| Cambio de Uso de Suelo; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política | 2021 | Galleguillos, Mauricio; Gimeno, Fernando; Puelma, Cristóbal; Zambrano-Bigiarini, Mauricio; Lara, Antonio; Rojas, Maisa | Disentangling the effect of future land use strategies and climate change on streamflow in a Mediterranean catchment dominated by tree plantations | Journal of Hydrology | | 10.1016/j.jhydrol.2021.126047 | Climate 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. | https://linkinghub.elsevier.com/retrieve/pii/S0022169421000949 | 126047 | 595.0 | Thomson Reuters ISI | catchments, 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 |
| Cambio de Uso de Suelo | 2021 | Urrutia-Jalabert, R.; Barichivich, J.; Rozas, V.; Lara, A.; Rojas, Y.; Bahamondez, C.; Rojas-Badilla, M.; Gipoulou-Zuñiga, T.; Cuq, E. | Climate response and drought resilience of Nothofagus obliqua secondary forests across a latitudinal gradient in south-central Chile | Forest Ecology and Management | | 10.1016/j.foreco.2021.118962 | The 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. | https://linkinghub.elsevier.com/retrieve/pii/S0378112721000517 | 118962 | 485.0 | Thomson Reuters ISI | climatology, 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 |
| Cambio de Uso de Suelo; Agua y Extremos | 2021 | Barría, Pilar; Chadwick, Cristián; Ocampo-Melgar, Anahí; Galleguillos, Mauricio; Garreaud, Rene; Díaz-Vasconcellos, Raúl; Poblete, David; Rubio-Álvarez, Eduardo; Poblete-Caballero, Dagoberto | Water management or megadrought: what caused the Chilean Aculeo Lake drying? | Regional Environmental Change | | 10.1007/s10113-021-01750-w | The 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. | http://link.springer.com/10.1007/s10113-021-01750-w | 19 | 21.0 | Thomson Reuters ISI | anthropogenic, attribution, decision making, drought, land use/land cover, water budget |
| Cambio de Uso de Suelo | 2021 | Lavergne, 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, Léa | Temperature differently affected methanogenic pathways and microbial communities in sub-Antarctic freshwater ecosystems | Environment International | | 10.1016/j.envint.2021.106575 | Freshwater 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. | https://linkinghub.elsevier.com/retrieve/pii/S0160412021002002 | 106575 | 154.0 | Thomson Reuters ISI | bacteria, 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 |
| Cambio de Uso de Suelo | 2021 | Vásquez-Lavín, Felipe; Carrasco, Moisés; Barrientos, Manuel; Gelcich, Stefan; Ponce Oliva, Roberto D. | Estimating discount rates for environmental goods: Are People’s responses inadequate to frequency of payments? | Journal of Environmental Economics and Management | | 10.1016/j.jeem.2021.102446 | Most 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. | https://linkinghub.elsevier.com/retrieve/pii/S0095069621000292 | 102446 | 107.0 | Thomson Reuters ISI | economic 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 |
| Cambio de Uso de Suelo | 2021 | León-Muñoz, Jorge; Aguayo, Rodrigo; Marcé, Rafael; Catalán, Núria; Woelfl, Stefan; Nimptsch, Jorge; Arismendi, Ivan; Contreras, Camila; Soto, Doris; Miranda, Alejandro | Climate and Land Cover Trends Affecting Freshwater Inputs to a Fjord in Northwestern Patagonia | Frontiers in Marine Science | | 10.3389/fmars.2021.628454 | Freshwater 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. | https://www.frontiersin.org/articles/10.3389/fmars.2021.628454/full | 628454 | 8.0 | Thomson Reuters ISI | climate change, hydrological modeling, land cover change, land-ocean interface, patagonia, water quality |
