Abstract:

By addressing the trade-offs between food production and biodiversity conservation at landscape and ecoregion scales, the land sparing/sharing debate has made a significant contribution to land use science. However, as global population and food consumption grow, and urbanization and transnational trade intensify, land use trade-offs need to be analyzed at broader scales. These analyses should specifically consider the role of environmental heterogeneity on biodiversity distribution and agricultural suitability, the costs and benefits transferred far away from the focal land use, institutional and economic factors influencing stability and resilience, technology-related factors as mediators of agriculture suitability, and bundles of different environmental services. In addition, land use strategies to balance agriculture and biodiversity conservation must consider local socioeconomic constraints and trade-offs.

Author affiliation: Grau, Ricardo. Universidad Nacional de Tucumán; Argentina;

Author affiliation: Kuemmerle, Tobias. University Berlin. Geography Department, Humboldt; Alemania;

Author affiliation: Macchi, Leandro. Universidad Nacional de Tucuman. Facultad de Cs.naturales E Instituto Miguel Lillo. Instituto Miguel Lillo; Argentina; Potsdam Institute for Climate Impact Research. Earth System Analysis; Alemania;

Abstract:

Tropical deforestation is a main driver of the global biodiversity crisis. Impact assessments typically focus on species' presence, which means impacts are detected when local extinctions have occurred – and thus when it is too late. Here, we pioneer the combined use of two approaches that can detect deforestation impacts earlier, at the level of populations (using occupancy modelling) and at the level of individuals (using stress hormonal indicators). We tested this approach for the collared peccary (Pecari tajacu) in the Argentine Chaco, a global deforestation hotspot. We used camera-trap data to model peccary occupancy in relation to woodland cover and loss, and measured glucocorticoid metabolites in peccary feces to assess individuals' stress level in deforestation areas. We found that peccary occupancy was highest in remote areas with high woodland cover, but low otherwise. Peccaries were typically absent from areas where deforestation had been widespread recently. Where peccaries were present, physiological stress was correlated with the extent of edge between cropland and forest (a proxy for food availability), and not with deforestation. This, and the observation that peccaries disappear quickly as deforestation progresses, suggests that peccaries do not adapt well to the new conditions in deforestation frontiers. Interms of conservation management, our results under pin the importance of protecting large, contiguous woodland blocks to prevent large mammals from going extinct in deforestation frontiers. More broadly, weshow how combining stress hormonal indicators and occupancy modelling can provide deepins ights into processes underlying local extinctions in dynamic landscapes.

Author affiliation: Semper Pascual, Asunción. Humboldt-Universität zu Berlin. Geography Department; Alemania

Author affiliation: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina

Author affiliation: Baumann, Matthias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Busso, Juan M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Ecología del Litoral. Laboratorio de Biología de la Conservación; Argentina

Author affiliation: Gomez Valencia, Bibiana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Grupo de Estudios de Sistemas Ecológicos en Ambientes Agrícolas; Argentina. Instituto de Investigaciones de Recursos Biológicos Alexander von Humboldt; Colombia

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Abstract:

Carbon emissions from land-use changes in tropical dry forest systems are poorly understood, although they are likely globally significant. The South American Chaco has recently emerged as a hot spot of agricultural expansion and intensification, as cattle ranching and soybean cultivation expand into forests, and as soybean cultivation replaces grazing lands. Still, our knowledge of the rates and spatial patterns of these land-use changes and how they affected carbon emissions remains partial. We used the Landsat satellite image archive to reconstruct land-use change over the past 30 years and applied a carbon bookkeeping model to quantify how these changes affected carbon budgets. Between 1985 and 2013, more than 142 000 km2 of the Chaco's forests, equaling 20% of all forest, was replaced by croplands (38.9%) or grazing lands (61.1%). Of those grazing lands that existed in 1985, about 40% were subsequently converted to cropland. These land-use changes resulted in substantial carbon emissions, totaling 824 Tg C between 1985 and 2013, and 46.2 Tg C for 2013 alone. The majority of these emissions came from forest-to-grazing-land conversions (68%), but post-deforestation land-use change triggered an additional 52.6 Tg C. Although tropical dry forests are less carbon-dense than moist tropical forests, carbon emissions from land-use change in the Chaco were similar in magnitude to those from other major tropical deforestation frontiers. Our study thus highlights the urgent need for an improved monitoring of the often overlooked tropical dry forests and savannas, and more broadly speaking the value of the Landsat image archive for quantifying carbon fluxes from land change.

