EN
The studies of vegetation were carried out in the years 2010–2013. One of the study objectives was to update the assessment of the natural value of psammophilous grasslands 20 years after the establishment of Kózki nature reserve (mazowieckie voivodship). The phytosociological survey results were compared with the archive survey results available in the nature reserve’s documentation. There were noted some significant changes in the species composition of plant communities. The assessment of natural values of psammophilous grasslands confirmed the occurrence a simplified form of the Corynephoro-Silenetum tataricae association – priority habitats for protection, the presence of 6 dry grassland indicator species, one endangered species (Carex praecox) and one plant species (Helichrysum arenarium) under legal protection was determined.