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|Título:||Impacts of experimentally imposed drought on leaf respiration and morphology in an Amazon rain forest|
|Autor:||Metcalfe, Daniel B.|
Chaves, Maria Manuela
Aragão, Luiz E. O. C.
Costa, António L. da
Braga, Alan P.
Gonçalves, Paulo L.
Athaydes, João de
Costa, Mauricio da
Almeida, Samuel S.
Leaf dark respiration
Night-time foliar carbon emissions
Specific leaf area
Leaf area index
Through-fall exclusion experiment
|Citação:||Functional Ecology, 24, 524-533|
|Resumo:||1. The Amazon region may experience increasing moisture limitation over this century. Leaf dark respiration (R) is a key component of the Amazon rain forest carbon (C) cycle, but relatively little is known about its sensitivity to drought. 2. Here, we present measurements of R standardized to 25 C and leaf morphology from different canopy heights over 5 years at a rain forest subject to a large-scale through-fall reduction (TFR) experiment, and nearby, unmodified Control forest, at the Caxiuana˜ reserve in the eastern Amazon. 3. In all five post-treatment measurement campaigns, mean R at 25 C was elevated in the TFR forest compared to the Control forest experiencing normal rainfall. After 5 years of the TFR treatment, R per unit leaf area and mass had increased by 65% and 42%, respectively, relative to pre-treatment means. In contrast, leaf area index (L) in the TFR forest was consistently lower than the Control, falling by 23% compared to the pre-treatment mean, largely because of a decline in specific leaf area (S). 4. The consistent and significant effects of the TFR treatment on R, L and S suggest that severe drought events in the Amazon, of the kind that may occur more frequently in future, could cause a substantial increase in canopy carbon dioxide emissions from this ecosystem to the atmosphere.|
|Aparece nas colecções:||BIOL - Artigos em revistas internacionais|
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|FE 24 524–533.pdf||343,29 kB||Adobe PDF||Ver/Abrir|
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