In this paper, we investigate the microgeographical distribution of ants nests in an
intensively grazed dune pasture. A total of seven species were recorded. By the application of a
forward multiple logistic regression we were able to determine nesting choice for the three common
species Lasius niger, L. psammophilus and Myrmica specioides. The rst could be identi ed as a pioneer species, while the two latter species, which are typical of dry, sandy dune grounds, differ
slightly in their nesting preference. The effect of nest building on soil structure was investigated
for a mound-building species (Formica cunicularia) and for a non-mound-building species (Lasius
psammophilus). Both species signi cantly decrease the thickness of the organic and water-capturing
soil layer, while the mound-building species additionally affects the soil lime content (an increase)
and the soil hardness (a decrease). Mound building in dense Calamagrostis vegetation also stimulates
the germination of a characteristic and rare plant species, Thymus pulegioides