Habitat and Niche Analysis of Grassland Ants (Hymenoptera: Formicidae)
40 grasslands and 8 niche [Ni] dimensions are studied for habitat and Ni analysis of grassland inhabiting ants of the Hungarian Great Plain. On the basis of the bimodality of histograms for the Nr of species against the Nr of occupied habitats, and the positive correlation between distribution and density, 2 species groups can be distinguished among typical grassland ants. These correspond to Hanski's core and satellite groups. In satellite species, there is a negative correlation between habitat breadth and intracommunity Ni components. Both values are high in core species. Density is positively correlated with multidimensional Ni breadth. The most intensive post-competitive Ni segregation is established in activity and vertical microhabitat dimensions. Interspecific competition is significant in the organization of grassland ant communities.