This undergraduate thesis was done, with the help of Slovenia Forest Service. It analyses the influence of past forest management and natural disturbances on the changes of the tree species composition in the north, northeast and south side of the Plešivška kopa forests. Through field work carried out on 179 sample plots, which were located in four regeneration centers, eight gaps (created by sanitation cutting), four stands in regeneration and three matured forests; and with the help of seedling and regeneration census, we studied tree species, composition, density and the quality of different tree species. On the northern side the beech is the dominant species in seedling in regeneration sycamore. Sycamore is the dominant species in regeneration on the north-eastern side of the study area and spruce on the southern side. The highest density are in seedling and regeneration on N and NE. Spruce trees are of the best quality, European ash and beech trees the worst. Sycamore, wych elm, European ash and common whitebeam are heavily damaged by ungulate. Based on results we have predicted the future structure of these forests, whilst also setting the guidelines for their future management. The synthesis of collected data and results show that humans, natural disturbances and ungulates all have strong impact on the vegetation development of Plešivška kopa forests.