• habitat specialization;
  • interactions;
  • local diversity;
  • regional diversity;
  • species richness;
  • stochastic equilibrium


The species saturation hypothesis in ground-dwelling ant communities was tested, the relationship between local and regional species richness was studied and the possible processes involved in this relationship were evaluated in the present paper. To describe the relationship between local and regional species richness, the ground-dwelling ant fauna of 10 forest remnants was sampled, using 10 1 m2 quadrats in each remnant. The ants were extracted from the litter by using Winkler sacs. Using regression analyses, an asymptotic pattern between local and regional species richness was detected. This saturated pattern may be related to three processes: (i) high interspecific competition; (ii) habitat species specialization; or (iii) stochastic equilibrium. It is concluded that non-interactive processes, such as stochastic equilibrium and habitat specialization may act as factors regulating species richness in this community. The predominance of locally restricted species, in all sampled remnants, seems to indicate the occurrence of a high degree of habitat specialization by the ant species. This result is evidence for the hypothesis that community saturation has been generated by non-interactive processes. Although ants are frequently described as highly interactive, it is possible that interspecific competition is not important in the structuring of ground-dwelling ant communities.