Communities of oribatids (Acari: Oribatida) in the agrocenoses in the vicinity of Dubliany (Male Polissia)

Abstract

We investigated the taxonomic composition and structural specifics of the oribatids population in main agrocenoses’ types of Male Polissya. The studied communities are compared to the natural oribatid complexes based on literary data. In agrocoenoses, 14 oribatids species are found which belong to 10 families. Studied coenotic communities consist from 2 to 6 species of oribatid mites. There are 1 to 4 oribatid species per sample. The index of β diversity of oribatids in investigated agrocenoses is 5 times higher than in natural biotopes in the zone of deciduous forests. Comparative analysis of intra-coenotic H’ index of diversity shows that the largest contrast of intra-coenotic conditions for Oribatida was found in wheat agrocoenoses, the medium one in potato, corn, and soy coenoses, the smallest in rapeseed coenosis. Index of average oribatids population density in investigated agrocenoses varies in 30 times range of values. In investigated agrocoenoses genera of Oppidae, Mycobatidae, and Oribatulidae prevailed by species richness, each family is summarily presented by 2‒3 species. Analysis of H’ index for investigated oribatid groups shows that the smallest average diversity was noted in soya and rapeseed agrocoenoses, the largest in wheat coenosis. For 10 oribatid species, the potential to dominate is revealed in different types of investigated agrocenoses of Male Polissya. In some biotopes can be two to five dominating oribatid species. Six morpho-ecological types of oribatids are revealed. Structure of morpho-ecological (adaptive) oribatid types in agrocenoses is strongly different from that of the natural ecosystems of Ukraine. Agroecosystems are characterized by decreased diversity of the adaptive types of oribatids and the domination of non-specialized forms. We recognise three biotopical groups of oribatid mites in studied material: forest-meadow, meadow, and eurytopic species. The structure of ecological groups of oribatids is therefore reduced to three biotopical groups with the advantage of eurytopical representatives. Also in all types of agrocenoses eurybionic species group makes up 46‒87% of total quantity. As for hydropreferendum characteristics, only 2 to 3 ecogroups of oribatids found per coenosis.