Structured population models: a tool for linking individual and population levels in ecology

We address the problem of relating information on the effects of a particular stress on individuals to possible effects at the population level. Structured population models aim to predict population dynamics from a careful specification of the dynamics of individuals; however, in spite of major mathematical advances, there are only a few cases where such models have made significant contributions to ecological understanding. This paper reports progress to date on a project in which we construct both individual and population models of Daphnia. We present a model of individual growth and development which has been tested against results from several laboratories on D. pulex. We propose a simple, stage-structured population model and give a preliminary report of some of its properties.