Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

Journal Article · 26 April 2023 · Nature (London)

DOI:https://doi.org/10.1038/s41586-023-05971-3· OSTI ID:2424392

Tavares, Julia Valentim; Oliveira, Rafael S.; Mencuccini, Maurizio; Signori-Müller, Caroline; Pereira, Luciano; Diniz, Francisco Carvalho; Gilpin, Martin; Marca Zevallos, Manuel J.; Salas Yupayccana, Carlos A.; Acosta, Martin; Pérez Mullisaca, Flor M.; Barros, Fernanda de V.; Bittencourt, Paulo; Jancoski, Halina; Scalon, Marina Corrêa; Marimon, Beatriz S.; Oliveras Menor, Imma; Marimon, Ben Hur; Fancourt, Max; Chambers-Ostler, Alexander ; Esquivel-Muelbert, Adriane; Rowland, Lucy; Meir, Patrick; Lola da Costa, Antonio Carlos; Nina, Alex; Sanchez, Jesus M. B.; Tintaya, Jose S.; Chino, Rudi S. C.; Baca, Jean; Fernandes, Leticia; Cumapa, Edwin R. M.; Santos, João Antônio R.; Teixeira, Renata; Tello, Ligia; Ugarteche, Maira T. M.; Cuellar, Gina A.; Martinez, Franklin; Araujo-Murakami, Alejandro; Almeida, Everton; da Cruz, Wesley Jonatar Alves; del Aguila Pasquel, Jhon; Aragāo, Luís; Baker, Timothy R.; de Camargo, Plinio Barbosa; Brienen, Roel; Castro, Wendeson; Ribeiro, Sabina Cerruto; Coelho de Souza, Fernanda; Cosio, Eric G.; Davila Cardozo, Nallaret; da Costa Silva, Richarlly; Disney, Mathias; Espejo, Javier Silva; Feldpausch, Ted R.; Ferreira, Leandro; Giacomin, Leandro; Higuchi, Niro; Hirota, Marina; Honorio, Euridice; Huaraca Huasco, Walter; Lewis, Simon; Flores Llampazo, Gerardo; Malhi, Yadvinder; Monteagudo Mendoza, Abel; Morandi, Paulo; Chama Moscoso, Victor; Muscarella, Robert; Penha, Deliane; Rocha, Mayda Cecília; Rodrigues, Gleicy; Ruschel, Ademir R.; Salinas, Norma; Schlickmann, Monique; Silveira, Marcos; Talbot, Joey; Vásquez, Rodolfo; Vedovato, Laura; Vieira, Simone Aparecida; Phillips, Oliver L.; Gloor, Emanuel; Galbraith, David R.

Abstract

Tropical forests face increasing climate risk^1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example,$$$$\varPsi $$$$ $\Psi$ ₅₀) and hydraulic safety margins (for example, HSM₅₀) are important predictors of drought-induced mortality risk^3–5, little is known about how these vary across Earth’s largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters$$$$\varPsi $$$$ $\Psi$ ₅₀and HSM₅₀vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both$$$$\varPsi $$$$ $\Psi$ ₅₀and HSM₅₀influence the biogeographical distribution of Amazon tree species. However, HSM₅₀was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM₅₀are gaining more biomass than are low HSM₅₀forests. We propose that this may be associated with a growth–mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM₅₀in the Amazon^6,7, with strong implications for the Amazon carbon sink.

• Research Organization: Univ. of Campinas (UNICAMP), Sao Paulo (Brazil)
• Sponsoring Organization: USDOE
• OSTI ID: 2424392
• Journal Information: Nature (London), Journal Name: Nature (London) Journal Issue: 7959 Vol. 617; ISSN 0028-0836
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

Related Subjects

Science & Technology - Other Topics