Abstract: | ABSTRACT: Hierarchical diversity analysis of data on fish and aquatic insects showed that the component of diversity contributed by the species level was generally very small compared with the component at the generic level or with the total diversity. Very high rank correlations between generic diversity, in which genera were discriminated but not identified, and species diversity suggested that the purposes of environmental monitoring might best be served by working at the generic level rather than the species level. This is particularly true when an index of diversity is to be used as the major comparative and communicative tool. The savings of time and money could be appreciable. |