Diversity of the oribatid mite fauna (Acari, Oribatida) in two dry meadows in Styria (Austria)

Abstract

The oribatid mite fauna of two dry meadows has been studied and compared (Peggauer Wand, Zigöllerkogel). In autumn and summer at both sites, 10 samples were taken, and a total of 19,931 mites were identified, representing 42 families, 57 genera and 85 species. Mean abundance varied from 36,840 individuals m-2 up to 59,990 individuals m 2. The two habitats differed qualitatively in the composition of their oribatid mites. Individuals of Oppiidae were most abundant in all sample units. Very frequent taxa were Quadroppiidae and Suctobelbidae as well as Ceratozetidae. Most species exhibited a clumped distribution. Species richness was higher on Peggauer Wand. Differences in diversity were conspicuous between summer and autumn on Zigöllerkogel, whereas the presence of species on Peggauer Wand was more balanced. The composition of oribatid mite fauna of these two habitats differs remarkably (Sørensen-coefficient 0.55). Concerning their ecological requirements the collected species are classified as follows: 23.5 % xerothermophilous, 21.2 % euryoecious, 23.5 % silvicolous, 10.6 % praticolous, muscicolous, and hygrophilous, 21.2 % ‘unknown’. A comparison with published data of other dry habitats shows that each site harbours its own species community, probably depending on landform configuration, microclimate, and association of plants.