Summary:

The analysis of gatherings for soil mites (Acari) - with special emphasis of oribatid mites (Oribatida) - on post-arable land and forest land in 5-year cul-tivations and 8-year young forest stands of Scots pine and silver birch in Bory Tucholskie forests has been presented in the paper. Soil samples for acarological research were taken in the years 2006 and 2009 - in three seasons for every year: springtime (in mid-May), in summer (the beginning of August) and in autumn (in mid-October). Cultivations on the ferested post-arable land were characterized by lower density of mites than on the restored forest land. The all stands in the young forest stage were characterized by increased abundance of these arthropods. Oribatid mites were the most numerous group: their share in gatherings on post-arable land ranged from 63 to 81%, and on forest land their share was slightly higher - 79-87%. Overall, 39 species of oribatid mites were found on the study area - 25 occurred on post-arable land and 29 on forest land. Species diversity of these mites in cultivation and in the forest soil of young forest stand was considerably higher than that on post-arable land. Aforestation of post-arable land with biocenotic species (which is silver birch) did not bring the expected effect of increased biodiversity in the initial stage of succession. The most numerous oribatid mites on the studied area - depending on the variant - were: Tectocepheus velatus, Oppiella nova and Pergalumna nervosa.