Addressing the remarkable growth in concern at all levels for living things and the environment, this text also looks at increased appreciation of the links between the state of ecosystems and the state of humankind. Building on research and analysis by the conservation community worldwide, this book provides a comprehensive view of key global issues in biodiversity. It outlines some of the broad ecological relationships between humans and the rest of the material world and summarizes information on the health of the planet. Opening with an outline of some fundamental aspects of material cycles and energy flow in the biosphere, the book goes on to discuss the expansion of this diversity through geological time and the pattern of its distribution over the surface of the Earth, and trends in the condition of the main ecosystem types and the species integral to them.