Gene banks, captive breeding centres, zoos and botanical gardens can play a very valuable role if their activities are integrated in the framework of co-ordinated re-introduction or integrated conservation schemes.
Biodiversity, or biological diversity, refers to the variety of life and its processes. It includes the variety of living organisms, the genetic differences among them, the communities and ecosystems in which they occur, and the ecological and evolutionary processes that keep them functioning, changing and adapting.
The concept of biodiversity carries an imperative to consider the complexity of ecosystems and to proceed with caution in the face of our lack of knowledge. Strategies to protect or restore biodiversity must be premised on the interdependence among species, communities, habitats and natural cycles and undertaken from a holistic perspective, recognizing the limits of humankind's ability to manage complex ecological interrelationships and acknowledging the close links between biological and cultural diversity.
The priority in establishing the Pan-European Ecological Network is to take actions that conserve the existing biodiversity of European importance, thereby preventing further degradation. However, it will also be desirable to improve the conservation effect of the network by restoring natural values in the core areas, corridors and buffer zones that will be included in the network where these have become degraded. This will have a particular priority where habitat fragmentation has seriously disrupted the functioning of ecosystems or has substantially reduced the opportunities for species populations of European importance to survive. Restoration will also be important in areas that have a high potential natural value but which have been physically disrupted or polluted. Many European countries have experience of restoring degraded habitats and expertise in this area is gradually being built up, particularly with regard to rivers, wetlands and forests.