Forest Service scientists published an Ecological Bulletins book that contains a comprehensive analysis of ecological gradients in the Luquillo Mountains of Puerto Rico. Puerto Rico comprises six ecological life zones and is ideal for studying environmental gradients given dramatic differences in temperature and precipitation that are associated with a rise in elevation from sea level to more than 1,093 yards over a distance of 6.21 to 9.32 miles. Chapters in this volume cover climatic (precipitation and energy), abiotic (nutrients, carbon stores soil characteristics and biogeochemistry), and biotic (microbes, plants, and animal biodiversity) patterns and responses to gradients. These original and synthetic research findings should be of considerable interest to all concerned with understanding the importance of environmental gradients in molding the structure and functioning of ecological systems and to those dedicated to managing or conserving complex tropical ecosystems in light of global change. A Forest Service scientist at the International Institute of Tropical Forestry in Puerto Rico is a lead editor of this recently published book.