Ecosystem Health

Abstract

More and more environmental managers want to include ecological considerations in their management strategy. They have therefore asked the following question of ecologists and system ecologists: how can we express and measure that an ecosystem is ecologically sound? The doctor of medicine attempts to express the health condition of patients by the use of indicators such as blood pressure, temperature, kidney function, etc. The environmental manager is equally searching for ecological indicators that can assess ecosystem health. As an ecosystem is a very complex system, it is not surprising that it is not an easy task to find good ecological indicators to give the appropriate information, although many ecologists and system ecologists have been and are working with this problem. Rapport (1995) even uses the phrases ‘to take nature’s pulse’, ‘the problem of detecting diseases in nature’ and ‘clinical ecology’ to stress the parallelism with human pathology. Von Bertalanffy (1952) characterized the evolution of complex systems in terms of four major attributes:

• 1. Progressive integration (entails the development of integrative linkages between different species of biota and between biota, habitat and climate);

• 2. Progressive differentiation (progressive specialization as systems evolve biotic diversity to take advantage of abilities to partition resources more finely, etc.);

• 3. Progressive mechanization (covers the growing number of feedbacks and regulation mechanisms);

• 4. Progressive centralization (this probably does not refer to centralization in the political meaning, because ecosystems are characterized by short and fast feedbacks and decentralized control, but to the more developed co-operation among organisms (the Gaia effect) and the growing adaptation to all other components in the ecosystem).