An ecosystem assessment technique for environmental impact statements.

Abstract

The goal, policies, and procedural methods of the National Environmental Policy Act of 1969 (NEPA) may soon be applied to the planning of general environmental policies, land-use zonings, and program statements. Planning on such a broad scale should consider the substantive portion of NEPA and not merely comply with the procedural portions. A matrix framework is developed through the use of three ecosystem assessment worksheets that relate comprehensive characterizations of ecosystems and impacts to the capacity of the ecosystem to resist structural and functional changes following perturbations. This capacity, or homeostasis, has limits which can be used as a criterion for determining the necessary long-term mitigative commitments of energies and resources that may be required by man's activities. The worksheets present a simple impact ranking scheme that can be used as an aid in land-use zoning or comparison of alternatives. They are compatible with the procedures outlined in NEPA. The worksheets can serve as a guide for compliance with the substantive portions of NEPA and can educate decision makers in the concepts of ecosystem homeostasis.