EN
Skidding includes timber transport from the place of its harvest to the place of its storage, loading or pre−treatment. This process in the thinned stands can result in serious damage to the remaining trees. The purpose of the described research was to characterize and compare the size and location of damage in the thinned stands after forwarder skidding with the damages resulting from the combined forwarder and tractor ground skidding. These tests also aimed at determining whether the contractor’s experience affects the level of damage. The research was carried out on four study plots located in the Chojnów Forest District (C Poland). Although the works on each plot were performed by different contractor, they had equipment of comparable technical and overall parameters.The height of the damage, the distance of the damaged tree from the skidding trail and the size of the damage were measured. Damage was classified according to the degree of the tissue damage. The most serious damage occurs at a distance of up to 1 m from the skidding trail and at a height of up to 1 m. The most severe damage was over ⅛ of the trunk perimeter. No significant dependence of the size and location of damages on the skidding method was found.The highest fraction of the damaged trees was recorded on the area in the Młochów Forest Range (5.17%) where only the forwarder skidding took place. In the Sierzechów Forest Range (the same method of skidding, but almost twice as dense stand), there was significantly less damage (0.62%). In this case, the share of the damaged trees was the smallest, despite the highest number of trees. The reason for this may be the impact of the human factor on the amount of damage as the most experienced contractor worked on that study plot.