| Cambio de Uso de Suelo | 2021 | Carrasco, Jaime; Acuna, Mauricio; Miranda, Alejandro; Alfaro, Gabriela; Pais, Cristobal; Weintraub, Andrés | Exploring the multidimensional effects of human activity and land cover on fire occurrence for territorial planning | Journal of Environmental Management | | 10.1016/j.jenvman.2021.113428 | The 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. | https://linkinghub.elsevier.com/retrieve/pii/S0301479721014900 | 113428 | 297.0 | Thomson Reuters ISI | accuracy 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 |
| Cambio de Uso de Suelo | 2021 | Armenteras, Dolors; Dávalos, Liliana M.; Barreto, Joan S.; Miranda, Alejandro; Hernández-Moreno, Angela; Zamorano-Elgueta, Carlos; González-Delgado, Tania M.; Meza-Elizalde, María C.; Retana, Javier | Fire-induced loss of the world’s most biodiverse forests in Latin America | Science Advances | | 10.1126/sciadv.abd3357 | Fire 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. | https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.abd3357 | eabd3357 | 7.0 | Thomson Reuters ISI | deforestation, 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 |
| Cambio de Uso de Suelo | 2021 | Lara, Antonio; Jones, Julia; Little, Christian; Vergara, Nicolás | Streamflow response to native forest restoration in former Eucalyptus plantations in south central Chile | Hydrological Processes | | 10.1002/hyp.14270 | Global 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. | https://onlinelibrary.wiley.com/doi/10.1002/hyp.14270 | | 35.0 | Thomson Reuters ISI | aerodynamics, 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 |
| Cambio de Uso de Suelo | 2021 | Ponce Oliva, Roberto D.; Montevechio, Esteban Arias; Jorquera, Francisco Fernández; Vásquez-Lavin, Felipe; Stehr, Alejandra | Water Use and Climate Stressors in a Multiuser River Basin Setting: Who Benefits from Adaptation? | Water Resources Management | | 10.1007/s11269-020-02753-8 | Adapting 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. | http://link.springer.com/10.1007/s11269-020-02753-8 | 897-915 | 35.0 | Thomson Reuters ISI | agricultural 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 |
| Cambio de Uso de Suelo; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política | 2021 | Hoyos-Santillan, Jorge; Miranda, Alejandro; Lara, Antonio; Sepulveda-Jauregui, Armando; Zamorano-Elgueta, Carlos; Gómez-González, Susana; Vásquez-Lavín, Felipe; Garreaud, Rene D.; Rojas, Maisa | Diversifying Chile’s climate action away from industrial plantations | Environmental Science & Policy | | 10.1016/j.envsci.2021.06.013 | As 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. | https://linkinghub.elsevier.com/retrieve/pii/S1462901121001738 | 85-89 | 124.0 | Thomson Reuters ISI | carbon, 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 |
| Cambio de Uso de Suelo | 2021 | Flores Arévalo, Yarela; Ponce Oliva, Roberto D.; Fernández, Francisco J.; Vásquez-Lavin, Felipe | Sensitivity of Water Price Elasticity Estimates to Different Data Aggregation Levels | Water Resources Management | | 10.1007/s11269-021-02833-3 | The 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. | https://link.springer.com/10.1007/s11269-021-02833-3 | 2039-2052 | 35.0 | Thomson Reuters ISI | elasticity, 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 |
| Cambio de Uso de Suelo | 2021 | Ponce Oliva, Roberto D.; Fernández, Francisco J.; Vasquez-Lavín, Felipe; Arias Montevechio, Esteban; Julio, Natalia; Stehr, Alejandra | Nexus Thinking at River Basin Scale: Food, Water and Welfare | Water | | 10.3390/w13071000 | Water 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. | https://www.mdpi.com/2073-4441/13/7/1000 | 1000 | 13.0 | Thomson Reuters ISI | agricultural robots, agriculture, urban growth, economic welfare, food production, household level, river basins, water demand, water users, water resources |
