The Community Concept in Community Ecology

We argue that ecologists have conceived of the community concept in at least three ways (typological, functional, and statistical), and that ecologists have used “community,” as indicated by ecological terminology, in two main ways (type and group). The typological conception emphasizes phenomenological descriptions of co-occurring species, the functional conception emphasizes mathematical relationships among co-occurring species, and the statistical conception emphasizes the frequency of species’ co-occurrence. The type usage emphasizes idealized “types,” and the group usage emphasizes quantitative boundaries and/or mathematically precise interactions. We further argue that all of these senses of “community” are problematic. Ecologists seem unable to say precisely what a community is, in part because of the difficulty of (a) measuring community properties, (b) determining the temporal and spatial scale for various communities, and (c) evaluating the different meanings attributed to community terms. We suggest that although (a) and (b) appear to be difficulties that are heuristically useful for future ecological theorizing, (c) does not.