Drought Sensitivity of the Amazon Rainforest

Oliver L. Phillips , Luiz E.O.C. Aragao , Simon L. Lewis , Joshua, B. Fisher , Jon Lloyd , Gabriela Lopez-Gonzales , Yadvinder Malhi , Abel Monteagudo , Julie Peacock , Carlos A. Quesada , Geertje van Der Heijden , Samuel Almeida , Ieda Amaral , Luzmila Arroyo , Gerardo Aymard , Tim R. Baker , Olaf Banki , Lilian Blanc (1) , Damien Bonal (2) , Paulo Brando , Jérôme Chave (3) , Atila Cristina Alves de Oliveira , Nallaret Davila Cardozo , Claudia I. Czimczik , Ted R. Feldpausch , Maria Aparecida Freitas , Emanuel Gloor , Niro Higuchi , Eliana Jimenez , Gareth Lloyd , Patrick Meir , Casimiro Mendoza , Alexandra Morel , David A. Neill , Daniel Nepstad , Sandra Patino (1) , Maria Cristina Penuela , Adriana Prieto , Fredy Ramirez , Michael Schwarz , Javier Silva , Marcos Silveira , Anne Sota Thomas , Hans ter Steege , Juliana Stropp , Rodolfo Vasquez , Przemyslaw Zelazowski , Esteban Alvarez Davila , Sandy Andelman , Ana Andrade , Kuo-Jung Chao , Terry Erwin , Anthony Di Fiore , Euridice Honorio , Helen Keeling , Tim J. Killeen , William F. Laurance , Antonio Pena Cruz , Nigel C.A. Pitman , Percy Nunez Vargas , Hirma Ramirez-Angulo , Agustin Rudas , Rafael Salamao , Natalino Silva , John Terborgh , Armando Torres-Lezama

1 ECOFOG - Ecologie des forêts de Guyane
2 EEF - Ecologie et Ecophysiologie Forestières [devient SILVA en 2018]
3 EDB - Evolution et Diversité Biologique

Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 × 1015 to 1.6 × 1015 grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.

Mots clés: CARBON CYCLE; DROUGHT; AMAZON RAINFOREST

Domaines: Milieux et Changements globaux; Biodiversité et Ecologie

Oliver L. Phillips, Luiz E.O.C. Aragao, Simon L. Lewis, Joshua, B. Fisher, Jon Lloyd, et al.. Drought Sensitivity of the Amazon Rainforest. Science, 2009, 323, pp.1344-1347. ⟨10.1126/science.1164033⟩. ⟨hal-01032111⟩