QUANTIFYING THE TRENDS EXPECTED IN DEVELOPING ECOSYSTEMS

In this paper we describe an assessment of ecosystem health that is bo th comprehensive in that it is based on a series of common trends asso ciated with the process of ecological succession, and operational in t hat the indices capable of quantifying these trends can be easily calc ulated given appropriate simulation model output or estimates of mater ial exchange. We developed a simulation model which generated output c haracteristic of an ecosystem advancing through the various stages of succession to test the ability of a suite of systems-level information indices to quantify these trends. Our regression analyses suggest tha t these indices may be able to capture the trends associated with ecol ogical succession, hence the reversal of many of these trends characte ristic of ecosystem response to anthropogenic stress. We further argue that indice performance could be enhanced with the use of more dynami c modelling techniques. In addition, we introduce a methodology for th e valuation of non-marketed ecosystem components which could be easily included with our assessment of ecosystem health. We conclude that th is measure of ecosystem health in combination with the valuation techn ique may provide an informative compliment to many past and future reg ional modelling projects aimed at better understanding and managing th e impacts of anthropogenic stress on our regional ecosystems. (C) 1998 Elsevier Science B.V. All rights reserved.