Abstract

In summary, many extant definitions of the niche concept are based on the geometric metaphor which represents the niche as an object embedded in a geometric space. There are several difficulties with this approach; the activities of organisms are not fully described, certain attributes of the functional aspect of the niche are not represented, the life cycles of organisms are not described, and the heuristic value of the concept diminishes with increasing dimensionality.An alternative and complementary approach to the niche is the linguistic metaphor. This approach is based on the explanatory objective to explain the assembly of the ecosystems of successional seres from species pools and abiotic environmental factors. The linguistic metaphor suggests that a theory of ecosystem assembly is a generative grammar that associates particular species with environmental features. The niche of a particular species is defined in terms of the rules of a generative-transformational grammar used to derive an hierarchically organized description of that species. This approach also has conceptual difficulties: (1) empirically testing competence theories and distinguishing possible and impossible objects (e.g. species and ecosystems) are difficult, (2) evolutionary processes are difficult to incorporate, (3) the mathematical tools associated with grammars do not have the range of applicability of the mathematical tools associated with the geometric metaphor, and (4) the productions (hierarchical trees) of a grammar are not easily visualized.The geometric and linguistic metaphors of the niche should be viewed as complementary pictures of the same object. The geometric representation is most adept at describing community dynamics and stability, niche overlap, and organism response to abiotic environments. The linguistic metaphor represents well organism activities, niche dynamics, and ecosystem assembly