Pairwise versus presence-absence approaches for analysing biodiversity patterns

Abstract

It has been proposed that the study of co-occurrence of species, which is traditionally performed using full presence–absence matrices of sets of many species, could benefit from simply testing for random co-occurrence between pairs of species, and that use of a full presence–absence matrix is tantamount to regarding it as having some real ecological identity. Here I argue that although there are valid questions that can be answered using a pairwise approach, there are many others that naturally require the analysis of entire sets of species in a joint way, as provided for through the use of full presence–absence matrices. Moreover, there are theoretical and mathematical advantages to the use of presence–absence matrices, a few of which are briefly discussed in this short note.