aerial vehicles (uav), wetlands, anthropogenic impacts, carbon stocks, floristic compositions, hyperspectral, path models, random forests, structural equation modeling, structural information, vegetation, aboveground biomass, allometry, belowground biomass, carbon sequestration, climate change, mapping method, path analysis, peatland, remote sensing, scanning electron microscopy, spectral analysis, unmanned vehicle, vegetation cover, tracheophyta
Elemental and Mineralogical Composition of the Western Andean Snow (18°S–41°S)Alfonso, Juan A.; Cordero, Raul R.; Rowe, Penny M.; Neshyba, Steven; Casassa, Gino; Carrasco, Jorge; MacDonell, Shelley; Lambert, Fabrice; Pizarro, Jaime; Fernandoy, Francisco; Feron, Sarah; Damiani, Alessandro; Llanillo, Pedro; Sepulveda, Edgardo; Jorquera, Jose; Garcia, Belkis; Carrera, Juan M.; Oyola, Pedro; Kang, Choong-MinCiudades Resilientes2019.010.1038/s41598-019-44516-5The snowpack is an important source of water for many Andean communities. Because of its importance, elemental and mineralogical composition analysis of the Andean snow is a worthwhile effort. In this study, we conducted a chemical composition analysis (major and trace elements, mineralogy, and chemical enrichment) of surface snow sampled at 21 sites across a transect of about 2,500 km in the Chilean Andes (18–41°S). Our results enabled us to identify five depositional environments: (i) sites 1–3 (in the Atacama Desert, 18–26°S) with relatively high concentrations of metals, high abundance of quartz and low presence of arsenates, (ii) sites 4–8 (in northern Chile, 29–32°S) with relatively high abundance of quartz and low presence of metals and arsenates, (iii) sites 9–12 (in central Chile, 33–35°S) with anthropogenic enrichment of metals, relatively high values of quartz and low abundance of arsenates, (iv) sites 13–14 (also in central Chile, 35–37°S) with relatively high values of quartz and low presence of metals and arsenates, and v) sites 15–21 (in southern Chile, 37–41°S) with relatively high abundance of arsenates and low presence of metals and quartz. We found significant anthropogenic enrichment at sites close to Santiago (a major city of 6 million inhabitants) and in the Atacama Desert (that hosts several major copper mines).Scientific Reports2045-2322 Reuters ISI
Elucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic PeninsulaAlarcón-Schumacher, Tomás; Guajardo-Leiva, Sergio; Antón, Josefa; Díez, BeatrizZonas Costeras2019.010.3389/fmicb.2019.01014In Antarctic coastal waters where nutrient limitations are low, viruses are expected to play a major role in the regulation of bloom events. Despite this, research in viral identification and dynamics is scarce, with limited information available for the Southern Ocean (SO). This study presents an integrative-omics approach, comparing variation in the viral and microbial active communities on two contrasting sample conditions from a diatom-dominated phytoplankton bloom occurring in Chile Bay in the West Antarctic Peninsula (WAP) in the summer of 2014. The known viral community, initially dominated by Myoviridae family (∼82% of the total assigned reads), changed to become dominated by Phycodnaviridae (∼90%), while viral activity was predominantly driven by dsDNA members of the Phycodnaviridae (∼50%) and diatom infecting ssRNA viruses (∼38%), becoming more significant as chlorophyll a increased. A genomic and phylogenetic characterization allowed the identification of a new viral lineage within the Myoviridae family. This new lineage of viruses infects Pseudoalteromonas and was dominant in the phage community. In addition, a new Phycodnavirus (PaV) was described, which is predicted to infect Phaeocystis antarctica, the main blooming haptophyte in the SO. This work was able to identify the changes in the main viral players during a bloom development and suggests that the changes observed in the virioplankton could be used as a model to understand the development and decay of blooms that occur throughout the WAP. © 2019 Alarcón-Schumacher, Guajardo-Leiva, Antón and Díez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Frontiers in Microbiology1664-302X Reuters ISIcapsid protein, chlorophyll a, dna polymerase, ribulosebisphosphate carboxylase, rna 16s, transcriptome, algal bloom, alteromonadales, antarctica, article, asfarviridae, bayes theorem, bootstrapping, chlorophyll content, cryptophyta, diatom, dna base composition, environmental factor, flavobacteriales, gammaproteobacteria, gene sequence, genetic correlation, genetic similarity, genome analysis, haptophyta, maximum likelihood method, metagenome, metagenomics, microbial community, monte carlo method, myoviridae, nonhuman, oxygen concentration, phycodnaviridae, phylogeny, population abundance, pseudoalteromonas phage pm2, quality control, rna sequence, rna virus, seasonal variation, single-stranded rna virus, siphoviridae, taxonomy, virus cell interaction, virus identification
FROM THE PACIFIC TO THE TROPICAL FORESTS: NETWORKS OF SOCIAL INTERACTION IN THE ATACAMA DESERT, LATE IN THE PLEISTOCENESantoro, Calogero M.; Gayo, Eugenia M.; Capriles, José M.; Rivadeneira, Marcelo M.; Herrera, Katherine A; Mandakovic, Valentina; Rallo, Mónica; Rech, Jason A.; Cases, Bárbara; Briones, Luis; Olguín, Laura; Valenzuela, Daniela; Borrero, Luis A.; Ugalde, Paula C.; Rothhammer, Francisco; Latorre, Claudio; Szpak, PaulCiudades Resilientes2019.010.4067/S0717-73562019005000602The social groups that initially inhabited the hyper arid core of the Atacama Desert of northern Chile during the late Pleistocene integrated a wide range of local, regional and supra regional goods and ideas for their social reproduction as suggested by the archaeological evidence contained in several open camps in Pampa del Tamarugal (PdT). Local resources for maintaining their every-day life, included stone raw material, wood, plant and animal fibers, game, and fresh water acquired within a radius of -30 km (ca. 1-2 days journey). At a regional scale, some goods were introduced from the Pacific coast (60-80 km to the west, ca. 3-4 days journey), including elongated rounded cobbles used as hammer stones in lithic production, and shells, especially from non-edible species of mollusks. From the Andes (ranging 80-150 km to the east, ca. 5-8 days of journey), they obtained camelid fiber, obsidian and a high-quality chalcedony, in addition to sharing knowledge on projectile point designs (Patapatane and Tuina type forms). Pieces of wood of a tropical forest tree species (Ceiba spp.) from the east Andean lowlands (600 km away, ca. 30 days of journey) were also brought to the PdT. While local goods were procured by the circulation of people within the PdT, the small number of foreign items would have been acquired through some sort of exchange networks that integrated dispersed local communities throughout several ecosystems. These networks may have been a key factor behind the success exhibited by these early hunter-gatherers in the hyper arid ecosystems of the Atacama Desert at the end of the Pleistocene. Different lines of archaeological evidence including open camps, workshop-quarries, lithic artifacts, archaeofaunal remains, plant and animal fibers and textiles, archaeobotanical remains, and paleoecological data show that people of the PdT managed a wide range of cultural items from the Pacific coast, the Andean highland and the tropical forest, that were integrated with resources gathered locally within the socio-cultural systems established by the end of the Pleistocene. These results are interpreted as material expressions of multi-scalar networking for resource management and other social material and immaterial requirements, which in other words, means that these people were actively connected to regional (coastal and highland), and supra-regional (trans-Andean) exchange networks from and out of the PdT.Chungará (Arica)0717-7356 Reuters ISIandes, andes, atacama desert, bosque tropical, costa del pacífico, desierto de atacama, local, pacific coast, redes de interacción locales, regional and pan-andean networks of interaction, regionales y pan-andinas, tropical forest
Dietary diverstiy in the Atacama desert during the Late intermediate period of northern ChileAlfonso-Durruty, Marta P.; Gayo, Eugenia M.; Standen, Vivien; Castro, Victoria; Latorre, Claudio; Santoro, Calogero M.; Valenzuela, DanielaCiudades Resilientes2019.010.1016/j.quascirev.2019.04.022The Pacific Ocean that flanks the hyperarid Atacama Desert of Northern Chile is one of the richest biomass producers around the world. Thus, it is considered a key factor for the subsistence of prehistoric societies (including mixed-economy groups), that inhabited its coastal ecosystems as well as the neighboring inland areas. This study assesses the Arica Culture groups' diet (Late Intermediate Period; 1000–1530 CE), through stable isotope (on bone-collagen; δ 13 C and δ 15 N)and dental pathology data. Seventy-seven (n = 77)individuals from two inland (LLU54 and AZ8)and one coastal (CAM8)archaeological sites were studied. Results show an important, but lower than predicted by earlier studies, contribution of marine resources in the diet of all three groups. Dental pathologies and stable isotopes indicate that these groups' diet varied in correlation with their distance to the Pacific Ocean as well as group and individual preferences. The results challenge the idea that Arica Culture groups depended heavily on marine resources for their subsistence. In contrast, this study shows both that the Arica Culture groups’ diet was diverse, and that the terrestrial resources consumed were mostly contributed by C 3 /CAM plants instead of maize.Quaternary Science Reviews0277-3791 Reuters ISIecosystems, isotopes, landforms, marine biology, natural resources, pathology, archaeological site, atacama desert, coastal ecosystems, individual preference, intermediate periods, marine resources, stable isotopes, terrestrial resources, oceanography, archaeology, biomass, marine resource, pathology, prehistoric, stable isotope, atacama desert, chile, pacific ocean, zea mays
Summertime precipitation deficits in the southern Peruvian highlands since 1964Imfeld, Noemi; Barreto Schuler, Christian; Correa Marrou, Kris Milagros; Jacques‐Coper, Martín; Sedlmeier, Katrin; Gubler, Stefanie; Huerta, Adrian; Brönnimann, StefanZonas Costeras2019.010.1002/joc.6087Precipitation deficits remain a concern to the rural population in the southern Peru-vian highlands and knowledge about their occurrence is lacking because of scarcedata availability. For mountainous regions with sparse station networks, reanalysescan provide valuable information; however, known limitations in reproducing pre-cipitation are aggravated due to unresolved topographical effects. In this study, weassess in a first step the representation of precipitation during the rainy season(January–February–March) in seven reanalysis data sets in comparison to a newlygenerated gridded precipitation data set for Peru. In a second step, we assess sum-mer precipitation deficits in Peru during the second half of the 20th century.In the reanalyses data sets, we find biases strongly influenced by the topography ofthe models and low correlations for the rainy season. Thus, reanalyses do not solvethe problem of data scarcity for this region either. Furthermore, we confirm that ElNiño is not a sufficient stratification criterion for precipitation deficits during therainy season (JFM) in the southern Peruvian highlands. Based on observationalrecords and reanalyses, a considerable fraction of inter-annual variability of precipi-tation can be explained through upper-tropospheric zonal wind anomalies. Westerlywind anomalies, often related to the warming of the troposphere during an El Niñoevent, lead to dry conditions, but not all El Niño events produce these westerly windanomalies. Atmospheric simulations indicate differences between precipitation defi-cits in central Pacific and eastern Pacific El Niño flavours, which cannot beaddressed in observations due to reduced record length: Droughts in the southernPeruvian Andes during eastern Pacific El Niño events seem to be related to a stron-ger warming in the troposphere above the central Pacific ocean, whereas this is notthe case for droughts during central Pacific El Niño events. These results, however,need to be further corroborated by model studies and palaeoclimatological research.International Journal of Climatology0899-8418 Reuters ISIdrought, rain, topography, troposphere, atmospheric simulations, enso, interannual variability, mountain, peru, precipitation deficits, reanalysis, topographical effects, population statistics, annual variation, atmospheric modeling, data assimilation, drought, el nino-southern oscillation, mountain region, precipitation (climatology), rainfall, summer, peru
Assessing Snow Accumulation Patterns and Changes on the Patagonian IcefieldsBravo, Claudio; Bozkurt, Deniz; Gonzalez-Reyes, Álvaro; Quincey, Duncan J.; Ross, Andrew N.; Farías-Barahona, David; Rojas, MaisaGobernanza e Interfaz Ciencia y Política; Transversal2019.010.3389/fenvs.2019.00030Recent evidence shows that most Patagonian glaciers are receding rapidly. Due to the lack of in situ long-term meteorological observations, the understanding of how glaciers are responding to changes in climate over this region is extremely limited, and uncertainties exist in the glacier surface mass balance model parameterizations. This precludes a robust assessment of glacier response to current and projected climate change. An issue of central concern is the accurate estimation of precipitation phase. In this work, we have assessed spatial and temporal patterns in snow accumulation in both the North Patagonia Icefield (NPI) and South Patagonia Icefield (SPI). We used a regional climate model, RegCM4.6 and four Phase Partitioning Methods (PPM) in addition to short-term snow accumulation observations using ultrasonic depth gauges (UDG). Snow accumulation shows that rates are higher on the west side relative to the east side for both icefields. The values depend on the PPM used and reach a mean difference of 1,500 mm w.e., with some areas reaching differences higher than 3,500 mm w.e. These differences could lead to divergent mass balance estimations depending on the scheme used to define the snow accumulation. Good agreement is found in comparing UDG observations with modeled data on the plateau area of the SPI during a short time period; however, there are important differences between rates of snow accumulation determined in this work and previous estimations using ice core data at annual scale. Significant positive trends are mainly present in the autumn season on the west side of the SPI, while on the east side, significant negative trends in autumn were observed. Overall, for the rest of the area and during other seasons, no significant changes can be determined. In addition, glaciers with positive and stable elevation and frontal changes determined by previous works are related to areas where snow accumulation has increased during the period 2000–2015. This suggests that increases in snow accumulation are attenuating the response of some Patagonian glaciers to warming in a regional context of overall glacier retreat.Frontiers in Environmental Science2296-665X Reuters ISIglacier mass-balance, patagonian icefields, regional climate model, snow accumulation, snow trends
Spatial congruence among indicators of recovery completeness in a Mediterranean forest landscape: Implications for planning large-scale restorationAltamirano, Adison; Miranda, Alejandro; Meli, Paula; Dehennin, Joris; Muys, Bart; Prado, Marco; Catalán, Germán; Smith-Ramírez, Cecilia; Bustamante-Sánchez, Marcela; Lisón, Fulgencio; María Rey-Benayas, JoséCambio de Uso de Suelo2019.010.1016/j.ecolind.2019.03.046Natural regeneration has been proposed as a cost-effective forest restoration approach for both small and largescale initiatives. However, attributes for assessing the success of forest restoration through natural regeneration may vary among them in spatial patterns depending on the scale of analysis and on environmental gradients. Here we analysed the spatial patterns of recovery completeness (i.e. how similar attributes in restored forests are to the same attributes in reference forests) in response to environmental factors in a Mediterranean forest landscape of Central Chile. We evaluated (1) forest recovery completeness using basal area (BA), quadratic mean diameter (QMD), adult species density (ASD), adult species richness (ASR), and seedling species richness (SSR); (2) the spatial congruence of recovery completeness estimated by each of these indicators; and (3) the environmental factors potentially shaping these spatial patterns. We used field measurements and geospatial information sources to quantify and predict indicator responses by fitting boosted regression tree models. To assess the spatial congruence of predictions we overlaid high-level recovery completeness values for all indicators. Overall recovery completeness in the study area was 72.7%, suggesting positive prospects for attaining fully restored forests. Recovery completeness had a resulted higher for diversity (92.3%−99.6%) than structural forest attributes (33.5%−76.9%); however, spatial congruence among recovery indicators was low due to the uneven spatial responses of each indicator. The maximum potential spatial congruence was<10%, and was predicted only by two environmental variables (soil bulk density and slope). Our results suggest that low spatial congruence among forest recovery indicators may hinder the monitoring of restoration at large scales. The implications of such divergence in defining restoration success can be enormous given the current global challenge of forest restoration. Although our research was tested in a threatened region of global importance, our results may have wider significance for restoration planning providing cautionary notes and recommendations for the appropriate use of forest recovery indicators when monitoring large-scale restoration projects.Ecological Indicators1470-160X Reuters ISIcost effectiveness, recovery, reforestation, restoration, boosted regression trees, environmental gradient, environmental variables, forest restoration, geo-spatial informations, natural regeneration, quadratic mean diameter, vegetation recovery, conservation, basal area, diameter, forest ecosystem, mediterranean environment, plantation, regeneration, restoration ecology, seedling emergence, spatial analysis, species richness, chile
A late Pleistocene human footprint from the Pilauco archaeological site, northern Patagonia, ChileMoreno, Karen; Bostelmann, Juan Enrique; Macías, Cintia; Navarro-Harris, Ximena; De Pol-Holz, Ricardo; Pino, MarioCambio de Uso de Suelo2019.010.1371/journal.pone.0213572The present study describes the discovery of a singular sedimentary structure corresponding to an ichnite that was excavated at the paleo-archaeological site Pilauco (Osorno, Chile). The trace fossil is associated with megafauna bones, plant material and unifacial lithic tools. Here we present a detailed analysis of the Pilauco ichnite and associated sedimentary structures, as well as new radiocarbon data. The ichnological analysis confidently assigns the trace to the ichnospecies Hominipes modernus—a hominoid footprint usually related to Homo sapiens. Some particular characteristics of the Pilauco trace include an elongated distal hallux, lateral digit impressions obliterated by the collapsed sediment, and sediment lumps inside and around the trace. In order to evaluate the origin of the ichnite, trackmaking experiments are performed on re-hydrated fossil bed sediments. The results demonstrate that a human agent could easily generate a footprint morphology equivalent to the sedimentary structure when walking on a saturated substrate. Based on the evidence, we conclude that the trackmaker might well have been a bare-footed adult human. This finding, along with the presence of lithic artifacts in the same sedimentary levels, might represent further evidence for a pre-Clovis South American colonization of northern Patagonia, as originally proposed for the nearby Monte Verde site.PLOS ONE1932-6203 Reuters ISIcarbon 14, adult, ape, article, artifact, chile, demography, digit (body part), foot, fossil, hallux, human, morphology, radiometric dating, sedimentology, stratigraphy, walking speed, animal, archeology, fossil, hominid, sediment, animals, archaeology, chile, foot, fossils, geologic sediments, hominidae, humans
A Harmonized Nitrous Oxide (N2O) Ocean Observation Network for the 21st CenturyBange, Hermann W.; Arévalo-Martínez, Damian L.; de la Paz, Mercedes; Farías, Laura; Kaiser, Jan; Kock, Annette; Law, Cliff S.; Rees, Andrew P.; Rehder, Gregor; Tortell, Philippe D.; Upstill-Goddard, Robert C.; Wilson, Samuel T.Zonas Costeras2019.010.3389/fmars.2019.00157Nitrous oxide (N2O) is an important atmospheric trace gas involved in tropospheric warming and stratospheric ozone depletion. Estimates of the global ocean contribution to N2O emissions average 21% (range: 10 to 53%). Ongoing environmental changes such as warming, deoxygenation and acidification are affecting oceanic N2O cycling and emissions to the atmosphere. International activities over the last decades aimed at improving estimates of global N2O emissions, including (i) the MarinE MethanE and NiTrous Oxide database (MEMENTO) for archiving of quality-controlled data, and (ii) a recent large-scale inter-laboratory comparison by Working Group 143 of the Scientific Committee on Ocean Research (SCOR). To reduce uncertainties in oceanic N2O emission estimates and to characterize the spatial and temporal variability in N2O distributions in a changing ocean, we propose the establishment of a harmonized N2O Observation Network (N2O-ON) combining discrete and continuous data from various platforms. The network will integrate observations obtained by calibrated techniques, using time series measurements at fixed stations and repeated hydrographic sections on voluntary observing ships and research vessels. In addition to exploiting existing oceanographic infrastructure, we propose the establishment of central calibration facilities in selected international laboratories to improve accuracy, and ensure standardization and comparability of N2O measurements. Final data products will include a harmonized global N2O concentration and emission fields for use in model validation and projections of future oceanic N2O emissions, to inform the global research community and policy makers.Frontiers in Marine Science2296-7745 Reuters ISIcalibration, nitrous oxide, observation network, oceanic distribution, oceanic emissions
In-stream wetland deposits, megadroughts, and cultural change in the northern Atacama Desert, ChileTully, Craig D.; Rech, Jason A.; Workman, T. Race; Santoro, Calogero M.; Capriles, José M.; Gayo, Eugenia M.; Latorre, ClaudioCiudades Resilientes2019.010.1017/qua.2018.122A key concern regarding current and future climate change is the possibility of sustained droughts that can have profound impacts on societies. As such, multiple paleoclimatic proxies are needed to identify megadroughts, the synoptic climatology responsible for these droughts, and their impacts on past and future societies. In the hyperarid Atacama Desert of northern Chile, many streams are characterized by perennial flow and support dense in-stream wetlands. These streams possess sequences of wetland deposits as fluvial terraces that record past changes in the water table. We mapped and radiocarbon dated a well-preserved sequence of in-stream wetland deposits along a 4.3-km reach of the Río San Salvador in the Calama basin to determine the relationship between regional climate change and the incision of in-stream wetlands. The Río San Salvador supported dense wetlands from 11.1 to 9.8, 6.4 to 3.5, 2.8 to 1.3, and 1.0 to 0.5 ka and incised at the end of each of these intervals. Comparison with other in-stream wetland sequences in the Atacama Desert, and with regional paleoclimatic archives, indicates that in-stream wetlands responded similarly to climatic changes by incising during periods of extended drought at ~9.8, 3.5, 1.3, and 0.5 ka.Quaternary Research0033-5894 Reuters ISIdeposits, drought, groundwater, wetlands, atacama, atacama desert , chile, chile, climatic changes, cultural changes, megadroughts, regional climate changes, synoptic climatology, climate change, climate variation, climatology, cultural change, drought, fluvial deposit, paleoclimate, wetland, atacama desert, chile
Emergence of robust precipitation changes across crop production areas in the 21st centuryRojas, Maisa; Lambert, Fabrice; Ramirez-Villegas, Julian; Challinor, Andrew J.Ciudades Resilientes; Gobernanza e Interfaz Ciencia y Política2019.010.1073/pnas.1811463116A warming climate will affect regional precipitation and hence food supply. However, only a few regions around the world are currently undergoing precipitation changes that can be attributed to climate change. Knowing when such changes are projected to emerge outside natural variability—the time of emergence (TOE)—is critical for taking effective adaptation measures. Using ensemble climate projections, we determine the TOE of regional precipitation changes globally and in particular for the growing areas of four major crops. We find relatively early (<2040) emergence of precipitation trends for all four crops. Reduced (increased) precipitation trends encompass 1–14% (3–31%) of global production of maize, wheat, rice, and soybean. Comparing results for RCP8.5 and RCP2.6 clearly shows that emissions compatible with the Paris Agreement result in far less cropped land experiencing novel climates. However, the existence of a TOE, even under the lowest emission scenario, and a small probability for early emergence emphasize the urgent need for adaptation measures. We also show how both the urgency of adaptation and the extent of mitigation vary geographically.Proceedings of the National Academy of Sciences0027-8424 Reuters ISIarticle, climate change, crop production, france, maize, nonhuman, precipitation, probability, rice, soybean, wheat, adaptation, biological model, crop, growth, development and aging, adaptation, physiological, climate change, crop production, crops, agricultural, models, biological
Anthropogenic drying in central-southern Chile evidenced by long-term observations and climate model simulationsBoisier, Juan P.; Alvarez-Garretón, Camila; Cordero, Raúl R.; Damiani, Alessandro; Gallardo, Laura; Garreaud, René D.; Lambert, Fabrice; Ramallo, Cinthya; Rojas, Maisa; Rondanelli, RobertoCiudades Resilientes; Zonas Costeras; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2018.010.1525/elementa.328The socio-ecological sensitivity to water deficits makes Chile highly vulnerable to global change. New evidence of a multi-decadal drying trend and the impacts of a persistent drought that since 2010 has affected several regions of the country, reinforce the need for clear diagnoses of the hydro-climate changes in Chile. Based on the analysis of long-term records (50+ years) of precipitation and streamflow, we confirm a tendency toward a dryer condition in central-southern Chile (30–48°S). We describe the geographical and seasonal character of this trend, as well as the associated large-scale circulation pat- terns. When a large ensemble of climate model simulations is contrasted to observations, anthropogenic forcing appears as the leading factor of precipitation change. In addition to a drying trend driven by greenhouse gas forcing in all seasons, our results indicate that the Antarctic stratospheric ozone deple- tion has played a major role in the summer rainfall decline. Although average model results agree well with the drying trend’s seasonal character, the observed change magnitude is two to three times larger than that simulated, indicating a potential underestimation of future projections for this region. Under present-day carbon emission rates, the drying pathway in Chile will likely prevail during the next decades, although the summer signal should weaken as a result of the gradual ozone layer recovery. The trends and scenarios shown here pose substantial stress on Chilean society and its institutions, and call for urgent action regarding adaptation measures.Elementa: Science of the Anthropocene2325-1026 Reuters ISIanthropogenic effect, carbon emission, climate modeling, drought, greenhouse gas, long-term change, ozone depletion, simulation, streamflow, trend analysis, vulnerability, chile
Anthropocene and streamflow: Long-term perspective of streamflow variability and water rightsBarria, Pilar; Rojas, Maisa; Moraga, Pilar; Muñoz, Ariel; Bozkurt, Deniz; Alvarez, CamilaAgua y Extremos; Gobernanza e Interfaz Ciencia y Política; Transversal2019.010.1525/elementa.340Since 1981, water allocation in Chile has been based on a water use rights (WURs) market, with limited regulatory and supervisory mechanisms. The volume to be granted as permanent and eventual WURs is calculated from streamflow records, if stream gauge data are available, or from hydrologic parameter transfer from gauged to ungauged catchments, usually with less than 50 years of record. To test the per- formance of this allocation system, while analyzing the long-term natural variability in water resources, we investigated a 400 year-long (1590–2015) tree-ring reconstruction of runoff and historical water rights for Perquilauquén at Quella catchment, a tributary to the Maule River in Central Chile (35°S–36°30S). Furthermore, we assess how the current legislation would perform under a projected climate scenario, based on historical climate simulations of runoff calibrated against observed data, and future projections. Our analyses indicate that the allocation methodology currently applied by the Water Authority in Chile is very sensitive to the time window of data used, which leads to an underestimation of variability and long-term trends. According to the WURs database provided by the Chilean Water Directorate, WURs at Perquilauquén at Quella are already over-allocated. Considering regional climate projections, this condition will be exacerbated in the future. Furthermore, serious problems regarding the access and quality of infor- mation on already-granted WURs and actual water usage have been diagnosed, which further encumber environmental strategies to deal with and adapt to climate change. We emphasize the urgent need for a review and revision of current water allocation methodologies and water law in Chile, which are not concordant with the dynamics and non-stationarity of hydrological processes. Water scarcity and water governance are two of the key issues to be faced by Chile in the Anthropocene.Elementa: Science of the Anthropocene2325-1026 Reuters ISIanthropocene, catchment, database, human rights, hydrological regime, planning legislation, regional climate, regulatory framework, streamflow, tributary, water resource, water use efficiency, chile, maule, maule river
What is the ‘Social’ in Climate Change Research? A Case Study on Scientific Representations from ChileBilli, Marco; Blanco, Gustavo; Urquiza, AnahíCiudades Resilientes; Gobernanza e Interfaz Ciencia y Política2019.010.1007/s11024-019-09369-2Over the last few decades climate change has been gaining importance in international scientifc and political debates. However, the social sciences, especially in Latin America, have only lately become interested in the subject and their approach is still vague. Scientifc understanding of global environmental change and the process of designing public policies to face them are characterized by their complexity as well as by epistemic and normative uncertainties. This makes it necessary to problematize the way in which research eforts understand ‘the social’ of climate change. How do ‘the climate’ and ‘the social’ interpenetrate as scientifc objects? What does the resulting feld look like? Is the combination capable of promoting refexivity and collaboration on the issue, or does it merely become dispersed with difuse boundaries? Our paper seeks to answer these and other related questions using Chile as a case study and examining peer-reviewed scientifc research on the topic. By combining in-depth qualitative content analysis of each paper with a statistical meta-analysis, we were able to: characterize the key content and forms of such literature; identify divisions and patterns within it; and, discuss some factors and trends that may help explain these. We conclude that the literature displays two competing trends: while it is inclined to become fragmented beyond the scope of the ‘mitigation’ black box, it also tends to cluster along the lines of methodological distinctions traditionally contested within the social sciences. This, in turn, highlights the persistence of disciplinary divisions within an allegedly interdisciplinary feld.Minerva0026-4695 Reuters ISIchile, climate change, literature meta-analysis, scientific black boxes, scientific representations, social dimensions
Extreme ENSO-driven torrential rainfalls at the southern edge of the Atacama Desert during the Late Holocene and their projection into the 21th centuryOrtega, Cristina; Vargas, Gabriel; Rojas, Maisa; Rutllant, José A.; Muñoz, Práxedes; Lange, Carina B.; Pantoja, Silvio; Dezileau, Laurent; Ortlieb, LucGobernanza e Interfaz Ciencia y Política2019.010.1016/j.gloplacha.2019.02.011Extreme precipitation events and multi-annual droughts, especially in arid to semi-arid subtropical regions, are among the most critical El Niño Southern Oscillation (ENSO) and global climate change impacts. Here, we assess the variability of torrential rainfall during the Late Holocene and its projection into the 21st century at the southern edge of the hyperarid Atacama Desert. The analysis of historical data since the beginning of the 20th century reveals that most (76.5%) alluvial disasters in the southern Atacama Desert (26–30°S) have resulted from extreme rainfall events occurring between March and September under El Niño conditions, and more frequently during the warm phase of the Pacific Decadal Oscillation. Particular rainfall events under these ocean-climate conditions are associated with the convective phase of the Madden-Julian Oscillation (MJO) near the central-equatorial Pacific, resulting in warmer sea surface temperature (SST) there and in the triggering of persistent/intense Pacific South America (PSA) tropical-extratropical teleconnection patterns which result in blocking of the westerly flow at high latitudes and the subsequent deviation of storm tracks towards central-northern Chile. On a longer timescale, marine sediments from Tongoy Bay (30°S) reveal an increasing trend of stronger runoff by torrential coastal rain since ca. 3500 cal yr BP and even stronger heavy rainfall since ca. 1700 cal yr BP. Highly variable coastal sea surface temperatures in the same time span deduced from the sedimentary record can be explained by intensified southerly winds in connection with stronger alongshore pressure gradients and reduced coastal low-cloud cover. Both storm intensification and increased intensity of upwelling-favorable winds point to a variable climate conditioned by strengthened interannual ENSO and interdecadal ENSO-like variability during the Late Holocene. Climate projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5) indicate a reduction in annual precipitation of 15–30% during the current century, together with an intensification of the storms, such as the alluvial disaster on March 25, 2015 in Atacama. © 2019 Elsevier B.V.Global and Planetary Change0921-8181 Reuters ISIatmospheric pressure, atmospheric temperature, climate change, disasters, landforms, oceanography, oscillating flow, rain, storms, submarine geology, submarine geophysics, surface properties, surface waters, tropics, atacama desert, cmip5, extreme rainfall, pacific decadal oscillation, southern oscillation, teleconnection patterns, climate models, climate change, cloud cover, cmip, drought, el nino-southern oscillation, global climate, holocene, pressure gradient, rainfall, runoff, sea surface temperature, snowstorm, teleconnection, torrent, twenty first century, atacama desert, chile, coquimbo, pacific ocean, pacific ocean (south), tongoy bay
Enredando bosques y comunidades: territorialización de REDD+ en el ejido Felipe Carrillo Puerto, MéxicoTobasura Morales, David; Gurri, Francisco D.; Blanco Wells, Gustavo; Schmook, BirgitGobernanza e Interfaz Ciencia y Política2019.010.11144/Javeriana.cdr15-81.ebctAnalizamos los efectos discursivos y relacionales del proyecto piloto Reducción de Emisiones por Deforestación y Degradación (REDD+) en unidades domésticas con y sin derechos de acceso a la tierra en el ejido Felipe Carrillo Puerto, Quintana Roo. A partir de encuestas y entrevistas semiestructuradas, identificamos dispositivos que favorecen la adopción de prácticas de conservación por parte de los ejidatarios propietarios de la tierra, pero que restringen el manejo forestal tradicional. Estas dinámicas generan cambios en las estrategias de subsistencia de las unidades domésticas y limitan la participación y distribución de beneficios a mujeres, jóvenes y avecindados sin propiedad de la tierra.Cuadernos de Desarrollo Rural0122-1450 Reuters ISIadaptative strategies, environmental policies, redd+, use and access to forests
Monsoon Responses to Climate Changes—Connecting Past, Present and FutureSeth, Anji; Giannini, Alessandra; Rojas, Maisa; Rauscher, Sara A.; Bordoni, Simona; Singh, Deepti; Camargo, Suzana J.Gobernanza e Interfaz Ciencia y Política2019.010.1007/s40641-019-00125-yPurpose of Review: Knowledge of how monsoons will respond to external forcings through the twenty-first century has been confounded by incomplete theories of tropical climate and insufficient representation in climate models. This review highlights recent insights from past warm climates and historical trends that can inform our understanding of monsoon evolution in the context of an emerging energetic framework. Recent Findings: Projections consistent with paleoclimate evidence and theory indicate expanded/wetter monsoons in Africa and Asia, with continued uncertainty in the Americas. Twentieth century observations are not congruent with expectations of monsoon responses to radiative forcing from greenhouse gases, due to the confounding effect of aerosols. Lines of evidence from warm climate analogues indicate that while monsoons respond in globally coherent and predictable ways to orbital forcing and inter-hemispheric thermal gradients, there are differences in response to these forcings and also between land and ocean. Summary: Further understanding of monsoon responses to climate change will require refinement of the energetic framework to incorporate zonal asymmetries and the use of model hierarchies. © 2019, Springer Nature Switzerland AG.Current Climate Change Reports2198-6061 Reuters ISIclimate changes, global warming, monsoons, paleomonsoons
Strongest MJO on Record Triggers Extreme Atacama Rainfall and Warmth in AntarcticaRondanelli, R.; Hatchett, B.; Rutllant, J.; Bozkurt, D.; Garreaud, R.Zonas Costeras; Agua y Extremos; Transversal2019.010.1029/2018GL081475Tropical perturbations have been shown theoretically and observationally to excite long range atmospheric responses in the form of Rossby wave teleconnections that result from the equator to pole gradient of planetary vorticity. An extreme teleconnection event occurred during March 2015 in the Southeastern Pacific. As a result, extreme high temperatures were observed in Southwestern South America and the Antarctic Peninsula simultaneously with an extreme rainfall and flood event in the hyperarid Atacama desert.%%%%%%We show that the origin of these seemingly disconnected extreme events can be traced to a Rossby wave response to the strongest Madden‐Julian Oscillation (MJO) on record in the tropical central Pacific. A barotropic wavenumber 3 to 4 perturbation with group velocity between 15 to 30 m/s is consistent with the trajectory and timing followed by the upper level anomalies radiating away from the tropics after the MJO episode.Geophysical Research Letters0094-8276 Reuters ISIflood control, floods, mechanical waves, oil well flooding, rain, tropics, antarctic peninsula, antarctica, atmospheric response, climate dynamics, extremes, madden-julian oscillation, rossby wave, rossby wave response, climatology, air-sea interaction, barotropic wave, climate change, extreme event, flood, flooding, high temperature, madden-julian oscillation, rainfall, rossby wave, teleconnection, wave velocity, antarctic peninsula, antarctica, atacama desert, chile, pacific ocean, pacific ocean (central), pacific ocean (southeast), south america, west antarctica
Centennial‐Scale SE Pacific Sea Surface Temperature Variability Over the Past 2,300 YearsCollins, James A.; Lamy, Frank; Kaiser, Jérôme; Ruggieri, Nicoletta; Henkel, Susann; De Pol‐Holz, Ricardo; Garreaud, René; Arz, Helge W.Cambio de Uso de Suelo; Agua y Extremos2019.010.1029/2018PA003465Detailed temperature reconstructions over the past 2,000 years are important for contextualizing modern climate change. The midlatitude SE Pacific is a key region in this regard in terms of understanding the climatic linkages between the tropics and southern high latitudes. Multicentennial timescale temperature variability remains, however, poorly understood, due to a lack of long, high-temporal-resolution temperature records from this region and from the southern high latitudes in general. We present a unique alkenone sea surface temperature (SST) record from 44°S on the southern Chilean margin in the SE Pacific spanning the last 2,300 years at decadal resolution. The record displays relatively large changes including a cooling transition from 14 to 12.5 °C between 1,100 and 600 cal yr BP, in line with other Chile margin SST records and coeval with Antarctic cooling. This cooling is attributable to reduced Southern Ocean deep convection, driven by a late Holocene sea-ice increase in the Weddell Sea associated with increased El-Niño Southern Oscillation variability. Superimposed on the late Holocene cooling, we observe multicentennial timescale SST variability, including relatively cool SSTs (12.5 °C) from 950 to 500 cal yr BP, corresponding to the Medieval Climate Anomaly, and warmer SSTs (13 °C) from 500 to 200 cal yr BP, corresponding to the Little Ice Age. These oscillations may reflect either multicentennial internal variability of the Southern Ocean deep convection and/or multicentennial variability in the phasing of El-Niño Southern Oscillation and Southern Annular Mode events. ©2019. American Geophysical Union. All Rights Reserved.Paleoceanography and Paleoclimatology2572-4517 Reuters ISIclimate change, convection, cooling, el nino-southern oscillation, holocene, medieval warm period, reconstruction, sea ice, sea surface temperature, pacific ocean, pacific ocean (southeast), southern ocean, weddell sea
A vertical forest within the forest: millenary trees from the Valdivian rainforest as biodiversity hubsTejo, Camila F.; Fontúrbel, Francisco E.Cambio de Uso de Suelo2019.010.1002/ecy.2584Alerce (Fitzroya cupressoides (Molina) I.M. Johnst., Cupressaceae), known as Lahuan by the Mapuche people, is the most iconic endemic conifer of southern Chile and adjacent Argentina (Fig. 1). It can reach monumental dimensions (up to 5 m in diameter and over 50 m in height) and has remarkable longevity (Lara et al. 1999, Clement et al. 2001, Donoso‐Zeggers 2006, Urrutia‐Jalabert et al. 2015). The oldest alerce tree recorded is over 3,600 years old, making this species the second longest‐lived tree in the world after the North American Bristlecone pine (Pinus longaeva D. K. Bailey) (Lara and Villalba 1993).Ecology0012-9658 Reuters ISIanthropogenic effect, biodiversity, biota, coniferous tree, endangered species, forest canopy, forest ecosystem, rainforest, red list, temperate forest, tree, argentina, chile, los rios [chile], valdivia, biodiversity, forest, rain forest, tree, tropic climate, biodiversity, forests, rainforest, trees, tropical climate
Assessment of soil physical properties' statuses under different land covers within a landscape dominated by exotic industrial tree plantations in south-central ChileSoto, L.; Galleguillos, M.; Seguel, O.; Sotomayor, B.; Lara, A.Cambio de Uso de Suelo2019.010.2489/jswc.74.1.12Land use and land cover changes (LULCC) within a highly anthropized Mediterranean landscape dominated by industrial tree plantation leads to degradation of soil physical properties. This process has been more intense in the coastal range of south-central%%%Chile due to its soils, which are highly susceptible to erosion, combined with a long history of intensive land use changes during the last century, transitioning from native forest (NF) to agriculture and the more recent establishment of Pinus radiata and Eucalyptus spp. exotic tree plantations. In this context, the aim of this study was to assess the statuses of soil physical properties over different land cover situations. Historical land cover maps were determined via supervised classifications using the maximum likelihood classifier applied to satellite imagery. Five land use and land cover categories (LULC) were defined according to main land cover transitions associated with active and abandoned forestry operations that have been reported in the region: NF, pine plantation (P), eucalyptus plantation (Eu), early successional (E-S), and secondary successional (S-S). Successional stages were generated using change detection statistics considering changes between 2001 and 2014 maps. Soil samples were collected at%%%three depths in 39 plots that describe the five LULC. High clay contents were found in all%%%the LULC except Eu and P. These sites have shown more signs of degradation, with lower%%%organic matter (SOM) and macropores and higher shear strength (ShS). Soil organic matter was consistent with litter contribution and quality, establishing lower bulk density (Db) for NF and S-S and higher values for Eu and E-S. ShS and dispersion rate (DR) exhibit a correlation with SOM with lower ShS and higher DR when SOM increased. Relevant differences were identified for structural stability index (SSI) between LULC depending on soil physical quality, besides a positive correlation with SOM. Those results show the need to generate appropriate conditions of vegetation cover in order to recover soils subjected to current forestry management of industrial plantations.Journal of Soil and Water Conservation0022-4561 Reuters ISIanthropogenic effect, bulk density, forestry practice, land cover, land degradation, land use change, mediterranean environment, plantation forestry, pore space, shear strength, chile, eucalyptus, pinus radiata
Black carbon and other light-absorbing impurities in snow in the Chilean AndesRowe, Penny M.; Cordero, Raul R.; Warren, Stephen G.; Stewart, Emily; Doherty, Sarah J.; Pankow, Alec; Schrempf, Michael; Casassa, Gino; Carrasco, Jorge; Pizarro, Jaime; MacDonell, Shelley; Damiani, Alessandro; Lambert, Fabrice; Rondanelli, Roberto; Huneeus, Nicolas; Fernandoy, Francisco; Neshyba, StevenCiudades Resilientes; Zonas Costeras2019.010.1038/s41598-019-39312-0Vertical profiles of black carbon (BC) and other light-absorbing impurities were measured in seasonal snow and permanent snowfields in the Chilean Andes during Austral winters 2015 and 2016, at 22 sites between latitudes 18°S and 41°S. The samples were analyzed for spectrally-resolved visible light absorption. For surface snow, the average mass mixing ratio of BC was 15 ng/g in northern Chile (18–33°S), 28 ng/g near Santiago (a major city near latitude 33°S, where urban pollution plays a significant role), and 13 ng/g in southern Chile (33–41°S). The regional average vertically-integrated loading of BC was 207 µg/m 2 in the north, 780 µg/m 2 near Santiago, and 2500 µg/m 2 in the south, where the snow season was longer and the snow was deeper. For samples collected at locations where there had been no new snowfall for a week or more, the BC concentration in surface snow was high (~10–100 ng/g) and the sub-surface snow was comparatively clean, indicating the dominance of dry deposition of BC. Mean albedo reductions due to light-absorbing impurities were 0.0150, 0.0160, and 0.0077 for snow grain radii of 100 µm for northern Chile, the region near Santiago, and southern Chile; respective mean radiative forcings for the winter months were 2.8, 1.4, and 0.6 W/m 2 . In northern Chile, our measurements indicate that light-absorption by impurities in snow was dominated by dust rather than BC. © 2019, The Author(s).Scientific Reports2045-2322 Reuters ISI
Greenhouse gases, nutrients and the carbonate system in the Reloncaví Fjord (Northern Chilean Patagonia): Implications on aquaculture of the mussel, Mytilus chilensis, during an episodic volcanic eruptionYevenes, Mariela A.; Lagos, Nelson A.; Farías, Laura; Vargas, Cristian A.Zonas Costeras2019.010.1016/j.scitotenv.2019.03.037This study investigates the immediate and mid-term effects of the biogeochemical variables input into the Reloncaví fjord (41°40′S; 72°23′O) as a result of the eruption of Calbuco volcano. Reloncaví is an estuarine system supporting one of the largest mussels farming production within Northern Chilean-Patagonia. Field-surveys were conducted immediately after the volcanic eruption (23–30 April 2015), one month (May 2015), and five months posterior to the event (September 2015). Water samples were collected from three stations along the fjord to determine greenhouse gases [GHG: methane (CH 4 ), nitrous oxide (N 2 O)], nutrients [NO 3 − , NO 2 − , PO 4 3− , Si(OH) 4 , sulphate (SO 4 2− )], and carbonate systems parameters [total pH (pHT), temperature, salinity, dissolved oxygen (O 2 ), and total alkalinity (AT)]. Additionally, the impact of physicochemical changes in the water column on juveniles of the produced Chilean blue mussel, Mytilus chilensis, was also studied. Following the eruption, a large phytoplankton bloom led to an increase in pH T , due to the uptake of dissolved-inorganic carbon in photic waters, potentially associated with the runoff of continental soil covered in volcanic ash. Indeed, high surface SO 4 2− and GHG were observed to be associated with river discharges. No direct evidence of the eruption was observed within the carbonate system. Notwithstanding, a vertical pattern was observed, with an undersaturation of aragonite (Ω Ar < 1) both in brackish surface (<3 m) and deep waters (>10 m), and saturated values in subsurface waters (3 to 7 m). Simultaneously, juvenile mussel shells showed maximized length and weight at 4 m depth. Results suggest a localized impact of the volcanic eruption on surface GHG, nutrients and short-term effects on the carbonate system. Optimal conditions for mussel calcification were identified within a subsurface refuge in the fjord. These specific attributes can be integrated into adaptation strategies by the mussel aquaculture industry to confront ocean acidification and changing runoff conditions. © 2019 Elsevier B.V.Science of The Total Environment0048-9697 Reuters ISIalkalinity, aquaculture, biomineralization, carbonation, dissolved oxygen, greenhouse gases, molluscs, nitrogen oxides, nutrients, runoff, sulfur compounds, surface discharges, adaptation strategies, aquaculture industry, chilean patagonian fjord, dissolved inorganic carbon, mussel farming, ocean acidifications, physico-chemical changes, volcanic event, volcanoes, calcium carbonate, carbonic acid, dissolved oxygen, methane, nitrous oxide, sulfate, surface water, carbonic acid, methane, nitrous oxide, sea water, adaptive management, biogeochemical cycle, carbonate system, chemical oceanography, greenhouse gas, mussel culture, nutrient, ocean acidification, volcanic eruption, alkalinity, aquaculture, article, biogeochemical cycle, chilean, estuary, greenhouse gas, mussel, mytilus chilensis, nonhuman, ph, physical chemistry, phytoplankton, priority journal, runoff, salinity, temperature, volcanic ash, volcano, water sampling, analysis, animal, aquaculture, body constitution, chemistry, chile, environmental monitoring, greenhouse gas, mytilus, physiology, season, volcano, calbuco volcano, chile, los lagos, reloncavi fjord, mytilus chilensis, mytilus edulis, animals, aquaculture, body constitution, carbonates, chile, environmental monitoring, greenhouse gases, methane, mytilus, nitrous oxide, nutrients, seasons, seawater, volcanic eruptions
Integrating socio-ecological dynamics into land use policy outcomes: A spatial scenario approach for native forest conservation in south-central ChileManuschevich, Daniela; Sarricolea, Pablo; Galleguillos, MauricioCambio de Uso de Suelo2019.010.1016/j.landusepol.2019.01.042Chile is one of the first documented nations to undergo a forest transition dominated by tree farm expansion. Scenario modelling can inform the possible outcomes of forest conservation policies, especially when the scenarios are rooted in the political dynamics that shaped the current legislation. In Chile, tree farms of non-native Radiata Pine and Eucalyptus provide a fast return on investment. Today, fast-growing plantations compete for land area with forest conservation, putting the unique bundle of ecosystem services provided by the latter at risk. Based on a previous political analysis, we propose scenarios projected to 2030 to compare a business-as-usual scenario with A) a conservation scenario based on strict land use restrictions B) an optimistic conservation scenario; C) an unrestricted industrial land use scenario; and D) a restricted industrial land use scenario. The scenarios differ in terms of the implemented policy instruments and the land area required for each land use. We compared these scenarios in terms of carbon stock, control of erosion and wood production, all of which are relevant in the current Chilean political debate. A conservation scenario (A), that combines incentives and restrictions, would imply the largest increase in native forest and regulation services, namely carbon stock and erosion control. In contrast, an unrestricted industrial land use scenario (C) leads to the worst outcomes in terms of erosion compared to a business-as-usual scenario. This study seeks to link political and economic processes underpinning land use change to environmental outcomes, while contributing to the larger discussion on forest policy, forest transitions and environmental outcomes. © 2019Land Use Policy0264-8377 Reuters ISIconservation planning, ecosystem service, forest management, forestry policy, land use planning, nature conservation, policy implementation, policy making, spatial analysis, chile, eucalyptus, radiata
Estimation of atmospheric total organic carbon (TOC) – paving the path towards carbon budget closureYang, Mingxi; Fleming, Zoë L.Ciudades Resilientes2019.010.5194/acp-19-459-2019The atmosphere contains a rich variety of reactive organic compounds, including gaseous volatile organic carbon (VOCs), carbonaceous aerosols, and other organic compounds at varying volatility. Here we present a novel and simple approach to measure atmospheric non-methane total organic carbon (TOC) based on catalytic oxidation of organics in bulk air to carbon dioxide. This method shows little sensitivity towards humidity and near 100% oxidation efficiencies for all VOCs tested. We estimate a best-case hourly precision of 8 ppbC during times of low ambient variability in carbon dioxide, methane, and carbon monoxide (CO). As proof of concept of this approach, we show measurements of TOCCCO during August–September 2016 from a coastal city in the southwest United Kingdom. TOCCCO was substantially elevated during the day on weekdays (occasionally over 2 ppm C) as a result of local anthropogenic activity. On weekends and holidays, with a mean (standard error) of 102 (8) ppb C, TOCCCO was lower and showed much less diurnal variability. TOCCCO was significantly lower when winds were coming off the Atlantic Ocean than when winds were coming off land if we exclude the weekday daytime. By subtracting the estimated CO from TOCCCO, we constrain the mean (uncertainty) TOC in Atlantic-dominated air masses to be around 23 ( 8) ppbC during this period. A proton-transfer-reaction mass spectrometer (PTR-MS) was deployed at the same time, detecting a large range of organic compounds (oxygenated VOCs, biogenic VOCs, aromatics, dimethyl sulfide). The total speciated VOCs from the PTRMS, denoted here as Sum(VOC), amounted to a mean (uncertainty) of 12 ( 3) ppbC in marine air. Possible contributions from a number of known organic compounds present in marine air that were not detected by the PTR-MS are assessed within the context of the TOC budget. Finally, we note that the use of a short, heated sample tube can improve the transmission of organics to the analyzer, while operating our system alternately with and without a particle filter should enable a better separation of semi-volatile and particulate organics from the VOCs within the TOC budget. Future concurrent measurements of TOC, CO, and a more comprehensive range of speciated VOCs would enable a better characterization and understanding of the atmospheric organic carbon budget.Atmospheric Chemistry and Physics1680-7324 Reuters ISIaerosol, atmospheric chemistry, carbon budget, estimation method, human activity, oxidation, total organic carbon, volatile organic compound, united kingdom
Landscape restoration in a mixed agricultural-forest catchment: Planning a buffer strip and hedgerow network in a Chilean biodiversity hotspotRey Benayas, José M.; Altamirano, Adison; Miranda, Alejandro; Catalán, Germán; Prado, Marco; Lisón, Fulgencio; Bullock, James M.Cambio de Uso de Suelo2019.010.1007/s13280-019-01149-2Guidance for large-scale restoration of natural or semi-natural linear vegetation elements that takes into account the need to maintain human livelihoods such as farming is often lacking. Focusing on a Chilean biodiversity hotspot, we assessed the landscape in terms of existing woody vegetation elements and proposed a buffer strip and hedgerow network. We used spatial analysis based on Google Earth imagery and QGIS, field surveys, seven guidelines linked to prioritization criteria and seedling availability in the region's nurseries, and estimated the budget for implementing the proposed network. The target landscapes require restoring 0.89 ha km-2 of woody buffer strips to meet Chilean law; 1.4 ha km-2 of new hedgerows is also proposed. The cost of restoration in this landscape is estimated in ca. USD 6900 per planted ha of buffer strips and hedgerows. Financial incentives, education, and professional training of farmers are identified as key issues to implement the suggested restoration actions.Ambio0044-7447 Reuters ISIagricultural land, agroforestry, buffer zone, catchment, connectivity, conservation, ecosystem service, environmental restoration, gis, hedgerow, prioritization, spatial analysis, vegetation structure, chile, agriculture, biodiversity, chile, ecosystem, environmental protection, forest, human, agriculture, biodiversity, chile, conservation of natural resources, ecosystem, forests, humans
Rare calcium chloride–rich soil and implications for the existence of liquid water in a hyperarid environmentPfeiffer, Marco; Latorre, Claudio; Gayo, Eugenia; Amundson, RonaldCiudades Resilientes2019.010.1130/G45642.1We discovered permanently hydrated CaCl2-rich soils in Earth’s driest region, the Atacama Desert. The soils contain up to ∼15% CaCl2. X-ray diffraction indicates the rare minerals sinjarite, schoenite, and tachyhydrite. When water is added, the CaCl2 crust immediately turns white due to an apparent mineralogical phase change from sinjarite to a brine. The surfaces are nearly continuously wet due to the salt’s hygroscopicity. The Ca-enriched soils occur in rare exposures, possibly from shallow groundwater. Unlike the surface of adjacent abundant halite crusts, the CaCl2 outcrops remain continuously wet, with up to 12% water under modern, and essentially rainless, climatic conditions. The wet surface stabilizes the land surface and acts as a dust trap. The sediment began accumulating at ca. 14 ka, contains trace quantities of organic carbon, and has total nitrogen that isotopically reflects significant biologically mediated gaseous losses. These deliquescent salts are unique habitats for life within the climatic limits of life on Earth, and are a potential analog for transient liquid-water sources for microorganisms in Martian soils.Geology0091-7613 Reuters ISIcalcium chloride, groundwater, organic carbon, sodium chloride, atacama desert, climatic conditions, land surface, liquid water, martian soils, shallow groundwater, total nitrogen, wet surfaces, soils, arid environment, climate conditions, mineral, mineralogy, soil water, atacama desert, chile
Marine Radiocarbon Reservoir Age Along the Chilean Continental MarginMerino-Campos, Víctor; De Pol-Holz, Ricardo; Southon, John; Latorre, Claudio; Collado-Fabbri, SilvanaCambio de Uso de Suelo2019.010.1017/RDC.2018.81We present 37 new radiocarbon (14C) measurements from mollusk shells fragments sampled along the Chilean continental margin and stored in museum collections with known calendar age. These measurements were used to estimate the modern pre-bomb regional marine 14C age deviations from the global ocean reservoir (∆R). Together with previously published data, we calculated regional mean ∆R values for five oceanographic macro regions along the coast plus one for a mid-latitude open ocean setting. In general, upwelling regions north of 42ºS show consistent although sometimes highly variable ∆R values with regional averages ranging from 141 to 196 14C yr, whereas the mid-latitude open ocean location of the Juan Fernández archipelago and the southern Patagonian region show minor, ∆R of 40±38 14C yr, and 52±47 14C yr respectively. We attribute the alongshore decreasing pattern toward higher latitudes to the main oceanographic features along the Chilean coast such as perennial coastal upwelling in northern zone, seasonally variable upwelling at the central part and the large freshwater influence upon the southernRadiocarbon0033-8222 Reuters ISIaccelerator mass spectrometry, age, carbon isotope, continental margin, global ocean, mollusc, museum, radiocarbon dating, reservoir, shell, upwelling, chile, juan fernandez islands, patagonia, filicophyta
The cascade impacts of climate change could threaten key ecological interactionsFontúrbel, Francisco E.; Lara, Antonio; Lobos, David; Little, ChristianCambio de Uso de Suelo2018.010.1002/ecs2.2485Climate change is triggering ecological responses all over the world as a result of frequent, prolonged droughts. It could also affect ecological interactions, particularly pollination and seed dispersal, which play a key role in plant reproduction. We used a tripartite interaction with a mistletoe, its pollinator and its disperser animals to gain insight into this issue. We studied flower and fruit production, and visitation rates during average (2012) and dry (2015) austral summers. Drought in our study area affected precipitation and soil water availability. Although pollinator visits did not significantly differ in these summers, during the dry summer flower and fruit production experienced an important decline, as did seed disperser visits. Also, mistletoe mortality increased from 12% in 2012 to 23% in 2015. This empirical evidence suggests that the cascade effects of climate change may indirectly be hindering ecological interactions in the Valdivian temperate rainforest ecosystem we studied. Long‐term research is essential to provide the knowledge necessary to understand how key ecological processes may be affected in a changing world.Ecosphere2150-8925 Reuters ISIdromiciops gliroides, drought, sephanoides sephaniodes, soil moisture, temperate rainforests, tristerix corymbosus
Euro-Mediterranean climate variability in boreal winter: a potential role of the East Asian troughSen, Omer Lutfi; Ezber, Yasemin; Bozkurt, DenizTransversal2019.010.1007/s00382-018-4573-9Euro-Mediterranean climate variability has been associated mostly with the upstream atmospheric circulation and teleconnection patterns, the North Atlantic Oscillation and European blocking being the main ones. This study shows, for the first time, that the East Asian trough (EAT), a prominent circulation feature of the mid-troposphere in the downstream side, might exert a strong and significant role on the interannual variability of the Euro-Mediterranean climate during boreal winters. We performed empirical orthogonal function analysis on the regions of the EAT and Mediterranean trough (MedT), an important system modulating the climate of the region, to obtain the respective dominant modes of variability at 500-hPa geopotential heights. It appears that the leading modes, the intensity in the case of the EAT and the zonal displacement in the case of the MedT, are significantly correlated with each other (r = − 0.64, p < 0.001). Consequently, when the EAT is strong (weak), the MedT is observed in the west (east) of its climatological location resulting in a warmer (cooler) Middle East and northeastern Africa, a cooler (warmer) western Europe and northwestern Africa, and wetter (dryer) Italian, Balkan and Anatolian peninsulas. Given the fact that the EAT is also a key determinant of the East Asian winter climate, the identified mid-tropospheric link between East Asia and Mediterranean could help interpret some temperature and precipitation co-variability on the opposite sides of the Eurasian continent. We suggest that studies involving the Euro-Mediterranean climate should also consider the role of the EAT as it seems to be a potential driver of the year-to-year, perhaps longer-term, climate variability in the region.Climate Dynamics0930-7575 Reuters ISIair temperature, annual variation, atmospheric circulation, climate variation, precipitation (climatology), troposphere, winter, africa, anatolia, balkans, italian peninsula, mediterranean region, turkey
GIMMS NDVI time series reveal the extent, duration, and intensity of “blooming desert” events in the hyper-arid Atacama Desert, Northern ChileChávez, R.O.; Moreira-Muñoz, A.; Galleguillos, M.; Olea, M.; Aguayo, J.; Latín, A.; Aguilera-Betti, I.; Muñoz, A.A.; Manríquez, H.Cambio de Uso de Suelo; Agua y Extremos2019.010.1016/j.jag.2018.11.013The “blooming desert”, or the explosive development and flowering of ephemeral herbaceous and some woody desert species during years with abnormally high accumulated rainfall, is a spectacular biological phenomenon of the hyper-arid Atacama Desert (northern Chile) attracting botanists, ecologists, geo-scientists, and the general public from all over the world. However, the number of “blooming deserts”, their geographical distribution and spatio-temporal patterns have not been quantitatively assessed to date. Here, we used NDVI data from the Global Inventory Modeling and Mapping Studies (GIMMS) project to reconstruct the annual land surface phenology (LSP) of the Atacama Desert using a non-parametric statistical approach. From the reconstructed LSP, we detected the “blooming deserts” as positive NDVI anomalies and assessed three dimensions of the events: their temporal extent, intensity of “greening” and spatial extent. We identified 13 “blooming deserts” between 1981 and 2015, of which three (1997–98, 2002–03, and 2011) can be considered major events according to these metrics. The main event occurred in 2011, spanning 180 days between July and December 2011, and spread over 11,136 km 2 of Atacama dry plains. “Blooming deserts” in Atacama have been triggered by the accumulation of precipitation during a period of 2 to 12 months before and during the events. The proposed three-dimensional approach allowed us to characterize different types of “blooming deserts”: with longer episodes or larger spatial distribution or with different “greening” intensities. Its flexibility to reconstruct different LSP and detect anomalies makes this method a useful tool to study these rare phenomena in other deserts in the world also.International Journal of Applied Earth Observation and Geoinformation0303-2434 Reuters ISIdesert, extreme event, land surface, numerical model, phenology, precipitation intensity, remote sensing, time series, vegetation mapping, atacama desert, chile
Geohistorical records of the Anthropocene in ChileGayo, E. M.; McRostie, V.; Campbell, R.; Flores, C.; Maldonado, A.; Uribe-Rodriguez, M.; Moreno, P. I.; Santoro, C.; Christie, D. A.; Muñoz, A. A.; Gallardo, L.Ciudades Resilientes; Agua y Extremos10.1525/elementa.353The deep-time dynamics of coupled socio-ecological systems at different spatial scales is viewed as a key framework to understand trends and mechanisms that have led to the Anthropocene. By integrating archeological and paleoenvironmental records, we test the hypothesis that Chilean societies progressively escalated their capacity to shape national biophysical systems as socio-cultural complexity and pressures on natural resources increased over the last three millennia. We demonstrate that Pre-Columbian societies intentionally transformed Chile’s northern and central regions by continuously adjusting socio-cultural practices and/or incorporating technologies that guaranteed resource access and social wealth. The fact that past human activities led to cumulative impacts on diverse biophysical processes, not only contradicts the notion of pristine pre-Industrial Revolution landscapes, but suggests that the Anthropocene derives from long-term processes that have operated uninterruptedly since Pre-Columbian times. Moreover, our synthesis suggests that most of present-day symptoms that describe the Anthropocene are rooted in pre-Columbian processes that scaled up in intensity over the last 3000 years, accelerating after the Spanish colonization and, more intensely, in recent decades. The most striking trend is the observed coevolution between the intensity of metallurgy and heavy-metal anthropogenic emissions. This entails that the Anthropocene cannot be viewed as a universal imprint of human actions that has arisen as an exclusive consequence of modern industrial societies. In the Chilean case, this phenomenon is intrinsically tied to historically and geographically diverse configurations in society-environment feedback relationships. Taken collectively with other case studies, the patterns revealed here could contribute to the discussion about how the Anthropocene is defined globally, in terms of chronology, stratigraphic markers and attributes. Furthermore, this deep-time narrative can potentially become a science-based instrument to shape better-informed discourses about the socio-environmental history in Chile. More importantly, however, this research provides crucial “baselines” to delineate safe operating spaces for future socio-ecological systems.Elem Sci Anth2325-1026 Reuters ISIanthropocene, anthropogenic source, archaeology, biophysics, coevolution, colonization, complexity, heavy metal, historical record, landscape, metallurgy, paleoenvironment, social change
Dynamical downscaling over the complex terrain of southwest South America: present climate conditions and added value analysisBozkurt, Deniz; Rojas, Maisa; Boisier, Juan Pablo; Rondanelli, Roberto; Garreaud, René; Gallardo, LauraCiudades Resilientes; Zonas Costeras; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política; Transversal2019.010.1007/s00382-019-04959-yThis study evaluates hindcast simulations performed with a regional climate model (RCM, RegCM4) driven by reanalysis data (ERA-Interim) over the Pacific coast and Andes Cordillera of extratropical South America. A nested domain configuration at \(0.44^{\circ }\) ( \(\sim\) 50 km) and \(0.09^{\circ }\) ( \(\sim\) 10 km) spatial resolutions is used for the simulations. RegCM4 is also driven by a global climate model (GCM, MPI-ESM-MR) on the same domain configuration to asses the added values for temperature and precipitation (historical simulations). Overall, both 10 km hindcast and historical simulation results are promising and exhibit a better representation of near-surface air temperature and precipitation variability compared to the 50 km simulations. High-resolution simulations suppress an overestimation of precipitation over the Andes Cordillera of northern Chile found with the 50 km simulations. The simulated daily temperature and precipitation extreme indices from 10 km hindcast simulation show a closer estimation of the observed fields. A persistent warm bias ( \(\sim +\,{4\,}^{\circ }\hbox {C}\) ) over the Atacama Desert in 10 km hindcast simulation reveals the complexity in representing land surface and radiative processes over the desert. Difficulties in capturing the temperature trend in northern Chile are notable for both hindcast simulations. Both resolutions exhibit added values for temperature and precipitation over large parts of Chile, in particular, the 10 km resolves the coastal-valley Andes transitions over central Chile. Our results highlight that resolutions coarser than 50 km (e.g., GCMs and reanalysis) miss important climate gradients imposed by complex topography. Given that the highest spatial resolution of the current regional simulations over the South America is about 50 km, higher resolutions are important to improve our understanding of the dynamical processes that determine climate over complex terrain and extreme environments.Climate Dynamics0930-7575 Reuters ISIclimate conditions, climate modeling, climate variation, complex terrain, downscaling, regional climate, spatial analysis, temporal analysis, andes, atacama desert, chile, patagonia, equus asinus
2018 International Atmospheric Rivers Conference: Multi‐disciplinary studies and high‐impact applications of atmospheric riversRamos, Alexandre M.; Wilson, Anna M.; DeFlorio, Michael J.; Warner, Michael D.; Barnes, Elizabeth; Garreaud, Rene; Gorodetskaya, Irina V.; Lavers, David A.; Moore, Benjamin; Payne, Ashley; Smallcomb, Chris; Sodemann, Harald; Wehner, Michael; Ralph, Fred MartinAgua y Extremos2019.010.1002/asl.935Atmospheric rivers (ARs) play a vital role in shaping the hydroclimate of many regions globally, and can substantially impact water resource management, emergency response planning, and other socioeconomic entities. The second International Atmospheric Rivers Conference took place at the Scripps Institution of Oceanography, University of California, San Diego, during 25–28 June, 2018, in La Jolla, California, USA. It was sponsored by the Center for Western Weather and Water Extremes (CW3E). A total of 120 people attended the Conference with 94 abstracts submitted and 30 participating students. In addition to the conference, the Student Forecasting Workshop was organised in the same week. During this workshop, students were exposed to AR forecasting tools, and learned examples of how these tools could be used to make decisions for various applications. The main goals of this conference were to bring together experts from across the fields of hydrology, atmospheric, oceanic, and polar sciences, as well as water management, civil engineering, and ecology to advance the state of AR science and to explore the future directions for the field. The conference was organised into traditional oral and poster presentations, along with panel discussions and Breakout Groups. This format allowed enhanced interaction between participants, driving progress within the scientific community and the enhanced communication of societal needs by various stakeholders. Several emerging topics of research were highlighted, including subseasonal‐to‐seasonal (S2S) prediction of ARs and an overview of the AR Reconnaissance campaign. In addition to providing a forum to disseminate and debate new results from scientific talks and posters, the conference was equally effective and useful in linking scientists to users and decision‐makers that require improved knowledge on ARs to manage resources and prepare for hazards. The third International Atmospheric Rivers Conference will be held in Chile in 2020, and hosted by the University of Chile, Santiago.Atmospheric Science Letters1530-261X Reuters ISIatmosphere, conference proceeding, knowledge, research work, student, california, chile, la jolla, metropolitana, san diego, united states
Perception of thermal comfort in outdoor public spaces in the medium-sized city of Chillán, Chile, during a warm summerSmith, Pamela; Henríquez, CristiánCiudades Resilientes2019.010.1016/j.uclim.2019.100525The study of thermal comfort in Latin American cities has been gaining great relevance for urban environmental planning. Some studies have evaluated the relationship between environmental and perceived comfort; however, the causes and social determinants of the different perceptions of the population have not been explored. The perception of thermal comfort in public spaces in the city of Chillán (Chile), which has an inland Mediterranean climate, is discussed in this context. First, we measured the environmental thermal comfort, adapting the Actual Sensation Vote index. A survey of 362 users of the five selected public spaces was carried out between 29 January and 01 February 2016 to obtain perceived comfort and relate it to the individual climatic history, use of public space and place of residence in the city. The results show that perceived thermal discomfort dominates over comfort on summer days; however, those users who visit public spaces for recreational purposes feel more comfortable, as well as those living in low socioeconomic status (SES) neighborhoods. On the other hand, users living in areas with higher socioeconomic status, have higher expectations regarding thermal environmental conditions.Urban Climate2212-0955 Reuters ISIenvironmental comfort, perceived thermal comfort, public space, socioeconomic status
De crisis, ecologías y transiciones: reflexiones sobre teoría social latinoamericana frente al cambio ambiental globalBlanco Wells, Gustavo; Gunther, María GriseldaGobernanza e Interfaz Ciencia y Política2019.010.15446/rcs.v42n1.73190Este artículo contribuye a desplegar el campo de relaciones que se ha establecido entre las nociones de crisis y cambio ambiental global, a través de la revisión de las principales tradiciones de pensamiento ambiental con influencia en América Latina, a partir de la década de 1970. Con este objetivo, se examinan los rasgos distintivos de la representación de lo ambiental en la producción académica de las ciencias sociales regionales, las construcciones éticas sobre las que se sostiene esta producción y las relaciones que se establecen entre ecología, crisis y desarrollo. El texto presenta un panorama general tanto de la producción identificada con Latinoamérica, como de las adaptaciones e interpretaciones de otros idearios y pensamientos de origen no latinoamericano, pero de reconocida influencia regional. Metodológicamente, se realiza un trabajo de doble hermenéutica sobre la bibliografía relevante, principalmente a través de textos y autores que inspiran y fundan las perspectivas estudiadas. El primer apartado hace un recorrido analítico y descriptivo sobre las nociones de crisis y las respuestas éticas hacia la naturaleza que sirven de base a las propuestas teóricas. El segundo apartado presenta un panorama de la construcción de la problemática ambiental desde cinco grandes grupos de perspectivas teóricas: la economía ambiental y ecológica, el marxismo ecológico, la modernización ecológica, la ecología política, la ontología política y la perspectiva decolonial. Finalmente, se presentan las conclusiones y reflexiones sobre los alcances políticos y prácticos de la producción teórica ambiental en Latinoamérica. Afirmamos que el pensamiento social latinoamericano sobre el cambio ambiental global ―dadas las realidades sociomateriales sobre las que funda su evidencia― se encuentra en una posición privilegiada para aportar a la construcción de otras prácticas no centradas en la apropiación instrumental y a la visibilización de otras ontologías relacionales entre humanos y naturaleza no humana.Revista Colombiana de Sociología0120-159X Reuters ISIamérica latina, américa latina, cambio ambiental global, crise ecológica, crisis ecológica, ecologia política, ecological crisis, ecología política, environmental ethics, global environmental change, latin america, latin american social theory, mudança ambiental global, ontologia política, ontología política, political ecology, political ontology, teoria social latino-americana, teoría social latinoamericana, ética ambiental, ética ambiental
Sentencia Corte Suprema de 27 de agosto de 2018: Protección de Humedales ArtificialesMoraga, Pilar; Delgado, VerónicaGobernanza e Interfaz Ciencia y Política2018.0La Junta de Vecinos Jardín Oriente 3, Agrupación Cultural por los Humedales y Entornos Naturales y la Sociedad Educacional Winkler Contreras (dueña del colegio Da Vinci), todos vecinos del sector denominado Jardín Oriente de la comuna de Puerto Montt dedujeron recurso de protección en contra de la Inmobiliaria GPR Puerto Varas Limitada (en adelante, “Inmobiliaria GPR”), Inmobiliaria Socovesa Sur S.A. (a continuación Socovesa) y el Servicio de Vivienda y Urbanismo de la Región de Los Lagos (en adelante SERVIU). El principal cuestionamiento es el proceder arbitrario e ilegal de la Inmobiliaria GPR que intervino el Humedal Llantén sin contar con los permisos sectoriales para realizar las obras. Lo anterior significó la modificación del cauce denominado “estero sin nombre”, como consecuencia del drenaje de las aguas del humedal, lo cual unido a las fuertes precipitaciones que afectan normalmente a la Región y el desborde de la piscina que administran las segundas recurridas causó diversas inundaciones que dañaron severamente los inmuebles cercanos y el colegio Da Vinci, que debió ser cerrado durante dichos episodios, además de la afectación del ecosistema del humedal. A su vez se señala que la Inmobiliaria Socovesa mantiene en terrenos de su propiedad, una piscina de retención de aguas lluvias para los conjuntos habitacionales que construyó en el sector y que es administrada por el Servicio de Vivienda y Urbanismo (SERVIU), la cual en periodos de fuertes lluvias sobrepasa su capacidad provocando el desborde de sus aguas y, posterior anegamientos de los terrenos colindantes. La Corte Suprema acoge la acción de protección y sostiene que el actuar de los recurridos se aparta de la normativa jurídica ambiental y urbanística y, por ende, lesiona las garantías constitucionales del derecho a la integridad física y psíquica de toda persona (art. 19 Nº 1) y la de vivir en un medio ambiente libre de contaminación (art. 19 Nº 8), en este caso, “respecto de los habitantes del sector Oriente de la comuna de Puerto Montt”, disponiéndose las siguientes medidas: a) La Municipalidad deberá revisar los permisos de construcción y recepciones de obras que autorizó a los recurridos, sobre la base que el sector cuenta con un humedal y por él pasa una vía fluvial que es parte de la red primaria del Sistemas de Evacuación y Drenaje de Aguas Lluvias. b) SERVIU deberá planificar, estudiar y fiscalizar el correcto funcionamiento de la piscina de retención de aguas lluvias, cuyo funcionamiento deberá mantener la Inmobiliaria Socovesa. d) Inmobiliaria GPR desplegará todas las medidas que sean necesarias para la protección del Humedal, mientras la Seremi del Medio Ambiente de la Región de Los Lagos estudia y revisa la situación en que se encuentra el mismo, con el fin de adoptar las providencias del caso. e) En el plazo de tres años el colegio deberá ser reubicado para despejar el área de escurrimiento natural de las aguas lluvias del sector.Actualidad Jurídica Ambiental1989-5666 Reuters ISIA
The Role of Streamside Native Forests on Dissolved Organic Matter in Forested and Agricultural Watersheds in Northwestern PatagoniaBecerra-Rodas, Constanza; Little, Christian; Lara, Antonio; Sandoval, Jorge; Osorio, Sebastián; Nimptsch, JorgeCambio de Uso de Suelo; Agua y Extremos2019.010.3390/f10070595Streamside native forests are known for their key role in water provision, commonly referred to as buffers that control the input or output of nutrients from terrestrial to aquatic ecosystems (i.e., nitrogen or carbon cycle). In order to assess the functional role of indigenous forests along streamside channels, we measured 10 parameters associated with DOM (Dissolved Organic Matter) at 42 points in 12 small catchments (15–200 ha) dominated by native forests (reference, WNF), forest plantations (WFP) and agricultural lands (WAL) in which the land cover portion was calculated in the entire watershed and along 30 and 60-m wide buffer strips. We found that watersheds WFP and WAL were statistically different than WNF, according to DIC concentrations (Dissolved Inorganic Carbon) and the intensity of the maximum fluorescence of DOM components. Using linear models, we related streamside native forest coverage in buffer strips with DOM parameters. The increase of streamside native forest coverage in 60 m wide buffer strips (0–100%) was related to lower DIC concentrations (0.89 to 0.28 mg C L−1). In watersheds WFP and WAL, the humic and fulvic-like components (0.42 to 1.42 R.U./mg C L−1) that predominated were related to an increase in streamside native forest coverage in the form of a 60 m wide buffer strip (0–75%). This is evidence that streamside native forests influence outputs of detritus and lowered in-stream processing with concomitant downstream transport, and functional integrity and water quality. We propose that DOM quantity and quality may be a potential tool for the identification of priority areas near streams for conservation and ecological restoration in terms of recovery of water quality as an important ecosystem service. The results of this study are useful to inform policy and regulations about the width of streamside native forests as well as their characteristics and restrictions.Forests1999-4907 Reuters ISIaquatic ecosystems, biogeochemistry, biological materials, carbon, dissolution, organic compounds, runoff, water quality, watersheds, agricultural land, catchment management, dissolved organic matters, forest plantation, native forests, riparian vegetation, streamside native buffer, forestry, agricultural land, buffer zone, catchment, conservation management, dissolved organic carbon, ecosystem service, plantation forestry, restoration ecology, riparian vegetation, water quality, watershed, carbon, dissolving, forestry, organic compounds, runoff, water quality, patagonia
Percepciones del cambio climático en la Isla de Chiloé: Desafíos para la gobernanza localSapiains A., Rodolfo; Ugarte C., Ana M.; Hasbún M., JulioGobernanza e Interfaz Ciencia y Política2019.010.4067/S0718-22442019000100083Chiloé is an island in the south of Chile that presents multiple issues associated with the nonsustainable use of natural resources and high levels of poverty and inequality. Using qualitative methods, this article explores how keys stakeholders are perceiving and responding to climate change in such a complex social and environmental context. Results show this phenomenon is perceived as an emergent issue, whose social and environmental impacts are already happening. Generally individual responses are implemented, prevailing power asymmetries and competition over cooperation, coordination and exchange of experiences between stakeholders. A climate change governance system for the island should deal not only with institutional barriers but also promote social and cultural transformations.Magallania (Punta Arenas)0718-2244 Reuters ISIadaptation, chile, chiloé, climate change, governance, perceptions
Extreme Daily Rainfall in Central-Southern Chile and Its Relationship with Low-Level Horizontal Water Vapor FluxesValenzuela, Raúl A.; Garreaud, René D.Agua y Extremos2019.010.1175/JHM-D-19-0036.1Extreme rainfall events are thought to be one of the major threats of climate change given an increase of water vapor available in the atmosphere. However, before projecting future changes in extreme rainfall events, it is mandatory to know current patterns. In this study we explore extreme daily rainfall events along central-southern Chile with emphasis in their spatial distribution and concurrent synoptic-scale circulation. Surface rain gauges and reanalysis products from the Climate Forecast System Reanalysis are employed to unravel the dependency between extreme rainfall and horizontal water vapor fluxes. Results indicate that extreme rainfall events can occur everywhere, from the subtropical to extratropical latitudes, but their frequency increases where terrain has higher altitude, especially over the Andes Mountains. The majority of these events concentrate in austral winter, last a single day, and encompass a north–south band of about 200 km in length. Composited synoptic analyses identified extreme rainfall cases dominated by northwesterly (NW) and westerly (W) moisture fluxes. Some features of the NW group include a 300-hPa trough projecting from the extratropics to subtropics, a surface-level depression, and cyclonic winds at 850 hPa along the coast associated with integrated water vapor (IWV) > 30 mm. Conversely, features in the W group include both a very weak 300-hPa trough and surface depression, as well as coastal westerly winds associated with IWV > 30 mm. About half of extreme daily rainfall is associated with an atmospheric river. Extreme rainfall observed in W (NW) cases has a strong orographic (synoptic) forcing. In addition, W cases are, on average, warmer than NW cases, leading to an amplified hydrological response.Journal of Hydrometeorology1525-755X Reuters ISIdiurnal variation, extreme event, precipitation assessment, precipitation intensity, raingauge, spatiotemporal analysis, water flux, water vapor, chile
Public Spaces as Climate Justice Places? Climate Quality in the City of Chillán, ChileSmith, Pamela; Henríquez, CristiánCiudades Resilientes2019.010.1089/env.2018.0041The transformations brought about by climate change and the continued growth of cities are having an impact on urban climate. In urban spaces, especially in public spaces, environmental conditions are becoming more uncomfortable and this is affecting the health and quality of life of city dwellers. This study of climate quality in the city of Chillán revealed that there are insufficient public spaces to provide acceptable environmental quality for the entire population. It also showed that high-income areas, located in the peri-urban zones of the city, enjoy a better climate, environment, and air quality. This article analyzes urban climate injustice, as evidenced by the sharp socioeconomic differences in the quality of environment to which urban residents are exposed, and highlights the need for public spaces to improve the environmental quality for residentsEnvironmental Justice1939-4071 Reuters ISIclimate change, environmental conditions, environmental quality, periurban area, public space, quality of life, socioeconomic conditions, urban climate, urban growth, urban planning, urban population, bio bio, chile, chillan
The last glacial termination in the Coyhaique sector of central PatagoniaVilanova, I.; Moreno, P.I.; Miranda, C.G.; Villa-Martínez, R.P.Agua y Extremos2019.010.1016/j.quascirev.2019.105976Quaternary Science Reviews0277-3791 Reuters ISIglacial geology, lakes, reforestation, vegetation, biological productivity, continental landmass, deep water convection, glacial terminations, last glacial maximum, last glacial terminations, southern south america, southern westerly winds, climate change, climate change, glacial-interglacial cycle, global climate, ice-dammed lake, last glacial, last glacial maximum, precipitation (climatology), proglacial environment, treeline, upwelling, westerly, aisen, andes, chile, coihaique, patagonia, southern ocean
Significant decrease of photovoltaic power production by aerosols. The case of Santiago de ChileDel Hoyo, Mirko; Rondanelli, Roberto; Escobar, RodrigoZonas Costeras2019.010.1016/j.renene.2019.10.005Santiago de Chile frequently suffers from atmospheric pollution that contributes to the decrease of solarirradiance on the surface, leading to losses in the energy output of photovoltaic systems. In this study, asimple model is used to estimate the effect of aerosols on the solar irradiance over the city throughoutthe year, using as input AERONET sunphotometer data and other in-situ measurements. The results showreductions of 3.5% and 14.1% for global horizontal and direct normal irradiance respectively and an in-crease of 35.4% for diffuse horizontal irradiance between the actual condition in Santiago and a hypo-thetical atmosphere free of aerosols. These effects translate approximately to an annual difference in theenergy output of 7.2% and 8.7% for monocrystalline and amorphous silicon PV technologies respec-tively, and an annual difference of 16.4% for a CPV technology, showing that aerosols can have a sig-nificant effect on the photovoltaic energy production.Renewable Energy0960-1481 Reuters ISIaerosols, amorphous silicon, photovoltaic cells, photovoltaic effects, solar power generation, solar radiation, aeronet, chile, photovoltaics, santiago, solar irradiances, air pollution, aeronet, aerosol, atmospheric pollution, data set, irradiance, photovoltaic system, silicon, chile, metropolitana, santiago [metropolitana]