Author affiliation: Baumann, Matthias. Universität zu Berlin; Alemania

Author affiliation: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina. Universität zu Berlin; Alemania

Author affiliation: Piquer-Rodríguez, María. Universität zu Berlin; Alemania

Author affiliation: Gavier Pizarro, Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina

Author affiliation: Griffiths, Patrick. Universität zu Berlin; Alemania

Author affiliation: Hostert, Patrick. Universität zu Berlin; Alemania

Author affiliation: Kuemmerle, Tobias. Universität zu Berlin; Alemania

Abstract:

Carbon emissions from land‐use changes in tropical dry forest systems are poorly understood, although they are likely globally significant. The South American Chaco has recently emerged as a hot spot of agricultural expansion and intensification, as cattle ranching and soybean cultivation expand into forests, and as soybean cultivation replaces grazing lands. Still, our knowledge of the rates and spatial patterns of these land‐use changes and how they affected carbon emissions remains partial. We used the Landsat satellite image archive to reconstruct land‐use change over the past 30 years and applied a carbon bookkeeping model to quantify how these changes affected carbon budgets. Between 1985 and 2013, more than 142 000 km2 of the Chaco's forests, equaling 20% of all forest, was replaced by croplands (38.9%) or grazing lands (61.1%). Of those grazing lands that existed in 1985, about 40% were subsequently converted to cropland. These land‐use changes resulted in substantial carbon emissions, totaling 824 Tg C between 1985 and 2013, and 46.2 Tg C for 2013 alone. The majority of these emissions came from forest‐to‐grazing‐land conversions (68%), but post‐deforestation land‐use change triggered an additional 52.6 Tg C. Although tropical dry forests are less carbon‐dense than moist tropical forests, carbon emissions from land‐use change in the Chaco were similar in magnitude to those from other major tropical deforestation frontiers. Our study thus highlights the urgent need for an improved monitoring of the often overlooked tropical dry forests and savannas, and more broadly speaking the value of the Landsat image archive for quantifying carbon fluxes from land change.

Instituto de Recursos Biológicos

Author affiliation: Baumann, Matthias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; Argentina. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Author affiliation: Piquer Rodriguez, María. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Gavier Pizarro, Gregorio Ignacio. INTA. Instituto de Recursos Biológicos; Argentina

Author affiliation: Griffiths, Patrick. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Hostert, Patrick. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Abstract:

The dry forests of Latin America are among the most dynamic deforestation frontiers in the world and are important carbon and biodiversity reservoirs. Our knowledge on the spatial patterns of deforestation and its proximate drivers remains partial though. We used the full Landsat image archive to reconstruct deforestation and post-deforestation dynamics between 1987 and 2012 for the entire Paraguayan Chaco, where deforestation has been rampant recently. Our classification resulted in reliable land-use change maps (86.16%), highlighting drastic forest losses of almost 44,000 km2 between 1987 and 2012, equaling a deforestation rate of 27% and about 1% yearly, predominantly for grasslands. These likely represented new pastures, making pasture expansion the dominant proximate cause of deforestation. Cropland expansion, in contrast, only played a minor role as a proximate deforestation cause in the Paraguayan Chaco. Deforestation more than doubled between 2001 and 2012 (~29,000 km2) compared to 1987–2000 (~14,000 km2), due to leakage effects from the deforestation ban in the Paraguayan Atlantic Forests in 2004. Interestingly, while grasslands expanded in the Paraguayan Chaco between 1987 and 2000, cattle numbers decreased during the same time period, though strongly increased since. This apparent decoupling of area change and land-use intensity may indicate that the Paraguayan Chaco experienced an amplification period during the 1990s followed by an intensification period since 2001. Thus, our results highlight the need for both, a more detailed monitoring of post-deforestation dynamics and a land systems perspective in order to understand deforestation frontiers and thus ultimately to identify strategies to better balance production and conservation goals.

