info:eu-repo/semantics/article
Plant water relations of selected species in wet and dry tropical lowland forests in Costa Rica
Plant water relations of selected species in wet and dry tropical lowland forests in Costa Rica
Autor
Oberbauer, Steven F.
Institución
Resumen
The water relations of early and late-successional plant species of pre-montane wet forest and lowland dry forest in Costa Rica were compared during the dry season. Early-successional species had higher stomatal conductances (g) than late-successional species at both sites. The same pattern did not hold for plant water potentials (ψ). A wide array of daily patterns of ψ and g was found among species of the same successional status. Midday stomatal closure was found in more than half of the wet forest species and nearly all of the dry forest species examined. Despite the absence of substantial rainfall for several months, all species in the dry forest with expanding leaves at the time of sampling had predawn ψ values that were above -1.0 MPa, indicating available sources of soil water. Durante la época seca en Costa Rica (febrero-abril), se midió relaciones hídricas en varias etapas sucesionales de bosques húmedo y seco. En ambos, la conducción estomática es mayor en el bosque secundario que en las etapas posteriores. El potencial hídrico (ψ) es variable en cada estadio. En casi todas las especies del bosque seco, y en más de la mitad de las del bosque húmedo, los estomas se cierran cerca del medio día. En todas las especies con hojas nuevas en el bosque seco, el potencial hídrico superó el -1.0 MPa antes de la madrugada, a pesar de varios meses de poca lluvia. Ello indica la existencia de agua en el suelo.