ABSTRACT
Ecosystem health is related to the system’s capability to maintain some degree of biophysical integrity while supplying humans with valuable services (Rapport, 1995). Thus, the functional relationship between the diversity of organisms and the set of ecological services on which humanity depends must be addressed (Perrings et al., 1995). Signs of dysfunction, either structural or functional, associated with particular stresses can be identified by suitable indicators in the biophysical domain of ecosystems themselves. In the Mediterranean regions, where ecosystems have been shaped by the millennial historic and evolved interactions between man and nature, many forms of human disturbance are recognized to be important sustaining components of natural systems (Pickett and White, 1985); consequently in the Mediterranean, but not only there, we have often to deal with the question of defining both the extent to which ecosystem services start to be impaired by either natural or anthropogenic perturbation, and the extent up to which the services themselves are unimpaired, or even sustained, by human disturbances.
