Foreword; Preface; Contributors; Participating Institutions; Acknowledgements; 1. Biodiversity: Our Precious Heritage; 2. Discovering Life in America: Tools and Techniques of Biodiversity Inventory; 3. A Remarkable Array: Species Diversity in the United States; 4. Conservation Status of U.S. Species; 5. State of the States: Geographic Patterns of Diversity, Rarity, and Endemism; 6. The Geography of Imperilment: Targeting Conservation towards Critical Biodiversity Areas; 7. More than the Sum of the Parts: Diversity and Status of Ecological Systems; 8. Leading Threats to U.S. Biodiversity: What's Threatening Imperiled Species; 9. Strategies for Biodiversity Protection; 10. Owning Up to Our Responsibilities: Who Owns Lands Important for Biodiversity?; 11. Safeguarding Our Precious Heritage; Appendix A: Extinct and missing species of the United States; Appendix B: State Diversity, Endemism, and Rarity; Appendix C: Kuchler Potential Natural Vegetation Types; Appendix D: Principal Sources for the Natural Heritage Central Databases; Literature Cited