Instituto de Recursos Biológicos

Author affiliation: Baumann, Matthias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Israel, Christoph. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Piquer Rodriguez, María. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Gavier Pizarro, Gregorio Ignacio. INTA. Instituto de Recursos Biológicos; Argentina

Author affiliation: Volante, Jose Norberto. INTA. Estación Experimental Agropecuaria Salta. Laboratorio de Teledeteccion y SIG; Argentina

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Abstract:

Rising global demand for agricultural products results in agricultural expansion and intensification, with substantial environmental trade-offs. The South American Dry Chaco contains some of the fastest expanding agricultural frontiers worldwide, and includes diverse forms of land management, mainly associated with different land tenure regimes; which in turn are segregated along environmental gradients (mostly rainfall). Yet, how these regimes impact the environment and how trade-offs between production and environmental outcomes varies remains poorly understood. Here, we assessed how biodiversity, biomass stocks, and agricultural production, measured in meat-equivalents, differ among land tenure regimes in the Dry Chaco. We calculated a land-use outcome index (LUO) that combines indices comparing actual vs. potential values of 'preservation of biodiversity' (PI), 'standing biomass' (BI) and 'meat production' (MI). We found land-use outcomes to vary substantially among land-tenure regimes. Protected areas showed a biodiversity index of 0.75, similar to that of large and medium-sized farms (0.72 in both farming systems), and higher than in the other tenure regimes. Biomass index was similar among land tenure regimes, whereas we found the highest median meat production index on indigenous lands (MI = 0.35). Land-use outcomes, however, varied more across different environmental conditions than across land tenure regimes. Our results suggest that in the Argentine Dry Chaco, there is no single land tenure regime that better minimizes the trade-offs between production and environmental outcomes. A useful approach to manage these trade-offs would be to develop geographically explicit guidelines for land-use zoning, identifying the land tenure regimes more appropriate for each zone.

Author affiliation: Marinaro Fuentes, María Sofía. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina

Author affiliation: Grau, Hector Ricardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina

Author affiliation: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentina

Author affiliation: Kuemmerle, Tobias. Universität zu Berlin; Alemania

Author affiliation: Baumann, Matthias. Universität zu Berlin; Alemania

Abstract:

Agricultural expansion and intensification in South America's dry forests and grasslands increase agricultural production, but also result in major environmental trade-offs. The Pampas and Chaco regions of Argentina have been global hotspots of agricultural land-use change since the 2000s, yet our understanding of what drives the spatial patterns of these land-use changes remains partial. We parameterized a net returns model of agricultural land-use change to estimate the probability of agricultural expansion (conversions of woodlands to either cropland or grazing land) and agricultural intensification (conversion of grazing land to cropland) at the 1-km scale for the years 2000 and 2010. Uniquely, our model allowed us to quantify the importance of underlying causes (i.e., changes in agricultural profit) and spatial determinants (i.e., soil fertility, distance to markets, etc.), for Argentina's prime agricultural regions as a whole. We found that cropland and grazing land expansion into woodlands was much less sensitive to changes in profit-related factors than agricultural intensification. Profit-related variables, were a particularly strong cause of intensification in the Pampas, where cropland profits rose by 29% (compared to 18% in the Chaco). This suggests that further conversions of grazing land to cropland in the Pampas and Chaco is likely as long as agricultural demand, and thus returns to agriculture, continue to be high. The moderate impact of profit-related factors on affecting woodland conversion rates also suggests a limited potential of economic policies that affect marginal profits (e.g., taxes or subsidies) to alter deforestation rates and patterns in major ways. Policies that target socio-economic variables not included in our profit-focused framework (e.g., capital availability), area-based interventions (e.g., land zoning), or less-profit oriented actors (e.g., via community-based management) might be more effective in addressing deforestation rates in the Chaco.