Beyond inputs and outputs: Process‐oriented explanation of institutional change in climate adaptation governancePatterson, James; Voogt, Douwe L.; Sapiains, RodolfoGobernanza e Interfaz Ciencia y Política2019.010.1002/eet.1865Climate adaptation is a growing imperative across all scales and sectors of governance. This often requires changes in institutions, which can be difficult to realize. Explicitly process‐oriented approaches explaining how and why institutional change occurs are lacking. Overcoming this gap is vital to move beyond either input‐oriented (e.g., capacity) or output‐oriented (e.g., assessment) approaches, to understand how changes actually occur for addressing complex and contested governance issues. This paper analyses causal conditions and mechanisms by which institutions develop in climate adaptation governance. It focuses on urban climate governance through an in‐depth case study of Santiago, Chile, over a 12‐year period (2005–2017), drawing on primary and secondary data, including 26 semistructured interviews with policy, academic, and civil society actors. It identifies and explains a variety of institutional developments across multiple levels (i.e., programmatic, legislative, and constitutional), through a theory‐centric process tracing methodology. This reveals a multiple‐response pattern, involving several causal mechanisms and coexisting institutional logics. Findings suggest that although adaptation may be inherently protracted, institutions can nevertheless develop in both related and novel directions. Overall, the paper argues for a new research agenda on process‐oriented theorizing and analysis in climate and environmental governance.Environmental Policy and Governance1756-932X Reuters ISIadaptation, climate change, governance approach, input-output analysis, institutional framework, chile, metropolitana
Fischerella thermalis: a model organism to study thermophilic diazotrophy, photosynthesis and multicellularity in cyanobacteriaAlcorta, Jaime; Vergara-Barros, Pablo; Antonaru, Laura A.; Alcamán-Arias, María E.; Nürnberg, Dennis J.; Díez, BeatrizZonas Costeras2019.010.1007/s00792-019-01125-4The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus) is widely distributed in hot springs around the world. Morphologically, it has been described as early as 1837. However, its taxonomic placement remains controversial. F. thermalis belongs to the same genus as mesophilic Fischerella species but forms a monophyletic clade of thermophilic Fischerella strains and sequences from hot springs. Their recent divergence from freshwater or soil true-branching species and the ongoing process of specialization inside the thermal gradient make them an interesting evolutionary model to study. F. thermalis is one of the most complex prokaryotes. It forms a cellular network in which the main trichome and branches exchange metabolites and regulators via septal junctions. This species can adapt to a variety of environmental conditions, with its photosynthetic apparatus remaining active in a temperature range from 15 to 58 °C. Together with its nitrogen-fxing ability, this allows it to dominate in hot spring microbial mats and contribute signifcantly to the de novo carbon and nitrogen input. Here, we review the current knowledge on the taxonomy and distribution of F.thermalis, its morphological complexity, and its physiological adaptations to an extreme environment.Extremophiles1431-0651 Reuters ISIacclimatization, biological model, cyanobacterium, evolution, heat, microbiology, physiology, thermal spring, trichome, acclimatization, biological evolution, cyanobacteria, hot springs, hot temperature, models, biological, trichomes
Growth and steady state of the Patagonian AndesColwyn, David Auerbach; Brandon, Mark T.; Hren, Michael T.; Hourigan, Jeremy; Pacini, Astrid; Cosgrove, Martha G.; Midzik, Maya; Garreaud, René D.; Metzger, ChristineAgua y Extremos2019.010.2475/06.2019.01Water isotopes are an important tool for reconstructing the amount of atmospheric lifting related to high topography in the geologic past. However, our capacity for meaningful interpretation requires understanding the climatic setting and isolating the influence of orography on water isotopes. Patagonia’s simple, steady climatology and location within the Southern Westerlies makes it an ideal setting for successful application of water isotopes to measuring topography through time. Here we use hydrated volcanic glass to construct a new record of the size of the Patagonian Andes during the Cenozoic. We also utilize a novel method for identifying the contribution of orography in regional climate records. Our results show that variation in the observed record can largely be explained by variations in climate. Thus we conclude that the mountain range has maintained a size similar to modern since at least Paleocene. This result is in agreement with geologic data, which constrain the bulk of the surface uplift of the Andes to the Cretaceous. The reconstruction of the Patagonian Andes, which grew in the Cretaceous and remained high through the Cenozoic, is markedly different from the widely held view of Miocene formation of this mountain range. In particular, the topography appears to remain stable during the northward propagation and collision of offshore spreading centers.American Journal of Science0002-9599 Reuters ISIcenozoic, climate variation, collision zone, cretaceous, growth rate, isotopic composition, orographic effect, paleoatmosphere, paleocene, paleoclimate, paleotopography, reconstruction, regional climate, spreading center, volcanic glass, water chemistry, patagonia
Quality as a hidden dimension of energy poverty in middle-development countries. Literature review and case study from ChileUrquiza, Anahí; Amigo, Catalina; Billi, Marco; Calvo, Rubén; Labraña, Julio; Oyarzún, Tamara; Valencia, FelipeCiudades Resilientes2019.010.1016/j.enbuild.2019.109463The paper proposes a literature review and meta-analysis on different dimensions and approaches with respect to energy poverty and examines Chile as a case study for its manifestations in middle development countries. This phenomenon has acquired greater relevance, with a variety of definitions, indicators and methodologies being used to measure it. However, most of them are focused on either quantifying the lack of access to modern energy services in poor countries or assessing the inequality produced by the costs of accessing such services in developed countries. This results in the lack of a proper toolbox to tackle middle development countries, such as Chile: where access-based measures assign thresholds that are too low, so that almost nobody is energy poor; conversely, equality-based measures deploy excessively high ones, so that a very large proportion of the population is energy poor. The paper argues that this deficit is caused by the understanding of quality in terms of “standards” in access- and equality-based measures, which restricts its potential in economically, culturally, and geographically diverse territories. A context-sensitive three-dimensional framework to assess energy poverty is then proposed, and its policy implications are briefly discussed.Energy and Buildings0378-7788 Reuters ISIpublic policy, chile, development countries, energy access, energy equity, energy poverties, energy quality, developing countries
A 15,400-year long record of vegetation, fire-regime, and climate changes from the northern Patagonian AndesJara, Ignacio A.; Moreno, Patricio I.; Alloway, Brent V.; Newnham, Rewi M.Agua y Extremos2019.010.1016/j.quascirev.2019.106005Paleoecological studies from the northern Patagonian Andes (40–44°S) have identified past changes in vegetation, fire regimes and paleoclimate since the last glaciation, including variations in strength and position of the Southern Westerly Winds (SWW). The extent to which records west and east of the Andes provide a congruent paleoclimatic history, however, has not been explored in detail in the literature. Physical and biological contrasts are evident between these regions today and are to be expected in paleoclimate reconstructions. In this context, we present pollen and charcoal records from sediment cores collected in Lago Espejo, a small closed-basin lake located in the core sector of the northern Patagonian Andes that spans uninterrupted the last ∼15,400 years. Following glacier withdrawal, the vegetation surrounding Lago Espejo features scattered Nothofagus woodlands, including relatively thermophilous rainforest trees between ∼15,400 and 14,400 cal yr BP. The disappearance of these trees and an abrupt rise in Nothofagus at ∼14,400 cal yr BP mark the establishment of closed-canopy forests during the Antarctic Cold Reversal, followed by increases in the cold-tolerant hygrophilous conifer Podocarpus nubigena during the Younger Dryas (∼12,700–11,500 cal yr BP). The Holocene vegetation consists of Nothofagus-dominated forests with modest variation in composition and structure until the present, attesting to the resilience of these forest communities to climate change and natural disturbance regimes. Rapid deforestation, anthropogenic fires and the establishment of artificial meadows with exotic herbs introduced by Europeans at ∼150 cal yr BP, triggered a rapid, large-magnitude landscape transformation unprecedented in the last 14,000 years. The timing and structure of vegetation changes revealed by the Lago Espejo record suggest that changes in the SWW were the main driver of vegetation and fire regimes in the Andes of northern Patagonia over the last 15,400 years. Comparison between multiple reconstructions from northern Patagonia reveals overall coherent vegetation and fire regime changes in the western and Andean sectors, and a spatially variable and more divergent behaviour in sites located further east. This spatial patter is akin to the present-day correlation between precipitation and SWW in this region.Quaternary Science Reviews0277-3791 Reuters ISIcharcoal, deforestation, fires, glacial geology, repair, vegetation, disturbance regime, northern patagonia, nothofagus forests, southern andes, southern westerly winds, climate change, climate change, coniferous tree, fire history, holocene, hydrological regime, paleoclimate, palynology, rainforest, westerly, younger dryas, andes, patagonia, coniferophyta, nothofagus, podocarpus nubigenus
Bias correction of global high-resolution precipitation climatologies using streamflow observations from 9372 catchmentsBeck, Hylke E.; Wood, Eric F.; McVicar, Tim R.; Zambrano-Bigiarini, Mauricio; Alvarez-Garreton, Camila; Baez-Villanueva, Oscar M.; Sheffield, Justin; Karger, Dirk N.Agua y Extremos2019.010.1175/JCLI-D-19-0332.1We introduce a set of global high-resolution (0.05 ◦ ) precipitation ( P) climatologies corrected for bias using streamflow ( Q) observations from 9372 stations worldwide. For each station, we inferred the “true” long-term P using a Budyko curve, an empirical equation relating long-term P, Q, and potential evaporation. We subsequently calculated long-term bias correction factors for three state-of-the-art P climatologies (WorldClim V2, CHELSA V1.2, and CHPclim V1), after which we used random forest regression to produce global gap-free bias correction maps for the climatologies. Monthly climatological bias correction factors were calculated by disaggregating the long-term bias correction factors based on gauge catch efficiencies. We found that all three climatologies systematically underestimate P over parts of all major mountain ranges globally, despite the explicit consideration of orography in the production of each climatology. Additionally, all climatologies underestimate P at latitudes > 60 ◦ N, likely due to gauge under-catch. Exceptionally high long-term correction factors ( > 1 .5) were obtained for all three climatologies in Alaska, High Mountain Asia, and Chile — regions characterized by marked elevation gradients, sparse gauge networks, and significant snowfall. Using the bias-corrected WorldClim V2, we demonstrated that other widely used P datasets (GPCC V2015, GPCP V2.3, and MERRA-2) severely underestimate P over Chile, the Himalayas, and along the Pacific coast of North America. Mean P for the global land surface based on the bias-corrected WorldClim V2 is 862 mm yr −1 (a 9.4 % increase over the original WorldClim V2). The annual and monthly bias-corrected P climatologies have been released as the Precipitation Bias CORrection (PBCOR) dataset — downloadable via .Journal of Climate0894-8755 Reuters ISIcatchments, decision trees, earth (planet), gages, random forests, stream flow, surface measurement, correction factors, elevation gradient, empirical equations, global land surface, mountain ranges, potential evaporation, precipitation climatology, state of the art, climatology, catchment, correlation, precipitation (climatology), rainfall-runoff modeling, raingauge, sampling bias, spatial resolution, streamflow
Wildfire management in Mediterranean-type regions: paradigm change neededMoreira, Francisco; Ascoli, Davide; Safford, Hugh; Adams, Mark; Moreno, Jose Manuel; Pereira, Jose Cardoso; Catry, Filipe; Armesto, Juan; Bond, William J; Gonzalez, Mauro; Curt, Thomas; Koutsias, Nikos; McCaw, Lachlan; Price, Owen; Pausas, Juli; Rigolot, Eric; Stephens, Scott; Tavsanoglu, Cagatay; Vallejo, Ramon; Van Wilgen, Brian; Xanthopoulos, Gavriil; Fernandes, PauloCambio de Uso de Suelo2020.010.1088/1748-9326/ab541eDuring the last decades, climate and land use changes led to an increased prevalence of megafires in Mediterranean-type climate regions (MCRs). Here, we argue that current wildfire management policies in MCRs are destined to fail. Focused on fire suppression, these policies largely ignore ongoing climate warming and landscape-scale buildup of fuels. The result is a "firefighting trap" that contributes to ongoing fuel accumulation precluding suppression under extreme fire weather, and resulting in more severe and larger fires. We believe that a "business as usual" approach to wildfire in MCRs will not solve the fire problem, and recommend that policy and expenditures be rebalanced between suppression and mitigation of the negative impacts of fire. This requires a paradigm shift: policy effectiveness should not be primarily measured as a function of area burned (as it usually is), but rather as a function of avoided socio-ecological damage and loss.Environmental Research Letters1748-9326 Reuters ISIextreme weather, land use, australia, california, chile, management policy, mediterranean-type regions, south africa, wildfires, fires, expenditure, fire management, management practice, mediterranean environment, wildfire, australia, california, south africa, united states
Validation of Cryogenic Vacuum Extraction of Pore Water from Volcanic Soils for Isotopic AnalysisRivera, Diego; Gutierrez, Karen; Valdivia-Cea, Walter; Zambrano-Bigiarini, Mauricio; Godoy-Faúndez, Alex; Álvez, Amaya; Farías, LauraZonas Costeras; Agua y Extremos2019.010.3390/w11112214Andean headwater catchments are key components of the hydrological cycle, given that they capture moisture, store water and release it for Chilean cities, industry, agriculture, and cities in Chile. However, knowledge about within-Andean catchment processes is far from clear. Most soils in the Andes derive from volcanic ash Andosols and Arenosols presenting high organic matter, high-water retention capacity and fine pores; and are very dry during summer. Despite their importance, there is little research on the hillslope hydrology of Andosols. Environmental isotopes such as Deuterium and 18-O are direct tracers for water and useful on analyzing water-soil interactions. This work explores, for the first time, the efficiency of cryogenic vacuum extraction to remove water from two contrasting soil types (Arenosols, Andosols) at five soil water retention energies (from −1500 to −33 kPa). Two experiments were carried out to analyse the impact of extraction time, and initial water content on the amount of extracted water, while a third experiment tested whether the cryogenic vacuum extraction changed the isotopic ratios after extraction. Minimum extraction times to recover over 90% of water initially in the soil samples were 40–50 min and varied with soil texture. Minimum volume for very dry soils were 0.2 mL (loamy sand) and 1 mL (loam). After extraction, the difference between the isotope standard and the isotopic values after extraction was acceptable. Thus, we recommend this procedure for soils derived from volcanic ashes.Water2073-4441 Reuters ISIcatchments, cryogenics, isotopes, runoff, soil moisture, textures, volcanoes, cryogenic vacuum, environmental isotopes, hillslope hydrology, initial water contents, isotopic analysis, soil water retention, volcanic soils, water-soil interaction, extraction, catchment, deuterium, equipment component, extraction method, hillslope, isotopic analysis, soil water potential, tracer, volcanic ash, volcanic soil, water content, water retention, water-rock interaction, andes, chile
Detecting Nothofagus pumilio Growth Reductions Induced by Past Spring Frosts at the Northern Patagonian AndesSangüesa-Barreda, Gabriel; Villalba, Ricardo; Rozas, Vicente; Christie, Duncan A.; Olano, José MiguelAgua y Extremos2019.010.3389/fpls.2019.01413Frontiers in Plant Science1664-462X Reuters ISIclimate change, dendroecology, extreme event, frost damage, temperature pattern, tree rings, warm spring
+A 5680-year tree-ring temperature record for southern South AmericaLara, A.; Villalba, R.; Urrutia-Jalabert, R.; González-Reyes, A.; Aravena, J.C.; Luckman, B.H.; Cuq, E.; Rodríguez, C.; Wolodarsky-Franke, A.Cambio de Uso de Suelo; Agua y Extremos2020.010.1016/j.quascirev.2019.106087It is widely documented that the Earth’s surface temperatures have increased in recent decades. However, temperature increment patterns are not uniform around the globe, showing different or even contrasting trends. Here we present a mean maximum summer temperature record, based on tree-ring widths, over the past 5682 years (3672BC – 2009AD) for southern South America (SSA), covering from mid-Holocene to the present. This is the longest such record for the Southern Hemisphere (SH), and expands available annual proxy climate records for this region in more than 2060 years. Our record explains 49% of the temperature variation, and documents two major warm periods between 3140–2800BC and 70BC – 150AD, which coincide with the lack of evidence of glacier advances in SSA. Recent decades in the reconstruction (1959–2009) show a warming trend that is not exceptional in the context of the last five millennia. The long-term relationship between our temperature reconstruction and a reconstructed total solar irradiance record, with coinciding cycles at 293, 372, 432–434, 512 and 746 years, indicate a persistent influence of solar forcing on centennial climate variability in SSA. At interannual to interdecadal scales, reconstructed temperature is mainly related to the internal climate variability of the Pacific Ocean, including El Niño Southern Oscillation (ENSO) and longer oscillations. Our study reveals the need to characterize regional-scale climate variability and its drivers, which in the context of global-scale processes such as anthropogenic warming, interact to modulate local climate affecting humans and ecosystems.Quaternary Science Reviews0277-3791 Reuters ISIatmospheric pressure, forestry, holocenes, internal climate variability, long-term relationships, paleoclimatology, south america, temperature reconstruction, total solar irradiance, tree rings, climatology, el nino-southern oscillation, paleoclimate, paleotemperature, proxy climate record, tree ring, trend analysis, south america
Hydrological Processes Special Issue “Hydrological processes across climatic and geomorphological gradients of Latin America”Birkel, Christian; Moore, Georgianne W.; Zambrano‐Bigiarini, MauricioAgua y Extremos2019.010.1002/hyp.13648In this special issue of Hydrological Processes, we showcase the variety of ongoing research in catchments of the hydrometeorological, geomorphological, and biogeographical megadiverse region of Latin America and the Caribbean (LAC). The papers of this special issue address hydrological processes that regulate storage, mixing, and fluxes of water and solutes from the driest Atacama Desert in Chile (annual precipitation lower than 10 mm in some places) to the wettest mountainous areas of Central America (annual rainfall up to 8,000 mm), including the richest biodiversity on Earth present in the Amazon. Not only are tropical rainforest ecosystems poorly represented in hydrologic research, the LAC contains a myriad of unique lowland to montane ecosystems across the climate gradient that also includes snow and ice processes. Opportunities to advance understanding of how vegetation and landforms redistribute moisture abound in the remote reaches of Latin America. Such modulation of the hydrological cycle by vegetation and large‐scale connecting driving forces of rainfall generating moisture transport is the topic of the contributions briefly introduced in the following section. There are three major transcending themes covered in this special issue: 1) hydrological processes across climate gradients, 2) unique ecosystems with limited hydrological research, 3) effects of land use change on hydrology.Hydrological Processes0885-6087, 1099-1085 Reuters ISI
Role of synoptic activity on projected changes in upwelling-favourable winds at the ocean’s eastern boundariesAguirre, Catalina; Rojas, Maisa; Garreaud, René D.; Rahn, David A.Zonas Costeras; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2019.010.1038/s41612-019-0101-9The climate of the ocean’s eastern boundaries is strongly influenced by subtropical anticyclones, which drive a surface wind stress that promotes coastal upwelling of nutrient-rich subsurface water that supports high primary productivity and an abundance of food resources. Understanding the projected response of upwelling-favourable winds to climate change has broad implications for coastal biogeochemistry, ecology, and fisheries. Here we use a reanalysis, an ensemble of global climate simulations, and an objective algorithm to track anticyclones to investigate the projected changes in upwelling-favourable wind events at the California, Canary, Humboldt, and Benguela coastal upwelling systems. Except for the north Pacific, we find consistent poleward shifts of mean and upper percentile daily winds over the ocean basins. We propose that extratropical, synoptic-scale migratory anticyclones that force intense coastal upwelling events—which become more frequent at higher latitudes and less frequent at lower latitudes in the future—play an important role in the projected changes in upwelling-favourable wind events in these coastal upwelling systems. These changes complement large-scale processes such as the poleward shift of the subtropical ridge (STR) and stationary subtropical highs. Hence, both extratropical and tropical processes need to be considered to fully explain projected changes at the coastal upwelling systems under anthropogenic climate change.npj Climate and Atmospheric Science2397-3722 Reuters ISIanthropogenic effect, anticyclone, climate change, climate modeling, computer simulation, ensemble forecasting, extratropical environment, marine atmosphere, numerical model, synoptic meteorology, tropical environment, weather forecasting, wind field, wind stress, angola, benguela, california, canada, canary islands, humboldt, saskatchewan, spain, united states
Glacier decline in the Central Andes (33°S): Context and magnitude from satellite and historical dataRuiz Pereira, Sebastian Felipe; Veettil, Bijeesh KozhikkodanCiudades Resilientes2019.010.1016/j.jsames.2019.102249Central Andes (33°S) represent a water-scarce region. During arid years, glacier runoffmay constitute the mainhydrological input at warm season and hence a steadfast deglacierization may represent a decrease in the re-gional water-budget. Ice-retreat enables landscape transitions from proglacial towards a paraglacial environ-ment, allowing the formation of newly formed cryogenic deposits. Ice-surface changes in the Central Andes(33°S), including the high-mountain areas from Aconcagua, Mendoza and Maipo basins (Argentina and Chile),were studied using digitalized maps, aerial photographs, Landsat (1–8) and Sentinel-2A data for the periodbetween 1956 and 2015. Band ratio and Normalized Difference Snow Index (NDSI) methods were tested usingLandsat 8 and Sentinel-2A data for comparison. Geomorphological changes were assessed at Monos de Aguacatchment (2750–4000 m a.s.l.) in the Aconcagua basin (Chile) as a regionally representative landscape tran-sition case. Regional glacier shrinkage of 46 ± 5% between 1956 and 2016 was observed for the CentralAndean sub-basins in both Argentina and Chile at 33°S. Overall, 107.1 ± 5 km2of newly exposed surfaces aresubject to permafrost conditions. Such insights raise concern in terms of current and future environmental as-sessments for newly formed cryospheric elements in water scarce regions.1. IntroductionGlaciers around the world are losing mass at an unprecedented pacein the early 21st century (Zemp et al., 2015); South American Andes arenot exception (Davies and Glasser, 2012;Veettil et al., 2017a, 2017b).Andes Mountains in Chile and Argentina have more than 4000 km inlength from 17°30′Sto49oS, most of them are glacierized and the typeof glacier, climate, and topography vary latitudinally along the Andes(Lliboutry and Corte, 1998).Andean Glaciers can either belong to Dry Andes (17°30′Sto35oS) orWet Andes (35oSto49oS). Central Andes (between 31oS and 35oS),which is a part of the Dry Andes in Chile and Argentina, had a gla-cierized area of nearly 2200 km2(Lliboutry and Corte, 1998). Rock-glaciers, protalus and gelifluction lobes are predominant cryoformsbetween 31°S and 33°S and white glaciers are predominant featuresbetween 33°S and 49°S (García et al., 2017). The Andes MountainRange at 33°S has neoglacial and glacial limits oscillating between 3000and 3300 m a.s.l. for Chile and between and 3400–3650 m a.s.l. forArgentina, respectively (Espizua, 1993), despite the fact that thesemountain ranges belongs to similar climatic conditions.Photogrammetry and remote sensing have been a complementaryand sometimes alternative for traditional glaciological observations athigh altitudes (Paul et al., 2016; Veettil and de Souza, 2017). Recently,Veettil and Kamp (2017)discussed the suitability of various remotesensing data and methods for long-term monitoring of snow and ice inthe tropical Andes, mentioning the potential of high spatial resolutionsatellite data for delineating glacier boundaries. Medium resolutionLandsat series satellite data were mostly used since mid-1970s and thelatest of this series–Landsat 8 Operational Land Imager (OLI)–hasbetter geometric stability and radiometric performance (Kääb et al.,2016). Recently, images from the multispectral instrument (MSI) of theSentinel-2A satellite launched by the European Space Agency (ESA) areavailable at no cost from the United States Geological Survey (USGS).These data have been predicted to enhance worldwide glacier mon-itoring (Kääb et al., 2016) and have a spatial resolution of 10 m in fourand 20 m in six visible and infrared channels, instead of 15–30 m forLandsat 8. Further improvement is the higher temporal resolution (10days for Sentinel 2A instead of 16 days for Landsat 8 and better swath 13 March 2019; Received in revised form 6 June 2019; Accepted 24 June 2019∗Corresponding author. Ton Duc Thang University, Ho Chi Minh City, Vietnam.E-mail Veettil).Journal of South American Earth Sciences 94 (2019) 102249Available online 27 June 20190895-9811/ © 2019 Elsevier Ltd. All rights reserved.TJournal of South American Earth Sciences0895-9811 Reuters ISIcryosphere, deglaciation, geological mapping, glacier, mountain region, satellite data, sentinel, andes
Streamflow variations across the Andes (18°–55°S) during the instrumental eraMasiokas, M. H.; Cara, L.; Villalba, R.; Pitte, P.; Luckman, B. H.; Toum, E.; Christie, D. A.; Le Quesne, C.; Mauget, S.Agua y Extremos2019.010.1038/s41598-019-53981-xThe rivers originating in the southern Andes (18°–55°S) support numerous ecosystems and a large number of human populations and socio-economic activities in the adjacent lowlands of Chile, Argentina and Bolivia. Here we show that ca. 75% of the total variance in the streamflow records from this extensive region can be explained by only eight spatially coherent patterns of variability. Five (three) of these Andean patterns exhibit extreme dry (wet) conditions in recent years, with strong interannual variations in northern Chile; long-term drying trends between 31° and 41°S; a transitional pattern in the central Patagonian Andes; and increasing trends in northwestern Argentina and southern Bolivia, the Fueguian Andes, and the eastern portion of the South Patagonian Icefield. Multivariate regression analyses show that large-scale indices of ENSO variability can predict 20% to 45% of annual runoff variability between 28° and 46°S. The influence of Antarctic and North Pacific indices becomes more relevant south of 43°S and in northwestern Argentina and southern Bolivia, respectively, but their overall skill as predictors of Andean streamflows is weak. The analyses provide relevant new information to improve understanding of the spatial coherence, the main temporal features, and the ocean-atmospheric forcings of surface runoff across the southern Andes.Scientific Reports2045-2322 Reuters ISIantarctica, argentina, article, bolivia, chile, human, sea, skill, surface runoff
A Multiscale Productivity Assessment of High Andean Peatlands across the Chilean Altiplano Using 31 Years of Landsat ImageryChávez, Roberto O.; Christie, Duncan A.; Olea, Matías; Anderson, Talia G.Agua y Extremos2019.010.3390/rs11242955The high Andean peatlands, locally known as “bofedales”, are a unique type of wetland distributed across the high-elevation South American Altiplano plateau. This extensive peatland network stores significant amounts of carbon, regulates local and regional hydrological cycles, supports habitats for a variety of plant and animal species, and has provided critical water and forage resources for the livestock of the indigenous Aymara communities for thousands of years. Nevertheless, little is known about the productivity dynamics of the high Andean peatlands, particularly in the drier western Altiplano region bordering the Atacama desert. Here, we provide the first digital peatland inventory and multiscale productivity assessment for the entire western Altiplano (63,705 km2) using 31 years of Landsat data (about 9000 scenes) and a non-parametric approach for estimating phenological metrics. We identified 5665 peatland units, covering an area of 510 km2, and evaluated the spatiotemporal productivity patterns at the regional, peatland polygon, and individual pixel scales. The regional assessment shows that the peatland areas and peatlands with higher productivity are concentrated towards the northern part of our study region, which is consistent with the Altiplano north–south aridity gradient. Regional patterns further reveal that the last seven years (2011–2017) have been the most productive period over the past three decades. While individual pixels show contrasting patterns of reductions and gains in local productivity during the most recent time period, most of the study area has experienced increases in annual productivity, supporting the regional results. Our novel database can be used not only to explore future research questions related to the social, biological, and hydrological influences on peatland productivity patterns, but also to provide technical support for the sustainable development of livestock practices and conservation and water management policy in the Altiplano region.Remote Sensing2072-4292 Reuters ISIforestry, pixels, productivity, research and development management, time series, water conservation, water management, atacama, bofedal, hydrological cycles, nonparametric approaches, npphen, phenology, productivity assessment, water management policy, wetlands
Soil microbial community responses to labile organic carbon fractions in relation to soil type and land use along a climate gradientRamírez, Paulina B.; Fuentes-Alburquenque, Sebastián; Díez, Beatriz; Vargas, Ignacio; Bonilla, Carlos A.Zonas Costeras2020.010.1016/j.soilbio.2019.107692There has been a growing interest in studying the labile C pool in order to promote the sequestration and stabilization of soil organic carbon (SOC). Although labile SOC fractions have emerged as standardized indicators because of their potential to detect early SOC trends over time, the relationships between microbial attributes and labile SOC remains poorly understood. In this study, we explored the influence of labile SOC fractions on the topsoil bacteria-archaea community across 28 sites with different land use, climate aridity, and soil types across a wide range of SOC content (0.6–12%) in central Chile. We applied Illumina sequencing to the 16S rRNA to examine shifts in the diversity and composition of these soil microbial communities. Additionally, labile SOC fractions such as the permanganate oxidizable carbon (POXC) and light fraction organic matter (LFOM), along with the soil physicochemical properties were analyzed. The results demonstrated that among all of the environmental factors tested, the pH, POXC/SOC ratio and LFOM were key drivers of microbial community structure (β-diversity). The α-diversity metrics exhibited a decreasing trend when aridity increased, and community structure was found to vary, with high POXC/SOC in sites associated with drier conditions. In addition, POXC/SOC ratios and LFOM were clearly related to shifts in the relative abundances of specific taxonomic groups at genera level. When there was high POXC/SOC and low LFOM content, members of Bacteroidetes (Adhaeribacter, Flavisolibacter, and Niastella), Proteobacteria (Skermanella, Ramlibacter, and Sphingomonas), and Archaea (Thaumarchaeota) were found to be the most dominant groups; however, the microbial taxa responded differently to both labile C fraction types. These results have implications for understanding how labile C content can potentially be used to predict shifts in the microbial community, thus facilitating the development of predictive ecosystem models, as well as early warning indicators for soil degradation.Soil Biology and Biochemistry00380717 Reuters ISIland use, microorganisms, organic carbon, physicochemical properties, rna, soils, 16s rrna gene, archaea, bacterial diversity, light fraction, soil ph, stabilization, bacterium, climate change, community response, community structure, environmental factor, geodiversity, microbial activity, microbial community, odor, ph, relative abundance, soil carbon, soil microorganism, soil organic matter, soil type, species diversity, topsoil, chile, adhaeribacter, bacteria (microorganisms), bacteroidetes, niastella, proteobacteria, ramlibacter, skermanella, sphingomonas
Large-sample hydrology: recent progress, guidelines for new datasets and grand challengesAddor, Nans; Do, Hong X.; Alvarez-Garreton, Camila; Coxon, Gemma; Fowler, Keirnan; Mendoza, Pablo A.Agua y Extremos2019.010.1080/02626667.2019.1683182Large-sample hydrology (LSH) relies on data from large sets (tens to thousands) of catchments to go beyond individual case studies and derive robust conclusions on hydrological processes and models. Numerous LSH datasets have recently been released, covering a wide range of regions and relying on increasingly diverse data sources to characterize catchment behaviour. These datasets offer novel opportunities, yet they are also limited by their lack of comparability, uncertainty estimates and characterization of human impacts. This article (i) underscores the key role of LSH datasets in hydrological studies, (ii) provides a review of currently available LSH datasets, (iii) highlights current limitations of LSH datasets and (iv) proposes guidelines and coordinated actions to overcome these limitations. These guidelines and actions aim to standardize and automatize the creation of LSH datasets worldwide, and to enhance the reproducibility and comparability of hydrological studies.Hydrological Sciences Journal0262-6667, 2150-3435 Reuters ISIcatchments, cloud computing, runoff, uncertainty analysis, data standardization, data uncertainty, human intervention, reproducibilities, streamflow records, large dataset, anthropogenic effect, automation, catchment, data management, data set, guideline, hydrological modeling, parallel computing, standardization, streamflow
Salmon farming vulnerability to climate change in southern Chile: understanding the biophysical, socioeconomic and governance linksSoto, Doris; León‐Muñoz, Jorge; Dresdner, Jorge; Luengo, Carol; Tapia, Fabián J.; Garreaud, RenéAgua y Extremos2019.010.1111/raq.12336There has been a growing interest in studying the labile C pool in order to promote the sequestration and stabilization of soil organic carbon (SOC). Although labile SOC fractions have emerged as standardized indicators because of their potential to detect early SOC trends over time, the relationships between microbial attributes and labile SOC remains poorly understood. In this study, we explored the influence of labile SOC fractions on the topsoil bacteria-archaea community across 28 sites with different land use, climate aridity, and soil types across a wide range of SOC content (0.6–12%) in central Chile. We applied Illumina sequencing to the 16S rRNA to examine shifts in the diversity and composition of these soil microbial communities. Additionally, labile SOC fractions such as the permanganate oxidizable carbon (POXC) and light fraction organic matter (LFOM), along with the soil physicochemical properties were analyzed. The results demonstrated that among all of the environmental factors tested, the pH, POXC/SOC ratio and LFOM were key drivers of microbial community structure (β-diversity). The α-diversity metrics exhibited a decreasing trend when aridity increased, and community structure was found to vary, with high POXC/SOC in sites associated with drier conditions. In addition, POXC/SOC ratios and LFOM were clearly related to shifts in the relative abundances of specific taxonomic groups at genera level. When there was high POXC/SOC and low LFOM content, members of Bacteroidetes (Adhaeribacter, Flavisolibacter, and Niastella), Proteobacteria (Skermanella, Ramlibacter, and Sphingomonas), and Archaea (Thaumarchaeota) were found to be the most dominant groups; however, the microbial taxa responded differently to both labile C fraction types. These results have implications for understanding how labile C content can potentially be used to predict shifts in the microbial community, thus facilitating the development of predictive ecosystem models, as well as early warning indicators for soil degradation.Reviews in Aquaculture1753-5123, 1753-5131 Reuters ISIchilean patagonia, climate change, salmon-farming employment, vulnerability
Managing Forests for Both Downstream and Downwind WaterCreed, Irena F.; Jones, Julia A.; Archer, Emma; Claassen, Marius; Ellison, David; McNulty, Steven G.; van Noordwijk, Meine; Vira, Bhaskar; Wei, Xiaohua; Bishop, Kevin; Blanco, Juan A.; Gush, Mark; Gyawali, Dipak; Jobbágy, Esteban; Lara, Antonio; Little, Christian; Martin-Ortega, Julia; Mukherji, Aditi; Murdiyarso, Daniel; Pol, Paola Ovando; Sullivan, Caroline A.; Xu, JianchuCambio de Uso de Suelo2019.010.3389/ffgc.2019.00064Frontiers in Forests and Global Change2624-893X Reuters ISIadaptation, climate change, forest, hydrologic cycle, mitigation, policy, sustainability, water
Recent wildfires in Central Chile: Detecting links between burned areas and population exposure in the wildland urban interfaceSarricolea, Pablo; Serrano-Notivoli, Roberto; Fuentealba, Magdalena; Hernández-Mora, Marina; de la Barrera, Francisco; Smith, Pamela; Meseguer-Ruiz, ÓliverCiudades Resilientes2020.010.1016/j.scitotenv.2019.135894Wildfires are gaining importance in the Mediterranean regions owing to climate change and landscape changes due to the increasing closeness between urban areas and forests prone to wildfires. We analysed the dry season wildfire occurrences in the Mediterranean region of Central Chile (32°S–39°30′ S) between 2000 and 2017, using satellite images to detect burned areas, their landscape metrics and the land use and covers (vegetal) pre-wildfire, in order to determine the population living in areas that may be affected by wildfires. The existing regulations in western Mediterranean countries (Portugal, Spain, France, and Italy) were used to identify and define the wildland-urban interface (WUI) areas, quantifying the people inhabiting them and estimating the population affected by burned areas from 2001 to 2017. We used the Google Earth Engine to process MODIS products and extract both burned areas and land covers. We detected that 25% of the urban population inhabits WUI areas (i.e. Biobío, Araucanía and Valparaíso regions) where the urban population exposed to burned areas exceeds 40%. Most of the land use and land covers affected by wildfires are anthropogenic land covers, classified as savannas, croplands, evergreen broadleaf forests and woody savannas, representing >70% of the burned areas. Urban areas show only 0.6% of the burned surface from 2001 to 2017. We estimate that 55,680 people are potentially affected by wildfires, and 50% of them are in just one administrative region. These results show the imperative need for public policies as a regulating force for establishing WUI areas with the purpose of identifying wildfire risk in urban areas, such as establishing prevention methods as firewalls and prescribed fires.Science of The Total Environment00489697 Reuters ISIclimate change, ecosystems, forestry, geographic information systems, land use, land use and land cover, mediterranean ecosystem, mediterranean region, population exposure, urban population, western mediterranean, wildfire, wildland urban interface, fires, gis, hazard assessment, land cover, land use, modis, risk assessment, satellite imagery, urban population, wildfire, article, chile, cropland, evergreen, forest, france, geographic information system, human, italy, nonhuman, population exposure, portugal, public policy, satellite imagery, savanna, season, spain, urban area, urban population, wildfire, chile, environmental protection, chile, chile, conservation of natural resources, wildfires
Protecting Patagonian peatlands in ChileHoyos-Santillan, Jorge; Miranda, Alejandro; Lara, Antonio; Rojas, Maisa; Sepulveda-Jauregui, ArmandoCambio de Uso de Suelo; Gobernanza e Interfaz Ciencia y Política2019.010.1126/science.aaz9244In their Letter “Seeing Chile's forest for the tree plantations” (27 September, p. 1388), A. P. Durán and O. Barbosa explain how Chile's current proposal for reducing greenhouse gas emissions (1) inadequately addresses forest management with exotic tree plantations. We agree, but we are even more concerned that the proposal overlooks other ecosystems entirely. Chilean Patagonian peatlands cover 3.1 million hectares (2) and contain approximately 4800 million tons of carbon accumulated over 18,000 years (3, 4). This is 4.7 times more carbon than the aboveground biomass of forests in Chile (4, 5). Peat in Chile is classified as a fossil resource, allowing it to be exploited by the Ministry of Mining (6). Chile should invest in the protection of this important ecosystem. Because of the slow peat accumulation in sub-Antarctic regions (less than 1 mm per year) (4), exploitation of peatlands compromises their carbon sequestration capacity, shifting peatlands from net carbon sinks into net carbon sources (7). Protecting Chile's Patagonian peatlands would help the country achieve carbon neutrality by 2050 (8, 9). To protect the peatlands, Chile must end their classification as fossil resources. Instead, Chile should present peatland preservation as part of its greenhouse gas reduction contributions at the 2019 United Nations Climate Change Conference (COP25) (now planned for Madrid, Spain, instead of Chile). Patagonian peatlands should also be recognized as overlooked carbon sinks of regional importance in Chile's new Climate Change Law (10).Science0036-8075, 1095-9203 Reuters ISIchile, ecosystem, forest, tree, chile, ecosystem, forests, trees
A multiscale analysis of the tornadoes of 30–31 May 2019 in south-central ChileBarrett, Bradford S.; Marin, Julio C.; Jacques-Coper, MartinZonas Costeras2020.010.1016/j.atmosres.2019.104811On 30 and 31 May 2019, tornadoes occurred in the cities of Los Angeles and Talcahuano/Concepción in south-central Chile, in a region where tornado activity is not common. The main goal of this study was to analyze these tornadoes across multiple scales: synoptic, mesoscale, and subseasonal. On the synoptic scale, the tornadoes were associated with an anomalous 500-hPa trough and associated surface cyclone to the west of Chile. A strong (20+ m s−1) low-level jet accompanied this trough, potentially enhanced by flow blocking by the Andes. A relatively warm and saturated surface layer combined with cold upper-level temperatures in the trough to yield 200–500 J kg−1 of CAPE on both days. This CAPE was accompanied by high levels of both deep-layer and low-level shear. Storm motions inferred by lightning swaths and GOES-IR imagery, along with estimates of storm motion and updraft helicity from a high-resolution WRF simulation, suggested this CAPE-shear combination was sufficient for the tornadic thunderstorms to be supercells. Finally, anomalies of sea level pressure, 500-hPa height, and surface dew point temperature from 27 to 31 May 2019 resembled long-term composite anomalies for MJO phases 1 and 2, suggesting a subseasonal link between the extreme event in Chile and convection in the tropics.Atmospheric Research01698095 Reuters ISIsea level, storms, chile, dewpoint temperature, meso-scale modeling, multi scale analysis, sea level pressure, synoptic meteorology, tornadic thunderstorms, upper level temperatures, tornadoes, air temperature, atmospheric convection, cyclone, jet stream, mesoscale meteorology, sea level pressure, synoptic meteorology, thunderstorm, tornado, updraft, andes, bio bio, chile, concepcion [bio bio], los angeles [bio bio], talcahuano
Surface indicators are correlated with soil multifunctionality in global drylandsEldridge, David J.; Delgado‐Baquerizo, Manuel; Quero, José L.; Ochoa, Victoria; Gozalo, Beatriz; García‐Palacios, Pablo; Escolar, Cristina; García‐Gómez, Miguel; Prina, Aníbal; Bowker, Mathew A.; Bran, Donaldo E.; Castro, Ignacio; Cea, Alex; Derak, Mchich; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan J.; Gatica, Gabriel M.; Gómez‐González, Susana; Ghiloufi, Wahida; Gutierrez, Julio R.; Guzman, Elizabeth; Hernández, Rosa M.; Hughes, Frederic M.; Muiño, Walter; Monerris, Jorge; Ospina, Abelardo; Ramírez, David A.; Ribas‐Fernández, Yanina A.; Romão, Roberto L.; Torres‐Díaz, Cristian; Koen, Terrance B.; Maestre, Fernando T.Cambio de Uso de Suelo2019.010.1111/1365-2664.13540Multiple ecosystem functions need to be considered simultaneously to manage and protect the many ecosystem services that are essential to people and their environments. Despite this, cost effective, tangible, relatively simple, and globally‐relevant methodologies to monitor in situ soil multifunctionality, i.e. the provision of multiple ecosystem functions by soils, have not been tested at the global scale. We combined correlation analysis and structural equation modelling to explore whether we could find easily measured, field‐based indicators of soil multifunctionality (measured using functions linked to the cycling and storage of soil carbon, nitrogen, and phosphorus). To do this, we gathered soil data from 120 dryland ecosystems from five continents. Two soil surface attributes measured in situ (litter incorporation and surface aggregate stability) were the most strongly associated with soil multifunctionality, even after accounting for geographic location and other drivers such as climate, woody cover, soil pH and soil electric conductivity. The positive relationships between surface stability and litter incorporation on soil multifunctionality was greater beneath the canopy of perennial vegetation than in adjacent, open areas devoid of vascular plants. The positive associations between surface aggregate stability and soil functions increased with increasing mean annual temperature. Synthesis and applications. Our findings demonstrate that a reduced suite of easily measured in situ soil surface attributes can be used as potential indicators of soil multifunctionality in drylands worldwide. These attributes, which relate to plant litter (origin, incorporation, cover), and surface stability, are relatively cheap and easy to assess with minimal training, allowing operators to sample many sites across widely varying climatic areas and soil types. The correlations of these variables are comparable to the influence of climate or soil, and would allow cost‐effective monitoring of soil multifunctionality under changing land use and environmental conditions. This would provide important information for evaluating the ecological impacts of land degradation, desertification and climate change in drylands worldwide.Journal of Applied Ecology0021-8901, 1365-2664 Reuters ISIaggregate stability, climate change, desertification, dryland farming, ecosystem function, numerical model, soil surface, soil type, vascular plant, tracheophyta
Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxesLovejoy, Shaun; Lambert, FabriceCiudades Resilientes2019.010.5194/cp-15-1999-2019Abstract. Atmospheric variability as a function of scale has been divided in various dynamical regimes with alternating increasing and decreasing fluctuations: weather, macroweather, climate, macroclimate, and megaclimate. Although a vast amount of data are available at small scales, the larger picture is not well constrained due to the scarcity and low resolution of long paleoclimatic time series. Using statistical techniques originally developed for the study of turbulence, we analyse the fluctuations of a centimetric-resolution dust flux time series from the EPICA Dome C ice core in Antarctica that spans the past 800 000 years. The temporal resolution ranges from annual at the top of the core to 25 years at the bottom, enabling the detailed statistical analysis and comparison of eight glaciation cycles and the subdivision of each cycle into eight consecutive phases. The unique span and resolution of the dataset allows us to analyse the macroweather and climate scales in detail. We find that the interglacial and glacial maximum phases of each cycle showed particularly large macroweather to climate transition scale τc (around 2 kyr), whereas mid-glacial phases feature centennial transition scales (average of 300 years). This suggests that interglacials and glacial maxima are exceptionally stable when compared with the rest of a glacial cycle. The Holocene (with τc≈7.9 kyr) had a particularly large τc, but it was not an outlier when compared with the phases 1 and 2 of other cycles. We hypothesize that dust variability at larger (climate) scales appears to be predominantly driven by slow changes in glaciers and vegetation cover, whereas at small (macroweather) scales atmospheric processes and changes in the hydrological cycles are the main drivers. For each phase, we quantified the drift, intermittency, amplitude, and extremeness of the variability. Phases close to the interglacials (1, 2, 8) show low drift, moderate intermittency, and strong extremes, while the “glacial” middle phases 3–7 display strong drift, weak intermittency, and weaker extremes. In other words, our results suggest that glacial maxima, interglacials, and glacial inceptions were characterized by relatively stable atmospheric conditions but punctuated by frequent and severe droughts, whereas the mid-glacial climate was inherently more unstable.Climate of the Past1814-9332 Reuters ISIdust, extreme event, flux measurement, glaciation, hydrological cycle, ice core, interglacial, last glacial maximum, paleoclimate, resolution, scale effect, time series analysis, antarctica, dome concordia, east antarctica
The Anthropocene in ChileBauer, C.; Correa, C.; Gallardo, L.; González, G.; Guridi, R.; Latorre, C.; Pommier, E.; Riffo, S.; Saavedra, B.; Simonetti, C.; Tironi, M.Ciudades Resilientes2019.010.1215/22011919-7754578Environmental Humanities2201-1919, 2201-1919 Reuters ISIA
La compleja definición del problema socioambiental: racionalidades y controversiasMorales, Bárbara; Aliste, Enrique; Neira, C Ignacio; Urquiza, AnahíCiudades Resilientes2019.010.5354/0719-0527.2019.54834Drawing from a qualitative approach, this article addresses some of the elements that allow thematizing the socioenvironmental problem from its own complexity, and considering the point of view of different actors, which are part of this discussion in the Chilean context, and giving special emphasis on the controversies generated around the terms “development” and “sustainability.” First, we address the elements – theoretical and empirical – that allow thematizing the complexity of the socioenvironmental problem. Second, we discuss a number of definitions given to “development” and their link to the origins of the problem. Third, we present options proposed by actors to move towards sustainability. The article concludes with reflections oriented to multiple perspectives about this issue.Revista Mad0718-052743-5140.0Thomson Reuters ISIchile, complexity, development, socio-environmental problems, sustainability
In and out of glacial extremes by way of dust−climate feedbacksShaffer, Gary; Lambert, FabriceCiudades Resilientes2018.010.1073/pnas.1708174115Mineral dust aerosols cool Earth directly by scattering incoming solar radiation and indirectly by affecting clouds and biogeochemical cycles. Recent Earth history has featured quasi-100,000-y, glacial−interglacial climate cycles with lower/higher temperatures and greenhouse gas concentrations during glacials/interglacials. Global average, glacial maxima dust levels were more than 3 times higher than during interglacials, thereby contributing to glacial cooling. However, the timing, strength, and overall role of dust−climate feedbacks over these cycles remain unclear. Here we use dust deposition data and temperature reconstructions from ice sheet, ocean sediment, and land archives to construct dust−climate relationships. Although absolute dust deposition rates vary greatly among these archives, they all exhibit striking, nonlinear increases toward coldest glacial conditions. From these relationships and reconstructed temperature time series, we diagnose glacial−interglacial time series of dust radiative forcing and iron fertilization of ocean biota, and use these time series to force Earth system model simulations. The results of these simulations show that dust−climate feedbacks, perhaps set off by orbital forcing, push the system in and out of extreme cold conditions such as glacial maxima. Without these dust effects, glacial temperature and atmospheric CO2 concentrations would have been much more stable at higher, intermediate glacial levels. The structure of residual anomalies over the glacial−interglacial climate cycles after subtraction of dust effects provides constraints for the strength and timing of other processes governing these cycles.Proceedings of the National Academy of Sciences0027-8424 Reuters ISIcarbon dioxide, ice, atmospheric deposition, climate, cold, concentration (parameters), conference paper, controlled study, dust, dust radiative forcing, environmental parameters, glacial maxima, glacial period, glaciation, interglacial, iron fertilization forcing, land use, priority journal, sea, sediment, simulation, temperature, time series analysis
Onset and Evolution of Southern Annular Mode-Like Changes at Centennial TimescaleMoreno, P. I.; Vilanova, I.; Villa-Martínez, R.; Dunbar, R. B.; Mucciarone, D. A.; Kaplan, M. R.; Garreaud, R. D.; Rojas, M.; Moy, C. M.; De Pol-Holz, R.; Lambert, F.Cambio de Uso de Suelo; Ciudades Resilientes; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2018.010.1038/s41598-018-21836-6The Southern Westerly Winds (SWW) are the surface expression of geostrophic winds that encircle the southern mid-latitudes. In conjunction with the Southern Ocean, they establish a coupled system that not only controls climate in the southern third of the world, but is also closely connected to the position of the Intertropical Convergence Zone and CO2 degassing from the deep ocean. Paradoxically, little is known about their behavior since the last ice age and relationships with mid-latitude glacier history and tropical climate variability. Here we present a lake sediment record from Chilean Patagonia (51°S) that reveals fluctuations of the low-level SWW at mid-latitudes, including strong westerlies during the Antarctic Cold Reversal, anomalously low intensity during the early Holocene, which was unfavorable for glacier growth, and strong SWW since ∼7.5 ka. We detect nine positive Southern Annular Mode-like events at centennial timescale since ∼5.8 ka that alternate with cold/wet intervals favorable for glacier expansions (Neoglaciations) in southern Patagonia. The correspondence of key features of mid-latitude atmospheric circulation with shifts in tropical climate since ∼10 ka suggests that coherent climatic shifts in these regions have driven climate change in vast sectors of the Southern Hemisphere at centennial and millennial timescales.Scientific Reports2045-2322 Reuters ISIantarctica, article, climate change, cold stress, glaciation, holocene, lake sediment, latitude, southern hemisphere, tropic climate, writing
Portugal and Chile: Longing for sustainable forestry while rising from the ashesGómez-González, Susana; Ojeda, Fernando; Fernandes, Paulo M.Cambio de Uso de Suelo2018.010.1016/j.envsci.2017.11.006The recent catastrophic wildfires in Portugal and Chile shared similar features, not just because they developed under extreme weather conditions but also because extensive forest plantations were involved. Dense forest plantations of flammable pine and eucalypt species favor the development of high-intensity large fires, threatening people and the forest industry sustainability under increasingly frequent and severe drought events. Preventive land-use planning and cost-effective fuel management are key elements of sustainable forestry. Understanding the fire ecology context prior to plantation establishment is also crucial for the success of fire management planning. Although the forest industry has contributed to the economy of these countries, improved regulation and science-based management policies are strongly needed. Fuel treatment strategies can be optimized by risk-based modeling approaches, and should be mandatory in wildland-urban interfaces. The tragedy caused by these wildfires is an opportunity to change towards more sustainable landscape arrangements that reconcile ecosystem services, biodiversity conservation, and protection from life-threatening wildfires.Environmental Science & Policy1462-9011 Reuters ISIfuel, ash, chile, conservation biology, cost effectiveness analysis, drought, environmental planning, environmental policy, environmental protection, environmental sustainability, eucalyptus, fire ecology, forest fire, forest management, forestry, government regulation, land use, landscape ecology, model, note, plantation, portugal, priority journal, risk assessment, species, sustainable development, wildfire
Spatial and temporal disaggregation of the on-road vehicle emission inventory in a medium-sized Andean city. Comparison of GIS-based top-down methodologiesGómez, C.D.; González, C.M.; Osses, M.; Aristizábal, B.H.Ciudades Resilientes2018.010.1016/j.atmosenv.2018.01.049Emission data is an essential tool for understanding environmental problems associated with sources and dynamics of air pollutants in urban environments, especially those emitted from vehicular sources. There is a lack of knowledge about the estimation of air pollutant emissions and particularly its spatial and temporal distribution in South America, mainly in medium-sized cities with population less than one million inhabitants. This work performed the spatial and temporal disaggregation of the on-road vehicle emission inventory (EI) in the medium-sized Andean city of Manizales, Colombia, with a spatial resolution of 1 km × 1 km and a temporal resolution of 1 h. A reported top-down methodology, based on the analysis of traffic flow levels and road network distribution, was applied. Results obtained allowed the identification of several hotspots of emission at the downtown zone and the residential and commercial area of Manizales. Downtown exhibited the highest percentage contribution of emissions normalized by its total area, with values equal to 6% and 5% of total CO and PM10 emissions per km2 respectively. These indexes were higher than those obtained in residential-commercial area with values of 2%/km2 for both pollutants. Temporal distribution showed strong relationship with driving patterns at rush hours, as well as an important influence of passenger cars and motorcycles in emissions of CO both at downtown and residential-commercial areas, and the impact of public transport in PM10 emissions in the residential-commercial zone. Considering that detailed information about traffic counts and road network distribution is not always available in medium-sized cities, this work compares other simplified top-down methods for spatially assessing the on-road vehicle EI. Results suggested that simplified methods could underestimate the spatial allocation of downtown emissions, a zone dominated by high traffic of vehicles. The comparison between simplified methods based on total traffic counts and road density distribution suggested that the use of total traffic counts in a simplified form could enhance higher uncertainties in the spatial disaggregation of emissions. Results obtained could add new information that help to improve the air pollution management system in the city and contribute to local public policy decisions. Additionally, this work provides appropriate resolution emission fluxes for ongoing research in atmospheric modeling in the city, with the aim to improve the understanding of transport, transformation and impacts of pollutant emissions in urban air quality.Atmospheric Environment1352-2310 Reuters ISIair quality, decision making, geographic information systems, housing, information management, particles (particulate matter), pollution, roads and streets, spatial distribution, traffic control, urban transportation, vehicles, emission inventories, medium-sized cities, on-road vehicle emissions, public policy decisions, spatial and temporal distribution, spatial disaggregation, top-down methods, vehicular emission, air pollution, air quality, atmospheric modeling, comparative study, emission inventory, gis, pollutant source, public transport, spatiotemporal analysis, top-down approach, traffic emission, urban pollution, air quality, article, car driving, colombia, geographic information system, industrial area, motorcycle, particulate matter, priority journal, traffic, andes, caldas, colombia, manizales, south america
Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, ChileJorquera, Hector; Barraza, Francisco; Heyer, Johanna; Valdivia, Gonzalo S.; Schiappacasse, Luis Nicolás; Montoya, Lupita D.Ciudades Resilientes2018.010.1016/j.envpol.2018.01.085Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM2.5 was also performed. This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 μg/m3, respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrations were then estimated as 12.5 and 26.5 μg/m3, respectively; therefore, 68% of indoor PM2.5 comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively high household air exchange rates (median: 1.06 h−1). This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and As originated from indoor sources. Using continuous indoor and outdoor PM2.5 measurements, a median indoor source strength of 75 μg PM2.5/min was estimated for the diurnal period, similar to literature results. For the evening period, the median estimate rose to 135 μg PM2.5/min, reflecting a more intense wood burning associated to cooking and space heating at night. Statistical test results (at the 90% confidence level) support the ongoing woodstove replacement program (reducing emissions) and household weatherization subsidies (reducing heating demand) for improving indoor air quality in southern Chile, and suggest that a cookstove improvement program might be helpful as well. In the city of Temuco, southern Chile, 68% of indoor PM2.5 comes from severe outdoor pollution due to intensive wood burning, enhanced by poor household building standards and fuel poverty.Environmental Pollution0269-7491 Reuters ISIbuilding codes, heating, indoor air pollution, smoke, software testing, urban growth, wood, elemental compositions, indoor air quality, infiltration factor, infiltration parameters, pm2.5 concentration, statistical evaluation, sustainable urban development, woodstove, air quality, arsenic, bromine, calcium, iron, rubidium, silicon, sulfur, titanium, air quality, cooking appliance, indoor air, infiltration, mass balance, particulate matter, smoke, sustainable development, urban atmosphere, wood, adult, air quality control, air sampling, ambient air, article, chemical composition, chile, circadian rhythm, cohort analysis, combustion, concentration (parameters), controlled study, cooking, environmental exposure, heating, household, human, indoor air pollution, night, particulate matter, smoke, urban area, winter, wood, air pollutant, air pollution, analysis, city, cooking, environmental monitoring, indoor air pollution, particulate matter, season, statistics and numerical data, araucania, chile, temuco, air pollutants, air pollution, air pollution, indoor, chile, cities, cooking, environmental monitoring, heating, humans, particulate matter, seasons, wood
Record-breaking climate anomalies lead to severe drought and environmental disruption in western Patagonia in 2016Garreaud, R. D.Agua y Extremos2018.010.3354/cr01505Traditionally a temperate and hyper-humid region, western Patagonia experienced its most severe drought during the summer and fall of 2016. Along with precipitation deficits larger than 50% there was a similar reduction in river discharge into coastal waters, a decline in vegetation productivity, excessive solar radiation at the surface, and frequent upwelling-favorable wind events offshore. The combination of these regional-scale anomalies seems to have set the stage for environmental disturbances that, although not new in western Patagonia, occurred with unprecedented magnitude, including severe urban air pollution episodes, large forest fires, and the worst ever recorded harmful algae bloom (HAB). The local climate anomalies were in turn related to the concomitant strong El Niño (through atmospheric teleconnections) and, to a lesser extent, anthropogenic climate change mediated by the positive polarity of the Southern Annular Mode (SAM) and internal variability, as both modes weakened the westerlies. Dryer than present conditions are consistently projected for northern Patagonia during the 21st century as a consequence of anthropogenic increases in radiative forcing; superposition of El Niño events in this altered climate may result in a higher frequency of extreme droughts and environmental disruptions like those observed in 2016.Climate Research0936-577X Reuters ISIclimate change, environment, hab, harmful algal bloom, patagonia, sam, southern annular mode
Heat shock and plant leachates regulate seed germination of the endangered carnivorous plant <i>Drosophyllum lusitanicum</i>Gómez-González, Susana; Paniw, Maria; Antunes, Kamila; Ojeda, FernandoCambio de Uso de Suelo2018.010.5194/we-18-7-2018In fire-prone ecosystems, many plant species have specialized mechanisms of seed dormancy that ensure a successful recruitment after fire. A well-documented mechanism is the germination stimulated by firerelated cues, such as heat shock and smoke. However, less is known about the role of inhibitory germination signals (e.g. allelopathy) in regulating post-fire recruitment. Plant leachates derived from the unburned vegetation can enforce dormancy by means of allelopathic compounds, acting as a signal of unfavourable (highly competitive) niche for germination in pyrophyte species. Here, we assessed the separate effects of heat shock and plant leachates on seed germination of Drosophyllum lusitanicum, an endangered carnivorous plant endemic to Mediterranean fire-prone heathlands. We performed a germination experiment in which seeds were subjected to three treatments: (1) 5 min at 100 °C, (2) watering with plant leachate, and (3) control. Germination rate and seed viability was determined after 63 days. Heat shock stimulated seed germination in D. lusitanicum while plant leachates had inhibitory germination effects without reducing seed viability. Thus, both positive and negative signals could be involved in its successful post-fire recruitment. Fire would break seed dormancy and stimulate seed germination of D. lusitanicum through high temperatures, but also by eliminating allelochemical compounds from the soil. These results help to understand the population dynamics patterns found for D. lusitanicum in natural populations, and highlight the role of fire in the ecology and conservation of this endangered species. Seed dormancy imposed by plant-derived leachates as an adaptive mechanism should be considered more in fire ecology theory.Web Ecology1399-1183 Reuters ISIcarnivorous plant, dormancy, endangered species, germination, heat shock, leachate, population dynamics, species conservation, drosophyllum lusitanicum
Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016)León-Muñoz, Jorge; Urbina, Mauricio A.; Garreaud, René; Iriarte, José LuisAgua y Extremos2018.010.1038/s41598-018-19461-4A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Ninõ event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. This led to very dry conditions and higher than normal solar radiation reaching the surface. Using time series of atmospheric, hydrologic and oceanographic data we show here that an increase in surface water temperature and reduced freshwater input resulted in a weakening of the vertical stratification in the fjords and sounds of this region. This allowed the advection of more saline and nutrient-rich waters, ultimately resulting in an active harmful algal bloom in coastal southern Chile.Scientific Reports2045-2322 Reuters ISIalgal bloom, chile, climate, growth, development and aging, microalga, chile, climate, harmful algal bloom, microalgae
Influence of Glacier Melting and River Discharges on the Nutrient Distribution and DIC Recycling in the Southern Chilean PatagoniaVargas, Cristian A.; Cuevas, L. Antonio; Silva, Nelson; González, Humberto E.; De Pol-Holz, Ricardo; Narváez, Diego A.Cambio de Uso de Suelo2018.010.1002/2017JG003907The Chilean Patagonia constitutes one of the most important and extensive fjord systems worldwide, therefore can be used as a natural laboratory to elucidate the pathway of both organic and inorganic matter in the receiving environment. In this study we use data collected during an intensive oceanographic cruise along the Magellan Strait into the Almirantazgo Fjord in southern Patagonia to evaluate how different sources of dissolved inorganic carbon (DIC) and recycling may impact particulate organic carbon (POC) δ13C and influence the nutrients and carbonate system spatial distribution. The carbonate system presented large spatial heterogeneity. The lowest total alkalinity and DIC were associated to freshwater dilution observed near melting glaciers. The δ13CDIC analysis suggests that most DIC in the upper 50 m depth was not derived from terrestrial organic matter remineralization. 13C-depleted riverine and ice-melting DIC influence the DIC pool along the study area, but due to that DIC concentration from rivers and glaciers is relatively low, atmospheric carbon contribution or biological processes seem to be more relevant. Intense undersaturation of CO2 was observed in high chlorophyll waters. Respired DIC coming from the bottom waters seems to be almost insignificant for the inorganic carbon pool and therefore do not impact significantly the stable carbon isotopic composition of dissolved organic carbon and POC in the upper 50 m depth. Considering the combined effect of cold and low alkalinity waters due to ice melting, our results highlight the importance of these processes in determining corrosive waters for CaCO3 and local acidification processes associated to calving glacier in fjord ecosystems.Journal of Geophysical Research: Biogeosciences2169-8953 Reuters ISIalkalinity, carbon cycle, carbon isotope, carbonate system, chlorophyll, dissolved inorganic carbon, fjord, glacier, melting, nutrient dynamics, ocean acidification, organic matter, particulate organic carbon, remineralization, river discharge, spatial distribution, chile, magellan strait, patagonia
ENSO Influence on Coastal Fog-Water Yield in the Atacama Desert, Chiledel Río, Camilo; Rivera, Daniela; Siegmund, Alexander; Wolf, Nils; Cereceda, Pilar; Larraín, Horacio; Lobos, Felipe; Garcia, Juan-Luis; Osses, Pablo; Zanetta, Nicolás; Lambert, FabriceCiudades Resilientes2018.010.4209/aaqr.2017.01.0022Fog water represents an alternative, abundant and currently unexploited fresh water resource in the coastal Atacama Desert (~20°S). Here, the stratocumulus clouds meet the Coastal Cordillera, producing highly dynamic advective marine fog, a major feature of the local climate that provides water to a hyper-arid environment. One of the main issues that arises in harvesting fog water is our limited understanding of the spatial and inter-annual variability of fog clouds and their associated water content. Here we assess the role of regional-wide El Niño Southern Oscillation (ENSO) forcing on local inter-annual fog-water yields along the coast of Atacama. We contrast 17 years of continuous fog-water data, with local and regional atmospheric and oceanographic variables to determine the link between them and the inter-annual dynamics of fog in northern Chile. Sea surface temperature (SST) in ENSO zone 1 + 2 shows significant correlations with offshore and coastal Atacama SST, as well as with local low cloud cover and fog water yields, which go beyond the annual cycle beat, exposing a potential causal link and influence of ENSO on fog along the Atacama. On the inter-annual time scale, we found that when ENSO 3 + 4 zone SST, specifically during summer, overcome a > 1°C temperature threshold, they incite significantly higher summer fog water yields and explain 79% of the fog variability. Furthermore, satellite images displaying regional extent Sc cloud and fog presence during ENSO extremes reveal higher cloud abundance during El Niño at this latitude. However, 75% of the yearly fog water is collected during winter, and does not appear to be affected in a significant manner by Pacific oscillations. Thus, our results suggest that the utilization of fog as a fresh water resource may be sustainable in the future, regardless of ENSO-induced variability in the region.Aerosol and Air Quality Research1680-8584 Reuters ISIatmospheric pressure, climatology, clouds, fog, nickel, oceanography, scandium, surface waters, water, atacama, fog water, southeast pacific (sep), southern oscillation, stratocumulus clouds, water resources, annual cycle, arid environment, cloud cover, correlation, el nino-southern oscillation, fog, satellite imagery, spatial variation, stratocumulus, sustainability, water resource, atacama desert, chile, coastal cordillera
AOT Retrieval Procedure for Distributed Measurements With Low-Cost Sun Photometers: AOT RETRIEVAL METHOD FOR SUN PHOTOMETERSToledo, F.; Garrido, C.; Díaz, M.; Rondanelli, R.; Jorquera, S.; Valdivieso, P.Zonas Costeras2018.010.1002/2017JD027309We propose a new application of inexpensive light-emitting diode (LED)-based Sun photometers, consisting of measuring the aerosol optical thickness (AOT) with high resolution within metropolitan scales. Previously, these instruments have been used at continental scales by the GLOBE program, but this extension is already covered by more expensive and higher-precision instruments of the AERONET global network. For this we built an open source two-channeled LED-based Sun photometer based on previous developments, with improvements in the hardware, software, and modifications on the calibration procedure. Among these we highlight the use of MODTRAN to characterize the effect introduced by using LED sensors in the AOT retrieval, an open design available for the scientific community and a calibration procedure that takes advantage of a CIMEL Sun photometer located within the city, enables the intercomparison of several LED Sun photometers with a common reference. We estimated the root-mean-square error in the AOT retrieved by the prototypes as 0.006 at the 564 nm and 0.009 at the 408 nm. This error is way under the magnitude of the AOT daily cycle variability measured by us in our campaigns, even for distances closer than 15 km. In addition to inner city campaigns, we also show aerosol-tracing applications by measuring AOT variations from the city of Santiago to the Andes glaciers. Measuring AOT at high spatial resolution in urban areas can improve our understanding of urban scale aerosol circulation, providing information for solar energy planning, health policies, and climatological studies, among others.Journal of Geophysical Research: Atmospheres2169-897X Reuters ISIaeronet, aerosol, calibration, electrode, energy planning, glacier, metropolitan area, photometer, solar power, spatial resolution, urban area, andes, chile, metropolitana
An unusual kind of diurnal streamflow variationCuevas, Jaime G.; Arumí, José L.; Zúñiga-Feest, Alejandra; Little, ChristianCambio de Uso de Suelo2018.010.1515/johh-2017-0041During hydrological research in a Chilean swamp forest, we noted a pattern of higher streamflows close to midday and lower ones close to midnight, the opposite of an evapotranspiration (Et)-driven cycle. We analyzed this diurnal streamflow signal (DSS), which appeared mid-spring (in the growing season). The end of this DSS coincided with a sustained rain event in autumn, which deeply affected stream and meteorological variables. A survey along the stream revealed that the DSS maximum and minimum values appeared 6 and 4 hours earlier, respectively, at headwaters located in the mountain forests/ plantations than at the control point in the swamp forest. Et in the swamp forest was higher in the morning and in the late afternoon, but this process could not influence the groundwater stage. Trees in the mountain headwaters reached their maximum Ets in the early morning and/or close to midday. Our results suggest that the DSS is a wave that moves from forests high in the mountains towards lowland areas, where Et is decoupled from the DSS. This signal delay seems to convert the link between streamflow and Et in an apparent, but spurious positive relationship. It also highlights the role of landscape heterogeneity in shaping hydrological processes.Journal of Hydrology and Hydromechanics0042-790X Reuters ISIevapotranspiration, groundwater, landforms, stream flow, wetlands, growing season, hydrological process, landscape heterogeneities, meteorological variables, mountain forests, riparian zones, streamflow variations, swamp forests, forestry, evapotranspiration, groundwater, groundwater-surface water interaction, growing season, headwater, montane forest, riparian zone, seasonal variation, streamflow, swamp forest, chile
Coupled human-climate signals on the fire history of upper Cachapoal Valley, Mediterranean Andes of Chile, since 1201 CERozas, Vicente; Le Quesne, Carlos; Rojas-Badilla, Moisés; González, Mauro E.; González-Reyes, ÁlvaroCambio de Uso de Suelo2018.010.1016/j.gloplacha.2018.05.013The long-term history of fire regimes in the Mediterranean Andes of Chile is almost unknown. Subalpine woodlands of Austrocedrus chilensis include long-lived trees resilient to low-intensity fires, which can provide valuable tree-ring-based information about fire history. In this work, we performed an annually resolved multicentury reconstruction of past fires from fire-scar records identified in relict Austrocedrus wood found on steep highly-eroded and rocky slopes with coarser fuel structure in the upper Cachapoal Valley, central Andes of Chile. We compared this fire record with historical land-use changes and extensive reconstructions of regional precipitation and temperature, as well as large-scale climatic patterns. The highest fire frequencies were recorded in the Spanish settlement period (1541–1750), when land-clearing activities, cattle ranching, agriculture, and mining practices became widespread after the Spanish conquest. At an interannual time scale, fire occurrence and precipitation were unconnected during the Spanish settlement. By contrast, in the indigenous period (1200–1540), under the influence of the aboriginal Chiquillanes people, fires occurred in wet years with high vegetation productivity. In the livestock grazing period (1751–1950), when large cattle ranches were established, fires occurred in dry years after a wet year. Fires in this period were likely ignited under conditions of high fuel flammability to improve plant production and promote intensive livestock grazing. At a multidecadal time scale, fires were more frequent in cold periods throughout the whole record. These findings suggest that herbaceous fuel accumulation and flammability, modulated by climate variation and human land uses, were the main factors promoting fires spread in this Mediterranean subalpine area. Our research emphasizes the importance of relict Austrocedrus wood for fire history reconstruction and expands knowledge about fire regime shifts over the past eight centuries in southern South America.Global and Planetary Change0921-8181 Reuters ISIforestry, fuels, land use, plants (botany), austrocedrus chilensis, dendrochronology, fire regimes, interannual time scale, land use history, multi-decadal time scale, southern south america, vegetation productivity, fires, climate variation, coniferous tree, dendrochronology, environmental factor, fire history, indigenous population, land use, land use change, nature-society relations, precipitation (climatology), subalpine environment, temperature effect, wood, woodland, andes, chile, mediterranean region, spain, austrocedrus, austrocedrus chilensis, bos
VEIN v0.2.2: an R package for bottom–up vehicular emissions inventoriesIbarra-Espinosa, Sergio; Ynoue, Rita; O&apos;Sullivan, Shane; Pebesma, Edzer; Andrade, María de Fátima; Osses, MauricioCiudades Resilientes2018.010.5194/gmd-11-2209-2018. Emission inventories are the quantification of pollutants from different sources. They provide important information not only for climate and weather studies but also for urban planning and environmental health protection. We developed an open-source model (called Vehicular Emissions Inventory – VEIN v0.2.2) that provides high-resolution vehicular emissions inventories for different fields of studies. We focused on vehicular sources at street and hourly levels due to the current lack of information about these sources, mainly in developing countries. The type of emissions covered by VEIN are exhaust (hot and cold) and evaporative considering the deterioration of the factors. VEIN also performs speciation and incorporates functions to generate and spatially allocate emissions databases. It allows users to load their own emission factors, but it also provides emission factors from the road transport model (Copert), the United States Environmental Protection Agency (EPA) and Brazilian databases. The VEIN model reads, distributes by age of use and extrapolates hourly traffic data, and it estimates emissions hourly and spatially. Based on our knowledge, VEIN is the first bottom–up vehicle emissions software that allows input to the WRF-Chem model. Therefore, the VEIN model provides an important, easy and fast way of elaborating or analyzing vehicular emissions inventories under different scenarios. The VEIN results can be used as an input for atmospheric models, health studies, air quality standardizations and decision making.Geoscientific Model Development1991-9603 Reuters ISIdeveloping world, emission inventory, environmental protection, pollutant source, road transport, traffic emission, urban planning, brazil, united states
Microbial activity during a coastal phytoplankton bloom on the Western Antarctic Peninsula in late summerAlcamán-Arias, María E; Farías, Laura; Verdugo, Josefa; Alarcón-Schumacher, Tomás; Díez, BeatrizZonas Costeras2018.010.1093/femsle/fny090Phytoplankton biomass during the austral summer is influenced by freezing and melting cycles as well as oceanographic processes that enable nutrient redistribution in the West Antarctic Peninsula (WAP). Microbial functional capabilities, metagenomic and metatranscriptomic activities as well as inorganic 13C- and 15N-assimilation rates were studied in the surface waters of Chile Bay during two contrasting summer periods in 2014. Concentrations of Chlorophyll a (Chla) varied from 0.3 mg m−3 in February to a maximum of 2.5 mg m−3 in March, together with a decrease in nutrients; however, nutrients were never depleted. The microbial community composition remained similar throughout both sampling periods; however, microbial abundance and activity changed with Chla levels. An increased biomass of Bacillariophyta, Haptophyceae and Cryptophyceae was observed along with night-grazing activity of Dinophyceae and ciliates (Alveolates). During high Chla conditions, HCO3− uptake rates during daytime incubations increased 5-fold (>2516 nmol C L−1 d−1), and increased photosynthetic transcript numbers that were mainly associated with cryptophytes; meanwhile night time NO3− (>706 nmol N L−1 d−1) and NH4+ (41.7 nmol N L−1 d−1) uptake rates were 2- and 3-fold higher, respectively, due to activity from Alpha-/Gammaproteobacteria and Bacteroidetes (Flavobacteriia). Due to a projected acceleration in climate change in the WAP, this information is valuable for predicting the composition and functional changes in Antarctic microbial communities.FEMS Microbiology Letters1574-6968 Reuters ISIammonia, bicarbonate, carbon 13, chlorophyll a, nitrate, nitrogen 15, surface water, bacterial protein, sea water, algal bloom, alphaproteobacteria, antarctica, bacteroidetes, biomass, carbon fixation, coastal waters, concentration (parameters), cryptophyta, diatom, dinoflagellate, gammaproteobacteria, haptophyta, incubation time, metagenomics, metatranscriptomics, microbial activity, microbial community, nitrogen fixation, nonhuman, omics, population abundance, priority journal, salinity, short survey, species composition, summer, water sampling, water temperature, bacterium, chemistry, classification, ecosystem, eukaryote, genetics, growth, development and aging, metabolism, microbiology, microflora, photosynthesis, phytoplankton, season, antarctic regions, bacteria, bacterial proteins, ecosystem, eukaryota, microbiota, photosynthesis, phytoplankton, seasons, seawater
Dendrohydrology and water resources management in south-central Chile: lessons from the Río Imperial streamflow reconstructionFernández, Alfonso; Muñoz, Ariel; González-Reyes, Álvaro; Aguilera-Betti, Isabella; Toledo, Isadora; Puchi, Paulina; Sauchyn, David; Crespo, Sebastián; Frene, Cristian; Mundo, Ignacio; González, Mauro; Vignola, RaffaeleAgua y Extremos2018.010.5194/hess-22-2921-2018Streamflow in south-central Chile (SCC,  ∼  37–42° S) is vital for agriculture, forestry production, hydroelectricity, and human consumption. Recent drought episodes have generated hydrological deficits with damaging effects on these activities. This region is projected to undergo major reductions in water availability, concomitant with projected increases in water demand. However, the lack of long-term records hampers the development of accurate estimations of natural variability and trends. In order to provide more information on long-term streamflow variability and trends in SCC, here we report findings of an analysis of instrumental records and a tree-ring reconstruction of the summer streamflow of the Río Imperial ( ∼  37° 40′ S–38° 50′ S). This is the first reconstruction in Chile targeted at this season. Results from the instrumental streamflow record ( ∼  1940 onwards) indicated that the hydrological regime is fundamentally pluvial with a small snowmelt contribution during spring, and evidenced a decreasing trend, both for the summer and the full annual record. The reconstruction showed that streamflow below the average characterized the post-1980 period, with more frequent, but not more intense, drought episodes. We additionally found that the recent positive phase of the Southern Annular Mode has significantly influenced streamflow. These findings agree with previous studies, suggesting a robust regional signal and a shift to a new hydrological scenario. In this paper, we also discuss implications of these results for water managers and stakeholders; we provide rationale and examples that support the need for the incorporation of tree-ring reconstructions into water resources management.Hydrology and Earth System Sciences1607-7938 Reuters ISIdrought, forestry, stream flow, accurate estimation, forestry production, hydrological regime, hydrological scenarios, southern annular mode, streamflow variability, tree-ring reconstruction, water resources management, water resources, climate signal, dendrochronology, drought, hydrological regime, paleohydrology, reconstruction, snowmelt, streamflow, water management, water resource, chile
Megafires in Chile 2017: Monitoring multiscale environmental impacts of burned ecosystemsde la Barrera, Francisco; Barraza, Francisco; Favier, Philomène; Ruiz, Vannia; Quense, JorgeCiudades Resilientes2018.010.1016/j.scitotenv.2018.05.119During the summer of 2017, several megafires in South-Central Chile burned down forest plantations, native forests, shrublands and human settlements. National authorities identified the relevant effects of the wildfires on infrastructure and ecosystems. However, other indirect effects such as the risk of flooding or, increased air pollution were not assessed. The present study assesses: i) the geographic characterization of wildfires, ii) amount of damage to ecosystems and the severity of wildfires, iii) the effects of megafires on air quality in nearby and distant urban areas, and iv) identification of cities potentially exposed to landslides and flooding. We ran remote sensing analyses based on the Normalized Burn Ratio taken from Landsat imagery, “active fires” from MODIS, and ASTER GDEM. The particulate matter (PM10 and PM2.5) levels measured on 34 Chilean's municipalities were correlated with the burning area/distance ratio by Spearman correlation. Socionatural hazards were evaluated using multi-criteria analyses combining proximity to burned areas, severity, potential flow of water and sediments as indicated by the Digital Elevation Model, drainage networks and the location of human settlements. 91 burned areas were identified, covering 529,794 ha. The most affected ecosystems were forest plantations and native shrublands. We found significant correlations between burned area/distance ratios and PM2.5 and PM10 levels, leading to increased levels over the Chilean air quality standard in the most populated cities. 37 human settlements were at increased risk of landslides and flooding hazards after fires and eleven could now be characterized as dangerously exposed. The 2017 wildfires in Chile have had an impact at both a small and large scale, with far-reaching air pollutants dispersing and affecting >74% of the Chilean population. The impact of the wildfires was also extended over time, creating future potential for landslides and flooding, with the risk increasing in rainy seasons.Science of The Total Environment0048-9697 Reuters ISIair pollution, air quality, damage detection, fires, floods, forestry, hazards, landslides, particles (particulate matter), remote sensing, risk assessment, digital elevation model, ecosystem services, impact of wildfires, multi criteria analysis, natural hazard, particulate matter, remote sensing analysis, spearman correlation, ecosystems, air quality, atmospheric pollution, ecosystem service, environmental impact assessment, environmental monitoring, geographical variation, remote sensing, risk assessment, wildfire, air pollution, air quality, article, atmospheric dispersion, chile, city, ecosystem health, environmental impact assessment, environmental monitoring, flooding, forest, hazard assessment, land drainage, landslide, particle size, particulate matter, priority journal, remote sensing, scrub, sediment, spatial analysis, urban area, water flow, wildfire, chile
Applying knowledge governance to understand the role of science in environmental regulation: The case of arsenic in ChileIbarra, Cecilia; O’Ryan, Raúl; Silva, BárbaraGobernanza e Interfaz Ciencia y Política2018.010.1016/j.envsci.2018.05.002The relationship between scientific knowledge and decision-making surrounding environmental issues is complex and represents a flourishing area of scholarship and practice. However, a sense of frustration persists regarding efforts to increase the use of science for decision-making. Regulations of copper smelter arsenic emissions developed in Chile during the 1990s represent a successful example of science informing policy making. The case involved production and use of local science in contrast to the common practice of copying international ambient standards. In this paper, we investigate arsenic regulation in Chile in the 1990s and focus on the role of the major science intervention during the process, project FONDEF2-24. The case is examined through the lens of knowledge governance (van Kerkhoff and Pilbeam, 2017). This theoretically-oriented approach guides our critical reflection on the relationship between knowledge and policy making, taking into consideration the formal and informal rules that shape the intervention and the underlying social and cultural patterns. The success of the science intervention’s influence on policy is better understood with such a perspective. We expand the knowledge governance approach by scrutinizing the relations of coherence between levels of analysis to assess their alignment. The approach could be helpful for studying other cases, particularly at times when a new field of policy is emerging.Environmental Science & Policy1462-9011 Reuters ISIarsenic, copper, article, chile, climate change, conceptual framework, environmental management, environmental policy, epistemology, government regulation, knowledge, mining, priority journal, rural population, social interaction, south and central america, water contamination
