The Amazon rainforest has become slower at recovering from longer periods of drought over the past two decades, damaging its complex ecosystem and pushing the world’s largest tropical forest nearer a possible tipping point, researchers have said.
A study published in the journal Nature Climate Change, found that more than three-quarters of the rainforest has been losing its ability to recover from shocks, such as droughts and fires, and return to a healthy state.
“In (forest) areas that are closer to human land use, such as urban areas and croplands, they tend to be losing resilience faster,” said Chris Boulton, one of the report authors from the University of Exeter’s Global Systems Institute.
Drier areas that receive less rainfall also have been particularly hard hit, he said during an online event.
Curbing rising Amazon deforestation is vital to preventing runaway climate change impacts because of the vast amount of planet-heating carbon dioxide absorbed by the forest’s trees.
Researchers looked at satellite data that estimated the total amount of biomass – trees and other plants – in a given area as well as the water content of trees and how green the vegetation appeared, all indicators of forest health and resilience.
They also examined month-to-month changes as the forest responded to fluctuating weather conditions over a 20-year period, a long enough time span to observe changes in resilience, Boulton said.
The resilience of the Amazon ecosystem in particular dropped during major droughts in 2005 and 2010, part of an ongoing decline from the early 2000s to 2016, when the most recent data was collected, the study found.