| Cambio de Uso de Suelo | 2021 | Rabanal, Felipe E.; Úbeda, Carmen; Tejo, Camila F.; Lavilla, Esteban O. | Tree-Holes as Alternative Reproductive Sites of Batrachyla antartandica Barrio, 1967 (Anura: Batrachylidae) | South American Journal of Herpetology | | 10.2994/SAJH-D-18-00064.1 | Although 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. | https://bioone.org/journals/south-american-journal-of-herpetology/volume-20/issue-1/SAJH-D-18-00064.1/Tree-Holes-as-Alternative-Reproductive-Sites-of-Batrachyla-antartandica-Barrio/10.2994/SAJH-D-18-00064.1.full | | 20.0 | Thomson Reuters ISI | amphibia, arboreality, microhabitats, phytotelmata, reproductive modes, temperate rainforests |
| Cambio de Uso de Suelo | 2022 | Olivera-Guerra, L.; Quintanilla, M.; Moletto-Lobos, I.; Pichuante, E.; Zamorano-Elgueta, C.; Mattar, C. | Water dynamics over a Western Patagonian watershed: Land surface changes and human factors | Science of The Total Environment | | 10.1016/j.scitotenv.2021.150221 | Warming 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. | https://linkinghub.elsevier.com/retrieve/pii/S0048969721052980 | 150221 | 804.0 | Thomson Reuters ISI | atmospheric 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 |
| Cambio de Uso de Suelo | 2021 | Soto, Daniel P.; Donoso, Pablo J.; Zamorano-Elgueta, Carlos; Ríos, Andrea I.; Promis, Álvaro | Precipitation declines influence the understory patterns in Nothofagus pumilio old-growth forests in northwestern Patagonia | Forest Ecology and Management | | 10.1016/j.foreco.2021.119169 | Forest 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. | https://linkinghub.elsevier.com/retrieve/pii/S0378112721002577 | 119169 | 491.0 | Thomson Reuters ISI | ecosystems, 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 |
| Cambio de Uso de Suelo | 2021 | Miranda, Alejandro; Catalán, Germán; Altamirano, Adison; Zamorano-Elgueta, Carlos; Cavieres, Manuel; Guerra, Javier; Mola-Yudego, Blas | How Much Can We See from a UAV-Mounted Regular Camera? Remote Sensing-Based Estimation of Forest Attributes in South American Native Forests | Remote Sensing | | 10.3390/rs13112151 | Data 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. | https://www.mdpi.com/2072-4292/13/11/2151 | 2151 | 13.0 | Thomson Reuters ISI | antennas, 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 |
| Cambio de Uso de Suelo; Transversal | 2021 | Pais, Cristobal; Miranda, Alejandro; Carrasco, Jaime; Shen, Zuo-Jun Max | Deep fire topology: Understanding the role of landscape spatial patterns in wildfire occurrence using artificial intelligence | Environmental Modelling & Software | | 10.1016/j.envsoft.2021.105122 | Increasing 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. | https://linkinghub.elsevier.com/retrieve/pii/S1364815221001651 | 105122 | 143.0 | Thomson Reuters ISI | application 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 |
| Cambio de Uso de Suelo; Agua y Extremos | 2021 | Bertin, Lizette J.; Christie, Duncan A.; Sheppard, Paul R.; Muñoz, Ariel A.; Lara, Antonio; Alvarez, Claudio | Chemical Signals in Tree Rings from Northern Patagonia as Indicators of Calbuco Volcano Eruptions since the 16th Century | Forests | | 10.3390/f12101305 | The 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. | https://www.mdpi.com/1999-4907/12/10/1305 | 1305 | 12.0 | Thomson Reuters ISI | forestry, 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 |
| Cambio de Uso de Suelo | 2021 | Sotes, Gastón J.; Cavieres, Lohengrin A.; Gómez-González, Susana | High competitive ability of Centaurea melitensis L. (Asteraceae) does not increase in the invaded range | Biological Invasions | | 10.1007/s10530-020-02396-1 | Understanding 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. | http://link.springer.com/10.1007/s10530-020-02396-1 | 693-703 | 23.0 | Thomson Reuters ISI | angiosperm, 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 |
