The Institute for Tropical Ecosystem Studies (ITES) operates as a unit within the Faculty of Natural Sciences of the Rio Piedras campus of the University of Puerto Rico. Researchers at ITES conduct ecological research relevant to the management of natural ecosystems, establish and maintain long-term experimental and reference studies of tropical ecosystems, apply knowledge gained to develop mechanisms for the restoration of degraded tropical ecosystems, and increas public awareness of the importance of natural ecosystems to human welfare through undergraduate and graduate education.

The ITES staff currently has seven Ph.D. and two post-doctoral scientists. Funding for the research programs at ITES comes from the University of Puerto Rico and competitive grants. The four major projects underway are:

• The Luquillo Experimental Forest (LEF) Long-Term Ecological Research Program (funded by the National Science Foundation since 1988 and with the cooperation of the USDA Forest Service) has the goal of integrating studies of disturbance regime and forest structure and dynamics with a landscape perspective. Two central research questions address 1) the relative importance of different disturbance types within the four tropical rain forest life zones of the LEF and 2) the importance of the biota in restoring ecosystem productivity after disturbance. Twenty-seven scientists from 15 institutions are collaborating on this program.

• The Minority Research Center of Excellence in Tropical Terrestrial Ecology is a joint effort between ITES, the Biology Department, Rio Piedras, and NSF. The goal of this program is the expansion of research opportunities in ecology for minority students. A core research project concerning the control of primary productivity along an elevational gradient was the focus of the first phase of the program from 1988-94. The present phase of the program consists of a series of research projects for student involvement in three areas: primary productivity and ecological processes, variation in natural populations, and tropical forest regeneration after human disturbance. Graduate and undergraduate students are being trained in ecological research through close interactions with 11 faculty members.

• The Tropical Atmospheric Science Center (TASC) program encompasses studiesof chemical exchanges between the tropical ocean, atmosphere, and the land in a multidisciplinary fashion involving ITES, UPR-Rio Piedras, UPR Mayaguez, the USDA Forest Service, and the Arecibo Radio Observatory. This program is funded by the National Aeronautics and Space Administration through its Experimental Program to Stimulate Competitive Research (EPSCoR). Scientists from ITES are measuring changes in cloud over and density before and after hurricane damage and preparing spatially-explicit estimates of soil carbon and nitrogen pools and of dry deposition in complex terrain.

• The NASA Institutional Research Award project is using the land use history of Puerto Rico as a natural laboratory to study environmental consequences of land use change in the tropics.  The purpose of this work is to determine the importance of land history, climate and soils, and biotic forces in a landscape recovering from human use.