Composition, diversity, and distribution of a Chihuahuan Desert ant community (Mapimi, Mexico)

The Mapimi Chihuahuan Desert ant community was studied,in 11 different vege tation sites grouped as rich shrubs (5 sites), poor shrubs (3), and grassla nds (3). The community was composed of 32 species, with species richness va rying in the range of 11-26 species per site. Species richness showed signi ficant intergroup differences; but neither abundance nor biomass showed int ergroup differences. The most abundant species were Forelius maccooki and F . pruinosus; biomass was dominated by the larger species Pogonomyrmex rugos us and Aphaenogaster corkerelli. Five trophic guilds were recognized, with dominance of omnivores and granivores. Omnivorous biomass was higher in shr ubs than in grasslands, but no differences were observed in granivores. The community was dominated by small and very small ants; and size patterns va ried in function of guilds and vegetation. (C) 2000 Academic Press.