EN
180 vascular plant taxa are found in the Las Mariański forest reserve, including 21 protected and endangered species. In the last 40 years, the total number of species has increased, including the number of anthropophytes. Spontaneous forest succession has taken place on previously open terrain, resulting in a slight increase in the share of species typical for the class Querco-Fagetea and a 9% decrease in the share of thermophilic species typical of the classes Festuco-Brometea, Trifolio-Geranietea and Koelerio-Corynephoretea. There was an increase in the cover coefficients for the tree layer (Acer pseudoplatanus and A. platanoides) in patches of Tilio-Carpinetum. There are fluctuations in the cover of Carpinus betulus, Tilia cordata, Fraxinus excelsior, Ulmus glabra and U. minor. Species that once formed the understory, such as Acer campestre and Fagus sylvatica, now appear in the higher layers. Comparison of present-day phytosociological relevés with those collected in the 1960s and 1990s did not reveal any significant directional changes in the oak-hornbeam woodland vegetation. Symptoms of degeneration were recorded in all of the forest communities in the reserve. For example, the cover of shrubs on the forest floor as increased. Foreign species are spreading throughout the biochore are of the oak-hornbeam woodland, which constitutes a serious threat to the flora of the nature reserve.