1. Introduction: Recent Trends in Science.- 1.1. How Did It start?.- 1.2. Physics versus Ecology.

- 1.3. Ecology and Physics.- 1.4. Recent Trends in Science.- 1.5.

The Ecosystem as Object of Research.- 2. Do We Need a New, Holistic Ecology?.- 2.1. Two Ecologies.- 2.2.

Complexity of Ecosystems.- 2.3. Ecology and Quantum Theory.- 2.4. Holism versus Reductionism.- 3.

Models in Ecology.- 3.1. Modelling in Ecology.- 3.2. Modelling Elements.- 3.

3. The Modelling Procedure.- 3.4. Types of Models.- 3.5. Complexity of Models.

- 3.6. Modelling Constraints.- 3.7. Application of Models as Scientific, Experimental Tools.- 4. Energy and Ecology.

- 4.1. Conservation of Energy and Matter.- 4.2. Energy Flows in Ecosystems.- 4.3.

The Maximum Power Principle.- 4.4. Embodied Energy/Emergy.- 5. Entropy and Ecology.- 5.1.

The Second Law of Thermodynamics Applied to Ecosystems.- 5.2. Information and Entropy.- 5.3. Ecosystems Generate Entropy.- 5.

4. Ecosystems are Non-isolated Systems.- 5.5. Energy Sources and Sinks establish Order.- 5.6. Self-organization.

- 5.7. The Maximum Entropy or Maximum Energy Dissipation Theory.- 6. Exergy and Ecology.- 6.1. The Application of Exergy in Ecological Thermodynamics.

- 6.2. Exergy and Information.- 6.3. Application of Exergy in Ecosystem Theory.- 6.4.

Exergy and Modelling.- 6.5. The Fourth or Ecological Law of Thermodynamics.- 7. Network and Hierarchical Concepts of Ecosystems.- 7.1.

Networks in Ecology.- 7.2. Network Concepts.- 7.3. Hierarchical Theory of Ecosystems.- 7.

4. Network Thermodynamics.- 8. Utility Theory, Indirect Effect and Ascendency.- 8.1. Toward a Wider Application of Network Theory.- 8.

2. Energy Transfer and Utilization Coefficients in Networks.- 8.3. The Indirect Effects in Networks.- 8.4. Ascendency.

- 9. Catastrophe Theory and Ecology.- 9.1.What Is Applied Catastrophe Theory?.- 9.2. Application of Catastrophe Theory to Explain Shifts in Oxygen Concentration as Function of Time in a Stream.

- 9.3. Application of Catastrophe Theory on a Lake Ecosystem.- 9.4. General Application of Catastrophe Theory in Ecology.- 9.5.

Ecosystems and Catastrophe Theory.- 10. Chaos, Fractals and Ecology.- 10.1. Introduction and Definitions.- 10.2.

Bifurcation and Fractal Dimension.- 10.3. Ecological Implications.- 10.4. Parameter Estimations and Chaos.- 11.

Dynamic of Ecosystems.- 11.1. Ecosystem Properties.- 11.2. Modelling Structural Dynamics.- 11.

3. Constraints on Ecological Parameters.- 11.4. Application of Exergy as Goal Function in Ecological Modelling.- 11.5. Structural Dynamic Models of Ecosystems.

- 11.6. Structural Dynamic Models in Population Dynamics.- 12. A Tentative Pattern of Ecosystem Theories.- 12.1. Presentation of a Pattern.

- 12.2. A Central Law of Ecosystem Theories.- 12.3. The Relation to Other Theories.- 12.4.

Tools: Networks and Models.- 12.5. Ecosystem Properties.- 12.6. The Application of ELT in Specific Cases.- 13.

Epilogue.- 14. Appendix 1. Definitions of Concepts.- 15. References.