Plasticity of physiological adaptations in epiphytes.

The distribution of epiphytes within the tree crown is, in part, a result of physiological adaptations to the heterogeneous microclimate. However, individuals of a species are also catable of plastic adaptations to a given environment. Traits found in plants of given place therefore do not necessarily predispose them to this location. The project will investigate the physiological plasticity of epiphytes (bromeliads, orchids, ferns) in relation to their distribution within the crown. We plan to measure the following parameters: SLA, leaf thickness, stomata density, N, C/N and N isotope ratios, osmotic potential, photosynthesis and photoinhibition.