A hallmark of environmental science is understanding how ecosystems respond to global change. Much of this research focuses on short-term ecosystem responses, such as how an ecosystem responds to a sudden onset of drought. But previous conditions can modify that response. In the same way a formative childhood experience might change how an adult responds to stress, legacy effects can change the direction or magnitude of ecosystem responses to disturbance.
A study at the U.S. National Science Foundation-supported Konza Prairie Long-Term Ecological Research site modified a 25-year irrigation experiment to show that historical irrigation patterns determined the sensitivity of carbon cycling to drought. The results suggest that long-term legacies play a significant role in how an ecosystem responds to short-term stress. The findings were published in Global Change Biology.
"Soil is a living ecosystem that doesn't soon forget conditions from years ago," says Doug Levey, a program director in NSF's Division of Environmental Biology. "Today's droughts and fires may severely alter the trajectory of tomorrow's grasslands and forests."
Researchers at Konza Prairie LTER began irrigating a long strip of prairie in the 1990s. Initially, they wanted to study how avoiding drought might change the ecosystem, from plant community composition to soil nutrient availability.