Introduction

This chapter expands the discussion of the analysis of spatial structure to include the dimension of time, and the spatial dynamics of ecological processes and the resulting patterns. The intimate relationship between spatial structure and temporal change in ecological systems was eloquently described by Watt (1947) in his famous discourse on pattern and process in plant communities. His theme was that a plant community could be viewed as a working mechanism with dynamic behaviour of development, degradation and regeneration. In many plant communities, the various phases of the dynamic process coexist, and have an identifiable spatial relationship to each other (Figure 6.1). In communities of animals, the relationship between spatial locations and dynamic processes are even more obvious, as animals move through the spatial structure of their habitat to find resources or mates and to avoid predation. At the level of populations, we need to recognize that a population of a given density is not homogeneously distributed, and that the dynamics of different subpopulations' densities may be very different depending on location. At the level of the individual organism and its immediate environment, we need to realize that an individual is usually affected by very local, rather than global, conditions, and that these may change significantly over relatively small distances and over relatively small time periods. In considering almost any system, our concepts of spatial structure and its importance will include implicitly, if not explicitly, a temporal component.