“Resilience is being lost more rapidly in the parts of the rainforest that are closer to human activity and in parts with less rainfall.
“Many researchers speculate that a tipping point may be reached, but our study provides important empirical evidence that we are approaching that tipping point.”
drought
The study used a variety of data sources, including satellite data on vegetation optical depth (VOD) – a measure of the total biomass of trees and other plants in a given area.
Despite the changing climate, average rainfall in the Amazon has not changed significantly in recent decades. But the dry season has become longer and droughts have become more common and severe.
The study’s VOD measurements showed a slight decrease in overall biomass, but a more pronounced loss in resilience.
The researchers highlighted the difference between resilience and the average “state” of a tropical rainforest.
Professor Tim Renton, Director of the Exeter Global Systems Institute, explained: “The rainforest looks more or less the same, but it may be losing resilience – the speed at which it recovers from major events such as droughts slower.”
degradation
“If too much resiliency is lost, withering may be inevitable – but that won’t become apparent until after a major event in which the system collapses,” Professor Boers said.
“Many interrelated factors — including drought, fire, deforestation, degradation and climate change — could collectively reduce resilience and trigger the Amazon to cross a tipping point.”
Professor Lenton added: “This provides new and compelling evidence to support efforts to reverse deforestation and degradation in the Amazon, restoring some of its resilience to ongoing climate change.”
The research is part of the Earth System Tipping Points project funded by the EU’s Horizon 2020 programme, with additional funding from the Leverhulme Trust and the Alan Turing Institute.
The paper is published in the journal natural climate changehave the right Significant loss of Amazon rainforest resilience since early 2000s.
this author
Brendan Montague is the editor ecologist. This article is based on a press release from the University of Exeter.
