Prefaces. 1. Introduction: Recent Trends in Science. 2. Do We Need a New, Holistic Ecology? 3. Models in Ecology. 4. Energy and Ecology. 5. Entropy and Ecology. 6. Exergy and Ecology. 7. Network and Hierarchical Concepts of Ecosystems. 8. Utility Theory, Indirect Effect and Ascendency. 9. Catasrophe Theory and Ecology. 10. Chaos, Fractals and Ecology. 11. Ecosystem Health. 12. Development of Ecosystems. 13. Dynamic of Ecosystems. 14. Goal Functions. 15. A Tentative Pattern of Ecosystem Theories. 16. Epilogue. 17. Appendix 1: Definitions of Concepts. 18. References. 19. Index.