Eutrophication is the enrichment of the environment with nitrogen and phosphorus, mostly by burning fossil fuels and using fertilizers in agriculture. This leads to the biotic homogenization of phytocenoses, which are more homogeneous and thus lead to the loss of biodiversity in time and space. The aim of this work was to find out how fertilization together with other managements (canopy reduction and raking) affects the species composition, species richness and species eveness of oak forests of the Fageto-Quercetum unit. We performed phytosociological records on areas of 100 m2 on 5 experimental plots, which were composed of 8 areas of 400 m2 with different types of management (canopy reduction, raking, fertilization). Changes in the species composition of the undergrowth were analyzed using Juice 7.0, Microsoft Excel ® and CANOCO 5. We found out that the plots managed only by fertilization did not show a statistically significant change in species richness, species composition and species eveness. The plots that were managed by fertilization, together with the canopy reduction and raking, significantly increased the species richness, but H´ Shannon index of diverzity and Pielou index of eveness did not increase significantly. The canopy reduction together with the effect of time had the most positive effect on the species richness. Oligotrophic grass species such as Luzula luzuloides, Calamagrostis arundinacea and mesotrophic grasses such as Melica uniflora were the most abundant in control plots. Species that were stable and did not change their coverage and constancy regardless of the type of management were Dentaria bulbifera, Symphytum tuberosum and seedlings of Oak, Beech, Maple, Cherry and Fir. The species that significantly increased the constancy and coverage on the managed areas were predominantly nitrophytes such as Impatiens parviflora, Alliaria petiolata, Urtica dioica, Geranium robertianum, Taraxacum sp., Moehringia trinervia, Galium aparine, for which were fertilization with other management suitable. However, oak species such as Astragalus glycyphyllos, Clinopodium vulgare, Primula veris, Veronica chamaedrys have also spread on the managed areas. Mesotrophic grasses such as Poa nemoralis and Carex muricata also spread on the managed areas.