Inst. de Recursos Biológicos

Author affiliation: Piquer Rodriguez, María. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Butsic, V. University of California Berkeley. Department of Environmental Science, Policy and Management; Estados Unidos

Author affiliation: Gartner, P. Leibniz Centre for Agricultural Landscape Research; Alemania

Author affiliation: Macchi, Leandro. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Baumann, Matthias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Gavier Pizarro, Gregorio Ignacio. INTA. Instituto de Recursos Biológicos; Argentina

Author affiliation: Volante, Jose Norberto. INTA. Estación Experimental Agropecuaria Salta; Argentina

Author affiliation: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; Argentina. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Abstract:

Context: Land-use change is the main driver of habitat loss and fragmentation worldwide. The rate of dry forest loss in the South American Chaco is among the highest in the world, mainly due to the expansion of soybean production and cattle ranching. Argentina recently implemented a national zoning plan (i.e., the Forest Law) to reduce further forest loss. However, it is unclear how the effects of past deforestation and the implementation of the Forest Law will affect forest connectivity in the Chaco. Objective: Our main goal was to evaluate the potential effect of the Forest Law on forest fragmentation and connectivity in the Argentine Chaco. Methods: We studied changes in the extent, fragmentation, and connectivity of forests between 1977 and 2010, by combining agricultural expansion and forest cover maps, and for the future in a scenario analysis. Results Past agricultural expansion translated into an overall loss of 22.5 % of the Argentine Chaco’s forests, with deforestation rates in 2000–2010 up to three times higher than in the 1980s. Forest fragmentation and connectivity loss were highest in 1977–1992, when road construction fragmented large forest patches. Our future scenario analysis showed that if the Forest Law will be implemented as planned, forest area and connectivity in the region will decline drastically. Conclusions: Land-use planning designed to protect stepping stones could substantially mitigate connectivity loss due to deforestation, with the co-benefit of preserving the greatest amount of biodiversity priority areas across all evaluated scenarios. Including scenario analyses that assess forest fragmentation and connectivity at the ecoregion scale is thus important in upcoming revisions of the Argentine Forest Law, and, more generally, in debates about sustainable resource use.

Instituto de Recursos Biológicos

Author affiliation: Piquer Rodriguez, María. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Torella, Sebastián Andrés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Grupo de Estudios de Sistemas Ecológicos en Ambientes Agrícolas; Argentina

Author affiliation: Gavier Pizarro, Gregorio Ignacio. INTA. Instituto de Recursos Biológicos. Grupo de Biodiversidad, Ecología y Gestión Ambiental; Argentina

Author affiliation: Volante, Jose Norberto. INTA. Estación Experimental Agropecuaria Salta. Laboratorio de Teledetección y SIG; Argentina

Author affiliation: Somma, Daniel Jorge. INTA. Estación Experimental Agropecuaria Pergamino; Argentina

Author affiliation: Guizburg, Rubén G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Grupo de Estudios de Sistemas Ecológicos en Ambientes Agrícolas; Argentina

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania

Abstract:

Tropical and Subtropical dry forests around the globe are experiencing rapid clearing and concomitant biodiversity loss (1). In their Research Article "Plantdiversity patterns in neotropical dry forests and their conservation implications" (23 September 2016, p. 1383), DRYFLOR et al. highlight the often underappreciated, yet exceptional floristic richness and uniqueness of these forests, and they provide compelling arguments for ramping up efforts to protect them. We applaud the DRYFLOR team for their seminal work, but we are also concerned about the exclusion of the Gran Chaco, frequently considered the world's largest continuous tropical dry forest region.

