Línea de investigación:

Cambio de uso de suelo

Los cambios de uso de suelo, como la conversión de ecosistemas no perturbados a paisajes extractivos y la consiguiente alteración de los regímenes de fuego natural, han contribuido considerablemente al cambio global. Estos cambios han producido impactos sobre la biodiversidad, la estructura y función del ecosistema, los servicios ecosistémicos y su disponibilidad, así como la proliferación de especies exóticas de animales y plantas, lo que resulta en la homogeneización de la biósfera.

El centro y sur de Chile ha experimentado dichos cambios en los últimos 40 años. El patrón dominante ha sido la conversión de bosques nativos a plantaciones forestales exóticas de pino y eucalipto que se extienden sobre un total de 2,75 millones de hectáreas. Esta región del país es un valioso caso de estudio para la investigación sobre los forzantes y los impactos del cambio de uso de suelo, sus interacciones y modelado y predicción.

La línea de investigación trabajará en el diseño de paisajes diversificados para reemplazar ests áreas homogéneas, incluyendo múltiples categorías de cambio de uso de suelo desde una perspectiva de cuenca con el fin de garantizar la producción combinada de bienes y servicios ecosistémicos. También se presentarán evaluaciones de costos para proyectos de restauración basados ​​en la conversión de plantaciones forestales a bosques nativos.

Todo este conocimiento será crucial para orientar a los toma de decisiones y así garantizar el progreso hacia paisajes más resistentes y resilientes. El desafío específico de comprender los incendios, sus forzamientos, regímenes e impactos, y la relevancia de este tema para política pública, brinda una oportunidad única para producir resultados que puedan ser aplicables a otros problemas y otras regiones.

INVESTIGADOR PRINCIPAL

CO-INVESTIGADOR PRINCIPAL

INVESTIGADORES ASOCIADOS

INVESTIGADORES ADJUNTOS

INVESTIGADORES POSTDOCTORALES

ESTUDIANTES

Nombre Apellido
Celeste Estrella Soto Uribe
Javiera Chahúan Pérez
David Banda
Marco Aurelio Cortés Bianchi
Francisco Díaz
Santiago Ancapichún Hernández
Paulina Riquelme Ocampo
Elizabeth Ramírez Zamorano
Matias Maximiliano Quiroz Farías
Fernando Gimeno Molina
Cristobal Puelma Jirón
Tania Jaclyn Gipoulou Zúñiga
Dagoberto Poblete
Javiera Andrea Wiehoff Matus
Estefanía Pizarro
Humberto Bernasconi Muñoz
Lorenzo Palma
Victoria Hernández Urrutia
Elda Brant
Nicole Burger Acevedo
Eduardo Mattos
Victor Merino Campos
Camila Molina González
Francisco Enrique Tello Arriagada
Angela Bustos Salazar
Andrés Ceballos Comisso
Mauricio Montiel
Andrea Leiva

