Mite (Acari) occurrence in selected substrates used for a restoration of degraded soils

The number and groups of mites (Acari) and species composition of oribatid mites (Oribatida) were analysed in three different substrates used for the restoration of degraded soils: (1) pine forest litter, (2) apple orchard litter, and (3) pine chips. The study was conducted in the years 2011-2012, on microplots of the area of 1m2 , established in a belt of trees of a nursery in Białe Błota (Bydgoszcz Forest District). Average biannual mite density per 50 cm3 of the investigated substrates ranged from 14.6 to 54.43 individuals. The highest numbers of mites were found in shredded forest litter and the lowest in pine chips. The most abundant mites in the studied material were oribatid mites, accounting for 57.3 % of these arthropods. The highest number of oribatid mites was found in the forest litter (28), and the lowest (20) in pine chips. The number of species in both types of litter was similar in the first and second year of the study, but it rose three times in the pine chips substrate over the study period. Oribatid species in the litter substrates were dominated by the eurytopic Tectocepheus velatus, and the most abundant species in the pine chips substrate was Oribatula tibialis. The experiment indicated a possibility of practical use of the shredded litter in the reintroduction of soil mesofauna and soil regeneration. This may facilitate the soil inoculation process, e.g., by using seeders specially adapted for this purpose. Additionally, a quick colonization of wood chips by acarofauna may suggest the possibility of using them as an excellent substrate for soil regeneration.