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Altrichter, Mariana. Prescott College. Department of Environmental Studies; Estados Unidos

Author affiliation: Baldi, Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina

Author affiliation: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentina

Author affiliation: Cuellar, Erika. Santa Cruz; Bolivia

Author affiliation: Cuellar, Rosa Leny. Fundación Kaa Iya; Bolivia

Author affiliation: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; Argentina

Author affiliation: Díaz, Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de las Yungas; Argentina

Author affiliation: Gavier Pizarro, Gregorio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; Argentina

Author affiliation: Ginzburg, Rubén Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina

Author affiliation: Giordano, Anthony J.. Society for the Preservation of Endangered Carnivores and their International Ecological Study; Estados Unidos. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de las Yungas; Argentina

Author affiliation: Grau, Hector Ricardo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de las Yungas; Argentina

Author affiliation: Jobbagy Gampel, Esteban Gabrie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina

Author affiliation: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina

Author affiliation: Macchi, Leandro. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de las Yungas; Argentina

Author affiliation: Mastrangelo, Matias Enrique. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Laboratorio de Agroecología; Argentina

Author affiliation: Matteucci, Silvia Diana. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Grupo de Ecología del Paisaje y Medio Ambiente; Argentina

Author affiliation: Noss, Andrew. University of Florida; Estados Unidos

Author affiliation: Paruelo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Author affiliation: Piquer Rodríguez, Maria. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Romero Muñoz, Alfredo. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Semper-Pascual, Asunción. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Thompson, Jeffrey J.. Guyra Paraguay; Paraguay. Consejo Nacional de Ciencia y Tecnología; Paraguay

Author affiliation: Torrella, Sebastián Andrés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina

Author affiliation: Torres, Ricardo Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Museo de Zoología; Argentina

Author affiliation: Volante, José Norberto. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Salta-Jujuy. Estación Experimental Agropecuaria Salta; Argentina

Author affiliation: Yanosky, Alberto. Guayra Paraguay; Paraguay

Author affiliation: Zak, Marcelo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Abstract:

Habitat loss is the primary cause of local extinctions. Yet, there is considerable uncertainty regarding how fast species respond to habitat loss, and how time‐delayed responses vary in space. We focused on the Argentine Dry Chaco (c. 32 million ha), a global deforestation hotspot, and tested for time‐delayed response of bird and mammal communities to landscape transformation. We quantified the magnitude of extinction debt by modelling contemporary species richness as a function of either contemporary or past (2000 and 1985) landscape patterns. We then used these models to map communities' extinction debt. We found strong evidence for an extinction debt: landscape structure from 2000 explained contemporary species richness of birds and mammals better than contemporary and 1985 landscapes. This suggests time‐delayed responses between 10 and 25 years. Extinction debt was especially strong for forest specialists. Projecting our models across the Chaco highlighted areas where future local extinctions due to unpaid extinction debt are likely. Areas recently converted to agriculture had highest extinction debt, regardless of the post‐conversion land use. Few local extinctions were predicted in areas with remaining larger forest patches. Synthesis and applications. The evidence for an unpaid extinction debt in the Argentine Dry Chaco provides a substantial window of opportunity for averting local biodiversity losses. However, this window may close rapidly if conservation activities such as habitat restoration are not implemented swiftly. Our extinction debt maps highlight areas where such conservation activities should be implemented.

Inst. de Recursos Biológicos

Author affiliation: Semper-Pascal, Asunción. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Macchi, Leandro. Humboldt-University Berlin. Geography Department; Alemania. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; Argentina

Author affiliation: Sabatini, Francesco María. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Decarre, Julieta. INTA. Instituto de Recursos Biológicos; Argentina

Author affiliation: Baumann, Matthias. Humboldt-University Berlin. Geography Department; Alemania

Author affiliation: Blendinger, Pedro G. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; Argentina.

Author affiliation: Gomez Valencia, Bibiana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Grupo de Estudios de Sistemas Ecológicos en Ambientes Agrícolas; Argentina

Author affiliation: Mastrangelo, Matias Enrique. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Grupo de Estudios de Agroecosistemas y Paisajes Rurales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Kuemmerle, Tobias. Humboldt-University Berlin. Geography Department; Alemania. Humboldt-University Berlin. Integrative Research Institute for Transformations in Human Environment Systems; Alemania