Noticias relacionadas al tema

Línea de InvestigaciónAñoAutoresTítuloRevistaFicha de PublicaciónDOIAbstractAccesoPáginasVolumenIndex
Cambio de Uso de Suelo2017Castillo-Riffart, Ivan; Galleguillos, Mauricio; Lopatin, Javier; Perez-Quezada, J. F.Predicting Vascular Plant Diversity in Anthropogenic Peatlands: Comparison of Modeling Methods with Free Satellite DataRemote Sensing10.3390/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.http://www.mdpi.com/2072-4292/9/7/681681Vol.9 is.7Thomson Reuters ISI
Agua y Extremos; Cambio de Uso de Suelo2017Garreaud, R., Alvarez-Garreton, C., Barichivich, J., Boisier, J. P., Christie, D., Galleguillos, M., LeQuesne, C., McPhee, J., Zambrano-Bigiarini, M.The 2010-2015 mega drought in Central Chile: Impacts on regional hydroclimate and vegetationHydrology and Earth System Sciences Discussions10.5194/hess-2017-191Since 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.https://www.hydrol-earth-syst-sci-discuss.net/hess-2017-191/1-37Thomson Reuters ISI
Cambio de Uso de Suelo2017Gómez-González, S., Paula, S., Cavieres L.A., Pausas, J.Postfire responses of the woody flora of Central Chile: insights from a germination experimentPloS One10.1371/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.http://dx.plos.org/10.1371/journal.pone.0180661e0180661vol.12Thomson Reuters ISI
Cambio de Uso de Suelo2017Holz, A., Paritsis, J., Mundo, I. A., Veblen, T. T., Kitzberger, T., Williamson, G. J., Aráoz, E., Bustos-Schindler, C., González, M. E., Grau, H. R., Quezada, J. M.Southern Annular Mode drives multicentury wildfire activity in southern South AmericaProceedings of the National Academy of Sciences10.1073/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.http://www.pnas.org/lookup/doi/10.1073/pnas.17051681149552-9557vol.36ScIELO
Cambio de Uso de Suelo2017Joetzjer, E., Pillet, M., Ciais, P., Barbier, N., Chave, J., Schlund, M., Maignan, F., Barichivich, J., Luyssaert, S., Hérault, B., von Poncet, F., Poulter, B.Assimilating satellite-based canopy height within an ecosystem model to estimate aboveground forest biomassGeophysical Research Letters10.1002/2017GL074150Despite 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.http://doi.wiley.com/10.1002/2017GL0741506823-6832vol.44Thomson Reuters ISI
Cambio de Uso de Suelo; Ciudades Resilientes2017McRostie, V. B., Gayo, E. M., Santoro, C. M., De Pol-Holz, R., Latorre, C.The pre-Columbian introduction and dispersal of Algarrobo (Prosopis, Section Algarobia) in the Atacama Desert of northern ChilePloS One10.1371/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.
http://dx.plos.org/10.1371/journal.pone.0181759e0181759vol.12Thomson Reuters ISI
Cambio de Uso de Suelo2017Ortega-Solís, G., Díaz, I., Mellado-Mansilla, D., Tello, F., Moreno, R., Tejo, C.Ecosystem engineering by Fascicularia bicolor in the canopy of the South-American temperate rainforestForest Ecology and Management10.1016/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.http://linkinghub.elsevier.com/retrieve/pii/S0378112717302074417-428Vol.400Thomson Reuters ISI
Cambio de Uso de Suelo2017Osborn, T. J., Barichivich, J., Harris, I., van der Schrier, G., & Jones, P. D
Monitoring global drought using the self-calibrating Palmer Drought Severity Index.

