Mathematical Methods for Comparing Structures of Ecological Communities: A Survey for Ecotoxicologists

Abstract

Analyses of experimental data in ecotoxicology often involve making comparisons between or among the structures of different ecological communities. Not surprisingly, many methods have been developed for defining and comparing community structure: species richness, diversity indices, similarity indices, biotic indices. Most were developed for use in detecting environmental stress in aquatic ecosystems, but many perform equally well for terrestrial communities. This brief review examines the most frequently used and/or useful of these methods in order to explore differing approaches to the problems of quantifying community structure and comparing one community with another. The species richness method, S, is discussed. Diversity indices surveyed include: Shannon's H', Simpson's D, Brillouin's H, McIntosh's M, Cairns' Sequential Comparison Index, SCI, Hurlbert's “encounter” Index, PIE, and, Keefe and Bergersen's TU. Five similarity indices are reviewed: Jaccard's Index, Percentage Similarity Index, PSC, Bray-Curtis Index, Euclidean (or “ecological”) distance, and, Pinkham and Pearson's Index, B. Biotic indices covered are Beck's Biotic Index, Chandler's Biotic Score (CBS), Chutter's Index, and the Index of Biotic Integrity.