Extreme Cases: A Strategy for Ecological Risk Assessment in Ecosystem Health

Abstract

ABSTRACT

I contend that focusing on the “absence of health,” or what I will call “extreme cases,” provides a basis for agreement about ecosystem health in ecosystem management. An extreme case is defined where there exists (1) scientific agreement about models, (2) scientific agreement about scale, (3) policy agreement that the risks will be great and unnecessarily so. Scientific agreement requires that a link be established between biodiversity and ecosystem processes, goods, and services. I discuss recent work concerning ecosystem engineers that demonstrates such a link. Agreement about scale requires consensus about the scale of management decisions, both spatial and temporal, and reconciliation of management goals and objectives of the various stakeholders in an ecosystem. Finally, policy agreement requires that ecological risks be great and unnecessarily so. Where these extreme cases do not apply, I suggest that it will be useful to appeal to stakeholder negotiations to seek agreement concerning ecosystem health.