Toward an Ecological Approach for the Assessment of Ecosystem Health

ABSTRACT

Many ecologists express difficulty with the concept of ecosystem health. Ecosystem health must have definable and objective norms that allow for rigorous hypothesis testing for it to be acceptable to those ecologists. One step toward objective measurement of ecosystem health is to characterize ecosystem health by diversity–abundance relationships. The log-normal relationship between diversity and abundance characterizes taxocenes (i.e., taxonomically related groups that have similar ecological functions). Under conditions of stress, the patterns of diversity and abundance often change and are no longer log-normal. This change in patterns has been shown for some, but not all, marine and terrestrial taxocenes tested. The interdisciplinary possibilities for using log-normality, and deviation from it, as a measure of natural and anthropogenic ecosystem health are discussed. The interdisciplinarity of ecosystem health is illustrated with an example of blueberry pollinator decline caused by insecticide spraying in New Brunswick, Canada, and related economic and human health costs.