An Integrative Approach to the Study of Plant-Animal Interactions1

I am tempted to give one more instance showing how plants and animals, remote in the scale of nature, are bound together by a web of complex relations. (Darwin, 1859) Ecologists have been studying the inter-actions between plants and animals for as long as there have been ecologists. Charles Darwin studied the complex web of inter-actions even before he wrote his revolu-tionary book On the Origin of Species. In-deed, even his grandfather, Erasmus Dar-win, was keenly aware of these interactions; he earned a small fortune for the family by writing poetry about the love lives of plants, accomplished through their relation-ships with animals (Gould, 1977). The study of plant-animal interactions has played a key role in the development of ecological theory. I give two examples here. Hairston et al. (1960) began with a particular view of the relationship between plants and their herbivores. This work in-spired a generation of theory and empirical work on the structure of ecological com-munities, which helped define ideas of ‘‘top-down’ ’ and ‘‘bottom-up’ ’ effects. The concept of coevolution was first developed to describe the results of the relationship between particular plant species and the herbivorous insects that feed on them (Er-lich and Raven, 1964). It has since been widely applied to describe the evolutionary results of a wide variety of ecological re-lationships between two or more biological entities (Futuyma and Slatkin, 1983). However, the study of plant-animal in-teractions has only recently begun to define itself as a distinct subdiscipline. I searche