On the operative use of community overlap in analyzing incidence data

Abstract

Although overlap of communities is a key issue in studies ranging from community ecology to biogeography, a clear definition of community overlap and related terms hinder the development of the field. The absence of a unified terminology is remarkable even when the overlap of a pair or multiple communities is characterized. As a remedy, I suggest a definition of community overlap and two measures of it (number of overlapping species and total overlap size). Although both measures quantify different aspects of community overlap, in studying pairs of communities they yield identical results. The present findings demonstrate the need for a unified terminology in research on community overlap as well as for pairwise and multiple measures for quantifying the phenomenon.