Preface; Acknowledgements; Introduction: Enrichment of ecosystem theory M. Higashi and T. P Burns; Part I. Perspectives on the network approach to ecosystems: 1. Networks in ecology R. Margalef; 2. Formal agency in ecosystem development R. E. Ulanowicz; 3. Network thermodynamics: a unifying approach to dynamic nonlinear living systems D. C. Mikulecky; 4. Improving predicability in networks: system specification through hierarchy theory T. F. H. Allen and R. V. O'Neill; Part II. Network approaches to problems in ecosystems ecology: 5. Network trophic dynamics: an emerging paradigm in ecosystems ecology M. Higashi, B. C. Patten and T. P. Burns; 6. Positive feedback and ecosystem organisation D. L. De Angelis and W. M. Post; 7. Structure, stability and succession of model competition systems K. Kawasaki, H. Nakajima, N. Shigesada and E. Teramoto; 8. Hierarchal evolution in ecological networks: environs and selection T. P. Burns, B. C. Patten and M. Higashi; 9. Control theory in the study of ecosystems: a summary view B. Hannon and J. Bentsman; 10. Do economics-like principles predict ecosystem behaviour under changing resource constraints? R. Herendeen; Concluding remarks: Network ecology: indirect determination of the life-environment relationship in ecosystems B. C. Patten; Indexes.