Interactions between plastic responses to light and water availability in experiments with tree seedlings

ABSTRACT: Phenotypic plasticity, water stress and shade tolerance have been separate targets of numerous studies concerned with plant ecology and distribution. The main objective of the study was to combine these three topics in a single study case. In this study we quantified the plastic phenotypic responses to light, exploring the interactions between light and water availability and determining the influence of phenotypic plasticity on survival. Phenotypic plasticity partially explained the differences among species in survival in sun and deep shade. The interactions between light and water availability found in plant responses showed that phenotypic plasticity involves costs that negatively influenced survival under some specific environmental conditions, pointing to the need for detailed studies of the adaptive value of phenotypic plasticity in response to cooccurring stresses.