South America Rapidly Losing Natural Ecosystems, New UMD Study Shows

A new study out today from Department of Geographical Sciences researchers reveals that the South American continent has lost 20% of its natural ecosystems since 1985—equivalent to about 22 soccer fields of natural land being degraded or converted by human activity each minute for more than three decades.

Researchers in the Global Land Use and Discovery (GLAD) laboratory completed a comprehensive analysis of satellite data from 1985 to 2018. Results published in Science Advances show a substantial expansion of pastures, croplands and tree plantations (by 23%, 160% and 288%, respectively), enabling the continent’s transformation into a global center of agricultural commodity production.

Researchers also discovered approximately 136 million acres of land—a combined area roughly the size of Spain—altered from a natural state without any discernable use or economic benefits, representing a significant loss of ecosystem services.

“In recent years, we have seen fires rage and deforestation rise across South America’s forests, causing global outcry,” said Viviana Zalles, a postdoctoral researcher in the Department of Geographical Sciences and lead author on the study. “Our results highlight the fact that these events are only the most recent manifestation of an ongoing transformation of South America’s ecosystems, the unprecedented scale of which we present in our paper.”

This is the first continental-scale analysis of land-use changes in South America using the full data archive available from joint NASA/U.S. Geological Survey Landsat program—the longest continuous global record of the Earth's surface. It was directed by geographical sciences Professors Matt Hansen and Peter Potapov, with collaborators from the Federal University of Goiás, Brazil, and the State University of New York College of Environmental Science and Forestry.