Contents. 1. People and nature in conflict. PART I: Conceps of ecology. 2. Ecosystems: the flow of energy and materials. 3. Ecosystems and environmental change. 4. Population: growth and regulation. 5. The earth's major ecosystems. PART II: Environmenatl quality and management. 6. The water cycle. 7. Water pollution. 8. Managing our aquatic resources. 9. Weather and climate. 10. Air pollution. 11. Air quality management. 12. The earth's crustal resources. 13. Waste management. 14. Managing endangered species. 15. Land use management. PART III: Fundamental problems: population, food, and energy. 16. Human population: growth and ocntrol. 17. Food resources and hunger. 18. Assessing the energy crisis. 19. Averting the energy crisis. 20. Where do we go from here?