Revision with unchanged content. Tropical rain forests contain most of the world’s known biological diversity. Understanding how this diversity persists in the face of anthropogenic disturbance is an increasingly critical issue. To manage and preserve intact ecosystems, and to restore degraded ones, a better knowledge of the basic ecological processes that affect them is necessary. We must be able to answer such questions as: How are plant communities structured? How is diversity maintained in species-rich ecosystems? What ecological factors determine which plants grow where? Many processes are known to shape plant communities, but what is their relative importance? Approaching answers to these questions is the primary focus of this book. The book presents a case study, built upon experiments performed in a Peruvian rain forest. The author conducted a series of manipulative experiments on tree seedlings to dissect the various forces that shape their coexistence. This book is directed to an audience of ecologists, forest researchers, and conservationists.