Data/hora: 02/06/2024 17:53:22

Provedor de dados: | Brazilian Journal of Plant Physiology
País: | Brazil
Título: | Seasonal leaf gas exchange and water potential in a woody cerrado species community
Autores: | Prado,Carlos Henrique Britto de Assis; Wenhui,Zhang; Cardoza Rojas,Manuel Humberto; Souza,Gustavo Maia.
Data: | 2004-04-01
Ano: | 2004
Palavras-chave: | Cerrado; Deciduousness; Network connectance; Stomatal conductance; Photosynthesis.
Resumo: | Predawn leaf water potential (psipd) and morning values of leaf gas exchange, as net photosynthesis (A), stomatal conductance (gs), transpiration (E), and morning leaf water potential (psimn) were determined seasonally in 22 woody cerrado species growing under natural conditions. Despite the lower mean values of psipd in the dry season (-0.35 ± 0.23 MPa) compared to the wet season (-0.08 ± 0.03 MPa), the lowest psipd in the dry season (-0.90 ± 0.00 MPa) still showed a good nocturnal leaf water status recovery for all species studied through out the year. Mean gs values dropped 78 % in the dry season, when the vapor pressure of the air was 80% greater than in the wet season. This reduction in gs led to an average reduction of 33% in both A and E, enabling the maintainance of water use efficiency (WUE) during the dry season. Network connectance analysis detected a change in the relationship between leaf gas exchange and psimn in the dry season, mainly between gs-E and E-WUE. A slight global connectance value increase (7.25 %) suggested there was no severe water stress during the dry season. Multivariate analysis showed no link between seasonal response and species deciduousness, suggesting similar behavior in remaining leaves for most of the studied species concerning leaf gas exchange and psimn under natural drought.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100002
Editor: | Brazilian Journal of Plant Physiology
Relação: | 10.1590/S1677-04202004000100002
Formato: | text/html
Fonte: | Brazilian Journal of Plant Physiology  v.16 n.1 2004
Fonte: | info:eu-repo/semantics/openAccess