Faculty of Mathematics and Natural Sciences - Biogeography

Faculty of Mathematics and Natural Sciences | Geography Department | Biogeography | News | Deforestation threatens forest-dependent people in the Gran Chaco

Deforestation threatens forest-dependent people in the Gran Chaco


Levers, C., Romero-Muñoz, A., Baumann, M., De Marzo, T., Fernández, P.D., Gasparri, N.I., Gavier-Pizarro, G.I., le Polain de Waroux, Y., Piquer-Rodríguez, M., Semper-Pascual, A. & Kuemmerle, T.



Millions of people globally rely on forest-based resources for their livelihoods, and deforestation is putting them at risk. We mapped homesteads of forest-dependent people in the Chaco and showed they are widespread across Chaco forests, that their numbers have declined drastically since the 1980s, and that expanding commodity agriculture diminishes their resource base.


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% 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.

Link to the manuscript: https://doi.org/10.1073/pnas.2100436118

Citation:  Levers C, Romero-Muñoz A, Baumann M, De Marzo, T, Fernández PD, Gasparri NI, Gavier-Pizarro GI, le Polain de Waroux Y, Piquer-Rodríguez M, Semper-Pascual A & Kuemmerle T (2021). Agricultural expansion and the ecological marginalization of forest-dependent people. Proceedings of the National Academy of Sciences of the United States of America, Volume 118.


Fig.:© T. Kuemmerle