The Institute of Ecology (TIE) was organized to provide a mech anism for addressing ecological and environmental issues that were beyond the special interests of ecology as a profession. One method of evaluating such issues is the workshop, and this report describes the results of the third TIE workshop on a major environmental subject. The ecology of tropical regions is of interest to all the inhabitants of the biosphere. The tropics provide mankind with both the opportunity for and the challenge of essential resources, land for settlement and development, and waters for numerous uses. Moreover, they provide examples of misuse of the landscape, fragility of ecological systems, and serious environmental problems. Unfortunately, the study of the ecology of the tropics has not kept pace with the ecology of other regions. The purpose of this report, therefore, is to determine the research approaches that will lead to advances in our theoretical un derstanding of tropical systems and, more importantly, in the applica tion of that knowledge to human problems. Although the principal focus of the report is on the neotropics, it will be useful to the full spectrum of persons concerned with the tropics around the world government officials, sCientists, students of ecology, and others. TIE is especially pleased to thank the numerous scientists and ad ministrators who participated in the workshop and who contributed to this report. Arthur D.

Set includes revised editions of some issues.

Forestry professors used to remind students that, whereas physicians bury their mistakes, foresters die before theirs are noticed. But good institutions live longer than the scientists who contribute to building them, and the half-century of work of the USDA Forest Service's Institute of Tropical Forestry (ITF) is in plain view: an unprecedented corpus of accomplishments that would instill pride in any organization. There is scarcely anyone interested in current issues of tropical forestry who would not benefit from a refresher course in ITF's findings: its early collaboration with farmers to establish plantations, its successes in what we now call social forestry, its continuous improvement of nursery practices, its screening trials of native species, its development of wood-processing technologies appropriate for developing countries, its thorough analysis of tropical forest function, and its holistic approach toward conservation of endangered species. Fortunately, ITF has a long history of information exchange through teaching; like many others, I got my own start in tropical forest ecology fromjust such a course in Puerto Rico. And long before politicians recognized the global importance of tropical forestry, the ITF staff served actively as ambassadors of the discipline, visiting tropical coun tries everywhere to learn and, when invited to do so, to help solve local problems. It is a general principle of biogeography that species' turnover rates on islands are higher than those on continents. Inevitably, the same is true of scientists assigned to work on islands.