Rozmiar i charakter naruszeń wierzchniej warstwy gleby powstałych podczas pozyskiwania i zrywki drewna w trzebieżach wczesnych drzewostanów świerkowych

The study concerns the impact of two harvesting technologies – one based on a traditional horse skidding and one using a small MultiFKS winch powered by chainsaw motor on the size and nature of damage to the surface soil layer. The study was conducted in a spruce stand where early thinning was carried out. The total share of soil disturbed during harvesting operations was not large accounting for 2.99% of the cutting area for horse skidding and 1.73% for skidding using a MultiFKS winch. The volume of damage to the topsoil was 8.38 m3/ha and 2.64 m3/ha, respectively. The likelihood of disturbances of the soil layer was 47% for horse skidding and 31% for skidding by means of a winch. Both technologies were character−ized by a similar, ca 5% likelihood of cutting of topsoil to a depth larger than 5 cm. For both technologies the likelihood of soil compaction was significantly lower than soil cutting.