State of the Climate 2016, Bulletin of the American Meteorological Society
10.1175/2017BAMSStateoftheClimate.1
http://journals.ametsoc.org/doi/10.1175/2017BAMSStateoftheClimate.1S32-S33
vol.98Thomson Reuters ISI
Cambio de Uso de Suelo; Ciudades Resilientes2017Osorio, D., Steele, J., Sepúlveda, M., Gayo, E. M., Capriles, J. M., Herrera, K., Ugalde, P., De Pol-Holz, R., Latorre, C., Santoro, C. M.The Dry Puna as an ecological megapatch and the peopling of South America: Technology, mobility, and the development of a late Pleistocene/early Holocene Andean hunter-gatherer tradition in northern ChileQuaternary International10.1016/j.quaint.2017.07.010Current scientific evidence shows that humans colonized South America at least 15,000 years ago, but there are still many unknown aspects of this process, including the major and minor migratory routes involved, and the pattern of successive occupation of a diverse continental mosaic of ecosystems. In this context, the role of the Andean highlands (3400 meters above sea level) has been neglected, because of the supposedly harsh conditions for humans including hypoxia and cold climate. Nevertheless, the environmental and cultural resources available in the high Andes constitutes an important “megapatch” that should be assessed in terms of human settlement patterns. We review the evidence for late Pleistocene/early Holocene hunter-gatherer occupation of one part of this megapatch, the northern Chilean Dry Puna, in its palaeoecological context. We focus on lithic technology, faunal remains, radiocarbon dates, and other archaeological materials related to different social activities, which allow us to suggest that groups of hunter-gatherers organized and adapted their way of life to highland ecosystems through logistical mobility, and curatorial strategies for lithic tool kits that included projectile points and other formalized tools. The morphology and technological processes involved are recognized over vast territories along the high Andes. We identify this material expression as the high south central Andean Archaic hunter-gatherer tradition, which also featured long distance mobile settlement systems and communication processes over this broad and distinct megapatch. More speculatively, we outline the hypothesis that these highland ecosystems constituted a suitable migratory route that may have been key for the early peopling of the continent, and contrast it with the alternative hypothesis of the initially secondary and seasonally intermittent exploitation of this habitat by hunter-gatherers dispersing along the Pacific coastal corridor.http://linkinghub.elsevier.com/retrieve/pii/S1040618216312368vol. in pressThomson Reuters ISI
Agua y Extremos, Cambio de Uso de Suelo2017Puchi, P., Muñoz, A. A., González, M. E., Abarzúa, A., Araya, K., Towner, R., Fitzek, R., Holz, A., Stahle, D.Potencial de los anillos de crecimiento de Pilgerodendron uviferum para el estudio histórico de las Iglesias de Chiloé, Patrimonio de la HumanidadBosque10.4067/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.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-92002017000100012&lng=en&nrm=iso&tlng=en109-121vol.38Thomson Reuters ISI
Ciudades Resilientes; Cambio de Uso de Suelo2017Santoro, C. M., Gayo, E. M., Carter, C., Standen, V. G., Castro, V., Valenzuela, D., De Pol-Holz, R., Marquet, P. A., Latorre, C.Loco or no Loco? Holocene Climatic Fluctuations, Human Demography, and Community Based Management of Coastal Resources in Northern ChileFrontiers in Earth Science10.3389/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.http://journal.frontiersin.org/article/10.3389/feart.2017.00077/fullvol.5Thomson Reuters ISI
Agua y Extremos; Cambio de Uso de Suelo2017Simi, E., Moreno, P. I., Villa-Martínez, R., Vilanova, I., de Pol-Holz, R.Climate change and resilience of deciduous Nothofagus forests in central-east Chilean Patagonia over the last 3200 years: RESILIENCE OF DECIDUOUS NOTHOFAGUS FORESTS IN PATAGONIAJournal of Quaternary Science10.1002/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.http://doi.wiley.com/10.1002/jqs.2948845-856vol.32 is.6Thomson Reuters ISI
Cambio de Uso de Suelo2018Assal,T. J., González, M. E., Sibold, J. S.Burn severity controls on postfire Araucaria-Nothofagus regeneration in the Andean CordilleraJournal of Biogeography10.1111/jbi.13428Aim: The aim of the study was to investigate postfire regeneration patterns of Araucaria-Nothofagus forests on the west slope of the Andes; to evaluate the relationship between remotely sensed burn severity and forest mortality; and to assess controls of burn severity on forest response at local spatio-temporal scales. Location: Araucanía region in the western Andean Range of south-central Chile where fire occurred during the 2001–2002 season. Methods: Sampling of prefire stand structure and postfire vegetation response was performed along a burn severity gradient a decade after the fire. We evaluated the relationship between field-measured tree mortality and satellite-derived burn severity using a generalized linear model. We fit zero-inflated mixture models to regeneration data of each genus to assess the importance of abiotic variables, stand characteristics, and biotic interactions. Results: The relative version of the delta Normalized Burn Ratio explained 85% of the variability