Phytosociological studies carried out in the forests of Silesian Upland and Głubczyce Plateau during the years 1994-2000 showed a widespread distribution of Impatiens parv!flora. It ranges from coniferous and mixed forests to alder carrs, riverside carrs, oak-hornbeam phytocoenoses, and beechwood associations. The optimal conditions for Impatiens parviflora are those found in Ti/io-Carpinetum typicum. Nevertheless, the highest percentage cover of that species occurred in heavily degenerated communities which were the result of clear-felling and tree planting.

Forest stand decomposition of the Silesian Beskids which is followed by the tree cutting has been observed since the beginning of the 21st century. Changes in forest management due to the introduction of heavy machines for forest work mainly for skidding have been observed in the Silesian Beskids for the last decade. The paper presents results of a three-year investigation of erosion gullies forming in mountain forest after the skidding performed with use of heavy equipment. In the Wilczy Potok catchment comprising an area of above 100 ha 40 gullies were identified. The measurement of the length and depth of gullies showed that the total volume of soil and rock material removed from the catchment area due to erosion accelerated by skidding exceeded 9 000 m3. The year erosion rate for deep gullies was found to be 10%. The presented results show that necessary protective actions and preventive measures should be taken to mitigate the soil degradation processes.