3 Results

3.1 Ant species richness

In total, 12 ant species were collected in the four habitats over all 90 sampling plots (see Fig. 2a and Table S3). The species Formica rufa (one single individual worker ant found on one sampling plot in new grasslands) was excluded from the analysis as a likely stray individual. Lasius niger was the only species which occurred in all four habitats. Three ant species were exclusively found in old grasslands: Lasius fuliginosus, Lasius alienus agg. andServiformica cunicularia .
The highest cumulated ant species richness was found in old grasslands (eight ant species, see Fig. 2b) and new grasslands (seven ant species). Species richness did not significantly differ between these two grassland habitats (see Table S4). While habitats in cereal crops (CN: three species; and CF: two species) showed significantly lower ant species richness compared to both grassland habitats (p < 0.05 for all comparisons) and did not significantly differ between each other (p = 0.264). Species loss/nestedness (βSNEr) accounted for 45.83 % of the observed dissimilarity (βSOR) in species composition across the four habitats (see Fig. 2c and Table S5).