9615341 Nadkarni Long-term ecological processes in tropical cloud forests and their canopy communities are poorly understood relative to many other habitats and ecosystem components. The major objective of the proposed research is to build upon a unique set of data that has been gathered over the past decade at the Monteverde Cloud Forest Reserve in Costa Rica. Proposed work includes testing of two hypotheses concerning the role that canopy components play in forest nutrient cycling and dynamics. They will address processes that allow live and dead canopy components to serve as nutrient capacitors in this forest by efficiently capturing allogenic atmospheric nutrients, retaining them in the canopy, and then transferring them to other ecosystem parts. This research will also support participation in the ongoing long-term multi-site study of litter and stem decomposition. Anticipated results include new information on long-term aspects of tropical cloud forest and canopy ecology, synthesis of more than a decade of descriptive, experimental, and modeling work at the site, and integration with ongoing research, educational, and conservation activities in the Monteverde region.