Design and evaluation of laboratory ecological system studies are considered in relation to problems and objectives in environmental toxicology. Ecological systems are defined to be organismic systems together with their level-specific, co-extensive environmental systems and to occur at individual, population, and multispecies levels of biological organization. So that the basis for judgments on the relevance and adequacy of laboratory ecological system studies for solution of problems in environmental toxicology will be clear, a conceptual framework defining with abstract generalizations the nature of biological systems is presented and employed. And a graphical calculus is used to deduce isocline systems and dynamic as well as steady-state behaviors of multispecies systems, so as to illustrate the importance of empirical evaluation of the capacities, not simply the performances, of laboratory ecological systems. Within the context of apparent toxicological problems and this conceptual framework, the relevance and adequacy of laboratory ecological system studies on toxicant effects and behaviors are evaluated.

Prepared by Department of Fisheries and Wildlife, Oak Creek Laboratory of Biology, Oregon State University, under grant no. R802286. Issued Dec. 1977. Includes bibliographical references (pages 112-115).