in canopy mortality. Nearly 12,000 hectares burned; the majority at high severity (67%). Regeneration densities of both genera were lower at higher levels of burn severity and higher with greater total basal area (live, dead, and down trees). The relative effect size of burn severity on regeneration was nearly twice as large for Nothofagus, which suggests information legacies of Araucaria have cascading effects on postdisturbance material legacies. Main conclusions: Araucaria-Nothofagus mortality from wildfire can be readily mapped using satellite-derived burn severity. Although environmental site characteristics and biotic interactions mediate regeneration, basal area, and burn severity are the main mechanisms controlling regeneration. Forest refugia and postfire regeneration are vulnerable to recurrent fire. Therefore, we expect future fire (either increased severity or frequency), driven by landscape level changes, as a potential mechanism that can reduce local resilience of these forests as initial postfire material legacies (e.g., refugia and regeneration) are removed from the landscape. Our findings highlight an approach to quantify important attributes of forest disturbance and refugia, and identify areas for monitoring postdisturbance regeneration as the forests throughout south-central Chile and Argentina face a multitude of potential change agents.http://doi.wiley.com/10.1111/jbi.13428Thomson Reuters ISI
Cambio de Uso de Suelo2018Barichivich, J., Gloor, E., Peylin, P., Brienen, R. J. W., Schöngart, J., Espinoza, J. C., Pattnayak, K. C.Recent intensification of Amazon flooding extremes driven by strengthened Walker circulationScience Advances10.1126/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.http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aat8785eaat8785vol.4 is.9Thomson Reuters ISI
Ciudades Resilientes; Gobernanza e Interfaz entre Ciencia y Política, Cambio de Uso de Suelo2018Gallardo, L., Barraza, F., Ceballos, A., Galleguillos, M., Huneeus, N., Lambert, F., Ibarra, C., Munizaga, M., O'Ryan, R., Osses, M.,Tolvett, S., Urquiza, A., Véliz, K.Evolution of air quality in Santiago: The role of mobility and lessons from the science-policy interfaceElementa: Science of the Anthropocene10.1525/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.https://www.elementascience.org/article/10.1525/elementa.293/38vol.6 is.1Thomson Reuters ISI
Cambio de Uso de Suelo2018Gómez-González, S., Ojeda, F., Fernandes, P.M.Portugal and Chile: Longing for sustainable forestry while rising from the ashesEnvironmental Science & PolicyVer ficha10.1016/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.http://linkinghub.elsevier.com/retrieve/pii/S1462901117307694104-107vol.81Thomson Reuters ISI
Cambio de Uso de Suelo2018Gómez-González, S., Paniw, M., Antunes, K., Ojeda, F.Heat shock and plant leachates regulate seed germination of the endangered carnivorous plant Drosophyllum lusitanicumWeb Ecology10.5194/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 fire-related 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.
https://www.web-ecol.net/18/7/2018/7-13vol.18 is.1Thomson Reuters ISI
Cambio de Uso de Suelo2018Jimenez J.C., Barichivich J., Mattar C., Takahashi K., Santamaría-Artigas A., Sobrino J.A., Malhi Y.Spatio-temporal patterns of thermal anomalies and drought over tropical forests driven by recent extreme climatic anomaliesPhilosophical Transactions of the Royal Society B: Biological Sciences10.1098/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).http://rstb.royalsocietypublishing.org/lookup/doi/10.1098/rstb.2017.030020170300Vol.373 is.1760Thomson Reuters ISI
Cambio de Uso de Suelo; Ciudades Resilientes2018Mazzeo, A., Huneeus, N., Ordoñez, C., Orfanoz-Cheuquelaf, A., Menut, L., Mailler, S., Valari, M., Denier van der Gon, H., Gallardo, L., Muñoz, R., Donoso, R., Galleguillos, M., Osses, M., Tolvett, S.
Impact of residential combustion and transport emissions on air pollution in Santiago during winter
Atmospheric Environment
10.1016/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.
https://linkinghub.elsevier.com/retrieve/pii/S1352231018304345195-208vol.190Thomson Reuters ISI
Cambio de Uso de Suelo2018McWethy, D. B., Pauchard, A., García, R. A., Holz, A., González, M. E., Veblen, T. T., Stahl, J., Currey, B.Landscape drivers of recent fire activity (2001-2017) in south-central ChilePLOS ONE10.1371/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.http://dx.plos.org/10.1371/journal.pone.0201195e0201195vol.13 is.8Thomson Reuters ISI
Cambio de Uso de Suelo2018Miranda, A., Altamirano, A., Lara, A., Zamorano-Elgueta, C., Hernández, H. J., González, M. E., Pauchard,A., Promis, A.Monitoreo de la superficie de los bosques nativos de Chile: un desafío pendienteBosque (Valdivia)10.4067/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.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-92002018000200265&lng=en&nrm=iso&tlng=en265-275vol.39 is.2Thomson Reuters ISI
Agua y Extremos; Cambio de Uso de Suelo; Ciudades Resilientes; Gobernanza e Interfaz entre Ciencia y Política2018Moreno, P. I., Vilanova, I., Villa-Martinez, R., Dunbar, R. B., Mucciarone, D. A., Kaplan, M. R., Garreaud, R., Rojas, M., De Polz-Holz, R., Lambert, F.
Onset and Evolution of Southern Annular Mode-Like Changes at Centennial Timescale
Scientific Reports
