This review and synthesis of the patterns and theories of biodiversity provides a firm scientific basis for the study and management of the Earth's biosphere. Beginning with a practical definition of biodiversity and an overview of diversity patterns on Earth, this book develops a conceptual framework that extends traditional theories of species diversity to explain both the general patterns of diversity and the apparent exceptions to these patterns. The author demonstrates the common features underlying diversity patterns at scales ranging from the polar-equatorial gradients to the margins of temporary ponds, and develops a mechanistic explanation of diversity patterns in different ecosystems. Many of the major concepts in ecology are incorporated into the framework for understanding patterns of diversity on landscapes. Case studies apply the theories and models to savannas, coral reefs, rain forests and other ecosystems. . This book presents ideas that will stimulate and challenge professionals and students in ecology, evolutionary biology, resource management, forestry, geography, and environmental economics.