Amazon forest biogeography predicts resilience and vulnerability to drought.

Autor: Chen S; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA. slchen@arizona.edu., Stark SC; Department of Forestry, Michigan State University, East Lansing, MI, USA., Nobre AD; National Institute for Space Research (INPE), São José dos Campos, Brazil., Cuartas LA; National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN), São José dos Campos, Brazil., de Jesus Amore D; National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN), São José dos Campos, Brazil., Restrepo-Coupe N; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.; Cupoazu LLC, Etobicoke, Ontario, Canada., Smith MN; Department of Forestry, Michigan State University, East Lansing, MI, USA.; School of Environmental and Natural Sciences, College of Science and Engineering, Bangor University, Bangor, UK., Chitra-Tarak R; Los Alamos National Laboratory, Earth and Environmental Sciences, Los Alamos, NM, USA., Ko H; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA., Nelson BW; Brazil's National Institute for Amazon Research (INPA), Manaus, Brazil., Saleska SR; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA. saleska@arizona.edu.; Department of Environmental Sciences, University of Arizona, Tucson, AZ, USA. saleska@arizona.edu.
Jazyk: angličtina
Zdroj: Nature [Nature] 2024 Jul; Vol. 631 (8019), pp. 111-117. Date of Electronic Publication: 2024 Jun 19.
DOI: 10.1038/s41586-024-07568-w
Abstrakt: Amazonia contains the most extensive tropical forests on Earth, but Amazon carbon sinks of atmospheric CO 2 are declining, as deforestation and climate-change-associated droughts 1-4 threaten to push these forests past a tipping point towards collapse 5-8 . Forests exhibit complex drought responses, indicating both resilience (photosynthetic greening) and vulnerability (browning and tree mortality), that are difficult to explain by climate variation alone 9-17 . Here we combine remotely sensed photosynthetic indices with ground-measured tree demography to identify mechanisms underlying drought resilience/vulnerability in different intact forest ecotopes 18,19 (defined by water-table depth, soil fertility and texture, and vegetation characteristics). In higher-fertility southern Amazonia, drought response was structured by water-table depth, with resilient greening in shallow-water-table forests (where greater water availability heightened response to excess sunlight), contrasting with vulnerability (browning and excess tree mortality) over deeper water tables. Notably, the resilience of shallow-water-table forest weakened as drought lengthened. By contrast, lower-fertility northern Amazonia, with slower-growing but hardier trees (or, alternatively, tall forests, with deep-rooted water access), supported more-drought-resilient forests independent of water-table depth. This functional biogeography of drought response provides a framework for conservation decisions and improved predictions of heterogeneous forest responses to future climate changes, warning that Amazonia's most productive forests are also at greatest risk, and that longer/more frequent droughts are undermining multiple ecohydrological strategies and capacities for Amazon forest resilience.
(© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE