Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

The aim of this study was to analyse the frequency and extent of mechanical damage of tree stems in mountain spruce stands of varying forest cover index and ground slope, without taking into account the technology used in obtaining wood. The study was conducted in 17 spruce stands located in the Sudetes and the Carpathians. In the stands the 1 ha test surfaces were established. The damage on trees with dbh ≥ 18 cm was measured. As a result of the analysis it was found that the most damaged trees grew in the stand with forest cover ratio of 0.7 and 1.0, while taking into account the decline of the area most damage was found in the stands with a slope of 16 to 25°. The study, however, showed no clear relationship between the position of necrosis on tree stems (its size and height) and forest cover and a decrease of the area.