Oribatid mite (Acari: Oribatida) diversity in different forest stands of Borjom-Kharagauli National Park (Georgia)

We studied oribatid mite diversity in two sites of virgin Pleistocene forests in Borjom-Kharagauli National Park in Georgia. The aim was to explore the effects of microhabitat and tree species on the composition and the relative abundance of oribatid mites. Investigations revealed high species richness (96 species in total) with community composition varying according to the microhabitat type. Carabodes tenuis Forsslund, 1953 was registered for the first time for Caucasian fauna. Soil and canopy (twig)-dwelling oribatid communities comprises rather distinctive groups unlike moss and litter. No difference was observed between moss and litter dweller mites. One species, Camisia horrida (Hermann, 1804), was found only in canopy samples, but was very rare. Poroliodes farinosus (C.L. Koch, 1840), Carabodes labyrinthicus (Michael, 1879) and Phauloppia rauschensis (Sellnick, 1908) were found frequently in canopy habitats, with P. rauschensis abundant on tree twigs and almost absent from forest floor. The presence of beech trees (Fagus orientalis Lipsky) was correlated with the number of species per site. The results showed that geographic distance between sites is an important determinant in oribatid community composition and can have stronger effects than a microhabitat type.