Given the problems of the environment in relation to the ever-growing civi lization activities of man, it is not surprising that in recent years more and more related data have been collected, phenomena have been observed and concerns have been expressed. The ecological systems of man's environment react to the impact of these civilization activities. In fact, quite often these reactions occur as shocks and surprises. Acid rain and the related forest die backs are but one example. Ecological systems consist of many compo nents and their dynamics is thus complex. The study of complexity is the...