Critical transitions in the Amazon forest system

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Flores, Bernardo M. ; Montoya, Encarni ; Sakschewski, Boris ; Nascimento, Nathalia ; Staal, Arie ; Betts, Richard A. ; Levis, Carolina ; Lapola, David M. ; Esquivel-Muelbert, Adriane ; Jakovac, Catarina ; Nobre, Carlos A. ; Oliveira, Rafael S. ; Borma, Laura S. ; Nian, Da ; Boers, Niklas ; Hecht, Susanna B. ; ter Steege, Hans ; Arieira, Julia ; Lucas, Isabella L. ; Berenguer, Erika ; Marengo, Jose A. ; Gatti, Luciana V. ; Mattos, Caio R. C. ; Hirota, Marina

• Tipo de documento: Artigo Científico
• Fonte: Nature; v. 626, n. 7999, p. 25-pg., 2024-02-15.

Resumo

The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern1-3. For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system1. Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions and potentially exacerbate regional climate change. Using examples of disturbed forests across the Amazon, we identify the three most plausible ecosystem trajectories, involving different feedbacks and environmental conditions. We discuss how the inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action. Keeping the Amazon forest resilient in the Anthropocene will depend on a combination of local efforts to end deforestation and degradation and to expand restoration, with global efforts to stop greenhouse gas emissions. Analyses of drivers of water stress are used to predict likely trajectories of the Amazon forest system and suggests potential actions that could prevent system collapse. (AU)

• Processo FAPESP: 19/07773-1 - Restaurando ecossistemas neotropicais secos - seria a composição funcional das plantas a chave para o sucesso?
• Beneficiário: Rafael Silva Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/08940-6 - ODS 2.4-AM: entendendo o papel de redes sociais sobre a segurança alimentar ante extremos climáticos no Amazonas
• Beneficiário: David Montenegro Lapola
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50848-9 - INCT 2014: INCT para Mudanças Climáticas (INCT-MC)
• Beneficiário: Jose Antonio Marengo Orsini
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático