TESTING THE SPECIES TRAITS–ENVIRONMENT RELATIONSHIPS: THE FOURTH‐CORNER PROBLEM REVISITED

Functional ecology aims at determining the relationships between species traits and environmental variables in order to better understand biological processes in ecosystems. From a methodological point of view, this biological objective calls for a method linking three data matrix tables: a table L with abundance or presence–absence values for species at a series of sites, a table R with variables describing the environmental conditions of the sites, and a table Q containing traits (e.g., morphological or behavioral attributes) of the species. Ten years ago, the fourth‐corner method was proposed to measure and test the relationships between species traits and environmental variables using tables R , L , and Q…