Facing the climate change conundrum at the South Pole: actors’ perspectives on the implications of global warming for Chilean Antarctic governanceGladkova, Ekaterina; Blanco-Wells, Gustavo; Nahuelhual, LauraGobernanza e Interfaz Ciencia y Política2018.010.1080/17518369.2018.1468195Antarctica is recognized as being geopolitically and scientifically important, and as one of the regions with the greatest potential to affect and be affected by global climate change. Still, little is known in practice about how climate change will be handled within the main governance framework of the continent: the Antarctic Treaty System (ATS). Using qualitative interviews, participant observations and policy document analysis, this paper explores the perspectives of Chilean scientific, political and non-governmental actors regarding the implications of climate change for the current Antarctic governance framework. Results corroborate a misalignment of the climate change agenda and the ATS, stemming from the divergent views displayed by a wide network of actors. From the interviews, two predominant visions emerge: (i) climate change as an opportunity, where actors recognize the role of Antarctica in regulating global climate and stress greater opportunities to conduct Antarctic-based climate change research, the need for strategic international collaboration, and the reinforcement of Chile’s position in Antarctica through science; (ii) climate change as a burden where actors acknowledge climate change as a global problem, largely external to Antarctica, express disbelief regarding the effectiveness of local actions to tackle climate change and do not associate with climate change governance. The study concludes that climate change may become a dividing, rather than a unifying, field of action in Chilean Antarctic governance, reinforcing previously existing geopolitical tendencies.Polar Research1751-8369 Reuters ISIantarctic treaty, climate change, geopolitics, global climate, global warming, governance approach, perception, antarctica, chile, east antarctica, south pole
Foehn Event Triggered by an Atmospheric River Underlies Record-Setting Temperature Along Continental AntarcticaBozkurt, D.; Rondanelli, R.; Marín, J. C.; Garreaud, R.Zonas Costeras; Agua y Extremos; Transversal2018.010.1002/2017JD027796A record‐setting temperature of 17.5°C occurred on 24 March 2015 at the Esperanza station located near the northern tip of the Antarctic Peninsula (AP). We studied the event using surface station data, satellite imagery, reanalysis data, and numerical simulations. The Moderate Resolution Imaging Spectroradiometer Antarctic Ice Shelf Image Archive provides clear evidence for disintegration and advection of sea ice, as well as the formation of melt ponds on the ice sheet surface at the base of the AP mountain range. A deep low‐pressure center over the Amundsen‐Bellingshausen Sea and a blocking ridge over the southeast Pacific provided favorable conditions for the development of an atmospheric river with a northwest‐southeast orientation, directing warm and moist air toward the AP, and triggering a widespread foehn episode. A control simulation using a regional climate model shows the existence of local topographically induced warming along the northern tip of the AP (∼60% of the full temperature signal) and the central part of the eastern AP (>90% of the full temperature signal) with respect to a simulation without topography. These modeling results suggest that more than half of the warming experienced at Esperanza can be attributed to the foehn effect (a local process), rather than to the large‐scale advection of warm air from the midlatitudes. Nevertheless, the local foehn effect also has a large‐scale advection component, since the atmospheric river provides water vapor for orographic precipitation enhancement and latent heat release, which makes it difficult to completely disentangle the role of local versus large‐scale processes in explaining the extreme event.Journal of Geophysical Research: Atmospheres2169-897X Reuters ISIadvection, atmospheric moisture, climate change, climate modeling, extreme event, foehn, high temperature, ice shelf, meteorology, modis, regional climate, temperature, amundsen sea, antarctic peninsula, antarctica, bellingshausen sea, pacific ocean, pacific ocean (southeast), southern ocean, west antarctica, esperanza
Evolution of air quality in Santiago: The role of mobility and lessons from the science-policy interfaceGallardo, Laura; Barraza, Francisco; Ceballos, Andrés; Galleguillos, Mauricio; Huneeus, Nicolás; Lambert, Fabrice; Ibarra, Cecilia; Munizaga, Marcela; O'Ryan, Raúl; Osses, Mauricio; Tolvett, Sebastián; Urquiza, Anahí; Véliz, Karina D.Ciudades Resilientes; Gobernanza e Interfaz Ciencia y Política2018.010.1525/elementa.293Worldwide, urbanization constitutes a major and growing driver of global change and a distinctive feature of the Anthropocene. Thus, urban development paths present opportunities for technological and societal transformations towards energy efficiency and decarbonization, with benefits for both greenhouse gas (GHG) and air pollution mitigation. This requires a better understanding of the intertwined dynamics of urban energy and land use, emissions, demographics, governance, and societal and biophysical processes. In this study, we address several characteristics of urbanization in Santiago (33.5°S, 70.5°W, 500 m a.s.l.), the capital city of Chile. Specifically, we focus on the multiple links between mobility and air quality, describe the evolution of these two aspects over the past 30 years, and review the role scientific knowledge has played in policy-making. We show evidence of how technological measures (e.g., fuel quality, three-way catalytic converters, diesel particle filters) have been successful in decreasing coarse mode aerosol (PM10) concentrations in Santiago despite increasing urbanization (e.g., population, motorization, urban sprawl). However, we also show that such measures will likely be insufficient if behavioral changes do not achieve an increase in the use of public transportation. Our investigation seeks to inform urban development in the Anthropocene, and our results may be useful for other developing countries, particularly in Latin America and the Caribbean where more than 80% of the population is urban.Elem Sci Anth2325-1026 Reuters ISIaerosol, air quality, anthropocene, atmospheric pollution, capital city, climate change, developing world, energy efficiency, global change, greenhouse gas, mobility, particulate matter, policy making, pollution control, urban development, urban population, urban sprawl, urbanization, chile, latin america
The PMIP4 contribution to CMIP6 – Part 1: Overview and over-arching analysis planKageyama, Masa; Braconnot, Pascale; Harrison, Sandy P.; Haywood, Alan M.; Jungclaus, Johann H.; Otto-Bliesner, Bette L.; Peterschmitt, Jean-Yves; Abe-Ouchi, Ayako; Albani, Samuel; Bartlein, Patrick J.; Brierley, Chris; Crucifix, Michel; Dolan, Aisling; Fernandez-Donado, Laura; Fischer, Hubertus; Hopcroft, Peter O.; Ivanovic, Ruza F.; Lambert, Fabrice; Lunt, Daniel J.; Mahowald, Natalie M.; Peltier, W. Richard; Phipps, Steven J.; Roche, Didier M.; Schmidt, Gavin A.; Tarasov, Lev; Valdes, Paul J.; Zhang, Qiong; Zhou, TianjunCiudades Resilientes2018.010.5194/gmd-11-1033-2018This paper is the first of a series of four GMD papers on the PMIP4-CMIP6 experiments. Part 2 (Otto-Bliesner et al., 2017) gives details about the two PMIP4-CMIP6 interglacial experiments, Part 3 (Jungclaus et al., 2017) about the last millennium experiment, and Part 4 (Kageyama et al., 2017) about the Last Glacial Maximum experiment. The mid-Pliocene Warm Period experiment is part of the Pliocene Model Intercomparison Project (PlioMIP) – Phase 2, detailed in Haywood et al. (2016). The goal of the Paleoclimate Modelling Intercomparison Project (PMIP) is to understand the response of the climate system to different climate forcings for documented climatic states very different from the present and historical climates. Through comparison with observations of the environmental impact of these climate changes, or with climate reconstructions based on physical, chemical, or biological records, PMIP also addresses the issue of how well state-of-the-art numerical models simulate climate change. Climate models are usually developed using the present and historical climates as references, but climate projections show that future climates will lie well outside these conditions. Palaeoclimates very different from these reference states therefore provide stringent tests for state-of-the-art models and a way to assess whether their sensitivity to forcings is compatible with palaeoclimatic evidence. Simulations of five different periods have been designed to address the objectives of the sixth phase of the Coupled Model Intercomparison Project (CMIP6): the millennium prior to the industrial epoch (CMIP6 name: past1000); the mid-Holocene, 6000 years ago (midHolocene); the Last Glacial Maximum, 21 000 years ago (lgm); the Last Interglacial, 127 000 years ago (lig127k); and the mid-Pliocene Warm Period, 3.2 million years ago (midPliocene-eoi400). These climatic periods are well documented by palaeoclimatic and palaeoenvironmental records, with climate and environmental changes relevant for the study and projection of future climate changes. This paper describes the motivation for the choice of these periods and the design of the numerical experiments and database requests, with a focus on their novel features compared to the experiments performed in previous phases of PMIP and CMIP. It also outlines the analysis plan that takes advantage of the comparisons of the results across periods and across CMIP6 in collaboration with other MIPs.Geoscientific Model Development1991-9603 Reuters ISIclimate change, climate forcing, climate prediction, climate variation, cmip, environmental impact, holocene, last glacial maximum, last interglacial, paleoclimate, paleoenvironment, pliocene
Self-organizing processes in urban green commons. The case of the Angachilla wetland, Valdivia-ChileCorrea, Heidy; Blanco-Wells, Gustavo; Barrena, José; Tacón, AlbertoGobernanza e Interfaz Ciencia y Política2018.010.18352/ijc.856This article focuses on self-organizing processes in contested urban social-ecological systems. It analyzes a wetland conservation program and civic management effort in the Angachilla sector of the city of Valdivia, Chile in a 15-year time frame. The aim is to understand what triggers collective actions and self-organization in the attempts of preserving an urban green common. The study uses a qualitative approach based on action-research methodologies. It examines key variables influencing self-organizing processes; including social-environmental crises, governance vacuums, wetland valuation, and leadership. It also discusses collective strategies for the transformation of negative feedback loops, such as norms and regulations detrimental to wetland protection, and those related to resistance to change of wetland surface area due to unregulated urbanization. From an Urban Green Commons perspective, this work illustrates the complexity of dealing with contested nature, making it a resource difficult to govern collectively given all the different interests and values in place. It also shows that there have been successful periods of active wetland management that have influenced active democratic processes regarding land use and land use change in the city.International Journal of the Commons1875-0281 Reuters ISIchile, self-organization, social-ecological systems, urban green commons, wetlands
The first 300-year streamflow reconstruction of a high-elevation river in Chile using tree rings: HIGH-ELEVATION CHILEAN RIVER STREAMFLOW RECONSTRUCTIONBarria, Pilar; Peel, Murray C.; Walsh, Kevin J. E.; Muñoz, ArielAgua y Extremos2018.010.1002/joc.5186In central Chile, increasing demand for water and decreasing runoff volumes due to drier conditions have placed catchments in this zone under water stress. However, scarcity of observed data records increases the difficulty of planning future water supply. Instrumental records suggest a reduction in streamflow over the last 56 years. However, this change is not statistically significant and the lack of meteorological stations with long records in this mountainous region hampers a deeper analysis, motivating the use of tree rings to analyse whether these changes are part of a long-term trend. This work represents the first high-elevation runoff reconstruction in Chile using 300 years of tree ring chronologies of Araucaria araucana and Astroceudrus chilensis. The upper part of Biobío river melting season runoff (October–March) and pluvial season runoff (April–September) was reconstructed and analysed to investigate the influence of large-scale climatic drivers on runoff generation, current drought trends and to improve the understanding of climate variability in this region. We obtained positive correlations between the 20-year moving average of reconstructed pluvial season runoff and reconstructed Pacific Decadal Oscillation (PDO), which is indicative of multi-decadal variability. We also found a negative correlation between the 11-year moving average of reconstructed melting season runoff and the PDO and positive correlations with the Southern Annular Mode (SAM). Important differences in the runoff variability of the upper and the lower part of the catchment were identified which are in part led by the influence of the large-scale climatic features that drive runoff generation in both regions. We found that the changes observed in the instrumental records are part of multi-decadal cycles led by the PDO and SAM for pluvial season runoff and melting season runoff, respectively.International Journal of Climatology0899-8418 Reuters ISIcatchments, climate change, digital storage, drought, forestry, melting, stream flow, water supply, decadal variability, high elevation, meteorological station, negative correlation, pacific decadal oscillation, positive correlations, southern annular mode, tree-ring chronologies, runoff, chronology, decadal variation, hydrology, reconstruction, river, runoff, streamflow, tree ring, chile, araucaria araucana
Climate variability and forest fires in central and south-central ChileUrrutia-Jalabert, Rocío; González, Mauro E.; González-Reyes, Álvaro; Lara, Antonio; Garreaud, RenéCambio de Uso de Suelo; Agua y Extremos2018.010.1002/ecs2.2171This paper evaluates the relationship between fire occurrence (number and burned area) and climate variability (precipitation and maximum temperatures) across central and south-central Chile (32°–43° S) during recent decades (1976–2013). This region sustains the largest proportion of the Chilean population, contains ecologically important remnants of endemic ecosystems, the largest extension of forest exotic plantations, and concentrates most of the fire activity in the country. Fire activity in central Chile was mainly associated with above-average precipitation during winter of the previous year and with dry conditions during spring to summer. The later association was particularly strong in the southern, wetter part of the study region. Maximum temperature had a positive significant relationship with burned area across the study region, with stronger correlations toward the south. Fires in central Chile were significantly related to El Nino~ –Southern Oscillation, through rainfall anomalies during the year previous to the fire season. The Antarctic Oscillation during winter through summer was positively related to fires across the study area due to drier/warmer conditions associated with the positive polarity of this oscillation. Climate change projections for the region reveal an all-season decrease in precipitation and increases in temperature, that may likely result in an increment of the occurrence and the area affected by fires, as it has been observed during a multi-year drought afflicting central Chile since 2010.Ecosphere2150-8925 Reuters ISIantarctic oscillation, climate change, el niño–southern oscillation (enso), exotic plantations, forest fires, mediterranean forests, temperate forests
δ 18 O of Fissurella maxima as a proxy for reconstructing Early Holocene sea surface temperatures in the coastal Atacama desert (25°S)Flores, Carola; Gayo, Eugenia M.; Salazar, Diego; Broitman, Bernardo R.Ciudades Resilientes2018.010.1016/j.palaeo.2018.03.031Fissurella maxima is a keyhole limpet that is abundant and well preserved in archaeological shell midden sites along the coast of Chile, making it an appropriate species to use for reconstructions of past sea surface temperature (SST). In the present study we evaluate the potential of F. maxima shells as a proxy of SST by analysing δ18O of modern shells collected alive from the Atacama desert (area of Taltal, 25°S) and archaeological shells from two Early Holocene rockshelter sites: 224A and Paposo Norte 9. Reconstructed SST from modern F. maxima shells were related to SST obtained from in situ thermometers, supporting the use of this mollusc species as a paleotemperature archive. Mean SST reconstructed from Early Holocene archaeological shells (14.13 °C) was 2.86 °C cooler than mean temperature recorded in modern shells (16.99 °C). Mean SST reconstructed from modern shells was ~1.04 °C warmer than the mean temperature of in situ thermometers (15.95°C). Hence the paleo–SST data from archaeological sites 224A and Paposo Norte 9 enrich the Early Holocene nearshore paleoceanographic scenario of the Pacific coast of South America, with mean SST cooler than present-day SST. Our results validate the use of F. maxima shells as a SST proxy and contribute to a better understanding of the latitudinal distribution of the coastal upwelling regime during the Early Holocene, temporal changes in the structure of the Humboldt Current along the Holocene, and its influence on human adaptation through the prehistory of South America.Palaeogeography, Palaeoclimatology, Palaeoecology0031-0182 Reuters ISIarchaeological evidence, calibration, carbonate, coastal zone, gastropod, holocene, in situ measurement, midden, oxygen isotope, paleoceanography, paleotemperature, proxy climate record, reconstruction, sea surface temperature, shell, stable isotope, thermometry, atacama desert, chile, humboldt current, pacific coast [chile], pacific coast [south america], pacific ocean, pacific ocean (southeast), fissurella maxima, mollusca
Local and remote black carbon sources in the Metropolitan Area of Buenos AiresDiaz Resquin, Melisa; Santágata, Daniela; Gallardo, Laura; Gómez, Darío; Rössler, Cristina; Dawidowski, LauraCiudades Resilientes2018.010.1016/j.atmosenv.2018.03.018Equivalent black carbon () mass concentrations in the fine inhalable fraction of airborne particles () were determined using a 7-wavelength Aethalometer for 17 months, between November 2014 and March 2016, for a suburban location of the Metropolitan Area of Buenos Aires (MABA), Argentina. In addition to describing seasonal and diurnal black carbon (BC) cycles for the first time in this region, the relative contributions of fossil fuel and remote and local biomass burning were determined by distinguishing different carbonaceous components based on their effect on light attenuation for different wavelengths. Trajectory analyses and satellite-based fire products were used to illustrate the impact of long-range transport of particles emitted by non-local sources. EBC data showed a marked diurnal cycle, largely modulated by traffic variations and the height of the boundary layer, and a seasonal cycle with monthly median EBC concentrations (in ) ranging from 1.5 (February) to 3.4 (June). Maximum values were found during winter due to the combination of prevailingly stable atmospheric conditions and the increase of fossil fuel emissions, derived primarily from traffic and biomass burning from the domestic use of wood for heating. The use of charcoal grills was also detected and concentrated during weekends. The average contribution of fossil fuel combustion sources to concentrations was 96%, with the remaining 4% corresponding to local and regional biomass burning. During the entire study period, only two events were identified during which concentrations attributed to regional biomass burning accounted for over 50% of total ; these events demonstrate the relevance of agricultural and forestry activities that take place far from the city yet whose emissions can affect the urban atmosphere of the MABA.Atmospheric Environment1352-2310 Reuters ISIaerosols, biomass, boundary layers, carbon, charcoal, atmospheric conditions, biomass-burning, black carbon, carbonaceous components, fossil fuel combustion, fossil fuel emissions, megacities, relative contribution, fossil fuels, black carbon, equivalent black carbon, fossil fuel, unclassified drug, aerosol, anthropogenic source, biomass burning, black carbon, boundary layer, concentration (composition), diurnal variation, fossil fuel, long range transport, metropolitan area, particle size, pollutant transport, seasonal variation, wavelength, aerosol, agriculture, airborne particle, argentina, article, atmospheric transport, attenuation, autumn, biomass burning, boundary layer, carbon source, circadian rhythm, combustion, concentration (parameters), exhaust gas, fire and fire related phenomena, forestry, heating, light, mass, particulate matter, priority journal, satellite imagery, seasonal variation, spatiotemporal analysis, spring, suburban area, summer, traffic, winter, wood, argentina, buenos aires [argentina]
New insights into the use of stable water isotopes at the northern Antarctic Peninsula as a tool for regional climate studiesFernandoy, Francisco; Tetzner, Dieter; Meyer, Hanno; Gacitúa, Guisella; Hoffmann, Kirstin; Falk, Ulrike; Lambert, Fabrice; MacDonell, ShelleyCiudades Resilientes2018.010.5194/tc-12-1069-2018Due to recent atmospheric and oceanic warming, the Antarctic Peninsula is one of the most challenging regions of Antarctica to understand in terms of both local- and regional-scale climate signals. Steep topography and a lack of long-term and in situ meteorological observations complicate the extrapolation of existing climate models to the sub-regional scale. Therefore, new techniques must be developed to better understand processes operating in the region. Isotope signals are traditionally related mainly to atmospheric conditions, but a detailed analysis of individual components can give new insight into oceanic and atmospheric processes. This paper aims to use new isotopic records collected from snow and firn cores in conjunction with existing meteorological and oceanic datasets to determine changes at the climatic scale in the northern extent of the Antarctic Peninsula. In particular, a discernible effect of sea ice cover on local temperatures and the expression of climatic modes, especially the Southern Annular Mode (SAM), is demonstrated. In years with a large sea ice extension in winter (negative SAM anomaly), an inversion layer in the lower troposphere develops at the coastal zone. Therefore, an isotope–temperature relationship (δ–T) valid for all periods cannot be obtained, and instead the δ–T depends on the seasonal variability of oceanic conditions. Comparatively, transitional seasons (autumn and spring) have a consistent isotope–temperature gradient of +0.69 ‰ °C−1. As shown by firn core analysis, the near-surface temperature in the northern-most portion of the Antarctic Peninsula shows a decreasing trend (−0.33 °C year−1) between 2008 and 2014. In addition, the deuterium excess (dexcess) is demonstrated to be a reliable indicator of seasonal oceanic conditions, and therefore suitable to improve a firn age model based on seasonal dexcess variability. The annual accumulation rate in this region is highly variable, ranging between 1060 and 2470 kg m−2 year−1 from 2008 to 2014. The combination of isotopic and meteorological data in areas where data exist is key to reconstruct climatic conditions with a high temporal resolution in polar regions where no direct observations exist.The Cryosphere1994-0424 Reuters ISIaccumulation rate, climate modeling, climate signal, data set, deuterium, ice cover, meteorology, regional climate, sea ice, stable isotope, surface temperature, topography, troposphere, warming, antarctic peninsula, antarctica, west antarctica
Atmospheric dynamics and habitability range in Earth-like aquaplanets obliquity simulationsNowajewski, Priscilla; Rojas, M.; Rojo, P.; Kimeswenger, S.Gobernanza e Interfaz Ciencia y Política2018.010.1016/j.icarus.2018.01.002We present the evolution of the atmospheric variables that affect planetary climate by increasing the obliquity by using a general circulation model (PlaSim) coupled to a slab ocean with mixed layer flux correction. We increase the obliquity between 30° and 90° in 16 aquaplanets with liquid sea surface and perform the simulation allowing the sea ice cover formation to be a consequence of its atmospheric dynamics. Insolation is maintained constant in each experiment, but changing the obliquity affects the radiation budget and the large scale circulation. Earth-like atmospheric dynamics is observed for planets with obliquity under 54°. Above this value, the latitudinal temperature gradient is reversed giving place to a new regime of jet streams, affecting the shape of Hadley and Ferrel cells and changing the position of the InterTropical Convergence Zone. As humidity and high temperatures determine Earth’s habitability, we introduce the wet bulb temperature as an atmospheric index of habitability for Earth-like aquaplanets with above freezing temperatures. The aquaplanets are habitable all year round at all latitudes for values under 54°; above this value habitability decreases toward the poles due to high temperatures.Icarus0019-1035 Reuters ISIastrobiology, atmospheres, atmospheres, dynamics, evolution, geophysics, meteorology, terrestrial planets
Alternative approaches for estimating missing climate data: application to monthly precipitation records in South-Central ChileBarrios, Alonso; Trincado, Guillermo; Garreaud, RenéAgua y Extremos2018.010.1186/s40663-018-0147-xBackground Over the last decades interest has grown on how climate change impacts forest resources. However, one of the main constraints is that meteorological stations are riddled with missing climatic data. This study compared five approaches for estimating monthly precipitation records: inverse distance weighting (IDW), a modification of IDW that includes elevation differences between target and neighboring stations (IDWm), correlation coefficient weighting (CCW), multiple linear regression (MLR) and artificial neural networks (ANN). Methods A complete series of monthly precipitation records (1995–2012) from twenty meteorological stations located in central Chile were used. Two target stations were selected and their neighboring stations, located within a radius of 25 km (3 stations) and 50 km (9 stations), were identified. Cross-validation was used for evaluating the accuracy of the estimation approaches. The performance and predictive capability of the approaches were evaluated using the ratio of the root mean square error to the standard deviation of measured data (RSR), the percent bias (PBIAS), and the Nash-Sutcliffe efficiency (NSE). For testing the main and interactive effects of the radius of influence and estimation approaches, a two-level factorial design considering the target station as the blocking factor was used. Results ANN and MLR showed the best statistics for all the stations and radius of influence. However, these approaches were not significantly different with IDWm. Inclusion of elevation differences into IDW significantly improved IDWm estimates. In terms of precision, similar estimates were obtained when applying ANN, MLR or IDWm, and the radius of influence had a significant influence on their estimates, we conclude that estimates based on nine neighboring stations located within a radius of 50 km are needed for completing missing monthly precipitation data in regions with complex topography. Conclusions It is concluded that approaches based on ANN, MLR and IDWm had the best performance in two sectors located in south-central Chile with a complex topography. A radius of influence of 50 km (9 neighboring stations) is recommended for completing monthly precipitation data.Forest Ecosystems2197-5620 Reuters ISIartificial neural networks, climatological data, cross-validation, multiple linear regression
Using the Weather Research and Forecasting (WRF) Model for Precipitation Forecasting in an Andean Region with Complex TopographyYáñez-Morroni, Gonzalo; Gironás, Jorge; Caneo, Marta; Delgado, Rodrigo; Garreaud, RenéAgua y Extremos2018.010.3390/atmos9080304The Weather Research and Forecasting (WRF) model has been successfully used in weather prediction, but its ability to simulate precipitation over areas with complex topography is not optimal. Consequently, WRF has problems forecasting rainfall events over Chilean mountainous terrain and foothills, where some of the main cities are located, and where intense rainfall occurs due to cutoff lows. This work analyzes an ensemble of microphysics schemes to enhance initial forecasts made by the Chilean Weather Agency in the front range of Santiago. We first tested different vertical levels resolution, land use and land surface models, as well as meteorological forcing (GFS/FNL). The final ensemble configuration considered three microphysics schemes and lead times over three rainfall events between 2015 and 2017. Cutoff low complex meteorological characteristics impede the temporal simulation of rainfall properties. With three days of lead time, WRF properly forecasts the rainiest N-hours and temperatures during the event, although more accuracy is obtained when the rainfall is caused by a meteorological frontal system. Finally, the WSM6 microphysics option had the best performance, although further analysis using other storms and locations in the area are needed to strengthen this result.Atmosphere2073-4433 Reuters ISIland use, rain, topography, complex topographies, flash flood, land surface models, meteorological forcing, mountainous terrain, precipitation forecasting, temporal simulation, weather research and forecasting models, weather forecasting, atmospheric modeling, computer simulation, ensemble forecasting, precipitation (climatology), regional climate, temporal analysis, topography, urban atmosphere, weather forecasting
The 2010-2015 Megadrought and its influence on the fire regime in central and south-central ChileGonzález, Mauro E.; Gómez-González, Susana; Lara, Antonio; Garreaud, René; Díaz-Hormazábal, IgnacioCambio de Uso de Suelo; Agua y Extremos2018.010.1002/ecs2.2300Forest fire activity has increased in recent years in central and south-central Chile. Drought conditions have been associated with the increase of large wildfires, area burned and longer fire seasons. This study examines the influence of drought on fire regimes and discusses landscape management opportunities to decrease fire hazard. Specifically, we investigate the effect of the 2010–2015 Megadrought (MD) compared to 1990–2009 period on fire activity (fire-season length, number of fires and burned area across months, fire sizes, regions and vegetation cover types, simultaneity, and duration of fires) in central and south-central Chile (32°–39° S), using contemporary fire statistics derived from the Chilean Forest Service. For large fire events (>200 ha) the average season length increased by 67 d (44%), comparing 2010–2015 to 1990–2009. Earlier and later ignition dates resulted in extended fire seasons in MD years. During the MD, the number, area burned, simultaneity, and duration of large fires increased significantly compared to the control period, including the unprecedented occurrence of large fires during winter. The burned area in large fires increased in all vegetation types, during the MD compared to the control period, especially in the exotic plantation cover type. The regions that were most affected by fire (i.e., total area burned) during the MD wereMaule, B ıo-B ıo, and Araucan ıa (35–39° S) that concentrate >75% of forest plantations in Chile. Although both maximum temperatures and precipitation are drivers of fire activity, a simple attribution analysis indicates that the sustained rainfall deficit during 2010–2015 was the most critical factor in the enhanced fire activity. Future climate change predictions indicate more recurrent, intense, and temporally extended droughts for central and south-central Chile. Under this scenario, land-use planning and fire and forest management strategies must promote a more diverse and less flammable landscape mosaic limiting high load, homogenous, and continuous exotic plantations.Ecosphere2150-8925 Reuters ISIdrought, fire regimes, fire-prone vegetation, fire-season length
Climate change governance in the Anthropocene: Emergence of Polycentrism in ChileArriagada, Rodrigo Antonio; Aldunce, Paulina; Blanco, Gustavo; Ibarra, Cecilia; Moraga, Pilar; Nahuelhual, Laura; O'Ryan, Raul; Urquiza, Anahí; Gallardo, LauraCiudades Resilientes; Gobernanza e Interfaz Ciencia y Política2018.010.1525/elementa.329Multilateral efforts are essential to an effective response to climate change, but individual nations define climate action policy by translating local and global objectives into adaptation and mitigation actions. We propose a conceptual framework to explore opportunities for polycentric climate governance, understanding polycentricity as a property that encompasses the potential for coordinating multiple centers of semiautonomous decision-making. We assert that polycentrism engages a diverse array of public and private actors for a more effective approach to reducing the threat of climate change. In this way, polycentrism may provide an appropriate strategy for addressing the many challenges of climate governance in the Anthropocene. We review two Chilean case studies: Chile’s Nationally Determined Contribution on Climate Change and the Chilean National Climate Change Action Plan. Our examination demonstrates that Chile has included a diversity of actors and directed significant financial resources to both processes. The central government coordinated both of these processes, showing the key role of interventions at higher jurisdictional levels in orienting institutional change to improve strategic planning and better address climate change. Both processes also provide some evidence of knowledge co-production, while at the same time remaining primarily driven by state agencies and directed by technical experts. Efforts to overcome governance weaknesses should focus on further strengthening existing practices for climate change responses, establishing new institutions, and promoting decision-making that incorporates diverse social actors and multiple levels of governance. In particular, stronger inclusion of local level actors provides an opportunity to enhance polycentric modes of governance and improve climate change responses. Fully capitalizing on this opportunity requires establishing durable communication channels between different levels of governance.Elem Sci Anth2325-1026 Reuters ISIaction plan, adaptive management, anthropocene, climate change, conceptual framework, decision making, environmental policy, financial system, governance approach, mitigation, strategic approach, chile
Temperature and agriculture are largely associated with fire activity in Central Chile across different temporal periodsGómez-González, Susana; González, Mauro E.; Paula, Susana; Díaz-Hormazábal, Ignacio; Lara, Antonio; Delgado-Baquerizo, ManuelCambio de Uso de Suelo2019.010.1016/j.foreco.2018.11.041Wildfires have important ecological and socio-economic implications worldwide. Identifying the major ecological drivers regulating fire activity across space and time is critical to formulating sustainable policies of landscape planning and management under global change scenarios. However, large scale studies quantifying the relative importance of relevant fire drivers across different time periods are largely lacking. We conducted a high-resolution spatial survey in Central Chile and used structural equation models (SEMs) to evaluate the direct and indirect effects of climate, human impact, land uses, and topography on the number of fires and burned area across two distinct periods of time (2000–2005 and 2011–2016). Mean temperature and agricultural use had the highest direct positive effect on the number of fires and burned area in the two studied periods, and thus were the major ecological predictors of fire activity. Human impact was also an important predictor of fire attributes. Topography had multiple indirect effects on fire activity by regulating land use, temperature, and human impact, but direct effects were negligible. Precipitation seasonality, drought and aridity indexes, native forests, and plantations, were less relevant predictors of fire activity. Even so, our SEMs suggested that areas dominated by native forests tended to have lower number of fires than those covered by croplands or plantations. Our results suggest that fire activity in Central Chile will be highly sensitive to increases in human pressure, land use change and warming by climate change. Because the relative importance of the predictors of fire activity was steady over time, the knowledge derived from this study provides critical insights for preventive fire management and landscape planning. The control of stubble burning, native forest restoration and sustainable forestry management could improve social adaptation to a fire-prone future.Forest Ecology and Management0378-1127 Reuters ISIclimate change, climate models, conservation, drought, ecology, economics, forestry, land use, topography, human impact, land-use change, large-scale studies, mediterranean-type climate, structural equation models, sustainable forestry, sustainable policies, wildfires, fires, agriculture, anthropogenic effect, drought, fire, fire management, land use change, landscape planning, mediterranean environment, temperature, topography, wildfire, conservation, drought, ecology, economics, forestry, land use, chile
Metalogue as a transdisciplinary collaboration toolUrquiza, A.; Amigo, C.; Billi, M.; Brandao, G.; Morales, B.Ciudades Resilientes2018.010.4067/S0717-554X2018000200182Contemporary society shows an increasing demand for participatory instances able to effectively foster the collaboration of diverse organizational, disciplinary and socio-cultural areas. The challenges intrinsic to such participatory instancesrequire the development of methodologies that may allow for the insertion of reflexivity within the dialogical interaction, while also promoting the collective construction of "boundary objects": such objects, in turn, by serving as a common reference for the different perspectives involved in the dialogue, have the potential of facilitating the future collaboration among such perspectives. To respond to these demands -and inspired by the notion of metalogue originally introduced by Gregory Bateson- this paper elaborates a systemic-constructivist proposal of observation and contextual intervention, aimed at fostering reflexivity within dialogical-participatory instances by inducing their participants to perform a second-order observation of the distinctions mobilized within the interaction. Building upon this reflexivity, the metalogue pursues the co-construction of documents able to coordinate the perspectives of the participants and the expectations of the structural and organizational arrangements in which they operate. In addition to justifying and describing the technique of the metalogue, the paper highlights some lessons learned, good practices and proposals derived from its application in various transdisciplinary experiences in Chile.Cinta moebio0717-554X182-19862Thomson Reuters ISIconstructivist, contextual intervention, interface, policy, reflexivity, science, transdiscipline
Los significados de la participación para el cambio climático en ChileSapiains Arrué, Rodolfo; Ugarte Caviedes, Ana María; Aldunce, PaulinaAgua y Extremos; Gobernanza e Interfaz Ciencia y Política2018.010.11144/Javeriana.ayd21-41.spccEste artículo analiza los distintos significados del concepto de participación, para avanzar hacia un modelo más inclusivo de gobernanza del cambio climático en Chile. Para ello, se presenta una revisión bibliográfica que discute distintas epistemologías, teorías y definiciones de la participación, con énfasis en las dificultades para su implementación en el contexto chileno. Posteriormente, se revisan los mecanismos de participación ciudadana desplegados en el desarrollo de instrumentos de gobernanza del cambio climático existentes en Chile. Se distinguen tipos de participación utilizados y se identifican experiencias conducidas desde la sociedad civil y la academia. Finalmente, se discuten los alcances y las limitaciones de los modelos de participación implementados y se resalta la importancia de incrementar la influencia de la sociedad civil y de mejorar los mecanismos existentes. Esto se explica por un escenario de cambio climático que posiblemente requerirá una mayor cantidad de actores involucrados en la toma de decisiones, para anticipar posibles divisiones frente al desarrollo de acciones de adaptación o mitigación más radicales, y que al mismo tiempo demandará mayores niveles de responsabilidad, compromiso y acción de la ciudadanía.Ambiente y Desarrollo2346-2876, 0121-7607 Reuters ISIA
Projected hydroclimate changes over Andean basins in central Chile from downscaled CMIP5 models under the low and high emission scenariosBozkurt, Deniz; Rojas, Maisa; Boisier, Juan Pablo; Valdivieso, JonásAgua y Extremos; Gobernanza e Interfaz Ciencia y Política; Transversal2018.010.1007/s10584-018-2246-7This study examines the projections of hydroclimatic regimes and extremes over Andean basins in central Chile (approximate to 30-40 degrees S) under a low and high emission scenarios (RCP2.6 and RCP8.5, respectively). A gridded daily precipitation and temperature dataset based on observations is used to drive and validate the VIC macro-scale hydrological model in the region of interest. Historical and future simulations from 19 climate models participating in CMIP5 have been adjusted with the observational dataset and then used to make hydrological projections. By the end of the century, there is a large difference between the scenarios, with projected warming of approximate to + 1.2 degrees C (RCP2.6), approximate to +3.5 degrees C (RCP8.5) and drying of approximate to - 3% (RCP2.6), approximate to - 30% (RCP8.5). Following the strong drying and warming projected in this region under the RCP8.5 scenario, the VIC model simulates decreases in annual runoff of about 40% by the end of the century. Such strong regional effect of climate change may have large implications for the water resources of this region. Even under the low emission scenario, the Andes snowpack is projected to decrease by 35-45% by mid-century. In more snowmelt-dominated areas, the projected hydrological changes under RCP8.5 go together with more loss in the snowpack (75-85%) and a temporal shift in the center timing of runoff to earlier dates (up to 5 weeks by the end of the century). The severity and frequency of extreme hydroclimatic events are also projected to increase in the future. The occurrence of extended droughts, such as the recently experienced mega-drought (2010-2015), increases from one to up to five events per 100 years under RCP8.5. Concurrently, probability density function of 3-day peak runoff indicates an increase in the frequency of flood events. The estimated return periods of 3-day peak runoff events depict more drastic changes and increase in the flood risk as higher recurrence intervals are considered by mid-century under RCP2.6 and RCP8.5, and by the end of the century under RCP8.5.Climatic Change0165-0009 Reuters ISIclimate change, drought, floods, image segmentation, probability density function, risk perception, runoff, daily precipitations, emission scenario, hydrological changes, hydrological modeling, low emission scenarios, recurrence intervals, region of interest, regional effects, climate models, air temperature, climate change, climate prediction, cmip, drought, extreme event, flood frequency, model validation, peak flow, precipitation (climatology), probability density function, runoff, scenario analysis, snowpack, andes, chile
The CAMELS-CL dataset: catchment attributes and meteorology for large sample studies – Chile datasetAlvarez-Garreton, Camila; Mendoza, Pablo A.; Boisier, Juan Pablo; Addor, Nans; Galleguillos, Mauricio; Zambrano-Bigiarini, Mauricio; Lara, Antonio; Puelma, Cristóbal; Cortes, Gonzalo; Garreaud, Rene; McPhee, James; Ayala, AlvaroCambio de Uso de Suelo; Agua y Extremos2018.010.5194/hess-22-5817-2018We introduce the first catchment dataset for large sample studies in Chile. This dataset includes 516 catchments; it covers particularly wide latitude (17.8 to 55.0°S) and elevation (0 to 6993ma.s.l.) ranges, and it relies on multiple data sources (including ground data, remote-sensed products and reanalyses) to characterise the hydroclimatic conditions and landscape of a region where in situ measurements are scarce. For each catchment, the dataset provides boundaries, daily streamflow records and basin-averaged daily time series of precipitation (from one national and three global datasets), maximum, minimum and mean temperatures, potential evapotranspiration (PET; from two datasets), and snow water equivalent. We calculated hydro-climatological indices using these time series, and leveraged diverse data sources to extract topographic, geological and land cover features. Relying on publicly available reservoirs and water rights data for the country, we estimated the degree of anthropic intervention within the catchments. To facilitate the use of this dataset and promote common standards in large sample studies, we computed most catchment attributes introduced by Addor et al. (2017) in their Catchment Attributes and MEteorology for Large-sample Studies (CAMELS) dataset, and added several others. We used the dataset presented here (named CAMELS-CL) to characterise regional variations in hydroclimatic conditions over Chile and to explore how basin behaviour is influenced by catchment attributes and water extractions. Further, CAMELS-CL enabled us to analyse biases and uncertainties in basin-wide precipitation and PET. The characterisation of catchment water balances revealed large discrepancies between precipitation products in arid regions and a systematic precipitation underestimation in headwater mountain catchments (high elevations and steep slopes) over humid regions. We evaluated PET products based on ground data and found a fairly good performance of both products in humid regions (r > 0.91) and lower correlation (r < 0.76) in hyper-arid regions. Further, the satellite-based PET showed a consistent overestimation of observation-based PET. Finally, we explored local anomalies in catchment response by analysing the relationship between hydrological signatures and an attribute characterising the level of anthropic interventions. We showed that larger anthropic interventions are correlated with lower than normal annual flows, runoff ratios, elasticity of runoff with respect to precipitation, and flashiness of runoff, especially in arid catchments. CAMELS-CL provides unprecedented information on catchments in a region largely underrepresented in large sample studies. This effort is part of an international initiative to create multi-national large sample datasets freely available for the community. CAMELS-CL can be visualised from and downloaded from and Earth System Sciences1607-7938 Reuters ISIarid regions, catchments, remote sensing, reservoirs (water), snow, time series, uncertainty analysis, catchment water balance, hydroclimatic conditions, in-situ measurement, multiple data sources, potential evapotranspiration, precipitation products, regional variation, snow water equivalent, runoff, catchment, climate conditions, data set, headwater, hydrometeorology, land cover, meteorological hazard, potential evapotranspiration, precipitation (climatology), remote sensing, runoff, streamflow, water budget, chile, camelidae
