The Use of Wood Chips for Revitalization of Degraded Forest Soil on Young Scots Pine Plantation

The aim of the study was to assess the impact of several methods of mulching degraded forest soil with wood chips on the development of mite (Acari) community, with particular emphasis to oribatid mites (Oribatida), and on the growth of young plantings of Scots pine (Pinus sylvestris L.). Mulching with wood chips should contribute to revitalize soil fauna and restore natural forests on degraded soils. Scots pine seedlings were planted at the post-military training ground. Four experimental treatments were tested: control—uncovered soil (C), mulching with wood chips (W), W + mycorrhiza preparation (WM), and W + forest litter (WL). At the end of the growing season in 2012, 2013 and 2014, the following plant measurements were carried out: length of annual increment of the main stem, stem base diameter, number and lengths of lateral shoots in the annual whorl. The mite calculations included average mite density, dominance index, species richness, oribatid mite diversity, average number of species, and Shannon general species diversity index. The use of mulching with wood chips did not significantly affect the growth characteristics of Scots pine plants, but strongly increased the mite community. After mulching, the total number and species diversity of Acari increased many times, and Oribatida began to dominate among micro-arthropods. The number of Oribatida increased most in W. The largest species diversity was observed in WL. 24 species of Oribatida were found that were used as the bio-indicators of soil succession changes. Tectocepheus velatus clearly dominated in all mulching treatments. Oppiella nova and Scutovertex sculptus were also numerous populations of Oribatida. The study shows that mulching with Scots pine wood chips, especially with the addition of forest litter, significantly enriches soil fauna and is therefore useful in the regeneration process of degenerated forest soils.