Rozmiar uszkodzeń drzew pozostających podczas nasiębiernej zrywki w drzewostanie sosnowym przy wykorzystaniu posztucznej metody szacowania

The purpose of the research was to present problems related to the damage to the stand resulting from the scraping works performed on its surface, mainly with the use of forwarder skidding. The research was conducted in thinned Scots pine stands in the IV and V age class in the Wipsowo Forest District (northern Poland). In the selected stands we carried out the inventory of the stand layers. Based on the obtained data, the level of damage to trees after thinning operations was calculated. Damage resulting from the skidding with forwarder in the individual manipulation plots was at a level of 18.2−18.7% in the method used by the Wipsowo Forest District, while in the method proposed by the author damage level equaled 3.9−9.8%. It was found out that the highest number of damage occurred in the belt up to 5 m from the skidding trail, especially at the width of the trails below 4 m. The damage is most affected by the stand density – the higher it is, the more trees are damaged.