Impacts of Atmospheric Rivers on Precipitation in Southern South AmericaViale, Maximiliano; Valenzuela, Raúl; Garreaud, René D.; Ralph, F. MartinAgua y Extremos2018.010.1175/JHM-D-18-0006.1This study quantifies the impact of atmospheric rivers (ARs) on precipitation in southern South America. An AR detection algorithm was developed based on integrated water vapor transport (IVT) from 6-hourly CFSR reanalysis data over a 16-yr period (2001-16). AR landfalls were linked to precipitation using a comprehensive observing network that spanned large variations in terrain along and across the Andes from 27° to 55°S, including some sites with hourly data. Along the Pacific (west) coast, AR landfalls are most frequent between 38° and 50°S, averaging 35-40 days yr-1. This decreases rapidly to the south and north of this maximum, as well as to the east of the Andes. Landfalling ARs are more frequent in winter/spring (summer/fall) to the north (south) of ~43°S. ARs contribute 45%-60% of the annual precipitation in subtropical Chile (37°-32°S) and 40%-55% along the midlatitude west coast (37°-47°S). These values significantly exceed those in western North America, likely due to the Andes being taller. In subtropical and midlatitude regions, roughly half of all events with top-quartile precipitation rates occur under AR conditions. Median daily and hourly precipitation in ARs is 2-3 times that of other storms. The results of this study extend knowledge of the key roles of ARs on precipitation, weather, and climate in the South American region. They enable comparisons with other areas globally, provide context for specific events, and support local nowcasting and forecasting. © 2018 American Meteorological Society.Journal of Hydrometeorology1525-755X Reuters ISIatmospheric transport, extratropical cyclone, precipitation (climatology), regional climate, topographic effect, water vapor, pacific ocean, pacific ocean (south), south america
Spatio-temporal patterns of thermal anomalies and drought over tropical forests driven by recent extreme climatic anomaliesJimenez, Juan C.; Barichivich, Jonathan; Mattar, Cristian; Takahashi, Ken; Santamaría-Artigas, Andrés; Sobrino, José A.; Malhi, YadvinderCambio de Uso de Suelo2018.010.1098/rstb.2017.0300The recent 2015-2016 El Niño (EN) event was considered as strong as the EN in 1997-1998. Given such magnitude, it was expected to result in extreme warming and moisture anomalies in tropical areas. Here we characterize the spatial patterns of temperature anomalies and drought over tropical forests, including tropical South America (Amazonia), Africa and Asia/Indonesia during the 2015-2016 EN event. These spatial patterns of warming and drought are compared with those observed in previous strong EN events (1982-1983 and 1997-1998) and other moderate to strong EN events (e.g. 2004-2005 and 2009-2010). The link between the spatial patterns of drought and sea surface temperature anomalies in the central and eastern Pacific is also explored. We show that indeed the EN2015-2016 led to unprecedented warming compared to the other EN events over Amazonia, Africa and Indonesia, as a consequence of the background global warming trend. Anomalous accumulated extreme drought area over Amazonia was found during EN2015-2016, but this value may be closer to extreme drought area extents in the other two EN events in 1982-1983 and 1997-1998. Over Africa, datasets disagree, and it is difficult to conclude which EN event led to the highest accumulated extreme drought area. Our results show that the highest values of accumulated drought area over Africa were obtained in 2015-2016 and 1997-1998, with a long-term drying trend not observed over the other tropical regions. Over Indonesia, all datasets suggest that EN 1982-1983 and EN 1997-1998 (or even the drought of 2005) led to a higher extreme drought area than EN2015-2016. Uncertainties in precipitation datasets hinder consistent estimates of drought severity over tropical regions, and improved reanalysis products and station records are required.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'. © 2018 The Author(s).Philosophical Transactions of the Royal Society B: Biological Sciences0962-8436 Reuters ISIclimate effect, drought stress, el nino, extreme event, precipitation (climatology), spatiotemporal analysis, temperature anomaly, tropical forest, tropical region, africa, amazonia, indonesia, africa, brazil, climate change, drought, el nino, forest, greenhouse effect, indonesia, season, temperature, tropic climate, africa, brazil, climate change, droughts, el nino-southern oscillation, forests, global warming, indonesia, seasons, temperature, tropical climate
Diurnal Changes in Active Carbon and Nitrogen Pathways Along the Temperature Gradient in Porcelana Hot Spring Microbial MatAlcamán-Arias, María E.; Pedrós-Alió, Carlos; Tamames, Javier; Fernández, Camila; Pérez-Pantoja, Danilo; Vásquez, Mónica; Díez, BeatrizZonas Costeras2018.010.3389/fmicb.2018.02353Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon ((HCO3)-C-13) and nitrogen ((NH4Cl)-N-15 and (KNO3)-N-15) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58 degrees C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66 degrees C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48 degrees C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48 degrees C. At 66 degrees C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.Frontiers in Microbiology1664-302X Reuters ISIcarbon and nitrogen assimilation, cyanobacteria, metagenomics, metatranscriptomics, microbial mat, neutral hot spring, photosynthesis
Distribution of dissolved methane and nitrous oxide in Chilean coastal systems of the Magellanic Sub-Antarctic region (50°–55°S)Farías, Laura; Bello, Estrella; Arancibia, Gresel; Fernandez, JosselineZonas Costeras2018.010.1016/j.ecss.2018.10.020Nitrous oxide (N2O) and methane (CH4) are greenhouse gases and active in the depletion of the ozone layer. These gases, originating from both anthropogenic and natural sources, are mainly released to the atmosphere from coastal areas, including continental shelves, estuaries and fjords. Surface distribution of dissolved N2O and CH4 during the austral spring were described within the Magellanic Sub-Antarctic region (50–55°S, Chile) with a coastal area that has a complex system of fjords, channels, gulf and, bays. A narrow range of N2O concentrations were observed from under-saturations (∼65%), as result of freshwater/glacial flow into fjord heads, to slight super-saturations (∼120–150%) in fjord mouths and adjacent marine zones. One exception was Otway Sound, where a penguin colony is situated, with N2O levels of up to 218%. In contrast, CH4 concentrations presented a wide range of saturations between 47.9% and 483%, with a spatial distribution that mainly corresponded to the type of hydrographic/geomorphologic basin; in the southern Patagonian Andes (mostly covered by the southern Ice Fields) CH4 levels varied between 65 and 80% in the marine area, and 180% saturation in the channels and fjords; whereas in the southern Patagonian tableland (Magellan Strait) higher CH4 concentrations, up to 483% saturation, were observed apparently associated with continental inputs (peatland and tundra vegetation). N2O concentrations were positively correlated with salinity and nutrients, indicating that the majority of N2O and nutrients (except silicate) originated from the Sub-Antarctic Water Mass (SAAW), which mixes with N2O-depleated freshwater. However, CH4 concentrations did not correlate with any oceanographic variables, suggesting that they originate from local marine/terrestrial interactions. The Magellanic Sub-Antarctic region acts as a modest source of N2O and CH4, to the atmosphere with effluxes of 6.20 ± 10.13 and 16.88 ± 27.04 μmol m−2 d−1 respectively. Due to climate change and a growth in anthropogenic activities such as salmon farming, future emissions of N2O and CH4 within this remote region remain uncertain.Estuarine, Coastal and Shelf Science0272-7714 Reuters ISIcoastal zone, concentration (composition), dissolved gas, fjord, freshwater, greenhouse gas, methane, nitrous oxide, ozone depletion, saturation, spring (season), subantarctic region, andes, antarctica, australia, chile, magellan strait, otway range, patagonia, victoria [australia], spheniscidae
Effect of climate on tree growth in the Pampa biome of Southeastern South America: First tree-ring chronologies from UruguayLucas, Christine; Puchi, Paulina; Profumo, Ludmila; Ferreira, Alex; Muñoz, ArielAgua y Extremos2018.010.1016/j.dendro.2018.10.004Tree-ring research in the highland tropics and subtropics represents a major frontier for understanding climate-growth relationships. Nonetheless, there are many lowland regions – including the South American Pampa biome – with scarce tree ring data. We present the first two tree-ring chronologies for Scutia buxifolia in subtropical Southeastern South America (SESA), using 54 series from 29 trees in two sites in northern and southern Uruguay. We cross-dated annual rings and compared tree growth from 1950 to 2012 with regional climate variability, including rainfall, temperature and the Palmer Drought Severity Index – PDSI, the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). Overall, ring width variability was highly responsive to climate signals linked to water availability. For example, tree growth was positively correlated with accumulated rainfall in the summer-fall prior to ring formation for both chronologies. Summer climate conditions were key for tree growth, as shown by a negative effect of hot summer temperatures and a positive correlation with PDSI in late austral summer. The El Niño phase in late spring/early summer favored an increase in rainfall and annual tree growth, while the La Niña phase was associated with less rainfall and reduced tree growth. Extratropical climate factors such as SAM had an equally relevant effect on tree growth, whereby the positive phase of SAM had a negative effect over radial growth. These findings demonstrate the potential for dendroclimatic research and climate reconstruction in a region with scarce tree-ring data. They also improve the understanding of how climate variability may affect woody growth in native forests – an extremely limited ecosystem in the Pampa biome.Dendrochronologia1125-7865 Reuters ISIbiochronology, biome, climate change, climate conditions, climate effect, clonal growth, dendrochronology, dendroclimatology, el nino-southern oscillation, endogenous growth, growth, rainfall, reconstruction, regional climate, subtropical region, temperature effect, tree ring, woody plant, argentina, pampas, rio de la plata, south america, uruguay, scutia buxifolia
Temporal and spatial evaluation of satellite rainfall estimates over different regions in Latin-AmericaBaez-Villanueva, Oscar Manuel; Zambrano-Bigiarini, Mauricio; Ribbe, Lars; Nauditt, Alexandra; Giraldo-Osorio, Juan Diego; Thinh, Nguyen XuanAgua y Extremos2018.010.1016/j.atmosres.2018.05.011Atmospheric Research01698095 Reuters ISIclock and data recovery circuits (cdr circuits), developing countries, efficiency, mean square error, pixels, precipitation (chemical), rain, satellites, time measurement, watersheds, chirpsv2, mswepv2, precipitation patterns, probability of detection, root mean squared errors, spatiotemporal variability, upscaling, validation of sres, rain gages, climate modeling, image analysis, pixel, precipitation assessment, satellite data, spatial resolution, spatiotemporal analysis, trmm, upscaling, colombia, magdalena basin
Seasonal drought effects on the water quality of the Biobío River, Central ChileYevenes, Mariela A.; Figueroa, Ricardo; Parra, OscarZonas Costeras2018.010.1007/s11356-018-1415-6Quantifying the effect of droughts on ecosystem functions is essential to the development of coastal zone and river management under a changing climate. It is widely acknowledged that climate change is increasing the frequency and intensity of droughts, which can affect important ecosystem services, such as the regional supply of clean water. Very little is understood about how droughts affect the water quality of Chilean high flow rivers. This paper intends to investigate the effect of an, recently identified, unprecedented drought in Chile (2010–2015), on the Biobío River water quality, (36°45′–38°49′ S and 71°00′–73°20′ W), Central Chile. This river is one of the largest Chilean rivers and it provides abundant freshwater. Water quality (water temperature, pH, dissolved oxygen, electrical conductivity, biological oxygen demand, total suspended solids, chloride, sodium, nutrients, and trace metals), during the drought (2010–2015), was compared with a pre-drought period (2000–2009) over two reaches (upstream and downstream) of the river. Multivariate analysis and seasonal Mann-Kendall trend analyses and a Theil-Sen estimator were employed to analyze trends and slopes of the reaches. Results indicated a significant decreased trend in total suspended solids and a slightly increasing trend in water temperature and EC, major ions, and trace metals (chrome, lead, iron, and cobalt), mainly in summer and autumn during the drought. The reduced variability upstream suggested that nutrient and metal concentrations were more constant than downstream. The results evidenced, due to the close relationship between river discharge and water quality, a slightly decline of the water quality downstream of the Biobío River during drought period, which could be attenuated in a post-drought period. These results displayed that water quality is vulnerable to reductions in flow, through historical and emerging solutes/contaminants and induced pH mobilization. Consequently, seasonal changes and a progressive reduction of river flow affect the ecosystem functionality in this key Chilean river. The outcomes from this research can be used to improve how low flow conditions and the effects of a reduction in the river volume and discharge are assessed, which is the case under the scenario of more frequent drought periods.Environmental Science and Pollution Research0944-1344, 1614-7499 Reuters ISIclimate change, drought, ecosystem function, ecosystem service, river discharge, river flow, river management, seasonal variation, water quality, water supply, water temperature, biobio river, chile, analysis, chemistry, chile, drought, environmental monitoring, river, season, water pollutant, water quality, chile, droughts, environmental monitoring, rivers, seasons, water pollutants, chemical, water quality
Monitoreo de la superficie de los bosques nativos de Chile: un desafío pendienteMiranda, Alejandro; Lara, Antonio; Altamirano, Adison; Zamorano-Elgueta, Carlos; Hernández, H Jaime; González, Mauro E; Pauchard, Aníbal; Promis, ÁlvaroCambio de Uso de Suelo2018.010.4067/S0717-92002018000200265Forest monitoring is important for decision making of forest management and conservation. In Chile, the forest monitoring system was initiated in 1994, which has been continued through the implementation of regional updates. This has enabled a temporal monitoring of the distribution and surface covered by native forest. However, while regional updates have reported increase in the surface covered by native forest, other studies have shown an opposite trend. Therefore, the capacity of the forest monitoring system to measure the temporal variation in forest areas was evaluated. Specifically, a review of reports and official data of the national forest monitoring system was carried out through the fulfillment of three basic criteria: i) comparability, ii) replicability and iii) quality. According to our results, the Chilean forest monitoring system does not fulfill their basic requirements because: (i) methodologies have not been consistent over time; (ii) it does not provide a baseline of land cover or forest loss that allows comparisons with changing forest area; iii) there is not adequate error estimation and how it can affect the results and analysis of monitoring. The national forest monitoring system requires a redefinition of its aims and methods, guiding them to the long term by convening different stakeholders looking for a national agreement.Bosque (Valdivia)0717-9200 Reuters ISIdeforestation, land cover change, land use change, national forest monitoring, redd+
Modelling Climate and Societal Resilience in the Eastern Mediterranean in the Last MillenniumXoplaki, Elena; Luterbacher, Jürg; Wagner, Sebastian; Zorita, Eduardo; Fleitmann, Dominik; Preiser-Kapeller, Johannes; Sargent, Abigail M.; White, Sam; Toreti, Andrea; Haldon, John F.; Mordechai, Lee; Bozkurt, Deniz; Akçer-Ön, Sena; Izdebski, AdamTransversal2018.010.1007/s10745-018-9995-9This article analyses high-quality hydroclimate proxy records and spatial reconstructions from the Central and Eastern Mediterranean and compares them with two Earth System Model simulations (CCSM4, MPI-ESM-P) for the Crusader period in the Levant (1095–1290 CE), the Mamluk regime in Transjordan (1260–1516 CE) and the Ottoman crisis and Celâlî Rebellion (1580–1610 CE). During the three time intervals, environmental and climatic stress tested the resilience of complex societies. We find that the multidecadal precipitation and drought variations in the Central and Eastern Mediterranean cannot be explained by external forcings (solar variations, tropical volcanism); rather they were driven by internal climate dynamics. Our research emphasises the challenges, opportunities and limitations of linking proxy records, palaeoreconstructions and model simulations to better understand how climate can affect human history.Human Ecology0300-7839, 1572-9915 Reuters ISIanthropology, climate effect, climate modeling, cmip, middle ages, paleoclimate, proxy climate record, reconstruction, levant, mediterranean region
Insight into anthropogenic forcing on coastal upwelling off south-central ChileAguirre, Catalina; García-Loyola, Sebastian; Testa, Giovanni; Silva, Diego; Farias, LauraZonas Costeras2018.010.1525/elementa.314Coastal upwelling systems off the coasts of Peru and Chile are among the most productive marine ecosystems in the world, sustaining a significant percentage of global primary production and fishery yields. Seasonal and interannual variability in these systems has been relatively well documented; however, an understanding of recent trends and the influence of climate change on marine processes such as surface cooling and primary productivity is limited. This study presents evidence that winds favorable to upwelling have increased within the southern boundary of the Humboldt Current System (35°–42°S) in recent decades. This trend is consistent with a poleward movement of the influence of the Southeast Pacific Anticyclone and resembles the spatial pattern projected by Global Circulation Models for warming scenarios. Chlorophyll a levels (from 2002 to present) determined by satellite and field-based time-series observations show a positive trend, mainly in austral spring–summer (December–January–February), potentially explained by observed increments in nutrient flux towards surface waters and photosynthetically active radiation. Both parameters appear to respond to alongshore wind stress and cloud cover in the latitudinal range of 35°S to 42°S. In addition, net annual deepening of the mixed layer depth is estimated using density and temperature profiles. Changes in this depth are associated with increasing winds and may explain cooler, more saline, and more productive surface waters, with the latter potentially causing fluctuations in dissolved oxygen and other gases, such as nitrous oxide, sensitive to changes in oxygenation. We argue that these recent changes represent, at least in part, a regional manifestation of the Anthropocene along the Chilean coast.Elem Sci Anth2325-1026 Reuters ISIannual variation, anthropocene, anthropogenic effect, anticyclone, climate change, cloud cover, coastal zone, cooling, dissolved oxygen, estimation method, marine ecosystem, mixed layer, oxygenation, primary production, satellite data, seasonal variation, upwelling, wind stress, chile, humboldt current, pacific ocean, pacific ocean (southeast), peru
First evidence of a mid-Holocene earthquake-triggered megaturbidite south of the Chile Triple JunctionPiret, Loïc; Bertrand, Sebastien; Kissel, Catherine; De Pol-Holz, Ricardo; Tamayo Hernando, Alvaro; Van Daele, MaartenCambio de Uso de Suelo2018.010.1016/j.sedgeo.2018.01.002Sedimentary Geology00370738 Reuters ISIbathymetry, deposits, geochemistry, grain size and shape, lakes, maps, sediments, submarine geology, chile triple junctions, environmental implications, glacial lake outburst flood, holocenes, paleoenvironmental study, patagonia, sediment provenance, turbidite, earthquakes, deposition, earthquake trigger, fjord, holocene, paleoenvironment, paleoseismicity, provenance, subduction zone, turbidite, chile, chile triple junction, pacific ocean, patagonia, foraminifera
An intercomparison of oceanic methane and nitrous oxide measurementsWilson, Samuel T.; Bange, Hermann W.; Arévalo-Martínez, Damian L.; Barnes, Jonathan; Borges, Alberto V.; Brown, Ian; Bullister, John L.; Burgos, Macarena; Capelle, David W.; Casso, Michael; de la Paz, Mercedes; Farías, Laura; Fenwick, Lindsay; Ferrón, Sara; Garcia, Gerardo; Glockzin, Michael; Karl, David M.; Kock, Annette; Laperriere, Sarah; Law, Cliff S.; Manning, Cara C.; Marriner, Andrew; Myllykangas, Jukka-Pekka; Pohlman, John W.; Rees, Andrew P.; Santoro, Alyson E.; Tortell, Philippe D.; Upstill-Goddard, Robert C.; Wisegarver, David P.; Zhang, Gui-Ling; Rehder, Gregor2018.010.5194/bg-15-5891-2018Large-scale climatic forcing is impacting oceanic biogeochemical cycles and is expected to influence the water-column distribution of trace gases, including methane and nitrous oxide. Our ability as a scientific community to evaluate changes in the water-column inventories of methane and nitrous oxide depends largely on our capacity to obtain robust and accurate concentration measurements that can be validated across different laboratory groups. This study represents the first formal international intercomparison of oceanic methane and nitrous oxide measurements whereby participating laboratories received batches of seawater samples from the subtropical Pacific Ocean and the Baltic Sea. Additionally, compressed gas standards from the same calibration scale were distributed to the majority of participating laboratories to improve the analytical accuracy of the gas measurements. The computations used by each laboratory to derive the dissolved gas concentrations were also evaluated for inconsistencies (e.g., pressure and temperature corrections, solubility constants). The results from the intercomparison and intercalibration provided invaluable insights into methane and nitrous oxide measurements. It was observed that analyses of seawater samples with the lowest concentrations of methane and nitrous oxide had the lowest precisions. In comparison, while the analytical precision for samples with the highest concentrations of trace gases was better, the variability between the different laboratories was higher: 36% for methane and 27% for nitrous oxide. In addition, the comparison of different batches of seawater samples with methane and nitrous oxide concentrations that ranged over an order of magnitude revealed the ramifications of different calibration procedures for each trace gas. Finally, this study builds upon the intercomparison results to develop recommendations for improving oceanic methane and nitrous oxide measurements, with the aim of precluding future analytical discrepancies between laboratories.Biogeosciences1726-4189 Reuters ISI
A plausible atmospheric trigger for the 2017 coastal El Niño: THE 2017 COASTAL EL NIÑOGarreaud, René D.Agua y Extremos2018.010.1002/joc.5426The far eastern tropical Pacific experienced a rapid, marked warming in early 2017, causing torrential rains along the west coast of South America with a significant societal toll in Peru and Ecuador. This strong coastal El Niño was largely unpredicted, even a few weeks before its onset, and it developed differently from either central or eastern events. Here we provide an overview of the event, its impacts and concomitant atmospheric circulation. It is proposed that a remotely forced, sustained weakening of the free tropospheric westerly flow impinging the subtropical Andes leads to a relaxation of the southeasterly (SE) trades off the coast, which in turn may have warmed the eastern Pacific throughout the weakening of upwelling in a near-coastal band and the lessening of the evaporative cooling farther offshore.International Journal of Climatology0899-8418 Reuters ISIevaporative cooling systems, oil well flooding, atmospheric circulation, eastern pacific, eastern tropical pacific, enso, evaporative cooling, peru, south america, torrential rain, nickel, atmospheric circulation, coastal zone, el nino, el nino-southern oscillation, flooding, troposphere, westerly, andes, ecuador, pacific ocean, pacific ocean (tropical), peru
Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millenniumDätwyler, Christoph; Neukom, Raphael; Abram, Nerilie J.; Gallant, Ailie J. E.; Grosjean, Martin; Jacques-Coper, Martín; Karoly, David J.; Villalba, Ricardo2018.010.1007/s00382-017-4015-0The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects. However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide new austral summer and annual mean SAM index reconstructions over the last millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions point towards changing teleconnection patterns that may be particularly important outside the summer months. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5–95% range of pre-industrial natural variability.Climate Dynamics0930-7575, 1432-0894 Reuters ISIannual variation, climate variation, holocene, paleoclimate, reconstruction, southern hemisphere, teleconnection, trend analysis, australia, new zealand, south america, tasmania
Synchronization of energy consumption by human societies throughout the HoloceneFreeman, Jacob; Baggio, Jacopo A.; Robinson, Erick; Byers, David A.; Gayo, Eugenia; Finley, Judson Byrd; Meyer, Jack A.; Kelly, Robert L.; Anderies, John M.Ciudades Resilientes2018.010.1073/pnas.1802859115We conduct a global comparison of the consumption of energy by human populations throughout the Holocene and statistically quantify coincident changes in the consumption of energy over space and time—an ecological phenomenon known as synchrony. When populations synchronize, adverse changes in ecosystems and social systems may cascade from society to society. Thus, to develop policies that favor the sustained use of resources, we must understand the processes that cause the synchrony of human populations. To date, it is not clear whether human societies display long-term synchrony or, if they do, the potential causes. Our analysis begins to fill this knowledge gap by quantifying the long-term synchrony of human societies, and we hypothesize that the synchrony of human populations results from (i) the creation of social ties that couple populations over smaller scales and (ii) much larger scale, globally convergent trajectories of cultural evolution toward more energy-consuming political economies with higher carrying capacities. Our results suggest that the process of globalization is a natural consequence of evolutionary trajectories that increase the carrying capacities of human societies.Proceedings of the National Academy of Sciences0027-8424 Reuters ISIarticle, bioenergy, biomass conversion, controlled study, cultural anthropology, environmental change, environmental sustainability, evolution, holocene, nonhuman, politics, population research, priority journal, social aspect, socioeconomics, archeology, ecosystem, history, human, social change, sociology, fossil fuel, archaeology, ecosystem, fossil fuels, history, ancient, humans, social change, socioeconomic factors, sociology
A new method to evaluate the vulnerability of watersheds facing several stressors: A case study in mediterranean ChileArriagada, Loretto; Rojas, Octavio; Arumí, José Luis; Munizaga, Juan; Rojas, Carolina; Farias, Laura; Vega, ClaudioZonas Costeras2019.010.1016/j.scitotenv.2018.09.237Freshwater systems are subjected to multiple anthropogenic stressors and natural disturbances that act as debilitating agents and modifiers of river systems, causing cumulative and synergistic effects that deteriorate their health and result in watershed vulnerability. This study proposes an easy-to-apply spatial method of watershed vulnerability evaluation using Geographic Information Systems (GIS) in the Andalién River watershed, located in the Chilean mediterranean. A watershed vulnerability index (WVI) based on three sub-indices – anthropogenic stressors, environmental fragility and natural disturbances – was developed. To determine the index grouping weights, expert surveys were carried out using the Delphi method. We subsequently normalized and integrated the factors of each sub-index with relative weights. The ranges of each thematic layer were re-classified to establish vulnerability scores. The watershed was divided into three sections: headwaters zone, transfer zone and depositional zone. The watershed vulnerability index showed that 41% of the watershed had very low vulnerability and 42% had medium vulnerability, while only 1% – in the depositional zone – had high vulnerability. A one-way ANOVA was carried out to analyze the vulnerability differences among the three sections of the watershed; it showed significant differences (F (2, 16) = 8.15: p < 0.05). The a posteriori test showed differences between the headwaters and depositional zones (Tukey test, p = 0.005) and between the transfer and depositional zones (Tukey test, p = 0.014). To validate the WVI, water quality was measured at 16 stations in the watershed; there was a significant correlation between vulnerability level and NO2 − levels (r = 0.8; p = 0.87; α = 0.05) and pH (r = 0.8; p = 0.80; α = 0.05). The WVI showed the cumulative effects of multiple stressors in the depositional zone of the watershed. This is the first study to evaluate and validate non-regulated watershed vulnerability with GIS using multiple anthropogenic and natural stressors.Science of The Total Environment0048-9697 Reuters ISIdeposition, geographic information systems, information management, information systems, information use, water quality, anthropogenic stressors, environmental fragility, freshwater systems, integrated management, multiple stressors, natural disturbance, vulnerability evaluations, vulnerability index, watersheds, anthropogenic effect, disturbance, environmental assessment, gis, headwater, integrated approach, vulnerability, watershed, article, chile, controlled study, environmental erosion, environmental impact, geographic information system, landfill, priority journal, spatial analysis, thematic analysis, water analysis, water management, water pollution, water quality, water supply, watershed, andalien river, bio bio, chile
Recent intensification of Amazon flooding extremes driven by strengthened Walker circulationBarichivich, Jonathan; Gloor, Emanuel; Peylin, Philippe; Brienen, Roel J. W.; Schöngart, Jochen; Espinoza, Jhan Carlo; Pattnayak, Kanhu C.Cambio de Uso de Suelo2018.010.1126/sciadv.aat8785The Amazon basin is the largest watershed on Earth. Although the variability of the Amazon hydrological cycle has been increasing since the late 1990s, its underlying causes have remained elusive. We use water levels in the Amazon River to quantify changes in extreme events and then analyze their cause. Despite continuing research emphasis on droughts, the largest change over recent decades is a marked increase in very severe floods. Increased flooding is linked to a strengthening of the Walker circulation, resulting from strong tropical Atlantic warming and tropical Pacific cooling. Atlantic warming due to combined anthropogenic and natural factors has contributed to enhance the change in atmospheric circulation. Whether this anomalous increase in flooding will last depends on the evolution of the tropical inter-ocean temperature difference.Science Advances2375-2548 Reuters ISI
Global Climate - d. Hydrological cycle - DroughtOsborn, T. J.; Barichivich, J.; Harris, I.; Schrier, G. VAN DER; Jones, P. D.Cambio de Uso de Suelo2018.010.1175/2018BAMSStateoftheClimate.1Bulletin of the American Meteorological Society0003-0007 Reuters ISIA
Ambient PM10 impacts brought by the extreme flooding event of March 24–26, 2015, in Copiapó, ChileJorquera, Héctor; Villalobos, Ana María; Barraza, FranciscoCiudades Resilientes2018.010.1007/s11869-018-0549-5On March 24-26, 2015, the Chilean city of Copiapó (27° 22′ S, 70° 20′ W), located in the hyperarid Atacama Desert, suffered an intense flooding brought by an extreme, unique rainfall event with a 35-year record of daily precipitation. A receptor model (positive matrix factorization, version 5) analysis, applied to ambient PM10 chemical speciation from three short-term sampling campaigns, resolved four sources: crustal/road dust, sea salt, secondary sulfates, and emissions from Paipote copper smelter located 8 km east of Copiapó. Wind trajectories computed with US NOAA’s Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) supported the above source identification and explained variability in source contributions. It was found that crustal/road dust increased 50 μg/m3, in April 8-10, 2015, as compared with values in November 2014 and October-November 2015, respectively. This was the dominant PM10 source after the flooding and before debris were cleaned up, being on order of magnitude higher that the other source contributions. The Paipote copper smelter contributed with primary PM10 emissions and secondary sulfates; this combined contribution averaged 11.8 μg/m3. Sea salt contributions contributed an average of 3.3 μg/m3. In normal conditions, crustal/road dust averaged 2.9 μg/m3, but the other resolved sources also contributed with crustal elements as their emissions are transported by winds to Copiapó. The positive matrix factorization solution included an unresolved concentration of 7.4 μg/m3. The small number of samples and the lack of measurements of nitrate, ammonia, and organic and elemental carbon may explain this result. Hence, sources such as secondary nitrates and combustion sources plus fugitive dust from sources surrounding Copiapó might be included in that unresolved concentration.Air Quality, Atmosphere & Health1873-9318 Reuters ISIambient air, dust, extreme event, flooding, particulate matter, pollution effect, smelting, source apportionment, suspended particulate matter, sustainable development, urban development, atacama, atacama desert, chile, copiapo
Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CEBüntgen, Ulf; Wacker, Lukas; Galván, J. Diego; Arnold, Stephanie; Arseneault, Dominique; Baillie, Michael; Beer, Jürg; Bernabei, Mauro; Bleicher, Niels; Boswijk, Gretel; Bräuning, Achim; Carrer, Marco; Ljungqvist, Fredrik Charpentier; Cherubini, Paolo; Christl, Marcus; Christie, Duncan A.; Clark, Peter W.; Cook, Edward R.; D’Arrigo, Rosanne; Davi, Nicole; Eggertsson, Ólafur; Esper, Jan; Fowler, Anthony M.; Gedalof, Ze’ev; Gennaretti, Fabio; Grießinger, Jussi; Grissino-Mayer, Henri; Grudd, Håkan; Gunnarson, Björn E.; Hantemirov, Rashit; Herzig, Franz; Hessl, Amy; Heussner, Karl-Uwe; Jull, A. J. Timothy; Kukarskih, Vladimir; Kirdyanov, Alexander; Kolář, Tomáš; Krusic, Paul J.; Kyncl, Tomáš; Lara, Antonio; LeQuesne, Carlos; Linderholm, Hans W.; Loader, Neil J.; Luckman, Brian; Miyake, Fusa; Myglan, Vladimir S.; Nicolussi, Kurt; Oppenheimer, Clive; Palmer, Jonathan; Panyushkina, Irina; Pederson, Neil; Rybníček, Michal; Schweingruber, Fritz H.; Seim, Andrea; Sigl, Michael; Churakova, Olga; Speer, James H.; Synal, Hans-Arno; Tegel, Willy; Treydte, Kerstin; Villalba, Ricardo; Wiles, Greg; Wilson, Rob; Winship, Lawrence J.; Wunder, Jan; Yang, Bao; Young, Giles H. F.Agua y Extremos2018.010.1038/s41467-018-06036-0Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the 14C content in 484 individual tree rings formed in the periods 770–780 and 990–1000 CE. Distinct 14C excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved 14C measurements are needed.Nature Communications2041-1723 Reuters ISIcarbon 14, carbon isotope, chronology, concentration (composition), cosmogenic radionuclide, solar radiation, spatiotemporal analysis, tree ring, article, atmospheric radioactivity, chronology, proton radiation, radiation measurement, radiometric dating, space, spring, summer, weather
Active Crossfire Between Cyanobacteria and Cyanophages in Phototrophic Mat Communities Within Hot SpringsGuajardo-Leiva, Sergio; Pedrós-Alió, Carlos; Salgado, Oscar; Pinto, Fabián; Díez, BeatrizZonas Costeras2018.010.3389/fmicb.2018.02039Cyanophages are viruses with a wide distribution in aquatic ecosystems, that specifically infect Cyanobacteria. These viruses can be readily isolated from marine and fresh waters environments; however, their presence in cosmopolitan thermophilic phototrophic mats remains largely unknown. This study investigates the morphological diversity (TEM), taxonomic composition (metagenomics), and active infectivity (metatranscriptomics) of viral communities over a thermal gradient in hot spring phototrophic mats from Northern Patagonia (Chile). The mats were dominated (up to 53%) by cosmopolitan thermophilic filamentous true-branching cyanobacteria from the genus Mastigocladus, the associated viral community was predominantly composed of Caudovirales (70%), with most of the active infections driven by cyanophages (up to 90% of Caudovirales transcripts). Metagenomic assembly lead to the first full genome description of a T7-like Thermophilic Cyanophage recovered from a hot spring (Porcelana Hot Spring, Chile), with a temperature of 58°C (TC-CHP58). This could potentially represent a world-wide thermophilic lineage of podoviruses that infect cyanobacteria. In the hot spring, TC-CHP58 was active over a temperature gradient from 48 to 66°C, showing a high population variability represented by 1979 single nucleotide variants (SNVs). TC-CHP58 was associated to the Mastigocladus spp. by CRISPR spacers. Marked differences in metagenomic CRISPR loci number and spacers diversity, as well as SNVs, in the TC-CHP58 proto-spacers at different temperatures, reinforce the theory of co-evolution between natural virus populations and cyanobacterial hosts. Considering the importance of cyanobacteria in hot spring biogeochemical cycles, the description of this new cyanopodovirus lineage may have global implications for the functioning of these extreme ecosystems.Frontiers in Microbiology1664-302X Reuters ISIcrispr associated protein, aquatic environment, article, cyanobacterium, cyanophage, high throughput sequencing, mastigocladus, metagenomics, microbial diversity, nonhuman, phototrophy, phylogeny, rna extraction, rna sequence, single nucleotide polymorphism, thermal spring, transmission electron microscopy
Past and future global transformation of terrestrial ecosystems under climate changeNolan, Connor; Overpeck, Jonathan T.; Allen, Judy R. M.; Anderson, Patricia M.; Betancourt, Julio L.; Binney, Heather A.; Brewer, Simon; Bush, Mark B.; Chase, Brian M.; Cheddadi, Rachid; Djamali, Morteza; Dodson, John; Edwards, Mary E.; Gosling, William D.; Haberle, Simon; Hotchkiss, Sara C.; Huntley, Brian; Ivory, Sarah J.; Kershaw, A. Peter; Kim, Soo-Hyun; Latorre, Claudio; Leydet, Michelle; Lézine, Anne-Marie; Liu, Kam-Biu; Liu, Yao; Lozhkin, A. V.; McGlone, Matt S.; Marchant, Robert A.; Momohara, Arata; Moreno, Patricio I.; Müller, Stefanie; Otto-Bliesner, Bette L.; Shen, Caiming; Stevenson, Janelle; Takahara, Hikaru; Tarasov, Pavel E.; Tipton, John; Vincens, Annie; Weng, Chengyu; Xu, Qinghai; Zheng, Zhuo; Jackson, Stephen T.Agua y Extremos2018.010.1126/science.aan5360Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change and suggest that, without major reductions in greenhouse gas emissions to the atmosphere, terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity.Science0036-8075 Reuters ISIbiodiversity, climate change, ecosystem service, glacial-interglacial cycle, global climate, greenhouse gas, last glacial, terrestrial ecosystem, vegetation cover, article, atmosphere, biodiversity, carbon footprint, climate change, ecosystem, biodiversity, biodiversity, climate change
Elucidating the hydraulic vulnerability of the longest-lived Southern Hemisphere conifer to aridificationUrrutia-Jalabert, R.; Peña, M.P.; Coopman, R.E.; Carvajal, D.E.; Jiménez-Castillo, M.; Lara, A.; Cosimo, D.; Lobos-Catalán, P.Cambio de Uso de Suelo2018.010.1016/j.foreco.2018.08.027Drier climatic conditions will be the future scenario in many regions worldwide, including southern South America. Few studies have characterized the ecophysiological vulnerability of the endemic tree species that inhabit this area, to climate change. In this study we assessed the hydraulic vulnerability of the longest-lived tree of the Southern Hemisphere, Fitzroya cupressoides, focusing on adult trees and saplings from two highly disturbed populations: the Coastal Range (AC) and Central Depression (FN) of southern Chile, which represent contrasting site conditions. This, as a basis for the design of conservation strategies to safeguard the persistence of these endangered forests in a drier future. We assessed water potentials (WP) throughout a growing season, their relationships with environmental conditions, as well as leaf and stem (branch) traits and hydraulic safety margins. Despite that the studied summer was the second driest in the last seven decades, minimum WP were not that negative (−1.3 to −1.5 MPa); which could be partly explained by a high leaf capacitance in this species. Adult trees and saplings from both sites did not significantly differ in their WP at turgor loss point, and their associated leaf safety margins, which were relatively low in all cases. However, they significantly differed in the xylem WP causing a 50% loss of stem conductivity (P50): adults AC: −5.14, saplings AC: −2.53, adults FN: −3.71, and saplings FN: −3.87 MPa. These values led to a relatively large stem safety margin (SSM) in most cases, and their variation was not explained neither by wood density, nor by tracheid size changes. Moreover, there appears to be an ontogenic adjustment in the more restrictive site AC, which was not seen in FN. Within the continuum of species strategies to cope with water stress, Fitzroya has features of the two ends of the continuum: tissues with large SSM, and tissues that sustain milder operation pressures through capacitance. Although Fitzroya appears to be relatively resistant to water scarcity, saplings from AC, seem to be the most vulnerable to the aridification trend in southern Chile. Moreover, future drying could become a significant extra threat to the highly endangered Central Depression population. Conservation actions are urgently needed to secure the future of Fitzroya forests in southern Chile.Forest Ecology and Management0378-1127 Reuters ISIcapacitance, climate change, histology, tissue, conservation actions, conservation strategies, environmental conditions, fitzroya cupressoides, safety margin, southern hemisphere, southern south america, temperate rainforest, forestry, aridification, climate change, climate conditions, coniferous forest, conservation management, ecophysiology, endangered species, endemic species, environmental conditions, growing season, hydraulic conductivity, rainforest, safety, southern hemisphere, temperate environment, vulnerability, capacitance, fitzroya, forestry, histology, safety, saplings, southern hemisphere, tissue, chile, coastal range [taiwan], south america, taiwan, coniferophyta, fitzroya, fitzroya cupressoides
Landscape drivers of recent fire activity (2001-2017) in south-central ChileMcWethy, David B.; Pauchard, Aníbal; García, Rafael A.; Holz, Andrés; González, Mauro E.; Veblen, Thomas T.; Stahl, Julian; Currey, BryceCambio de Uso de Suelo2018.010.1371/journal.pone.0201195In recent decades large fires have affected communities throughout central and southern Chile with great social and ecological consequences. Despite this high fire activity, the controls and drivers and the spatiotemporal pattern of fires are not well understood. To identify the large-scale trends and drivers of recent fire activity across six regions in south-central Chile (~32–40 S Latitude) we evaluated MODIS satellite-derived fire detections and compared this data with Chilean Forest Service records for the period 2001–2017. MODIS burned area estimates provide a spatially and temporally comprehensive record of fire activity across an important bioclimatic transition zone between dry Mediterranean shrublands/ sclerophyllous forests and wetter deciduous-broadleaf evergreen forests. Results suggest fire activity was highly variable in any given year, with no statistically significant trend in the number of fires or mean annual area burned. Evaluation of the variables associated with spatiotemporal patterns of fire for the 2001–2017 period indicate vegetation type, biophysical conditions (e.g., elevation, slope), mean annual and seasonal climatic conditions (e.g., precipitation) and mean population density have the greatest influence on the probability of fire occurrence and burned area for any given year. Both the number of fires and annual area burned were greatest in warmer, biomass-rich lowland Bío-Bío and Araucanía regions. Resource selection analyses indicate fire ‘preferentially’ occurs in exotic plantation forests, mixed native-exotic forests, native sclerophyll forests, pasture lands and matorral, vegetation types that all provide abundant, flammable and connected biomass for burning. Structurally and compositionally homogenous exotic plantation forests may promote fire spread greater than native deciduous-Nothofagaceae forests which were once widespread in the southern parts of the study area. In the future, the coincidence of warmer and drier conditions in landscapes dominated by flammable and fuel-rich forest plantations and mixed native-exotic and sclerophyll forests are likely to further promote large fires in south-central Chile. © 2018 McWethy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.PLOS ONE1932-6203 Reuters ISIchile, climate change, controlled study, ecosystem fire history, environmental change, environmental exposure, environmental impact, forest fire, geographic distribution, landscape, population density, review, seasonal variation, trend study, wildfire, biomass, chile, ecosystem, environmental protection, fire, procedures, satellite imagery, statistics and numerical data, theoretical model, biomass, chile, climate change, conservation of natural resources, ecosystem, fires, models, theoretical, satellite imagery
Chronology, stratigraphy and hydrological modelling of extensive wetlands and paleolakes in the hyperarid core of the Atacama Desert during the late quaternaryPfeiffer, Marco; Latorre, Claudio; Santoro, Calogero M.; Gayo, Eugenia M.; Rojas, Rodrigo; Carrevedo, María Laura; McRostie, Virginia B.; Finstad, Kari M.; Heimsath, Arjun; Jungers, Matthew C.; De Pol-Holz, Ricardo; Amundson, RonaldCambio de Uso de Suelo; Ciudades Resilientes2018.010.1016/j.quascirev.2018.08.001The halite-encrusted salt pans (salars) present at low elevations of the hyperarid core of the Atacama Desert in northern Chile are unique features of one of the driest and possibly oldest deserts on Earth. Here we show that these landscapes were shallow freshwater lakes and wetlands during the last glacial period, periodically between ~46.9 ka and 7.7 ka. The moisture appears to have been sourced from increased Andean runoff and most of our chronologies for these deposits were coeval with the Central Andean Pluvial Event (17.5-14.2 ka and 13.8-9.7 ka), but we also find evidence for older as well as slightly younger wet phases. These environments supported a diverse hygrophyte vegetation, as well as an array of diatoms, ostracods and gastropods. Using a regional hydrological model, we estimate that recharge rates from 1.5 to 4 times present were required to activate and maintain these wetlands in the past. Activation in the late Pleistocene was part of a regional enhancement of water resources, extending from the Andes, downstream and through riparian corridors, to the lowest and most arid portions of the desert itself. This fundamentally unique environment was encountered by the earliest human explorers in the region, and most likely facilitated migration and encampments on a landscape that at present lacks macroscopic life on its surface.Quaternary Science Reviews0277-3791 Reuters ISIarid regions, hydrology, sedimentology, sodium chloride, stratigraphy, water resources, atacama desert, hyperaridity, late quaternary, paleogeography, south america, wetlands, arid region, aridity, chronology, gastropod, hydrological modeling, lake, paleoclimate, paleogeography, pleistocene, recharge, salt pan, sedimentology, stratigraphy, wetland, andes, atacama desert, chile, chile, bacillariophyta, gastropoda
Adding new evidence to the attribution puzzle of the recent water shortage over São Paulo (Brazil)Pattnayak, K.C.; Gloor, E.; Tindall, J.C.; Brienen, R.J.W.; Barichivich, J.; Baker, J.C.A.; Spracklen, D.V.; Cintra, B.B.L.; Coelho, C.A.S.Cambio de Uso de Suelo2018.010.1080/16000870.2018.1481690View references (44) São Paulo, Brazil has experienced severe water shortages and record low levels of its water reservoirs in 2013–2014. We evaluate the contributions of Amazon deforestation and climate change to low precipitation levels using a modelling approach, and address whether similar precipitation anomalies might occur more frequently in a warming world. Precipitation records from INMET show that the dry anomaly extended over a fairly large region to the north of São Paulo. Unique features of this event were anomalous sea surface temperature (SST) patterns in the Southern Atlantic, an extension of the sub tropical high into the São Paulo region and moisture flux divergence over São Paulo. The SST anomalies were very similar in 2013/14 and 2014/15, suggesting they played a major role in forcing the dry conditions. The SST anomalies consisted of three zonal bands: a cold band in the tropics, a warm band to the south of São Paulo and another cold band poleward of 40 S. We performed ensemble climate simulations with observed SSTs prescribed, vegetation cover either fixed at 1870 levels or varying over time, and greenhouse gases (GHGs) either fixed at pre-industrial levels (280 ppm CO2) or varying over time. These simulations exhibit similar precipitation deficits over the São Paulo region in 2013/14. From this, we infer that SST patterns and the associated large-scale state of the atmosphere were important factors in determining the precipitation anomalies, while deforestation and increased GHGs only weakly modulated the signal. Finally, analyses of future climate simulations from CMIP5 models indicate that the frequency of such precipitation anomalies is not likely to change in a warmer climate. © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Tellus A: Dynamic Meteorology and Oceanography1600-0870 Reuters ISIalgorithm, climate change, climate effect, climate forcing, deforestation, future prospect, hydrological response, pattern recognition, precipitation intensity, reservoir, resource scarcity, sea surface temperature, temperature anomaly, water supply, atlantic ocean, atlantic ocean (south), brazil, sao paulo [brazil]
On the evaluation of adaptation practices: a transdisciplinary exploration of drought measures in ChileLillo-Ortega, Gloria; Aldunce, Paulina; Adler, Carolina; Vidal, Marcela; Rojas, MaisaAgua y Extremos; Gobernanza e Interfaz Ciencia y Política2019.010.1007/s11625-018-0619-5A severe drought has affected central Chile since 2009. Various adaptation responses have been developed, and a participatory process is required to learn from them. To enable this, a transdisciplinary approach was adopted to achieve two objectives: first, to test an approach for assessing the effectiveness of existing measures to respond to drought, specifically to distil strengths and weaknesses of implementation, and developing recommendations; second, to reflect on results from a pilot project conducted to ascertain its potential for scalability in terms of processes employed. The research was organized per the three types of knowledge needed to address complex problems through transdisciplinarity: systems, target and transformation knowledge. Using the recent drought as a boundary object, we conducted the pilot in two locations in Chile where we carried out literature reviews, interviews and focus group discussions were carried out. We identified adaptation measures at national and local scale, a set of which were evaluated applying the Index for the Usefulness of Adaptation Practices (IUPA). Results indicate that through IUPA, we could systematically account for the perceived effectiveness of applied measures. Strengths such as autonomy in the decision-making process emerged as key factors that could also be applied in other contexts, whereas weaknesses such as lack of integration with other policy domains, programs or projects were identified. To address weaknesses, key recommendations were proposed, which are congruent with context-specific expectations, capacities, experiences and knowledge, given that they were articulated by local actors. Results present empirical evidence on the important utility of transdisciplinary approaches in the evaluation of adaptation measures and can support the development of metrics related to adaptation process at the local scale.Sustainability Science1862-4065 Reuters ISIchile, drought, evaluation of adaptation, index for the usefulness of adaptation practices (iupa), resilience, transdisciplinarity
Terrain-Trapped Airflows and Orographic Rainfall along the Coast of Northern California. Part II: Horizontal and Vertical Structures Observed by a Scanning Doppler RadarValenzuela, Raul A.; Kingsmill, David E.Agua y Extremos2018.010.1175/MWR-D-17-0227.1This study documents the mean properties and variability of kinematic and precipitation structures associated with orographic precipitation along the coast of Northern California in the context of terrain-trapped airflows (TTAs). TTAs are defined as relatively narrow air masses that consistently flow in close proximity and approximately parallel to an orographic barrier. Seven land-falling winter storms are examined with observations from a scanning X-band Doppler radar deployed on the coast at Fort Ross, California. Additional information is provided by a 915-MHz wind-profiling radar, surface meteorology, a GPS receiver, and balloon soundings. The composite kinematic structure during TTA conditions exhibits a significant horizontal gradient of wind direction from the coast to approximately 50 km offshore and a low-level jet (LLJ) that surmounts a weaker airflow offshore corresponding to the TTA, with a zone of enhanced precipitation evident between ~5 and 25 km offshore and oriented nearly parallel to the coastline. Conversely, the composite kinematic structure during NO-TTA conditions exhibits a smaller offshore horizontal gradient of wind direction and precipitation structures are generally enhanced within ~15 km of the coastline. Interstorm variability analysis reveals significant variations in kinematic structures during both TTA and NO-TTA conditions, whereas significant variations in precipitation structures are only evident during TTA conditions. The interstorm analysis also illustrates more clearly how LLJ vertical structures evident during NO-TTA conditions exhibit ascent along the coast and over the coastal mountains, which is in contrast to TTA conditions where the ascent occurs offshore and over the TTA.Monthly Weather Review0027-0644 Reuters ISIatmospheric movements, channel flow, doppler radar, global positioning system, kinematics, landforms, precipitation (chemical), storms, coastal meteorologies, horizontal gradients, kinematic structures, orographic effects, orographic precipitation, orographic rainfalls, precipitation structure, radars/radar observations, precipitation (meteorology), airflow, channel flow, coastal zone, doppler radar, hydrometeorology, orographic effect, precipitation assessment, rainfall, terrain, wind direction, california, united states
ACTA DE TARAPACÁ: “PUEBLO SIN AGUA, PUEBLO MUERTO”Santoro, Calogero M.; Castro, Victoria; Capriles, José M.; Barraza, José; Correa, Jacqueline; Marquet, Pablo A.; McRostie, Virginia; Gayo, Eugenia M.; Latorre, Claudio; Valenzuela, Daniela; Uribe, Mauricio; de Porras, Maria Eugenia; Standen, Vivien G.; Angelo, Dante; Maldonado, Antonio; Hamamé, Eva; Jofré, DaniellaCiudades Resilientes2018.010.4067/S0717-73562018000200169“The Tarapacá Declaration” draws attention to the urgent need to change how human societies have been using water in the Atacama Desert, based on a historical trajectory spanning several millennia. The Declaration, an initiative that summarizes the results of the CONICYT/PIA, Anillo project SOC1405, is oriented towards civil society and various political entities, aiming to generate technological and cultural changes to halt and mitigate the effects caused by anthropogenic activities in one of the oldest and most arid deserts in the world. In the course of the project, we established the urgent need to sensitize society to the wasteful overuse and misuse of water in the Atacama Desert, a non-renewable resource in relation to the economic scales of extraction of this element that depends, fundamentally, on fossil waters that have accumulated for millennia in the highlands of the Desert. In this way we want to avoid that this scientific knowledge is encapsulated in the universities and to echo the point made by Victoria Castro (2003): that to grow you have to educate.Chungará (Arica)0717-7356 Reuters ISI
Status and future of numerical atmospheric aerosol prediction with a focus on data requirementsBenedetti, Angela; Reid, Jeffrey S.; Knippertz, Peter; Marsham, John H.; Di Giuseppe, Francesca; Rémy, Samuel; Basart, Sara; Boucher, Olivier; Brooks, Ian M.; Menut, Laurent; Mona, Lucia; Laj, Paolo; Pappalardo, Gelsomina; Wiedensohler, Alfred; Baklanov, Alexander; Brooks, Malcolm; Colarco, Peter R.; Cuevas, Emilio; da Silva, Arlindo; Escribano, Jeronimo; Flemming, Johannes; Huneeus, Nicolas; Jorba, Oriol; Kazadzis, Stelios; Kinne, Stefan; Popp, Thomas; Quinn, Patricia K.; Sekiyama, Thomas T.; Tanaka, Taichu; Terradellas, EnricCiudades Resilientes2018.010.5194/acp-18-10615-2018Numerical prediction of aerosol particle properties has become an important activity at many research and operational weather centers. This development is due to growing interest from a diverse set of stakeholders, such as air quality regulatory bodies, aviation and military authorities, solar energy plant managers, climate services providers, and health professionals. Owing to the complexity of atmospheric aerosol processes and their sensitivity to the underlying meteorological conditions, the prediction of aerosol particle concentrations and properties in the numerical weather prediction (NWP) framework faces a number of challenges. The modeling of numerous aerosol-related parameters increases computational expense. Errors in aerosol prediction concern all processes involved in the aerosol life cycle including (a) errors on the source terms (for both anthropogenic and natural emissions), (b) errors directly dependent on the meteorology (e.g., mixing, transport, scavenging by precipitation), and (c) errors related to aerosol chemistry (e.g., nucleation, gas-aerosol partitioning, chemical transformation and growth, hygroscopicity). Finally, there are fundamental uncertainties and significant processing overhead in the diverse observations used for verification and assimilation within these systems. Indeed, a significant component of aerosol forecast development consists in streamlining aerosol-related observations and reducing the most important errors through model development and data assimilation. Aerosol particle observations from satellite- and ground-based platforms have been crucial to guide model development of the recent years and have been made more readily available for model evaluation and assimilation. However, for the sustainability of the aerosol particle prediction activities around the globe, it is crucial that quality aerosol observations continue to be made available from different platforms (space, near surface, and aircraft) and freely shared. This paper reviews current requirements for aerosol observations in the context of the operational activities carried out at various global and regional centers. While some of the requirements are equally applicable to aerosol-climate, the focus here is on global operational prediction of aerosol properties such as mass concentrations and optical parameters. It is also recognized that the term "requirements" is loosely used here given the diversity in global aerosol observing systems and that utilized data are typically not from operational sources. Most operational models are based on bulk schemes that do not predict the size distribution of the aerosol particles. Others are based on a mix of "bin" and bulk schemes with limited capability of simulating the size information. However the next generation of aerosol operational models will output both mass and number density concentration to provide a more complete description of the aerosol population. A brief overview of the state of the art is provided with an introduction on the importance of aerosol prediction activities. The criteria on which the requirements for aerosol observations are based are also outlined. Assimilation and evaluation aspects are discussed from the perspective of the user requirements.Atmospheric Chemistry and Physics1680-7324 Reuters ISIaerosol, aerosol formation, concentration (composition), data assimilation, numerical model, particle size, prediction
Impact of residential combustion and transport emissions on air pollution in Santiago during winterMazzeo, Andrea; Huneeus, Nicolás; Ordoñez, César; Orfanoz-Cheuquelaf, Andrea; Menut, Laurent; Mailler, Sylvan; Valari, Myrto; Denier van der Gon, Hugo; Gallardo, Laura; Muñoz, Ricardo; Donoso, Rodrigo; Galleguillos, Maurico; Osses, Mauricio; Tolvett, SebastianCambio de Uso de Suelo; Ciudades Resilientes2018.010.1016/j.atmosenv.2018.06.043Santiago (33.5°S, 70.5°W), the capital of Chile, is frequently affected by extreme air pollution events during wintertime deteriorating air quality (AQ) and thus affecting the health of its population. Intense residential heating and on-road transport emissions combined with poor circulation and vertical mixing are the main factors responsible for these events. A modelling system composed of a chemistry-transport model (CHIMERE) and a meteorological model (WRF) was implemented to assess the AQ impacts of residential and transportation sources in the Santiago basin. A two-week period of July 2015 with various days with poor AQ was simulated focusing on the impact on AQ with respect to fully inhalable particles (PM2.5) and nitrogen oxides (NOX). Three emission scenarios, within the range of targeted reductions of the decontamination plan of Santiago, were tested; namely 50% reduction of residential emission, 50% reduction of transport emissions and the combination of both. An additional scenario decreasing transport emissions in 10% was carried out to examine whether a linear dependence of surface concentrations on changes in emissions exists. The system was validated against surface and vertically resolved meteorological measurements. The model reproduces the daily surface concentration variability from the AQ monitoring network of Santiago. However, the model not fully captures the emissions variations inferred from the observations which may be due to missing sources such as resuspension of dust. Results show that, during the period studied, although both residential and transportation sources contribute to observed AQ levels in Santiago, reducing transport emissions is more effective in terms of reducing the number of days with pollution events than decreasing residential combustion. This difference in impact is largely due to the spatial distribution of the emission sources. While most of the residential combustion is emitted in the outskirts of the city, most of the transport emissions occur within the city, where most of the stations from AQ monitoring network of Santiago are located. As can be expected, the largest improvement of AQ in Santiago is achieved by the combined reduction of emissions in both sectors. Sensitivity analysis with 10% reduction in transport emissions reveals a linear behavior between emissions and concentrations for NOX and approximate linear behavior for PM2.5. The absence of secondary aerosols formation and dust resuspension in the current simulation could explain this deviation from linearity for fine particles. Nevertheless, it suggests that the results can be used for mitigation policies with emissions reductions below the 50% used in this study.Atmospheric Environment1352-2310 Reuters ISIair quality, combustion, dust, housing, nitrogen oxides, roads and streets, sensitivity analysis, chemistry transport model, meteorological measurements, meteorological modeling, mitigation policies, on-road emissions, pm2.5, residential emissions, road transport emissions, atmospheric movements, nitrogen oxide, air quality, atmospheric modeling, atmospheric pollution, climate modeling, combustion, environmental factor, extreme event, mitigation, nitrogen oxides, particulate matter, pollutant source, pollutant transport, pollution effect, pollution monitoring, pollution policy, public health, residential location, road traffic, spatial distribution, traffic emission, winter, air pollution, airborne particle, article, chile, combustion, concentration (parameters), exhaust gas, meteorology, model, particle size, priority journal, residential area, surface property, traffic and transport, winter, chile, metropolitana
Participatory Energy Transitions as Boundary Objects: The Case of Chile's Energía2050Urquiza, Anahí; Amigo, Catalina; Billi, Marco; Espinosa, PatricioCiudades Resilientes2018.010.3389/fenrg.2018.00134This paper analyzes the use of “participatory futures” within the context of energy transition, paying special attention to the case of Chile's long-term energy policy. Our main aim is to question the role of “participation” in such a context and particularly, to decouple the operative function of participation from its normative function. Structurally, we argue that the construction of a joint vision of desired energy futures must be understood as a deliberate attempt at governing the energy transition by way of governing the expectations of the actors and systems involved in it. Participatory approaches can promote the co-construction of such energy futures in the form of a boundary-object, able to resonate with and provide a common reference to the actors participating in its creation. On the other hand, participatory approaches can also be a way to make transitions more democratic, subjecting it to a broader influence and control from the citizenship. These two functions of “participation” are always potentially at odds with one another. Democratizing the transition, in fact, would require producing plural, dynamical imaginaries that are responsive and accountable to the public. On the contrary, the need to make transitions governable may close-up such imaginaries and narrow-down the participatory efforts to foster their normalization and acceptability on the part of the most influential actors in the self-government of the transition. To refine and exemplify our proposal, we perform a qualitative, exploratory case study of Chile's E2050 energy policy. Our findings show that “participation” may indeed have been used in the case to align partially conflicting expectations around a collectively-defined boundary object which may then act as a form of contextual, anticipatory and polycentric governance of the transition. However, from a democratic perspective, E2050 appears as a tokenization of the public in support of a pre-eminently technical and monolithic vision enacted by the Energy Ministry and the Consultative Committee. Within this context, the actual influence of the public on the policy and the possibility for political contestation are much more questionable.Frontiers in Energy Research2296-598X Reuters ISIenergy policy, boundary objects, chile, deliberative democracy, energy transitions, polycentric governance, public participation, public policy
Water markets and social–ecological resilience to water stress in the context of climate change: an analysis of the Limarí Basin, ChileUrquiza, Anahí; Billi, MarcoCiudades Resilientes2018.010.1007/s10668-018-0271-3The paper proposes an analysis of the social–ecological resilience of the Limarí Basin, an agriculture-intensive dryland in the north of Chile, featuring one of the most innovative market-based water managements and the most active water rights market in the country, but concurrently affected by an ongoing water stress situation. The Chilean water market, one of the main examples of the application of neoliberal policies in water management, has received mixed appraisals although, at present, few empirical studies evaluate the social and environmental conditions associated with their operation. This paper, on the contrary, maintains the necessity to assess the capacity of market-based models to face situations of water stress, particularly since mega-drought phenomena are projected to become a recurring and increasing problem during the following decades because of climate change. The study offers a mixed bottom-up and top-down qualitative empirical analysis of how the Chilean water market operates, providing relevant insights into four dimensions of the social–ecological resilience of the watershed: redundancy, diversity and flexibility; connectivity, collaboration and collective action; social–ecological memory and learning; self-organization and governance of system changes. The conclusion is that water scarcity is self-produced: despite the flexibility provided by market-based water management, the combined effect of strong deregulation, of the absence of territorial planning and integrated management of water resources, and of short-term attitudes and generalized mistrust, has led the system to the critical situation it is now facing.Environment, Development and Sustainability1387-585X, 1573-2975 Reuters ISIbottom-up approach, climate change, empirical analysis, environmental conditions, governance approach, innovation, qualitative analysis, self organization, territorial planning, top-down approach, water industry, water management, water planning, water stress, chile
Summer phyto- and bacterioplankton communities during low and high productivity scenarios in the Western Antarctic PeninsulaFuentes, Sebastián; Arroyo, José Ignacio; Rodríguez-Marconi, Susana; Masotti, Italo; Alarcón-Schumacher, Tomás; Polz, Martin F.; Trefault, Nicole; De la Iglesia, Rodrigo; Díez, BeatrizZonas Costeras2018.010.1007/s00300-018-2411-5Phytoplankton blooms taking place during the warm season drive high productivity in Antarctic coastal seawaters. Important temporal and spatial variations exist in productivity patterns, indicating local constraints influencing the phototrophic community. Surface water in Chile Bay (Greenwich Island, South Shetlands) is influenced by freshwater from the melting of sea ice and surrounding glaciers; however, it is not a widely studied system. The phyto- and bacterioplankton communities in Chile Bay were studied over two consecutive summers; during a low productivity period (chlorophyll a < 0.05 mg m−3) and an ascendant phototrophic bloom (chlorophyll a up to 2.38 mg m−3). Microbial communities were analyzed by 16S rRNA—including plastidial—gene sequencing. Diatoms (mainly Thalassiosirales) were the most abundant phytoplankton, particularly during the ascendant bloom. Bacterioplankton in the low productivity period was less diverse and dominated by a few operational taxonomic units (OTUs), related to Colwellia and Pseudoalteromonas. Alpha diversity was higher during the bloom, where several Bacteroidetes taxa absent in the low productivity period were present. Network analysis indicated that phytoplankton relative abundance was correlated with bacterioplankton phylogenetic diversity and the abundance of several bacterial taxa. Hubs—the most connected OTUs in the network—were not the most abundant OTUs and included some poorly described taxa in Antarctica, such as Neptunomonas and Ekhidna. In summary, the results of this study indicate that in Antarctic Peninsula coastal waters, such as Chile Bay, higher bacterioplankton community diversity occurs during a phototrophic bloom. This is likely a result of primary production, providing a source of fresh organic matter to bacterioplankton. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.Polar Biology0722-4060, 1432-2056 Reuters ISIalgal bloom, bacterioplankton, community composition, genetic analysis, organic matter, phylogenetics, phytoplankton, relative abundance, rna, sea ice, seasonality, seawater, summer, antarctic peninsula, antarctica, chilean margin, pacific ocean, west antarctica, bacillariophyta, bacteria (microorganisms), bacteroidetes, colwellia, neptunomonas, otus, pseudoalteromonas, thalassiosirales
Temporal dynamics of dissolved inorganic nitrogen (DIN) in the aphotic layer of a coastal upwelling system with variable dissolved oxygenFarías, Laura; Faúndez, Juan; Sanhueza-Guevara, SandraZonas Costeras2018.010.1016/j.jmarsys.2018.06.001Dissolved O2 (DO) concentration is critical to determining ecosystem functions such as organic matter respiration, which can favor fixed nitrogen loss and the accumulation of compounds such as NH4+. This dynamic is observed in central Chile's coastal upwelling system (36 °S), which presents seasonally O2 deficient waters and high biological productivity. Temporal dynamics for dissolved inorganic nitrogen (DIN: NO3−, NO2− and NH4+) are analyzed based on a ten year time series of monthly measurements of DO and DIN and a three year record of absolute DIN uptake rates (ρDIN), respective turnover rates (νDIN), and O2 utilization rates (OUR). Observed O2 deficit gradually increases from hypoxia to near anoxia as the system becomes more productive, favoring the accumulation of NO2− and NH4+. Three temporal phases within the aphotic layer were distinguished: (I) DO > 62 μmol L−1 (May to August), (II) 5 < DO < 62 μmol L−1 (September to December) and (III) DO < 5 μmol L−1 (January to April). From phase I to III, DO and NO3− inventories decreased by eight and two times, respectively, while NH4+ and NO2 inventories increased two- and five-fold, respectively. Uptake rates for NH4+ varied from 0.23 to 450 nmol N L−1 d−1 and from 1.42 to 184 nmol N L−1 d−1 for NO3−. Notably, integrated ρNH4+ increased during phase III, generating a NH4+ turnover time of 12–29 days; whereas integrated ρNO3− peaked during phase II, and removed the NO3− pool over an extended turnover time (>820 days). Integrated OUR gradually increased from phase I to III (from 225 to 422 mmol m−2 d−1), with DO pools replenished over 2.3 to 26 days. NH4+ regeneration rates ranged from 34 to 62 mmol m−2 d−1 and NH4+ pools were replenished within a few days. Variation in DO, which regulates N cycling, may explain the accumulation of N-species within the aphotic layer. Observed trends could be extrapolated to scenarios of upwelling-favorable winds, eutrophication and hypoxia.Journal of Marine Systems0924-7963 Reuters ISIcoastal engineering, dissolution, eutrophication, lakes, nitrogen, nitrogen oxides, aphotic layer, biological productivity, coastal upwelling, dissolved inorganic nitrogens, ecosystem functions, oxygen utilization, regeneration rate, temporal dynamics, dissolved oxygen, coastal zone, dissolved inorganic nitrogen, dissolved oxygen, eutrophication, hypoxia, nitrogen cycle, temporal variation, time series analysis, upwelling, chile
Human–environmental drivers and impacts of the globally extreme 2017 Chilean firesBowman, David M. J. S.; Moreira-Muñoz, Andrés; Kolden, Crystal A.; Chávez, Roberto O.; Muñoz, Ariel A.; Salinas, Fernanda; González-Reyes, Álvaro; Rocco, Ronald; de la Barrera, Francisco; Williamson, Grant J.; Borchers, Nicolás; Cifuentes, Luis A.; Abatzoglou, John T.; Johnston, Fay H.Agua y Extremos2018.010.1007/s13280-018-1084-1In January 2017, hundreds of fires in Mediterranean Chile burnt more than 5000 km2, an area nearly 14 times the 40-year mean. We contextualize these fires in terms of estimates of global fire intensity using MODIS satellite record, and provide an overview of the climatic factors and recent changes in land use that led to the active fire season and estimate the impact of fire emissions to human health. The primary fire activity in late January coincided with extreme fire weather conditions including all-time (1979–2017) daily records for the Fire Weather Index (FWI) and maximum temperature, producing some of the most energetically intense fire events on Earth in the last 15-years. Fire activity was further enabled by a warm moist growing season in 2016 that interrupted an intense drought that started in 2010. The land cover in this region had been extensively modified, with less than 20% of the original native vegetation remaining, and extensive plantations of highly flammable exotic Pinus and Eucalyptus species established since the 1970s. These plantations were disproportionally burnt (44% of the burned area) in 2017, and associated with the highest fire severities, as part of an increasing trend of fire extent in plantations over the past three decades. Smoke from the fires exposed over 9.5 million people to increased concentrations of particulate air pollution, causing an estimated 76 premature deaths and 209 additional admissions to hospital for respiratory and cardiovascular conditions. This study highlights that Mediterranean biogeographic regions with expansive Pinus and Eucalyptus plantations and associated rural depopulation are vulnerable to intense wildfires with wide ranging social, economic, and environmental impacts, which are likely to become more frequent due to longer and more extreme wildfire seasons.Ambio0044-7447 Reuters ISIatmospheric pollution, extreme event, forest fire, health risk, land cover, mediterranean environment, modis, native species, pollution incidence, satellite altimetry, smoke, chile, eucalyptus, chile, drought, fire, human, pine, weather, chile, droughts, fires, humans, pinus, weather
Temperature modulates Fischerella thermalis ecotypes in Porcelana Hot SpringAlcorta, Jaime; Espinoza, Sebastián; Viver, Tomeu; Alcamán-Arias, María E.; Trefault, Nicole; Rosselló-Móra, Ramon; Díez, BeatrizZonas Costeras2018.010.1016/j.syapm.2018.05.006Systematic and Applied Microbiology07232020 Reuters ISIallele, article, bacterial genome, bacterial strain, ecotype, fischerella, fischerella thermalis, genetic variability, matrix assisted laser desorption ionization time of flight mass spectrometry, metagenome, nitrogen fixation, nonhuman, photosynthesis, priority journal, proteomics, temperature, temperature acclimatization, thermal spring, thermophilic bacterium, chile, cyanobacterium, genetics, heat, isolation and purification, matrix-assisted laser desorption-ionization mass spectrometry, microbiology, molecular evolution, phylogeny, thermal spring, bacterial dna, proteome, rna 16s, chile, cyanobacteria, dna, bacterial, ecotype, evolution, molecular, hot springs, hot temperature, metagenome, phylogeny, proteome, rna, ribosomal, 16s, spectrometry, mass, matrix-assisted laser desorption-ionization
Co-construction of energy solutions: Lessons learned from experiences in ChileMontedonico, Marcia; Herrera-Neira, Francisca; Marconi, Andrés; Urquiza, Anahí; Palma-Behnke, Rodrigo2018.010.1016/j.erss.2018.08.004Energy Research & Social Science22146296 Reuters ISIco-construction, interdisciplinarity, participation, sociotechnical systems
Bacterial community structure in a sympagic habitat expanding with global warming: brackish ice brine at 85–90 °NFernández-Gómez, Beatriz; Díez, Beatriz; Polz, Martin F.; Arroyo, José Ignacio; Alfaro, Fernando D.; Marchandon, Germán; Sanhueza, Cynthia; Farías, Laura; Trefault, Nicole; Marquet, Pablo A.; Molina-Montenegro, Marco A.; Sylvander, Peter; Snoeijs-Leijonmalm, PaulineZonas Costeras2018.010.1038/s41396-018-0268-9Larger volumes of sea ice have been thawing in the Central Arctic Ocean (CAO) during the last decades than during the past 800,000 years. Brackish brine (fed by meltwater inside the ice) is an expanding sympagic habitat in summer all over the CAO. We report for the first time the structure of bacterial communities in this brine. They are composed of psychrophilic extremophiles, many of them related to phylotypes known from Arctic and Antarctic regions. Community structure displayed strong habitat segregation between brackish ice brine (IB; salinity 2.4–9.6) and immediate sub-ice seawater (SW; salinity 33.3–34.9), expressed at all taxonomic levels (class to genus), by dominant phylotypes as well as by the rare biosphere, and with specialists dominating IB and generalists SW. The dominant phylotypes in IB were related to Candidatus Aquiluna and Flavobacterium, those in SW to Balneatrix and ZD0405, and those shared between the habitats to Halomonas, Polaribacter and Shewanella. A meta-analysis for the oligotrophic CAO showed a pattern with Flavobacteriia dominating in melt ponds, Flavobacteriia and Gammaproteobacteria in solid ice cores, Flavobacteriia, Gamma- and Betaproteobacteria, and Actinobacteria in brine, and Alphaproteobacteria in SW. Based on our results, we expect that the roles of Actinobacteria and Betaproteobacteria in the CAO will increase with global warming owing to the increased production of meltwater in summer. IB contained three times more phylotypes than SW and may act as an insurance reservoir for bacterial diversity that can act as a recruitment base when environmental conditions change.The ISME Journal1751-7362 Reuters ISIbacterium, brackish water, brine, community structure, dominance, environmental conditions, extremophile, generalist, global warming, meltwater, oligotrophic environment, sea ice, seawater, specialist, arctic and antarctic, arctic ocean, actinobacteria, alphaproteobacteria, bacteria (microorganisms), balneatrix, betaproteobacteria, flavobacterium, gammaproteobacteria, halomonas, polaribacter, shewanella, sea water, actinobacteria, alphaproteobacteria, antarctica, arctic, bacterium, classification, ecosystem, flavobacteriaceae, gammaproteobacteria, greenhouse effect, ice cover, isolation and purification, microbiology, salinity, season, actinobacteria, alphaproteobacteria, antarctic regions, arctic regions, bacteria, ecosystem, flavobacteriaceae, gammaproteobacteria, global warming, ice cover, salinity, seasons, seawater
Burn severity controls on postfire Araucaria-Nothofagus regeneration in the Andean CordilleraAssal, Timothy J.; González, Mauro E.; Sibold, Jason S.2018.010.1111/jbi.13428Journal of Biogeography03050270 Reuters ISIbasal area, burning, coniferous forest, deciduous forest, environmental gradient, environmental monitoring, fire behavior, landscape ecology, mortality, regeneration, stand structure, vegetation dynamics, wildfire, andes, araucania, argentina, chile, cordillera, paraguay, tolhuaca national park, araucaria, araucaria araucana, nothofagus, tolhuaca
Assessment of methane and carbon dioxide emissions in two sub-basins of a small acidic bog lake artificially divided 30 years agoSepulveda-Jauregui, Armando; Martinez-Cruz, Karla; Lau, Maximilian; Casper, Peter2018.010.1111/fwb.13182Freshwater Biology00465070 Reuters ISIcarbon storage, dissolved greenhouse gases, humic substances, limnology, year-round experiment
Andean caravan ceremonialism in the lowlands of the Atacama Desert: The Cruces de Molinos archaeological site, northern ChileValenzuela, Daniela; Cartajena, Isabel; Santoro, Calogero M.; Castro, Victoria; Gayo, Eugenia M.Ciudades Resilientes2018.010.1016/j.quaint.2018.09.016Camelid caravans have played a key role in the complex systems of interregional social interaction that characterizes Andean history. In the northernmost region of Chile, the most frequent archaeological indicators of these caravan systems are trails and rock art images. Cruces de Molinos (LL-43), a rock art site in the Lluta valley, 1100 masl, 40 km from the Pacific littoral, expands the ceremonial role of rock art sites, materialized, not only as regards the iconography portrayed and alluding to these practices, but also in terms of articulated carcass remains and detached anatomical units of camelids, intentionally deposited in a cache beneath one of the engraved blocks. This paper analyzes the site considering the visual imagery, spatial location, archaeological deposits and features associated with rock art. Based on the predominance of camelid and caravan motifs in rock art images, the extraordinary setting and location of the site on the valley's upper slopes, which is far removed from local settlements, but closely connected with a llama caravan trade network linking the chaupiyunga ecozone with the highlands (sierra and Altiplano ecozones), we suggest that Cruces de Molinos was not a rest stop for caravanners, but a ceremonial place, and not for local farmers, but for highland herders. According to seven accelerator mass spectrometry (AMS) dates that place the occupation between cal. 1060–1190 CE in the Late Intermediate period.Quaternary International10406182 Reuters ISIarchaeological evidence, iconography, mammal, rock art, settlement history, spatiotemporal analysis, atacama desert, chile, camelidae, lama (mammal)
Assimilating satellite-based canopy height within an ecosystem model to estimate aboveground forest biomass: Assimilating Canopy Height Into BiomassJoetzjer, E.; Pillet, M.; Ciais, P.; Barbier, N.; Chave, J.; Schlund, M.; Maignan, F.; Barichivich, J.; Luyssaert, S.; Hérault, B.; von Poncet, F.; Poulter, B.Cambio de Uso de Suelo2017.010.1002/2017GL074150Despite advances in Earth observation and modeling, estimating tropical biomass remains a challenge. Recent work suggests that integrating satellite measurements of canopy height within ecosystem models is a promising approach to infer biomass. We tested the feasibility of this approach to retrieve aboveground biomass (AGB) at three tropical forest sites by assimilating remotely sensed canopy height derived from a texture analysis algorithm applied to the high-resolution Pleiades imager in the Organizing Carbon and Hydrology in Dynamic Ecosystems Canopy (ORCHIDEE-CAN) ecosystem model. While mean AGB could be estimated within 10% of AGB derived from census data in average across sites, canopy height derived from Pleiades product was spatially too smooth, thus unable to accurately resolve large height (and biomass) variations within the site considered. The error budget was evaluated in details, and systematic errors related to the ORCHIDEE-CAN structure contribute as a secondary source of error and could be overcome by using improved allometric equations.Geophysical Research Letters00948276 Reuters ISIbiomass, budget control, ecosystems, forestry, population statistics, systematic errors, aboveground biomass, allometric equations, earth observations, ecosystem model, optical satellite imagery, radar satellites, satellite measurements, secondary sources, satellite imagery, aboveground biomass, algorithm, canopy, ecosystem modeling, feasibility study, height determination, optical method, pleiades, radar imagery, remote sensing, satellite imagery, tropical forest
Temporal evolution of main ambient PM2. 5 sources in Santiago, Chile, from 1998 to 2012Barraza, Francisco; Lambert, Fabrice; Jorquera, Héctor; Villalobos, Ana María; Gallardo, LauraCiudades Resilientes2017.010.5194/acp-17-10093-2017The inhabitants of Santiago, Chile have been exposed to harmful levels of air pollutants for decades. The city’s poor air quality is a result of steady economic growth, and stable atmospheric conditions adverse to mixing and ventilation that favor the formation of oxidants and secondary aerosols. Identifying and quantifying the sources that contribute to the ambient levels of pollutants is key for designing adequate mitigation measures. Estimating the evolution of source contributions to ambient pollution levels is also paramount to evaluating the effectiveness of pollution reduction measures that have been implemented in recent decades. Here, we quantify the main sources that have contributed to fine particulate matter (PM2.5) between April 1998 and August 2012 in downtown Santiago by using two different source-receptor models (PMF 5.0 and UNMIX 6.0) that were applied to elemental measurements of 1243 24 h filter samples of ambient PM2.5. PMF resolved six sources that contributed to ambient PM2.5, with UNMIX producing similar results: motor vehicles (37.3 ± 1.1 %), industrial sources (18.5 ± 1.3 %), copper smelters (14.4 ± 0.8 %), wood burning (12.3 ± 1.0 %), coastal sources (9.5 ± 0.7 %) and urban dust (3.0 ± 1.2 %). Our results show that over the 15 years analyzed here, four of the resolved sources significantly decreased 95 % confidence interval: motor vehicles 21.3 % 2.6, 36.5, industrial sources 39.3 % 28.6, 48.4, copper smelters 81.5 % 75.5, 85.9, and coastal sources 58.9 % 38.5, 72.5, while wood burning did not significantly change and urban dust increased by 72 % 48.9, 99.9. These changes are consistent with emission reduction measures, such as improved vehicle emission standards, cleaner smelting technology, introduction of low-sulfur diesel for vehicles and natural gas for industrial processes, public transport improvements, etc. However, it is also apparent that the mitigation expected from the above regulations has been partially offset by the increasing amount of private vehicle use in the city, with motor vehicles becoming the dominant source of ambient PM2.5 in recent years. Consequently, Santiago still experiences ambient PM2.5 levels above the annual and 24 h Chilean and World Health Organization standards, and further regulations are required to reach ambient air quality standardsAtmospheric Chemistry and Physics1680-7324 Reuters ISI
Plankton composition, biomass, phylogeny and toxin genes in Lake Big Momela, TanzaniaHamisi, Mi; Lugomela, C; Lyimo, Tj; Bergman, B; Díez, BZonas Costeras2017.010.2989/16085914.2017.1334621Lake Big Momela, one of the East African soda lakes in Northern Tanzania characterised by highly saline-alkaline conditions, making them inhospitable to a range of organisms, although supporting massive growths of some adapted planktonic microorganisms that serve as food for birds, such as Lesser Flamingo. The temporal dynamics of plankton, with an emphasis on cyanobacteria, were examined in 2007 using morphological traits and ribosomal genetic markers (16S and 18S rRNA). Cyanobacterial genes encoding for hepatotoxins (mcyE and ndaF) were also screened. Rotifers and copepods dominated the zooplankton, whereas cyanobacteria, such as Anabaenopsis elenkinii and Arthrospira fusiformis dominated the phytoplankton community, and these being related to representatives in other East African soda lakes. The cyanobacteria community also showed distinct seasonal patterns influenced by environmental parameters, mainly salinity, pH and nitrate. Significant positive correlations were found between phytoplankton abundance and nitrate concentrations (r = 0.617, p = 0.033). No signals of the hepatotoxin synthetase genes mcyE and ndaF were retrieved from cyanobacteria during the whole year. In general, our data illustrate the presence of rich planktonic communities, including some unique and potentially endemic cyanobacteria.African Journal of Aquatic Science1608-5914, 1727-9364 Reuters ISIcyanotoxin, limnology, plankton diversity, soda lakes
Potencial de los anillos de crecimiento de Pilgerodendron uviferum para el estudio histórico de las Iglesias de Chiloé, Patrimonio de la HumanidadPuchi, Paulina; Muñoz, Ariel A; González, Mauro E; Abarzúa, Ana; Araya, Katerine; Towner, Ronald; Fitzek, Reinhard; Holz, Andrés; Stahle, DanielCambio de Uso de Suelo; Agua y Extremos2017.010.4067/S0717-92002017000100012Las iglesias de Chiloé son antiguas estructuras de madera reconocidas patrimonio de la humanidad por la UNESCO. Gran parte de su historia de construcción y reparaciones aún se desconoce. Considerando que muchas de las iglesias de Chiloé fueron construidas utilizando madera de Pilgerodendron uviferum, el objetivo de este trabajo fue evaluar el potencial de esta especie para datar piezas de madera de dos de estas históricas construcciones: las iglesias de Vilupulli e Ichuac. En Vilupulli se dataron piezas de 311 y 181 años provenientes de los pilares de la torre. Estas piezas fueron fechadas con cronologías de ancho de anillos de P. uviferum cercanas a las dos iglesias. También utilizando estas cronologías se dataron piezas de 79, 89, 97 y 135 años obtenidas a partir de los pilotes que sostienen el piso de la iglesia de Ichuac. Considerando que Vilupulli fue construida a principios del siglo XX, es posible que las muestras de la torre que presentaron fechas cercanas a 1918, sean parte del proceso tardío de construcción de la iglesia o de una restauración posterior. Por su parte, Ichuac fue construida a finales del siglo XIX, por lo que las piezas del piso que dataron entre 19201929, formarían parte de una posible restauración no descrita previamente en archivos históricos, la cual pudo ocurrir incluso varios años posterior a la fecha del anillo más reciente encontrado en las piezas estudiadas. Se concluye que P. uviferum tiene alto potencial para estudios históricos en estructuras patrimoniales en el sur de Chile.Bosque (Valdivia)0717-9200 Reuters ISIdendroarchaeology, historical structures, pilgerodendron uviferum
