Population Dynamic Models in Heterogeneous Environments

The title of this review implies certain biases which I would like to confront at the outset, suggesting in the process the alternative title Population Dynamics and Heterogeneous Environments. Although the principal focus is on models, the emphasis is on their role in the understanding of ecological questions and not on their intrinsic mathematical beauty. Further, it would prejudice the inquiry to regard environmental heterogeneity as a property of an independent background against which the ecological drama unfolds; in many situations, biological interac­ tions initiate or exaggerate heterogeneity. The scope is necessarily limited. Because of the simultaneous construction of closely related reviews in this volume, it is difficult to avoid overlap with the other entries; indeed, some degree of overlap may be desirable in order to facilitate transitions between articles. However, I avoid detailed discussion of the response of the individual or the population to patchy environments; these topics are covered in the reviews by Wiens (1 68) and Giesel (40). Similarly, models of the dynamics of the genetics of populations in heterogeneous environments are not discussed here; there is a vast literature on this topic (3, 1 2, 1 6, 26, 33-36, 38, 47-49, 5 1 , 55, 65, 66, 70, 7I, 79, 92, 94, 95, 97a, 1 02a, 139, 1 42, 1 44), sufficient certainly for a separate review. Finally, the mathematical details are kept to a minimum; for those details which are omitted, the reader is referred to (82), which is the mathematical comple­ ment to this review. In a few places, the considerations are so congruent that I have seen fit to borrow sections verbatim from (82).