This Research Improvement in Minority Institutions (RIMI) project will examine the long-term effects of disturbance on tropical rain forest ecosystems, the effects of high irradiance on photosynthesis in tropical tree seedlings, and the systematic studies of endemic tropical organisms. Studies on the patterns of revegetation on landslide areas will continue and plant species diversity will be examined as a function of size, elevation, and microhabitat. The physiological responses of early and late successional tree species will be compared by transplating them into the open landslide center, partially recolonized landslide edges, and into treefall gaps. Nutrients will be added to the various systems to examine the role of nourishment limitations in revegetation. This comprehensive investigation of how disturbance may play a major role in creating and maintaining diversity in rain forests will significantly increase the research capability of a predominantly minority institution. The principal investigators have excellent training and have published in solid refereed journals. Faculty and students working on this project will further strengthen those research skills for improving the institution's tropical biology program.