Agricultural production is the main cause of destructive fires in South America’s tropical dry forests
Research team has used satellite images to reconstruct the fire history of the Gran Chaco, one of the world’s largest dry forest regions
Every year, vast areas of forest burn in the South American Chaco, a tropical dry forest region that stretches across Argentina, Bolivia, and Paraguay and forms the second-largest forest region on the continent after the Amazon. Until now, the increasing fires in South America’s dry forests were often attributed to climate change and the more frequent and more extreme droughts it brings. However, a study published in the journal Nature Sustainability, conducted by researchers from Humboldt-University Berlin (HU) in collaboration with partners in Bolivia and Argentina, now challenges this assumption.
Reconstruction of fire history using satellite imagery
Using around 175,000 satellite images, the researchers reconstructed the fire history of the Chaco region and found that fires have broken out at least once since 1985 on two-thirds of the 1,1 million square-kilometer area. In drought years, the forest burns more often, but the study shows a strong connection between fires and agricultural production: in drier years, particularly large areas of forest are cleared for soybean cultivation and the expansion of industrialized cattle ranching, and the subsequent use of these lands often leads to fires breaking out during dry periods. These results are important because the fires release massive amounts of greenhouse gases and threaten both biodiversity and the livelihoods of local Indigenous communities.
These insights also gain importance in light of the new EU regulation for deforestation-free supply chains (EUDR), which will apply to large companies from December 30, 2026. The EUDR mandates due diligence requirements for seven raw materials and products derived from them. According to the regulation, raw materials such as soy and beef may not be produced on land that was deforested after December 31, 2020.
Since the Chaco is a global hotspot for the production of export goods such as soy and beef, the study provides the scientific basis for monitoring compliance with such regulations. It shows that stricter deforestation bans and improved fire management are essential to limit the ecological costs of agricultural expansion.
Fire dynamics in the Chaco are not a natural phenomenon
“When you look at the satellite images, you don’t see a natural phenomenon but rather fire dynamics that are closely tied to landscape transformation,” explains Dr. Matthias Baumann, lead author of the study and Senior Scientist at the Department of Geography at Humboldt-University Berlin. “Our data clearly show that drought periods are often used as favorable windows to clear land cheaply with fire. Fire here is not a natural disturbance or an accident but a tool of agribusinesses.”
Prof. Tobias Kümmerle, Professor at the Geography Department, and leader of the project SystemShift, funded by the European Research Council (ERC) in which the study was conducted, adds: “The idea that the forest simply bursts into flames because it gets drier falls short. Climate change and land use act together: in the Chaco, fires occur where humans are pushing back the forest to produce soy and beef. Some of these products then find their way to us in Europe.”
“This also gives us hope,” says Oswaldo Maillard, co-author of the study who works for the Bolivian foundation Fundación para la Conservación del Bosque Chiquitano. “If ranchers and farmers use fires more responsibly and we manage land use more effectively through instruments like the EUDR, we have a direct lever to stop these disastrous fires.” The study clearly shows that the fires in the Chaco are not an unavoidable climate fate but can be curbed again through smart policies and sustainable management.
The study was supported by the SystemShift project, funded by the European Research Council (ERC).
Publication:
“Fire dynamics in the South American Chaco and their link to agriculture and drought”
Matthias Baumann, Oswaldo Maillard, Ignacio Gasparri, Jamie Burton, Gregorio Gavier Pizarro & Tobias Kuemmerle
Nature Sustainability (2026). https://doi.org/10.1038/s41893-026-01793-z
Contact:
Conservation Biogeography Lab
Geography Department at Humboldt-Universität zu Berlin
hu.berlin/BioGeo
Prof. Dr. Tobias Kümmerle
+49 30 2093-9372
tobias.kuemmerle(at)hu-berlin.de
Dr. Matthias Baumann
+49 30 2093-45886
matthias.baumann(at)hu-berlin.de
HU press release, 30.03.2026