Data/hora: 12/06/2024 15:07:32

Provedor de dados: | 61
País: | Brazil
Título: | Light as an indicator of ecological succession in brazilwood (Caesalpinia echinata Lam.)
Autores: | Mengarda,Liana H. G.; Souza,Rogério L. F. de; Campostrini,Eliemar; Reis,Fabrício O.; Vendrame,Wagner A.; Cuzzuol,Geraldo R. F.
Data: | 2009-01-01
Ano: | 2009
Palavras-chave: | Chlorophyll fluorescence; Gas exchange; Growth; Light stress; Shade; Tropical tree.
Resumo: | The ecophysiological behavior of brazilwood (Caesalpinia echinata Lam.) plants was evaluated as affected by light quantity and quality. Nine-month-old plants were cultivated under 0%, 50%, and 80% artificial shading, and natural shading imposed by a closed canopy for a period of 392 days. At the end of that period growth parameters were measured, including relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf mass (SLM) and root:shoot ratio (R:S). Higher leaf area, dry mass and RGR were obtained under 50% artificial shade. Under full sunlight (0% shade), growth was satisfactory showing higher R:S and SLM. Growth was inhibited under 80% artificial and natural shading indicating that C. echinata is not pioneer-succession or climax specie. Simulating a gap, plants cultivated under artificial shade (50%) were transferred to full sunlight for an interval of 192 h, during which net photosynthesis (A), transpiration (E), stomatic conductance (gs), deficit of pressure vapor (VPDleaf-to-air) and the efficiency quantum potential of photosystem II (Fv/Fm) were analyzed. Plants transferred to full sunlight presented severe burning and abscission of the leaflets, as well as inhibition of A and of the photochemical efficiency of PSII (Fv/Fm). This observation associated with the reduced growth under full sunlight and better performance under moderate shade suggests characteristics of intermediate species.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100007
Editor: | Brazilian Journal of Plant Physiology
Relação: | 10.1590/S1677-04202009000100007
Formato: | text/html
Fonte: | Brazilian Journal of Plant Physiology  v.21 n.1 2009
Fonte: | info:eu-repo/semantics/openAccess