Colonization of hardwood and pine wood chips by mites (Acari), with particular reference to oribatid mites (Oribatida)

Abstract

The study was conducted in the years 2011–2012, in a forest nursery in Białe Błota (Bydgoszcz Forest District). The experiment was established in a 20 m wide belt of trees within a 110 years old stand growing on mixed fresh coniferous forest site. Litter bags containing hardwood and pine wood chips were placed on mineral soil of microplots and covered with a 5 cm layer of litter. The pattern of chips colonization differed between mites belonging to different orders. Predatory Mesostigmata colonized hardwood chips gradually but they were present in high numbers in pine chips from the beginning of the study. Abundance of Actinedida fluctuated within the two-year study cycle. Contrary to that, oribatid mites, which were a predominant mite type, colonized both types of chips gradually, while preferring the pine ones. At the end of the study, the structure of mite communities and mite abundance in pine chips were more similar to forest soil than in hardwood chips. The experiment demonstrated that pine chips provided most oribatid mites with more favorable living conditions than hardwood chips, as they were colonized at a quicker rate and by a greater number of species. The most abundant oribatid mite in both substrates was a eurytopic Tectocepheus velatus that showed no clear preferences towards either of the substrates. Majority of oribatid mites, e.g. Oppiella nova, Metabelba pulverulenta, Oribatula tibialis, Chamobates schuetzi, Galumna lanceata, preferred pine chips. The only species with clear preference for hardwood chips was Eniochthonius minutissimus. A comparison of usefulness of hardwood and pine wood chips in revitalization of degraded soils based on bioindication approach indicated higher suitability of pine chips that are also more available in Polish forests.