The role of habitat selection in landscape ecology

Abstract

Landscape ecology - whether it is defined as the fragmentation of habitats into insular or weakly coupled subpopulations or by the interaction of scale-dependent processes among ecological communities (or species, or populations) - involves forms of spatial analysis. Habitat selection analyses how organisms become distributed in response to spatial heterogeneity. Thus, processes associated with habitat selection should be central to landscape ecology. Insofar as the individuallevel activity of habitat selection has predictable population and community level consequences, habitat selection can form a mechanistic basis for understanding landscape ecology. A survey of any major ecological journal reveals considerable confusion and disagreement on the roles of spatially-dependent processes in the evolution, structure and function of natural systems. Part of the confusion is due, no doubt, to the complexity of spatial interactions. Processes responsible for spatial patterns may themselves be dependent upon spatial, temporal and even organizational scales. Some processes such as density-dependence (dependence on population size) operate across a spectrum of spatial and temporal scales. Assumptions of density-dependence are central to our views of natural selection, to our understanding of population dynamics and community structure and to our management of natural resources. Once again, habitat selection provides a natural forum for considering this central role of density-dependent and scale-interdependent processes. Within the conceptual framework of habitat selection, we feel it is possible to develop a set of inter-related theories that explain observed patterns of distribution and abundance at several ecological scales. (A similar claim can be made for a central role of habitat selection in evolutionary processes; see Evolutionary Ecology, 1987, Vol. 1, No. 4).