The Quality of Alder Raw Material from Stands Growing in Different Habitats

A study was carried out to determine the quality of alder raw material growing in different forest habitat types. The research work was conducted in the Włoszczowa Forest District in Poland. Measurements were taken in eight stands growing on three types of forest site: alder moist forest, alder-ash moist forest, and moist forest. In the selected stands, 4-are sample plots were established. In each circular sample plot, the DBH and height of all trees were measured. In the selected trees, the quality of the wood and the type of defects that influenced the result of wood classification were determined in the trunk butt end (on a length of 4 meters). In every other plot, a core was taken from a height of 1.3 m in a randomly selected tree to determine the presence of latent defects. The black alder tested on each site attained very good technical quality. The dominant volume share was that of veneer wood, the largest amount of which was identified in moist forest. Very small amounts of wood of lower quality classes were found. It was found that in less humid habitats than typical alder forests, black alder produces better-quality wood. However, when the borings were taken into account, the proportion of each quality class changed dramatically. Hard rot and soft rot caused wood from the best quality classes to be degraded to lower classes. The percentage of the best-quality wood fell from 60% to 7.57%, while that of the worst-quality wood increased from 5.94% to 40.57%.