Testing trade-offs and the dominance-impoverishment rule among ant communities

Aim: Ant communities are believed to be structured by competition, with dominant species competitively excluding subordinates (the dominance-impoverishment rule). However, a high number of seemingly similar species coexist, possibly due to interspecific trade-offs. Here, we examine the evidence for the dominance-impoverishment rule across a broad latitudinal gradient and explore whether trade-offs explain coexistence within and among ant communities.

Location: 40 sites in 19 countries across Europe, western North America and northern South America.

Taxon: Formicidae.

Methods: We conducted 2-h baiting experiments at each site. Three dominance scores were calculated for each species at each site where it occurred. We then examined the relationship between ant dominance and diversity and tested for the generality of three trade-offs (dominance-discovery, dominance-thermal tolerance and dominance-generalism) within and among ant communities along with the possible effects of enviro...