Data/hora: 03/06/2024 05:12:59

Biblioteca(s): | Embrapa Amazônia Oriental.
Data corrente: | 16/11/2015
Data da última atualização: | 30/05/2022
Autoria: | ROWLAND, L.; LOBO-DO-VALE, R. L.; CHRISTOFFERSEN, B. O.; MELÉM, E. A.; KRUIJT, B.; VASCONCELOS, S. S.; DOMINGUES, T.; BINKS, O. J.; OLIVEIRA, A. A. R.; METCALFE, D.; COSTA, A. C. L. da; MENCUCCINI, M.; MEIR, P.
Afiliação: | LUCY ROWLAND, University of Edinburgh; RAQUEL L. LOBO-DO-VALE, University of Lisbon; BRADLEY O. CHRISTOFFERSEN, University of Edinburgh / Los Alamos National Laboratory; ELIANE A. MELÉM, CPATU; BART KRUIJT, Alterra; STEEL SILVA VASCONCELOS, CPATU; TOMAS DOMINGUES, USP; OLIVER J . BINKS, University of Edinburgh; ALEX A. R. OLIVEIRA, UFPA; DANIEL METCALFE, Lund University; ANTONIO C. L. DA COSTA, UFPA; MAURIZIO MENCUCCINI, University of Edinburgh / ICREA at CREAF; PATRICK MEIR, University of Edinburgh / Australian National University.
Título: | After more than a decade of soil moisture deficit tropical rainforest trees maintain photosynthetic capacity, despite increased leaf respiration.
Ano de publicação: | 2015
Fonte/Imprenta: | Global Change Biology, v. 21, n. 12, p. 4662-4672, Dec. 2015.
DOI: | 10.1111/gcb.13035
Idioma: | Inglês
Conteúdo: | Determining climate change feedbacks from tropical rainforests requires an understanding of how carbon gain through photosynthesis and loss through respiration will be altered. One of the key changes that tropical rainforests may experience under future climate change scenarios is reduced soil moisture availability. In this study we examine if and how both leaf photosynthesis and leaf dark respiration acclimate following more than 12 years of experimental soil moisture deficit, via a through-fall exclusion experiment (TFE) in an eastern Amazonian rainforest. We find that experimentally drought-stressed trees and taxa maintain the same maximum leaf photosynthetic capacity as trees in corresponding control forest, independent of their susceptibility to drought-induced mortality. We hypothesize that photosynthetic capacity is maintained across all treatments and taxa to take advantage of short-lived periods of high moisture availability, when stomatal conductance (gs) and photosynthesis can increase rapidly, potentially compensating for reduced assimilate supply at other times. Average leaf dark respiration (Rd) was elevated in the TFE-treated forest trees relative to the control by 28.2 ± 2.8% (mean ± one standard error). This mean Rd value was dominated by a 48.5 ± 3.6% increase in the Rd of drought-sensitive taxa, and likely reflects the need for additional metabolic support required for stress-related repair, and hydraulic or osmotic maintenance processes. Following soil moisture deficit that is maintained for several years, our data suggest that changes in respiration drive greater shifts in the canopy carbon balance, than changes in photosynthetic capacity.
Palavras-Chave: | Capacidade fotossintética.
Thesagro: | Floresta Tropical; Mudança Climática; Seca; Solo.
Categoria do assunto: | K Ciência Florestal e Produtos de Origem Vegetal
Registro original: | Embrapa Amazônia Oriental (CPATU)
Exemplares: | CPATU - (51755-1) - UPC - AP - DD -  -  -  - DIS