Ver ficha10.1038/s41598-018-21836-6
The 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.http://www.nature.com/articles/s41598-018-21836-6vol.8 is.1Thomson Reuters ISI
Cambio de Uso de Suelo2018Osborn, T. J., Barichivich, J., Harris, I., van der Schrier, G., & Jones, P. DGlobal Climate - d. Hydrological cycle - DroughtBulletin of the American Meteorological Society10.1175/2018BAMSStateoftheClimate.1http://journals.ametsoc.org/doi/10.1175/2018BAMSStateoftheClimate.1S36-S37vol.99 is.8Thomson Reuters ISI
Cambio de Uso de Suelo2018Pattnayak, 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.Adding new evidence to the attribution puzzle of the recent water shortage over São Paulo (Brazil)Tellus A: Dynamic Meteorology and Oceanography10.1080/16000870.2018.1481690View 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.
https://www.tandfonline.com/doi/full/10.1080/16000870.2018.14816901-14vol.70 is.1Thomson Reuters ISI
Ciudades Resilientes; Cambio de Uso de Suelo2018Pfeiffer, M., Latorre, C., Santoro, C.M., Gayo, E.M., Rojas, R., Carrevedo, M.L., McRostie, V.B., Finstad, K., Heimsath, A., Jungers, M., Chong, G., De Pol-Holz, R., Amundson, R.Chronology, stratigraphy and hydrological modelling of extensive wetlands and paleolakes in the hyperarid core of the Atacama Desert during the late quaternaryQuaternary Science Reviews10.1016/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.https://linkinghub.elsevier.com/retrieve/pii/S0277379117310521224-245Vol.197Thomson Reuters ISI
Cambio de Uso de Suelo2018Piret, L., Bertrand, S., Kissel, C., De Pol-Holz, R., Tamayo Hernando, A., Van Daele, M.First evidence of a mid-Holocene earthquake-triggered megaturbidite south of the Chile Triple JunctionSedimentary Geology10.1016/j.sedgeo.2018.01.002Megaturbidites have been the focus of many paleoseismic and paleoenvironmental studies because they can provide evidence for catastrophic and/or hazardous events with potentially major environmental implications. During a recent research cruise in Baker Fjord, Chile (47°54'S-74°30'W), a megaturbidite was described between the Northern and Southern Patagonian Icefields. Here, we aim to determine the depositional processes of the megaturbidite and identify its origin. Based on the turbidite's location, a possible origin was the early Holocene drainage of paleo-lake General Carrera, which was recently proposed in the literature as having produced a Glacial Lake Outburst Flood (GLOF) that drained through Baker Fjord. Due to the fjord's location in a subduction zone, and close to the Chile Triple Junction, however, seismic activity must also be considered as a potential triggering mechanism. To achieve our goals, we undertook a multi-proxy analysis of sediment core MD07-3121, including sedimentology (grain size, loss-on-ignition, foraminifera counts), magnetic properties, bulk organic geochemistry, and radiocarbon dating, and we analysed bathymetric maps and sub-bottom profiles. Our grain-size results display a diagnostic fining upward trend and show evidence of seiching in the 733-cm-thick megaturbidite. The age of the event (5513-5211 cal yr BP) contradicts the hypothesis of an early Holocene GLOF origin. Bulk organic geochemical results indicate that the sediments that compose the turbidite are clearly of marine origin, which further goes against a GLOF origin. In addition, the megaturbidite is underlain by a 1136 cm thick mass transport deposit (MTD), also composed of marine sediments. According to the sub-bottom profiles, the MTD and the megaturbidite originate from the reworking of thick packages of sediment previously deposited on nearby sills and on the fjord's flanks. Furthermore, similar coeval deposits are found in an adjacent sub-basin. We therefore interpret these deposits to be triggered by an earthquake during the late mid-Holocene. While megathrust and intraslab earthquakes are possible in the region, we argue that a crustal earthquake is the most likely seismic trigger in the study area. This study reveals the first earthquake-triggered megaturbidite south of the Chile Triple Junction.http://linkinghub.elsevier.com/retrieve/pii/S0037073818300113Thomson Reuters ISI
Cambio de Uso de Suelo2018Rozas, V., Le Quesne, C., Rojas-Badilla, M., González, M., González-Reyes, A.Coupled human-climate signals on the fire history of upper Cachapoal Valley, Mediterranean Andes of Chile, since 1201 CEGlobal and Planetary Change10.1016/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.https://linkinghub.elsevier.com/retrieve/pii/S0921818117304988137-147vol.167Thomson Reuters ISI
Agua y Extremos; Cambio de Uso de Suelo2018Urrutia-Jalabert, R., González, M. E., González-Reyes, A., Lara, A., Garreaud, R.Climate variability and forest fires in central and south-central ChileEcosphere10.1002/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.
http://doi.wiley.com/10.1002/ecs2.2171e02171vol.9 is.4Thomson Reuters ISI
Cambio de Uso de Suelo2018Urrutia-Jalabert, R., Peña, M. P. Coopman, R. E., Carvajal, D. E., Jiménez-Castillo, M., Lara, A., Cosimo, D., Lobos-Catalán, P.
Elucidating the hydraulic vulnerability of the longest-lived Southern Hemisphere conifer to aridificationForest Ecology and Management
10.1016/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.https://linkinghub.elsevier.com/retrieve/pii/S037811271830793X472-484vol.430Thomson Reuters ISI