Damage to residual trees and regeneration during felling and timber extraction in mixed and pure beech stands

Abstract

This paper presents an analysis of damage to residual trees and the regeneration that occurs during harvesting using the half tree length method and timber extraction in winter operating conditions in a pure beech stand and a mixed stand of beech fir and spruce in the territory of the Srpska Republic. In this study, types of damage were investigated, as well as the size of wounds. Felling and processing of wood assortments were performed with a chainsaw and timber extraction on earth and by skid trail to a roadside landing on a truck road was performed with a tractor Timberjack 240C. The number of injuries that occurred during the felling and transport of trees in the mixed stand was on average 2.69 wounds per felled tree, whereas in the pure stand the average number of wounds per felled tree was 2.27. During the felling of trees in both sample plots, the largest number of injuries was to the crowns of neighbouring trees, which was followed by damage to the butt end, whereas the lowest number of injuries was incurred to the root collar. During the timber winching, the most common damage was to the root collar, whereas during timber skidding the most common type of damage was to the butt end. Damage to the regeneration was evident in both sample plots in the form of breakages of plants and their branches, as well as uprooting of whole plants. Damage to the butt end and root collar that occurred at the felling stage was in the form of bark peeling and other superficial wounds whose most common sizes were larger than 200 cm(2). The average area of injuries caused during the transport phase ranged from 50 to 200 cm(2).