The goal of this Integrative Graduate Education and Research Training (IGERT) program is to train Ph.D. students to apply an interdisciplinary and collaborative approach to environmental problems in urbanizing, tropical landscapes. Puerto Rico has a dynamic environmental history, suffering nearly complete deforestation, then enjoying forest recovery, and then experiencing urban sprawl as the economy modernized. This last shift produced environmental problems, overlaid by changes in climate and vulnerability to catastrophic storms. Set against these environmental problems are researchers from different disciplines at the University of Puerto Rico-RÃo Piedras (UPR-RP), all of whom study these problems, and who will improve communication among themselves and with researchers at other UPR campuses to achieve effective research and solutions. The IGERT program will bring these faculty and students together in an interdisciplinary and collaborative framework. Reflecting the strong interaction between natural and human systems, both research theme and training in the IGERT program will be based on an iterative model of human-environment interactions, addressing the question of how human activity alters ecosystems, and, in turn, how do altered ecosystem services change human activity in an urbanizing tropical environment. Dissertations will focus on these interactions and thus will have both natural and social science components. Students will be co-advised by faculty in natural and social sciences and other disciplines. A new, integrative core for the program is also aimed at the interactions between human and natural systems, and will include the development of six new courses. IGERT is an NSF-wide program intended to meet the challenges of educating U.S. Ph.D. scientists and engineers with the interdisciplinary background, deep knowledge in a chosen discipline, and the technical, professional, and personal skills needed for the career demands of the future. The program is intended to catalyze a cultural change in graduate education by establishing innovative new models for graduate education and training in a fertile environment for collaborative research that transcends traditional disciplinary boundaries.