A semantic taxonomy for diversity measures

Community diversity has been studied extensively in relation to its effects on ecosystem functioning. Testing the consequences of diversity on ecosystem processes will require measures to be available based on a rigorous conceptualization of their very meaning. In the last decades, literally dozens of measures of diversity have been proposed. However, rather than using unrelated metrics, we need to identify their separate components so that possible links between them and ecosystem functioning can be examined using an agreed-upon language. In this paper, first, a short overview on new and old measures of community diversity is presented. Next, I propose a general framework in which most of the existing measures of diversity are sorted into four interrelated semantic classes: richness, abundance-weighted diversity, evenness and divergence. In this view, this paper constitutes an attempt to organize the very large number of existing diversity measures avoiding ambiguities in the meaning of the different facets of community diversity.