Probability of Occurrence of Soil Disturbances during Timber Harvesting

This paper deals with the probability of occurrence of soil disturbance during timber harvesting operations. Studies were carried out in southern Poland in 26 stands differing in terrain, skidding method, stand age, amount of timber harvested, forest site type, stocking, and soil type. In each stand the occurrence of the following forms of disturbances was measured: soil surface disturbance, soil cover tearing off and soil compaction. Logistic regression models describing the probability of occurrence of respective disturbance forms were constructed. It was found that the probability of occurrence of soil surface disturbance depends on forest site type and stocking. Soil cover tearing off depends mainly on harvesting density, while soil compaction depends both on the harvesting system and on harvesting density