Ecological Neighborhoods: Scaling Environmental Patterns

In this paper we review, develop, and differentiate among concepts associated with environmental patterning (patch, division, and heterogeneity), spatial and temporal scales of ecological processes (ecological neighborhoods), and responses of organisms to environmental patterning (relative patch size, relative patch duration, relative patch isolation, and grain response). We generalize the concept of ecological neighborhoods to represent regions of activity or influence during periods of time appropriate to particular ecological processes. Therefore, there is no single ecological neighborhood for any given organism, but rather a number of neighborhoods, each appropriate to different processes. Neighborhood sizes can be estimated by examining the cumulative distribution of activity or influence of an organism as a function of increasingly large spatial units. The spatial and temporal dimensions of neighborhoods provide the scales necessary for assessing environmental patterning relative to particular ecological processes for a given species. Consistent application of the neighborhood concept will assist in the choice of appropriate study units, comparisons among different studies, and comparisons between empirical studies and theoretical postulates.