The pre-Columbian introduction and dispersal of Algarrobo (Prosopis, Section Algarobia) in the Atacama Desert of northern ChileMcRostie, Virginia B.; Gayo, Eugenia M.; Santoro, Calogero M.; De Pol-Holz, Ricardo; Latorre, ClaudioCambio de Uso de Suelo; Ciudades Resilientes2017.010.1371/journal.pone.0181759Archaeological and palaeoecological studies throughout the Americas have documented widespread landscape and environmental transformation during the pre-Columbian era. The highly dynamic Formative (or Neolithic) period in northern Chile (ca. 3700–1550 yr BP) brought about the local establishment of agriculture, introduction of new crops (maize, quinoa, manioc, beans, etc.) along with a major population increase, new emergent villages and technological innovations. Even trees such as the Algarrobos (Prosopis section Algarobia) may have been part of this transformation. Here, we provide evidence that these species were not native to the Atacama Desert of Chile (18–27S), appearing only in the late Holocene and most likely due to human actions. We assembled a database composed of 41 taxon specific AMS radiocarbon dates from archaeobotanical and palaeoecological records (rodent middens, leaf litter deposits), as well an extensive bibliographical review comprising archaeobotanical, paleoecological, phylogenetic and taxonomic data to evaluate the chronology of introduction and dispersal of these trees. Although Algarrobos could have appeared as early as 4200 yr BP in northernmost Chile, they only became common throughout the Atacama over a thousand years later, during and after the Formative period. Cultural and natural factors likely contributed to its spread and consolidation as a major silvicultural resource.PLOS ONE1932-6203 Reuters ISIcarbon 14, article, chile, chronology, desert, holocene, leaf litter, nonhuman, paleoecology, phylogeny, plant dispersal, prosopis, species introduction, taxonomy, agriculture, archeology, classification, crop, desert climate, genetics, history, human, phylogeny, physiology, prosopis, agriculture, archaeology, chile, crops, agricultural, desert climate, history, ancient, humans, phylogeny, plant dispersal, prosopis
Modeling study of biomass burning plumes and their impact on urban air quality; a case study of Santiago de ChileCuchiara, G.C.; Rappenglück, B.; Rubio, M.A.; Lissi, E.; Gramsch, E.; Garreaud, R.D.Agua y Extremos2017.010.1016/j.atmosenv.2017.07.002On January 4, 2014, during the summer period in South America, an intense forest and dry pasture wildfire occurred nearby the city of Santiago de Chile. On that day the biomass-burning plume was transported by low-intensity winds towards the metropolitan area of Santiago and impacted the concentration of pollutants in this region. In this study, the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem) is implemented to investigate the biomass-burning plume associated with these wildfires nearby Santiago, which impacted the ground-level ozone concentration and exacerbated Santiago's air quality. Meteorological variables simulated by WRF/Chem are compared against surface and radiosonde observations, and the results show that the model reproduces fairly well the observed wind speed, wind direction air temperature and relative humidity for the case studied. Based on an analysis of the transport of an inert tracer released over the locations, and at the time the wildfires were captured by the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS), the model reproduced reasonably well the transport of biomass burning plume towards the city of Santiago de Chile within a time delay of two hours as observed in ceilometer data. A six day air quality simulation was performed: the first three days were used to validate the anthropogenic and biogenic emissions, and the last three days (during and after the wildfire event) to analyze the performance of WRF/Chem plume-rise model within FINNv1 fire emission estimations. The model presented a satisfactory performance on the first days of the simulation when contrasted against data from the well-established air quality network over the city of Santiago de Chile. These days represent the urban air quality base case for Santiago de Chile unimpacted by fire emissions. However, for the last three simulation days, which were impacted by the fire emissions, the statistical indices showed a decrease in the model performance. While the model showed a satisfactory evidence that wildfires plumes that originated in the vicinity of Santiago de Chile were transported towards the urban area and impacted the air quality, the model still underpredicted some pollutants substantially, likely due to misrepresentation of fire emission sources during those days. Potential uncertainties may include to the land use/land cover classifications and its characteristics, such as type and density of vegetation assigned to the region, where the fire spots are detected. The variability of the ecosystem type during the fire event might also play a role.Atmospheric Environment13522310 Reuters ISIair quality, atmospheric humidity, atmospheric temperature, biomass, image reconstruction, meteorological instruments, pollution, radiometers, radiosondes, satellite imagery, weather forecasting, anthropogenic and biogenic emissions, atmospheric model, biomass-burning, ground level ozone concentration, moderate resolution imaging spectroradiometer, plume rise, weather research and forecasting models, wrf/chem, fires, ozone, air quality, anthropogenic effect, atmospheric modeling, atmospheric plume, biogenic emission, biomass burning, forecasting method, metropolitan area, modis, radiosonde, urban pollution, air quality, air temperature, article, biomass, circadian rhythm, combustion, humidity, land use, pasture, plume, priority journal, sensitivity analysis, simulation, summer, urban area, wind, chile, metropolitana, santiago [metropolitana]
Postfire responses of the woody flora of Central Chile: Insights from a germination experimentGómez-González, Susana; Paula, Susana; Cavieres, Lohengrin A.; Pausas, Juli G.Cambio de Uso de Suelo2017.010.1371/journal.pone.0180661Fire is a selective agent shaping plant traits and community assembly in fire-prone ecosystems. However, in ecosystems with no fire history, it can be a cause of land degradation when it is suddenly introduced by humans, as plant species may not be able to respond to such novel disturbance. Unlike other Mediterranean-type ecosystems (MTE) of the world, natural fires have not been frequent during the Quaternary in the matorral of Central Chile, and thus, plant adaptive responses are expected to be uncommon. We evaluated the effect of heat shock on seed survival and germination of 21 native woody plants of the Chilean matorral and compiled information on smoke-stimulation and resprouting, to evaluate the importance of fire-adaptive responses in the context of the other MTE. We found that in the Chilean woody flora negative seed responses to fire cues were more frequent than positive responses. Although resprouting is a relatively widespread trait, fire-stimulated germination is not as common in the Chilean matorral as in other MTE. The seeds of seven endemic species were strongly damaged by fire cues and this should be considered in post-fire restoration planning. However, our results also showed that many species were resistant to elevated doses of heat shock and in some, germination was even stimulated. Thus, future research should focus on the evolutionary causes of these responses. These findings could help to develop strategies for fire management in the Chilean matorral. In addition, they will improve our understanding of the evolutionary forces that shaped this plant community and to better frame this region among the other MTE worldwide.PLOS ONE1932-6203 Reuters ISIchile, endemic species, flora, germination, heat shock, human, nonhuman, plant community, smoke, woody plant, biomass, chile, evolution, fire, forest, genetic selection, genetics, growth, development and aging, plant seed, biological evolution, biomass, chile, fires, forests, germination, seeds, selection, genetic
Predicting Vascular Plant Diversity in Anthropogenic Peatlands: Comparison of Modeling Methods with Free Satellite DataCastillo-Riffart, Ivan; Galleguillos, Mauricio; Lopatin, Javier; Perez-Quezada, J. F.Cambio de Uso de Suelo2017.010.3390/rs9070681Peatlands are ecosystems of great relevance, because they have an important number of ecological functions that provide many services to mankind. However, studies focusing on plant diversity, addressed from the remote sensing perspective, are still scarce in these environments. In the present study, predictions of vascular plant richness and diversity were performed in three anthropogenic peatlands on Chiloé Island, Chile, using free satellite data from the sensors OLI, ASTER, and MSI. Also, we compared the suitability of these sensors using two modeling methods: random forest (RF) and the generalized linear model (GLM). As predictors for the empirical models, we used the spectral bands, vegetation indices and textural metrics. Variable importance was estimated using recursive feature elimination (RFE). Fourteen out of the 17 predictors chosen by RFE were textural metrics, demonstrating the importance of the spatial context to predict species richness and diversity. Non-significant differences were found between the algorithms; however, the GLM models often showed slightly better results than the RF. Predictions obtained by the different satellite sensors did not show significant differences; nevertheless, the best models were obtained with ASTER (richness: R2 = 0.62 and %RMSE = 17.2, diversity: R2 = 0.71 and %RMSE = 20.2, obtained with RF and GLM respectively), followed by OLI and MSI. Diversity obtained higher accuracies than richness; nonetheless, accurate predictions were achieved for both, demonstrating the potential of free satellite data for the prediction of relevant community characteristics in anthropogenic peatland ecosystems. © 2017 by the authors.Remote Sensing2072-4292 Reuters ISIdecision trees, ecology, ecosystems, forecasting, maximum likelihood, satellites, wetlands, aster, generalized linear model, random forests, richness, shannon index, sphagnum, forestry
Implementation of methane cycling for deep-time global warming simulations with the DCESS Earth system model (version 1.2)Shaffer, Gary; Fernández Villanueva, Esteban; Rondanelli, Roberto; Pedersen, Jens Olaf Pepke; Olsen, Steffen Malskær; Huber, MatthewZonas Costeras2017.010.5194/gmd-10-4081-2017Geological records reveal a number of ancient, large and rapid negative excursions of the carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth system over a short duration. These injections may have forced strong global warming events, sometimes accompanied by mass extinctions such as the Triassic-Jurassic and end-Permian extinctions 201 and 252 million years ago, respectively. In many cases, evidence points to methane as the dominant form of injected carbon, whether as thermogenic methane formed by magma intrusions through overlying carbon-rich sediment or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth system models for addressing such events should include a comprehensive treatment of methane cycling but such a treatment has often been lacking. Here we implement methane cycling in the Danish Center for Earth System Science (DCESS) model, a simplified but well-tested Earth system model of intermediate complexity. We use a generic methane input function that allows variation in input type, size, timescale and ocean–atmosphere partition. To be able to treat such massive inputs more correctly, we extend the model to deal with ocean suboxic/anoxic conditions and with radiative forcing and methane lifetimes appropriate for high atmospheric methane concentrations. With this new model version, we carried out an extensive set of simulations for methane inputs of various sizes, timescales and ocean–atmosphere partitions to probe model behavior. We find that larger methane inputs over shorter timescales with more methane dissolving in the ocean lead to ever-increasing ocean anoxia with consequences for ocean life and global carbon cycling. Greater methane input directly to the atmosphere leads to more warming and, for example, greater carbon dioxide release from land soils. Analysis of synthetic sediment cores from the simulations provides guidelines for the interpretation of real sediment cores spanning the warming events. With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, timescales and locations of methane injections driving specific, observed deep-time, global warming events.Geoscientific Model Development1991-9603 Reuters ISIair-sea interaction, anoxic conditions, carbon cycle, carbon dioxide, carbon isotope, climate modeling, extinction, global warming, jurassic, marine sediment, methane, permian, radiative forcing, sediment core, simulation, suboxic conditions, terrestrial environment, triassic, denmark
Southern Annular Mode drives multicentury wildfire activity in southern South AmericaHolz, Andrés; Paritsis, Juan; Mundo, Ignacio A.; Veblen, Thomas T.; Kitzberger, Thomas; Williamson, Grant J.; Aráoz, Ezequiel; Bustos-Schindler, Carlos; González, Mauro E.; Grau, H. Ricardo; Quezada, Juan M.Cambio de Uso de Suelo2017.010.1073/pnas.1705168114The Southern Annular Mode (SAM) is the main driver of climate variability at mid to high latitudes in the Southern Hemisphere, affecting wildfire activity, which in turn pollutes the air and contributes to human health problems and mortality, and potentially provides strong feedback to the climate system through emissions and land cover changes. Here we report the largest Southern Hemisphere network of annually resolved tree ring fire histories, consisting of 1,767 fire-scarred trees from 97 sites (from 22 °S to 54 °S) in southern South America (SAS), to quantify the coupling of SAM and regional wildfire variability using recently created multicentury proxy indices of SAM for the years 1531–2010 AD. We show that at interannual time scales, as well as at multidecadal time scales across 37–54 °S, latitudinal gradient elevated wildfire activity is synchronous with positive phases of the SAM over the years 1665–1995. Positive phases of the SAM are associated primarily with warm conditions in these biomass-rich forests, in which widespread fire activity depends on fuel desiccation. Climate modeling studies indicate that greenhouse gases will force SAM into its positive phase even if stratospheric ozone returns to normal levels, so that climate conditions conducive to widespread fire activity in SAS will continue throughout the 21st century. © 2017, National Academy of Sciences. All rights reserved.Proceedings of the National Academy of Sciences0027-8424, 1091-6490 Reuters ISIarticle, biomass, climate change, fire, forest, greenhouse gas, land use, ozone layer, priority journal, south america, southern hemisphere, temperature, tree
Local Perception of Drought Impacts in a Changing Climate: The Mega-Drought in Central ChileAldunce, Paulina; Araya, Dámare; Sapiain, Rodolfo; Ramos, Issa; Lillo, Gloria; Urquiza, Anahí; Garreaud, RenéAgua y Extremos; Gobernanza e Interfaz Ciencia y Política2017.010.3390/su9112053Droughts are a recurrent and complex natural hazard whose frequency and magnitude are expected to increase with climate change. Despite the advances in responding and adapting to droughts (with the development of new policies, for example), droughts continue to cause serious impacts and suffering. Developing well-targeted public policies requires further research on adaptation. Specifically, understanding the public perception of drought can help to identify drivers of and barriers to adaptation and options. This research seeks to understand the public perception of drought in central Chile in order to inform adaptation-related policies and decision-making processes. This study focused on the Mega-drought, which was a protracted dry spell afflicting central Chile since 2010.Sustainability2071-1050 Reuters ISIclimate change, climate effect, decision making, drought, natural hazard, perception, policy development, social policy, chile
The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experimentsKageyama, Masa; Albani, Samuel; Braconnot, Pascale; Harrison, Sandy P.; Hopcroft, Peter O.; Ivanovic, Ruza F.; Lambert, Fabrice; Marti, Olivier; Peltier, W. Richard; Peterschmitt, Jean-Yves; Roche, Didier M.; Tarasov, Lev; Zhang, Xu; Brady, Esther C.; Haywood, Alan M.; LeGrande, Allegra N.; Lunt, Daniel J.; Mahowald, Natalie M.; Mikolajewicz, Uwe; Nisancioglu, Kerim H.; Otto-Bliesner, Bette L.; Renssen, Hans; Tomas, Robert A.; Zhang, Qiong; Abe-Ouchi, Ayako; Bartlein, Patrick J.; Cao, Jian; Li, Qiang; Lohmann, Gerrit; Ohgaito, Rumi; Shi, Xiaoxu; Volodin, Evgeny; Yoshida, Kohei; Zhang, Xiao; Zheng, WeipengCiudades Resilientes2017.010.5194/gmd-10-4035-2017The Last Glacial Maximum (LGM, 21 000 years ago) is one of the suite of paleoclimate simulations included in the current phase of the Coupled Model Intercomparison Project (CMIP6). It is an interval when insolation was similar to the present, but global ice volume was at a maximum, eustatic sea level was at or close to a minimum, greenhouse gas concentrations were lower, atmospheric aerosol loadings were higher than today, and vegetation and land-surface characteristics were different from today. The LGM has been a focus for the Paleoclimate Modelling Intercomparison Project (PMIP) since its inception, and thus many of the problems that might be associated with simulating such a radically different climate are well documented. The LGM state provides an ideal case study for evaluating climate model performance because the changes in forcing and temperature between the LGM and pre-industrial are of the same order of magnitude as those projected for the end of the 21st century. Thus, the CMIP6 LGM experiment could provide additional information that can be used to constrain estimates of climate sensitivity. The design of the Tier 1 LGM experiment (lgm) includes an assessment of uncertainties in boundary conditions, in particular through the use of different reconstructions of the ice sheets and of the change in dust forcing. Additional (Tier 2) sensitivity experiments have been designed to quantify feedbacks associated with land-surface changes and aerosol loadings, and to isolate the role of individual forcings. Model analysis and evaluation will capitalize on the relative abundance of paleoenvironmental observations and quantitative climate reconstructions already available for the LGM.Geoscientific Model Development1991-9603 Reuters ISIaerosol, climate modeling, cmip, experimental design, greenhouse gas, land surface, last glacial maximum, paleoclimate, reconstruction, relative abundance
Loco or no Loco? Holocene Climatic Fluctuations, Human Demography, and Community Based Management of Coastal Resources in Northern ChileSantoro, Calogero M.; Gayo, Eugenia M.; Carter, Chris; Standen, Vivien G.; Castro, Victoria; Valenzuela, Daniela; De Pol-Holz, Ricardo; Marquet, Pablo A.; Latorre, ClaudioCambio de Uso de Suelo; Ciudades Resilientes2017.010.3389/feart.2017.00077The abundance of the southern Pacific mollusk loco (Concholepas concholepas), among other conspicuous marine supplies, are often cited as critical resources behind the long-term cultural and demographic fluctuations of prehistoric hunter-gatherers in the coastal Atacama Desert. These societies inhabited one of the world’s most productive marine environments flanked by one the world’s driest deserts. Both of these environments have witnessed significant ecological variation since people first colonized themat the end of the Pleistocene (c. 13,000 cal yr BP). Here, we examine the relationship between the relative abundance of shellfish (a staple resource) along a 9,500-year sequence of archeological shell midden accumulations at Caleta (a small inlet or cove) Vitor, with past demographic trends (established via summed probability distributions of radiocarbon ages) and technological innovations together with paleoceanographic data on past primary productivity. We find that shellfish extraction varied considerably from one cultural period to the next in terms of the number of species and their abundance, with diversity increasing during periods of regionally decreased productivity. Such shifts in consumption patterns are considered community based management decisions, and for the most part they were synchronous with large and unusual regional demographic fluctuations experienced by prehistoric coastal societies in northern Chile. When taken together with their technological innovations, our data illustrates how these human groups tailored their socio-cultural patterns to what were often abrupt and prolonged environmental changes throughout the Holocene.Frontiers in Earth Science2296-6463 Reuters ISIarid regions, climatology, demography, landforms, population dynamics, population statistics, shellfish, atacama desert, community-based management, cultural resources, demographic fluctuations, enso, holocene climate, socio-cultural patterns, technological innovation, probability distributions
A solar radiation database for ChileMolina, Alejandra; Falvey, Mark; Rondanelli, RobertoZonas Costeras2017.010.1038/s41598-017-13761-xChile hosts some of the sunniest places on earth, which has led to a growing solar energy industry in recent years. However, the lack of high resolution measurements of solar irradiance becomes a critical obstacle for both financing and design of solar installations. Besides the Atacama Desert, Chile displays a large array of "solar climates" due to large latitude and altitude variations, and so provides a useful testbed for the development of solar irradiance maps. Here a new public database for surface solar irradiance over Chile is presented. This database includes hourly irradiance from 2004 to 2016 at 90 m horizontal resolution over continental Chile. Our results are based on global reanalysis data to force a radiative transfer model for clear sky solar irradiance and an empirical model based on geostationary satellite data for cloudy conditions. The results have been validated using 140 surface solar irradiance stations throughout the country. Model mean percentage error in hourly time series of global horizontal irradiance is only 0.73%, considering both clear and cloudy days. The simplicity and accuracy of the model over a wide range of solar conditions provides confidence that the model can be easily generalized to other regions of the world.Scientific Reports2045-2322 Reuters ISIchile, solar radiation, time series analysis, article
The Chilean Coastal Orographic Precipitation Experiment: Observing the Influence of Microphysical Rain Regimes on Coastal Orographic PrecipitationMassmann, Adam K.; Minder, Justin R.; Garreaud, René D.; Kingsmill, David E.; Valenzuela, Raul A.; Montecinos, Aldo; Fults, Sara Lynn; Snider, Jefferson R.Agua y Extremos2017.010.1175/JHM-D-17-0005.1The Chilean Coastal Orographic Precipitation Experiment (CCOPE) was conducted during the austral winter of 2015 (May-August) in the Nahuelbuta Mountains (peak elevation 1.3 km MSL) of southern Chile (38°S). CCOPE used soundings, two profiling Micro Rain Radars, a Parsivel disdrometer, and a rain gauge network to characterize warm and ice-initiated rain regimes and explore their consequences for orographic precipitation. Thirty-three percent of foothill rainfall fell during warm rain periods, while 50% of rainfall fell during ice-initiated periods. Warm rain drop size distributions were characterized by many more and relatively smaller drops than ice-initiated drop size distributions. Both the portion and properties of warm and ice-initiated rainfall compare favorably with observations of coastal mountain rainfall at a similar latitude in California. Orographic enhancement is consistently strong for rain of both types, suggesting that seeding from ice aloft is not a requisite for large orographic enhancement. While the data suggest that orographic enhancement may be greater during warm rain regimes, the difference in orographic enhancement between regimes is not significant. Sounding launches indicate that differences in orographic enhancement are not easily explainable by differences in low-level moisture flux or nondimensional mountain height between the regimes.Journal of Hydrometeorology1525-755X, 1525-7541 Reuters ISIcloud microphysics, coastal zone, marine atmosphere, orographic effect, precipitation (climatology), precipitation assessment, size distribution, stratiform cloud, chile
Vertical segregation among pathways mediating nitrogen loss (N2 and N2O production) across the oxygen gradient in a coastal upwelling ecosystemGalán, Alexander; Thamdrup, Bo; Saldías, Gonzalo S.; Farías, LauraZonas Costeras2017.010.5194/bg-14-4795-2017The upwelling system off central Chile (36.5 S) is seasonally subjected to oxygen (O2)-deficient waters, with a strong vertical gradient in O2 (from oxic to anoxic conditions) that spans a few metres (30-50€m interval) over the shelf. This condition inhibits and/or stimulates processes involved in nitrogen (N) removal (e.g. anammox, denitrification, and nitrification). During austral spring (September 2013) and summer (January 2014), the main pathways involved in N loss and its speciation, in the form of N2 and/or N2O, were studied using 15N-tracer incubations, inhibitor assays, and the natural abundance of nitrate isotopes along with hydrographic information. Incubations were developed using water retrieved from the oxycline (25€m depth) and bottom waters (85€m depth) over the continental shelf off Concepción, Chile. Results of 15N-labelled incubations revealed higher N removal activity during the austral summer, with denitrification as the dominant N2-producing pathway, which occurred together with anammox at all times. Interestingly, in both spring and summer maximum potential N removal rates were observed in the oxycline, where a greater availability of oxygen was observed (maximum O2 fluctuation between 270 and 40€μmol€L'1) relative to the hypoxic bottom waters ( < €20€μmol€O2€L'1). Different pathways were responsible for N2O produced in the oxycline and bottom waters, with ammonium oxidation and dissimilatory nitrite reduction, respectively, as the main source processes. Ammonium produced by dissimilatory nitrite reduction to ammonium (DNiRA) could sustain both anammox and nitrification rates, including the ammonium utilized for N2O production. The temporal and vertical variability of /15N-NO3' confirms that multiple N-cycling processes are modulating the isotopic nitrate composition over the shelf off central Chile during spring and summer. N removal processes in this coastal system appear to be related to the availability and distribution of oxygen and particles, which are a source of organic matter and the fuel for the production of other electron donors (i.e. ammonium) and acceptors (i.e. nitrate and nitrite) after its remineralization. These results highlight the links between several pathways involved in N loss. They also establish that different mechanisms supported by alternative N substrates are responsible for substantial accumulation of N2O, which are frequently observed as hotspots in the oxycline and bottom waters. Considering the extreme variation in oxygen observed in several coastal upwelling systems, these findings could help to understand the ecological and biogeochemical implications due to global warming where intensification and/or expansion of the oceanic OMZs is projected.Biogeosciences1726-4189 Reuters ISIbioassay, biogeochemical cycle, bottom water, continental shelf, denitrification, ecosystem dynamics, environmental gradient, global warming, nitrogen, nitrogen cycle, organic matter, oxygen, oxygen minimum layer, tracer, upwelling, vertical profile, chile
Research on Climate Change Policies and Rural Development in Latin America: Scope and GapsLocatelli, Bruno; Aldunce, Paulina; Fallot, Abigaïl; Le Coq, Jean-François; Sabourin, Eric; Tapasco, JeimarAgua y Extremos2017.010.3390/su9101831Research on climate change policies can contribute to policy development by building an understanding of the barriers faced in policy processes, and by providing knowledge needed throughout policy cycles. This paper explores the thematic coverage of research on climate change policies related to rural areas, rural development, and natural resource management in Latin America. A three-tier framework is proposed to analyse the selected literature. The results show that research studies have focussed on the mitigation of greenhouse gas emissions from forests, and adaptations to climate change in agriculture. There is little policy research on other vulnerable sectors (e.g., water and health) and emitting sectors (e.g., energy and industry) in the context of rural development. Our analysis highlights the various research gaps that deserve increased scientific attention, including: cross-sector approaches, multi-level governance, and the stages of policy adoption, implementation and evaluation. In addition, the selected literature has a limited contribution to theoretical discussions in policy sciences.Sustainability2071-1050 Reuters ISIadaptive management, climate change, environmental policy, forest edge, greenhouse gas, natural resource, policy development, policy implementation, research work, resource management, rural area, rural development, latin america
Climate change and resilience of deciduous Nothofagus forests in central-east Chilean Patagonia over the last 3200 years: RESILIENCE OF DECIDUOUS NOTHOFAGUS FORESTS IN PATAGONIASimi, E.; Moreno, P. I.; Villa-Martínez, R.; Vilanova, I.; de Pol-Holz, R.Cambio de Uso de Suelo; Agua y Extremos2017.010.1002/jqs.2948We examine the response of Nothofagus forests to climate change and disturbance regimes over the last 3200 years near Coyhaique (45°S), central–east Chilean Patagonia, using fine‐resolution pollen and charcoal records from lake sediment cores. Closed‐canopy deciduous Nothofagus forests have dominated the region with little variation until the arrival of Chilean–European settlers, suggesting a predominance of cool‐temperate and wet conditions. Within this state we identify centennial‐scale episodes of forest fragmentation, increase in littoral macrophytes and volcanic/paleofire disturbance between 2700 and 3000 cal a BP, 2200 and 2500 cal a BP and over the last ∼250 years, which we interpret as intervals with negative hydrologic balance. Natural variability caused little impact on the physiognomy and composition of the vegetation in pre‐European time, in contrast to the accelerated shift that started during the late 19th century associated with deforestation, homogenization and synchronization of ecosystem changes at the landscape level, and spread of exotic plant species brought by Chilean and European settlers during a warm/dry interval. The resilience of deciduous Nothofagus forests to natural disturbance regimes and climate change was exceeded by large‐scale human disturbance since the late 19th century by fire, timber exploitation and livestock grazing. These disturbances caused an ecosystem shift towards artificial meadows and scrublands with frequent high‐magnitude fires.Journal of Quaternary Science0267-8179 Reuters ISIclimate variation, deciduous forest, disturbance, fire history, holocene, human activity, paleoclimate, paleoenvironment, tephra, chile, patagonia, nothofagus
The effect of climate change on electricity expenditures in MassachusettsVéliz, Karina D.; Kaufmann, Robert K.; Cleveland, Cutler J.; Stoner, Anne M.K.Ciudades Resilientes2017.010.1016/j.enpol.2017.03.016Climate change affects consumer expenditures by altering the consumption of and price for electricity. Previous analyses focus solely on the former, which implicitly assumes that climate-induced changes in consumption do not affect price. But this assumption is untenable because a shift in demand alters quantity and price at equilibrium. Here we present the first empirical estimates for the effect of climate change on electricity prices. Translated through the merit order dispatch of existing capacity for generating electricity, climate-induced changes in daily and monthly patterns of electricity consumption cause non-linear changes in electricity prices. A 2 °C increase in global mean temperature increases the prices for and consumption of electricity in Massachusetts USA, such that the average household’s annual expenditures on electricity increase by about 12%. Commercial customers incur a 9% increase. These increases are caused largely by higher prices for electricity, whose impacts on expenditures are 1.3 and 3.6 fold larger than changes in residential and commercial consumption, respectively. This suggests that previous empirical studies understate the effects of climate change on electricity expenditures and that policy may be needed to ensure that the market generates investments in peaking capacity to satisfy climate-driven changes in summer-time consumption.Energy Policy0301-4215 Reuters ISIcosts, electric power utilization, adaptation, annual expenditure, commercial customers, consumer expenditure, electricity expenditures, electricity prices, electricity-consumption, global-mean temperature, climate change, climate change, climate effect, electricity generation, electricity supply, energy use, price determination, massachusetts, united states
The 2010-2015 mega drought in Central Chile: Impacts on regional hydroclimate and vegetationGarreaud, R.; Alvarez-Garreton, Camila; Barichivich, Jonathan; Boisier, Juan Pablo; Christie, Duncan; Galleguillos, Mauricio; LeQuesne, Carlos; McPhee, James; Zambrano-Bigiarini, MauricioCambio de Uso de Suelo; Agua y Extremos2017.010.5194/hess-21-6307-2017Since 2010 an uninterrupted sequence of dry years, with annual rainfall deficits ranging from 25 to 45 %, has prevailed in Central Chile (western South America, 30–38° S). Although intense 1- or 2-year droughts are recurrent in this Mediterranean-like region, the ongoing event stands out because of its longevity and large spatial extent. The extraordinary character of the so-called Central Chile Mega Drought (MD) was established against century long historical records and a millennial tree-ring reconstruction of regional precipitation. The largest MD-averaged rainfall relative anomalies occurred in the northern, semi-arid sector of central Chile but the event was unprecedented to the south of 35° S. ENSO neutral conditions have prevailed since 2011 (but for the strong El Niño 2015) contrasting with La Niña conditions that often accompanied past droughts. The precipitation deficit diminished the Andean snowpack and resulted in amplified declines (up to 90 %) of river flow, reservoir volumes and groundwater levels along central Chile and westernmost Argentina. In some semiarid basins we also found a conspicuous decrease in the runoff-to-rainfall coefficient. A substantial decrease in vegetation productivity occurred in the shrubland-dominated, northern sector, but a mix of greening and browning patches occurred farther south where irrigated croplands and exotic forest plantations dominate. The ongoing warming in central Chile, making the MD one of the warmest 6-year period on record, may have also contributed to such complex vegetation changes by increasing potential evapotranspiration. The understanding of the nature and biophysical impacts of the MD contributes to preparedness efforts to face a dry, warm future regional climate scenario.Hydrology and Earth System Sciences1027-5606 Reuters ISIclimatology, drought, groundwater, nickel, rain, exotic forest plantations, historical records, irrigated cropland, potential evapotranspiration, precipitation deficits, tree-ring reconstruction, vegetation productivity, western south america, vegetation, agricultural land, drought, el nino, el nino-southern oscillation, groundwater, historical record, la nina, multireservoir system, plantation forestry, potential evapotranspiration, precipitation (climatology), rainfall-runoff modeling, regional climate, river flow, shrubland, snowpack, tree ring, vegetation dynamics, andes, argentina, chile, mediterranean region
Anomalías anatómicas en anillos de crecimiento anuales de Austrocedrus chilensis (D. Don) Pic.-Serm. et Bizzarri en el norte de su rango de distribuciónRojas-Badilla, Moisés; Álvarez, Claudio; Velásquez-Álvarez, Gonzalo; Hadad, Martín; Le Quesne, Carlos; Christie, Duncan A.Agua y Extremos2017.010.4067/S0717-66432017000200269Tree-ring anatomical anomalies have received little attention in southern South American trees, however they can contain valuable intra-annual environmental information. This study addressed for the first time the three most frequent tree- ring anomalies recorded in the northern and oldest known Austrocedrus chilensis forest in central Chile (32-35°S). Three anatomic anomalies described were: partially absent rings, intra-annual bands and frost rings. Partially absent rings resulted from cambial inactivity during a complete growing period and require dendrochronological tools to be detected. Intra- annual bands are consequence of the abundance-shortage of environmental resources during the growing season and can be detected by examining the undefined late-wood boundaries. Frost rings, are caused by extreme low temperatures and are characterized by collapsed cells in the tree-ring growth. Results indicate that the northern most population exhibited the highest rate of absent rings, while the occurrence of intra-annual bands seems to be rather minor in the study area. Finally, frost rings are registered mainly in the younger trees in all three studied sites. These results suggest the potential for future spatio-temporal studies that examine the frequency of these anatomical anomalies in A. chilensis chronologies along its wide geographical distribution. This will complement the current environmental information recorded by its growth rates.Gayana. Botánica0717-6643 Reuters ISIabsent rings, dendrochronology, frost rings, intra-annual bands, wood anatomy
Ecosystem engineering by Fascicularia bicolor in the canopy of the South-American temperate rainforestOrtega-Solís, Gabriel; Díaz, Iván; Mellado-Mansilla, Daniela; Tello, Francisco; Moreno, Ricardo; Tejo, CamilaCambio de Uso de Suelo2017.010.1016/j.foreco.2017.06.020Ecosystem engineers are organisms that modify habitats and resource flows, they therefore could have a disproportionate impact on the diversity of ecological communities. Evidence suggests that trash basket epiphytes (TBE) can be considered ecosystem engineers of forest canopies, due to their relationship with arboreal soil availability and treetop communities. Here we evaluated whether the TBE Fascicularia bicolor (Bromeliaceae), modulates temperature and humidity in the forest canopy. We also investigated if this bromeliad is related with greater arboreal soil accumulation and is associated to higher diversity of other epiphytic plants and invertebrates in the canopy of the South-American temperate rainforest (SATR), in Chile. We measured temperature and humidity in ten trees within the forest before and after the experimental addition of F. bicolor. We also related the presence of F. bicolor with occurrence of soil macrofauna and other canopy dwelling plants in a comparative field survey. Temperature variability in the canopy was reduced by F. bicolor. Soil availability was higher in siteswith mats of F. bicolor. The richness of vascular epiphytes was unaltered by the presence of F. bicolor,but species composition differed between sites with and without mats on each tree. At the group level,the cover of lichens and bryophytes was greater in sites without F. bicolor, while vascular epiphytes showa larger cover in sites with F. bicolor. The species richness of invertebrates increased in treetop sites colonized by F. bicolor but species composition was not different from soil in branch bifurcations. Our resultsshow that F. bicolor must be considered in forest management practices to determine which trees must belogged, in order to preserve the viability of populations of these key organisms in the treetops of South-American temperate rainforests.Forest Ecology and Management0378-1127 Reuters ISIanimals, ecosystems, professional aspects, soils, ecosystem engineering, forest management practices, measured temperatures, soil accumulations, species composition, temperate rainforest, temperature and humidities, temperature variability, forestry, bryophyte, colonization, ecosystem engineering, epiphyte, forest canopy, invertebrate, lichen, monocotyledon, rainforest, species richness, temperate environment, ecosystems, forest canopy, humidity, south america, bromeliaceae, bryophytes, fascicularia bicolor, invertebrata
Interfaz ciencia-políticas públicas en Chile: una mirada a la investigación en cambio climáticoBorquéz González, RoxanaGobernanza e Interfaz Ciencia y Política2017.010.15446/rcs.v40n2.66402En las últimas décadas, se han observado importantes cambios en torno a la relación entre la ciencia y la sociedad. Se ha transitado de un paradigma basado en que la ciencia está transformando la sociedad a otro que abre a la posibilidad de que la sociedad transforme la ciencia. El aporte de la esfera científica, al igual que el brindado por cada uno de los actores sociales, es fundamental para apoyar la toma de decisiones en política pública. Así lo ha demostrado el Panel Intergubernamental de Expertos sobre Cambio Climático (IPCC), que ha jugado un rol clave en la toma de acciones de la comunidad internacional. Sin embargo, la relación entre ciencia y política no ha sido suficientemente fluida en Chile. El objetivo del estudio fue identificar y analizar, a través de motodología cualitativa de carácter exploratorio, las brechas y los facilitadores de la relación entre investigadores del campo de las ciencias naturales y las políticas públicas en Chile, con énfasis en el área del cambio climático. Esto permitió analizar la estructura y la dinámica de incentivos a la actividad de las esferas científica y pública, y los mecanismos de comunicación y coordinaci;ón existentes entre ellas. Así, se identificaron ocho brechas y dos facilitadores. Resaltan el bajo interés de la esfera científica en realizar "asesorías" solicitadas por servicios públicos que generan poíticas públicas, la falta de incentivos o exigencias académicas para simplificar contenidos, así como la falta de comunicación y de interacción regular que generan una diferencia entre lo que la esfera político-administrativa espera de los científicos y la forma en que estos últimos ven como efectiva y útil su participación. Además, se observaron fallas de coordinación entre quien financia la investigación y quien genera la política pública. Los resultados también muestran que las brechas entre las esferas no se recducen únicamente al campo del cambio climático, sino que se deben también a la manera como están conformadas las estructuras científicas y políticas de Chile.Revista Colombiana de Sociología2256-5485, 0120-159X Reuters ISIA
Comunicación ambiental y proyectos energéticos renovables no convencionales. Análisis de contenido en medios de comunicación de masa chilenosBilli, M; Urquiza Gómez, A; Feres Klenner, CCiudades Resilientes2017.010.4185/RLCS-2017-1216Se observa la tematización mediática de proyectos Energéticos Renovables No Convencionales [ERNC] en términos de la relevancia y tratamiento otorgados a distintas fuentes y estructuras temáticas emergentes. Metodología. Análisis de contenido con enfoque mixto sobre una muestra de 100 artículos de prensa digital chilena relacionados con ERNC, usando el marco analítico de la Teoría de Sistemas Sociales de Niklas Luhmann. Resultados y Discusión. La primacía de fuentes solares y eólicas se acompaña a una reducida claridad terminológica, que sin embargo permite construir estructuras temáticas distintas en relación con sistemas sociales como economía, ciencia, política y derecho. Las referencias medioambientales son más escasas y menos profundas, privilegiando sus aspectos evocativos y con máxima capacidad de enlace. Conclusiones. En lugar que observar a los medios como mera transmisión de racionalidades externas a ellos debería prestarse atención a su capacidad de crear realidad y representar el entorno social y medioambiental.Revista Latina de Comunicación Social1138-5820 Reuters ISIchile, climate change mitigation, energy crisis, environmental communication, mass media, non-conventional renewable energies
Aplicar una distinción. Un programa sistémico-constructivista para la investigación social cualitativaUrquiza, Anahi; Billi, Marco; Leal, TomasCiudades Resilientes2017.010.5354/0719-0527.2017.47269Por lo menos desde el siglo XVIII, el ‘problema de la inducción’, es decir de cómo justificar las abstracciones que se hacen a partir de la observación empírica, ha estado al centro de un encendido debate tanto en la filosofía de la ciencia, como en la praxisde las ciencias sociales. Rechazando las acusaciones de ‘clausura empírica’ levantadas respecto de la Teoría de Sistemas Sociales de Niklas Luhmann, afirmamos por el contrario que esta proporciona una plataforma epistemológica y teórica privilegiada para hacer frente al citado dilema, explicitando las condiciones para producir un razonamiento de tipo ‘abductivo’. Dialogando, porun lado, con la comprensión de Luhmann respecto del conocimiento y de la ciencia, y por el otro, con diversos intentos para aplicar empíricamente la propuesta sistémica e integrarla con otros enfoques analíticos, el presente paperofrece un modelo generalpara comprender el rol y la relación de los principios de plausibilidad teórica y fundamentación empírica en la investigación social. A partir de ello, el artículo identifica los criterios de ‘isomorfismo’, ‘perspectivismo’, ‘transparencia’ e ‘iterabilidad’ como indicadores de aceptabilidad científica de una investigación sistémico-constructivista, y ofrece orientaciones para el diseño de un proceso de investigación de este tipo.Revista Mad0718-0527 Reuters ISIA
The Dry Puna as an ecological megapatch and the peopling of South America: Technolog