Data/hora: 19/06/2024 12:11:45

Biblioteca(s): | Embrapa Amazônia Oriental.
Data corrente: | 08/07/2005
Data da última atualização: | 02/12/2022
Autoria: | FORTINI, L. B.; MULKEY, S. S.; ZARIN, D. J.; VASCONCELOS, S. S.; CARVALHO, C. J. R. de.
Afiliação: | LUCAS B. FORTINI, University of Florida; STEPHEN S. MULKEY, University of Florida; DANIEL J. ZARIN, University of Florida; STEEL S. VASCONCELOS, University of Florida; CLAUDIO JOSE REIS DE CARVALHO, CPATU.
Título: | Drought constraints on leaf gas exchange by Miconia ciliata (Melastomataceae) in the understory of an eastern Amazonian regrowth forest stand.
Ano de publicação: | 2003
Fonte/Imprenta: | American Journal of Botany, v. 90, n. 7, p. 1064-1070, Jul. 2003.
Descrição Física: | il.
DOI: | 10.3732/ajb.90.7.1064
Idioma: | Inglês
Conteúdo: | Analyses of the effects of drought stress on Amazonian regrowth stands are lacking. We measured leaf gas exchange and leaf water potential of Miconia ciliata (Melastomataceae) in a dry-season irrigation experiment in 14-yr-old regrowth. In the dry season, irrigated plants maintained significantly higher leaf water potentials, photosynthetic capacity at light saturation (Amax), stomatal conductance (gs), internal CO2 concentration (Ci), and lower Amax/gs than control plants. The degree of dry-season down-regulation of control plant Amax, along with its fast recovery following rain, reveals the importance of occasional dry-season rains to the carbon budget of M. ciliata. During the wet season, we observed higher Amax for control plants than for plants that had been irrigated during the dry season. We hypothesize that reduced drought constraints on photosynthesis of irrigated plants advanced the flowering and fruiting phenology of irrigated plants into the dry season. Flowers and fruits of control plants developed later, during the wet season, potentially stimulating a compensatory reproductive photosynthesis response in nearby leaves. The relative drought intolerance of M. ciliata may be a deciding factor in its ability to survive through the dynamic successional development of the regrowth stand studied.
Palavras-Chave: | Floresta tripical; Miconia ciliata.
Thesagro: | Fenologia; Floresta Secundaria; Fotossíntese; Melastomataceae.
Thesaurus Nal: | Amazonia.
Categoria do assunto: | --
Registro original: | Embrapa Amazônia Oriental (CPATU)
Exemplares: | CPATU - (36553-1) - UPC - AP - DD -  -  -  - DIS