Increasing and widespread vulnerability of intact tropical rainforests to repeated droughts
Language
en
Article de revue
This item was published in
Proceedings of the National Academy of Sciences of the United States of America. 2022-07-22, vol. 119, n° 37, p. 2116626119
National Academy of Sciences
English Abstract
Intact tropical rainforests have been exposed to severe droughts in recent decades, which may threaten their integrity, their ability to sequester carbon, and their capacity to provide shelter for biodiversity. However, ...Read more >
Intact tropical rainforests have been exposed to severe droughts in recent decades, which may threaten their integrity, their ability to sequester carbon, and their capacity to provide shelter for biodiversity. However, their response to droughts remains uncertain due to limited high-quality, long-term observations covering extensive areas. Here, we examined how the upper canopy of intact tropical rainforests has responded to drought events globally and during the past 3 decades. By developing a long pantropical time series (1992 to 2018) of monthly radar satellite observations, we show that repeated droughts caused a sustained decline in radar signal in 93%, 84%, and 88% of intact tropical rainforests in the Americas, Africa, and Asia, respectively. Sudden decreases in radar signal were detected around the 1997–1998, 2005, 2010, and 2015 droughts in tropical Americas; 1999–2000, 2004–2005, 2010–2011, and 2015 droughts in tropical Africa; and 1997–1998, 2006, and 2015 droughts in tropical Asia. Rainforests showed similar low resistance (the ability to maintain predrought condition when drought occurs) to severe droughts across continents, but American rainforests consistently showed the lowest resilience (the ability to return to predrought condition after the drought event). Moreover, while the resistance of intact tropical rainforests to drought is decreasing, albeit weakly in tropical Africa and Asia, forest resilience has not increased significantly. Our results therefore suggest the capacity of intact rainforests to withstand future droughts is limited. This has negative implications for climate change mitigation through forest-based climate solutions and the associated pledges made by countries under the Paris Agreement.Read less <
English Keywords
rainforests
drought
remote sensing
radar
ANR Project
CEnter of the study of Biodiversity in Amazonia
Towards a Unified theory of biotic Interactions: the roLe of environmental - ANR-10-LABX-0041
ANAEE-Services - ANR-11-INBS-0001
Towards a Unified theory of biotic Interactions: the roLe of environmental - ANR-10-LABX-0041
ANAEE-Services - ANR-11-INBS-0001
Origin
Hal imported