Indicators of Ecosystem Response and Recovery

To facilitate effective protection of environmental systems subjected to anthropogenic activities, there must be basic understanding of three areas: how the variety of biological components of ecosystems are exposed to stress; how the ecosystems respond to that disturbance; and how they recover or adapt. Given a solid understanding of ecosystem exposure-response-recovery relationships and their uncertainties, we might reasonably balance risks to ecological systems with risks and benefits to other systems of human concern, such as economic or societal systems. While the approach to the problem seems straightforward, the simple fact is that we presently lack sufficient ecological understanding in all three areas for most environmental stresses. With limited ability to make reliable stress-response predictions, we are greatly constrained in making appropriate environmental decisions. Consequently, instances of unexpected, adverse effects on the environment from a particular human activity continue to intermingle with instances of expensive over-protection from other activities. In principle, ecological risk assessment would minimize these problems.