PLANT PHYSIOLOGICAL ECOLOGY OF TROPICAL FOREST CANOPIES

Mechanistic information about tropical canopy function is emerging at the leaf, tree, stand and landscape levels. With improved canopy acces s, comprehensive data are accumulating about seasonal and spatial vari ation in light, temperature and humidity, and corresponding variation in leaf carbon gain and water loss. At the whole-plant level, simultan eous measurements at different spatial scales have revealed the role o f boundary layer dynamics in regulating transpiration. Emergent proper ties of canopy function are being explored through models that integra te leaf and landscape-level exchange processes. Integration of exchang e processes that include functional diversity at different scales has the potential to validate regional estimates of gas exchange, which ar e critical to our understanding of the role of tropical forests in glo bal atmospheric carbon balance.