Oribatid mite (Acari: Oribatida) communities reveal the negative impact of the red oak (Quercus rubra L.) on soil fauna in Polish commercial forests

Abstract

The red oak (Quercus rubra L.) is a woody plant brought to Europe from North America for its decorative value and high tolerance to frost and pollution. The species has been planted for the reclamation of brownfield sites, and introduced to commercial forests to enrich local biodiversity. Although in Poland its presence was associated with depauperation of local flora, its invasive status is still under discussion. The aim of this study was to determine the impact of red oak stands on Acari communities (Oribatida, Mesostigmata, Astigmata, Prostigmata). In the detailed analyses we focused on the Oribatida species, one of the best bioindicators of soil condition. The presence of the red oak was compared to the pedunculate (native) oak, also planted on poor acid soils. The research design included oak stands introduced in commercial forests, divided into two groups: young and old. A total number of 240 soil samples were collected, and 173 species of oribatid mites were identified. A low proportion of the Oribatida species typical for the Palearctic region, specific to deciduous forests, with sexual reproduction and belonging to the trophic level of secondary decomposers, significantly distinguished the old alien oaks from old native oaks. The results presented in this work are one of the few which concern the reaction of soil oribatid mite community to plant invasions, and provide evidence of the harmful impact of these alien tree species, which can be overlooked in short-term studies.