Nato and Science.- I. Basic Ecological Principles.- 1. Factors Controlling the Stability and Breakdown of Ecosystems.- Discussion, Paper 1.- 2. Critical Areas for Maintaining Viable Populations of Species.- Discussion, Paper 2.- Study Group, Paper 2.- 3. Models and the Formulation and Testing of Hypotheses in Grazing Land Ecosystem Management.- 4. General Principles for Ecosystem Definition and Modelling.- Discussion, Papers 3 and 4.- 5. A Systems Approach to the Role of Nutrients in Controlling Rehabilitation of Terrestrial Ecosystems.- Discussion, Paper 5.- II: The Degradation of Land and Freshwater Ecosystems in Temperate Lands.- Opening Remarks by Session Chairman: An Approach to Ecosystem Degradation.- E. Sukopp.- 6. Prehistoric Man's Impact on Environments in North West Europe.- Discussion, Paper 6.- 7. The Degradation of Icelandic Ecosystems.- Discussion, Paper 7.- 8. The Degradation of Biogeocenoses in the Mediterranean Region.- Discussion, Paper 8.- 9. The Degradation of Ecosystems in the Rhine.- Discussion, Paper 9.- 10. The Role of Fire in the Degradation of Ecosystems.- Discussion, Paper 10.- III: The Restoration of Degraded Ecosystems.- Opening Remarks by Session Chairman.- A: The Restoration of the Soil.- 11. The Restoration of Soil Productivity.- Discussion, Paper 11.- 12. Soil Conservation in Iceland.- Discussion, Paper 12.- B: The Restoration of Vegetation and the Conservation of Plant Diversity.- 13. Erosion, Tree Growth, and Land Regeneration in Iceland.- Discussion, Paper 13.- 14. The Restoration of Vegetation on Derelict Land Produced by Industrial Activity.- Discussion, Paper 14.- 15. Forestry in the Federal Republic of Germany, with Particular Reference to the Rehabilita¬tion of Forest Ecosystems.- Discussion, Paper 15.- 16. Plant Genetic Resource Conservation and Ecosystem Rehabilitation.- Discussion, Paper 16.- C: The Role of Predators in Terrestrial Ecosystems.- 17. The Role of Predators in Ecosystem Management.- Discussion, Paper 17.- D: The Restoration and Management of Freshwater Ecosystems.- 18. The Restoration of Freshwater Ecosystems in in Sweden.- Discussion, Paper 18.- 19. Some Ecological Implications of Freshwater Systems Restoration.- Discussion, Paper 19.- 20. Freshwater Fauna and Fish-Stocking Programmes in Iceland.- Discussion, Paper 20.- 21. The Rational Management of Hydrological Systems.- Discussion, Paper 21.- E: Patterns of Land Use.- 22. The Balance between Agriculture, Forestry, Urbanisation, and Conservation: Optimal Pattern of Land Use.- Discussion, Paper 22.- 23. Ecological Principles for Physical Planning.- Discussion, Paper 23.- 24. The Application of Ecological Knowledge to Land Use Planning.- IV: Final Discussion.- V. Conclusions.- List of Participants.

This volume contains the papers presented at a conference on "The rehabilitation of severely damaged land and freshwater eco­ systems in temperate zones", held at Reykjavik, Iceland, from 4th to 11th July, 1976. The meeting was held under the auspices of the Ecosciences Panel of the N.A.T.O. Science Committee, and the organising expenses and greater part of the expenses of the speakers and chairmen were provided by N.A.T.O. The scientific programme was planned by M. W. Holdgate and M. J. Woodman, in consultation with numerous colleagues, and especially with the Administrative Director of the Conference in Iceland, Dr. Sturla Fridriksson. Iceland proved a particularly suitable location for such a Conference. Geologically, it is one of the youngest countries 1n the world, owing its origin to the up-welling of volcanic rock along the spreading zone of the mid-Atlantic ridge within the past 20 million years. Its structure, northern oceanic situation, recent glaciation and continuing volcanic activity make it distinct as a habitat and have given it a flora and fauna of especial interest. It is also a land of great natural beauty with its ice caps, waterfalls, volcanic landforms, geothermal features and dramatic coasts. In addition, its ecosystems have proved except­ ionally vulnerable to man's impact and it presents the kind of problem with which the Conference was concerned in an acute form.