Overlooked Decline in Grazing Livestock Brings Risks and Opportunities

By Joe Rojas-Burke

For decades, researchers have focused on the problem of overgrazing, in which expanding herds of cattle and other livestock degrade grasslands, steppes and desert plains. But a new global study reveals that in large regions of the world, livestock numbers are substantially declining, not growing — a process the authors call destocking.

“We often assume that rangelands are being degraded because we overgraze them, but the data show that it's not the whole story: Nearly half of livestock production occurs in areas that have experienced destocking over the past 25 years,” said study co-author Osvaldo Sala, an ecologist and professor at Arizona State University.

The findings are important because destocking isn’t just the reverse of overgrazing; it poses new ecological and land management challenges.

“We need to manage both processes,” Sala said. "It's not that destocking is automatically positive and that we should just leave it alone.”

When livestock numbers drop, for instance, unchecked plant growth can increase wildfire risk. Biodiversity might recover in some areas but decline in others, depending on how ecosystems respond.

As part of the study, which published this week in Proceedings of the National Academy of Sciences, the researchers analyze global changes in livestock numbers from 1999 to 2023 using data from the United Nations’ Food and Agriculture Organization.