TOWARD AN ECOLOGICAL APPROACH FOR THE ASSESSMENT OF ECOSYSTEM HEALTH

Many ecologists express difficulty with the concept of ecosystem healt h. Ecosystem health must have definable and objective norms that allow for rigorous hypothesis testing for it to be acceptable to those ecol ogists. One step toward objective measurement of ecosystem health is t o characterize ecosystem health by diversity-abundance relationships. The log-normal relationship between diversity and abundance characteri zes taxocenes (i.e., taxonomically related groups that have similar ec ological functions). Under conditions of stress, the patterns of diver sity and abundance often change and are no longer log-normal. This cha nge in patterns has been shown for some, but not all, marine and terre strial taxocenes tested. The interdisciplinary possibilities for using log-normality, and deviation from it, as a measure of natural and ant hropogenic ecosystem health are discussed. The interdisciplinarity of ecosystem health is illustrated with an example of blueberry pollinato r decline caused by insecticide spraying in New Brunswick, Canada, and related economic and human health costs.