Agricultural expansion and the ecological marginalization of forest-dependent people.

Agricultural expansion into subtropical and tropical forests causes major environmental damage, but its wider social impacts often remain hidden. Forest-dependent smallholders are particularly strongly impacted, as they crucially rely on forest resources, are typically poor, and often lack institutional support. Our goal was to assess forest-smallholder dynamics in relation to expanding commodity agriculture. Using high-resolution satellite images across the entire South American Gran Chaco, a global deforestation hotspot, we digitize individual forest-smallholder homesteads (n = 23,954) and track their dynamics between 1985 and 2015. Using a Bayesian model, we estimate 28,125 homesteads in 1985 and show that forest smallholders occupy much larger forest areas (>45% of all Chaco forests) than commonly appreciated and increasingly come into conflict with expanding commodity agriculture (18% of homesteads disappeared; n = 5,053). Importantly, we demonstrate an increasing ecological marginalization of forest smallholders, including a substantial forest resource base loss in all Chaco countries and an increasing confinement to drier regions (Argentina and Bolivia) and less accessible regions (Bolivia). Our transferable and scalable methodology puts forest smallholders on the map and can help to uncover the land-use conflicts at play in many deforestation frontiers across the globe. Such knowledge is essential to inform policies aimed at sustainable land use and supply chains.

The relative importance of COVID-19 pandemic impacts on biodiversity conservation globally.

The COVID-19 pandemic has had an enormous impact on almost all aspects of human society and endeavor; the natural world and its conservation have not been spared. Through a process of expert consultation, we identified and categorized, into 19 themes and 70 subthemes, the ways in which biodiversity and its conservation have been or could be affected by the pandemic globally. Nearly 60% of the effects have been broadly negative. Subsequently, we created a compendium of all themes and subthemes, each with explanatory text, and in August 2020 a diverse group of experienced conservationists with expertise from across sectors and geographies assessed each subtheme for its likely impact on biodiversity conservation globally. The 9 subthemes ranked highest all have a negative impact. These were, in rank order, governments sidelining the environment during their economic recovery, reduced wildlife-based tourism income, increased habitat destruction, reduced government funding, increased plastic and other solid waste pollution, weakening of nature-friendly regulations and their enforcement, increased illegal harvest of wild animals, reduced philanthropy, and threats to survival of conservation organizations. In combination, these impacts present a worrying future of increased threats to biodiversity conservation but reduced capacity to counter them. The highest ranking positive impact, at 10, was the beneficial impact of wildlife-trade restrictions. More optimistically, among impacts ranked 11-20, 6 were positive and 4 were negative. We hope our assessment will draw attention to the impacts of the pandemic and, thus, improve the conservation community's ability to respond to such threats in the future.

La pandemia de COVID-19 ha tenido un impacto enorme sobre casi todos los aspectos de la sociedad humana y sus proyectos; el mundo natural y su conservación no han sido la excepción. Por medio de un proceso de consultas a expertos, identificamos y categorizamos en 19 temas y 70 subtemas las maneras en las que la biodiversidad y su conservación han sido o podrían ser afectadas mundialmente por la pandemia. Casi el 60% de los efectos han sido claramente negativos. Posteriormente, creamos un compendio de todos los temas y subtemas, cada uno con textos explicativos, para que en agosto de 2020 un grupo diverso de conservacionistas experimentados con conocimiento de todos los sectores y geografías evaluara cada subtema de acuerdo con su probabilidad de impactar sobre la conservación de la biodiversidad en todo el mundo. Los nueve subtemas con la clasificación más alta tienen un impacto negativo. Estos temas son, en orden de clasificación: los gobiernos dejando de lado al ambiente durante su recuperación económica, reducción de los ingresos basados en el turismo de fauna, incremento en la destrucción de hábitat, financiamiento reducido del gobierno, aumento de la contaminación por plásticos y otros desechos sólidos, debilitamiento de las regulaciones en pro de la naturaleza y su aplicación, incremento en la captura ilegal de animales, disminución de la filantropía y amenazas para la supervivencia de las organizaciones de conservación. La combinación de estos impactos representa un futuro preocupante lleno de amenazas para la conservación de la biodiversidad y una capacidad reducida para contrarrestarlas. El impacto positivo con la clasificación más alta, el 10, fue el impacto benéfico de las restricciones en el mercado de fauna. De manera más optimista, entre los impactos clasificados de los lugares del 11 al 20, seis fueron positivos y cuatro fueron negativos. Esperamos que nuestra evaluación enfoque la atención hacia los impactos de la pandemia y así mejore la habilidad de la comunidad conservacionista para responder a tales amenazas en el futuro. Importancia Relativa de los Impactos de la Pandemia de COVID-19 sobre la Conservación Mundial de la Biodiversidad.

Habitat destruction and overexploitation drive widespread declines in all facets of mammalian diversity in the Gran Chaco.

Global biodiversity is under high and rising anthropogenic pressure. Yet, how the taxonomic, phylogenetic, and functional facets of biodiversity are affected by different threats over time is unclear. This is particularly true for the two main drivers of the current biodiversity crisis: habitat destruction and overexploitation. We provide the first long-term assessment of multifaceted biodiversity changes caused by these threats for any tropical region. Focussing on larger mammals in South America's 1.1 million km2 Gran Chaco region, we assessed changes in multiple biodiversity facets between 1985 and 2015, determined which threats drive those changes, and identified remaining key areas for all biodiversity facets. Using habitat and threat maps, we found, first, that between 1985 and 2015 taxonomic (TD), phylogenetic (PD) and functional (FD) diversity all declined drastically across over half of the area assessed. FD declined about 50% faster than TD and PD, and these declines were mainly driven by species loss, rather than species turnover. Second, habitat destruction, hunting, and both threats together contributed ~57%, ~37%, and ~6% to overall facet declines, respectively. However, hunting pressure increased where TD and PD declined most strongly, whereas habitat destruction disproportionally contributed to FD declines. Third, just 23% of the Chaco would have to be protected to safeguard the top 17% of all three facets. Our findings uncover a widespread impoverishment of mammal species richness, evolutionary history, and ecological functions across broad areas of the Chaco due to increasing habitat destruction and hunting. Moreover, our results pinpoint key areas that should be preserved and managed to maintain all facets of mammalian diversity across the Chaco. More generally, our work highlights how long-term changes in biodiversity facets can be assessed and attributed to specific threats, to better understand human impacts on biodiversity and to guide conservation planning to mitigate them.

Biodiversity at risk under future cropland expansion and intensification.

Agriculture is the leading driver of biodiversity loss. However, its future impact on biodiversity remains unclear, especially because agricultural intensification is often neglected, and high path-dependency is assumed when forecasting agricultural development-although the past suggests that shock events leading to considerable agricultural change occur frequently. Here, we investigate the possible impacts on biodiversity of pathways of expansion and intensification. Our pathways are not built to reach equivalent production targets, and therefore they should not be directly compared; they instead highlight areas at risk of high biodiversity loss across the entire option space of possible agricultural change. Based on an extensive database of biodiversity responses to agriculture, we find 30% of species richness and 31% of species abundances potentially lost because of agricultural expansion across the Amazon and Afrotropics. Only 21% of high-risk expansion areas in the Afrotropics overlap with protected areas (compared with 43% of the Neotropics). Areas at risk of biodiversity loss from intensification are found in India, Eastern Europe and the Afromontane region (7% species richness, 13% abundance loss). Many high-risk regions are not adequately covered by conservation prioritization schemes, and have low national conservation spending and high agricultural growth. Considering rising agricultural demand, we highlight areas where timely land-use planning may proactively mitigate biodiversity loss.