Flora of the Biloozerskyi National Nature Park (Kyiv and Cherkasy Oblasts, Ukraine): annotated checklist, analysis and regional features

The Biloozerskyi National Nature Park is a significant protected area in the Left-Bank Forest-Steppe of Ukraine and includes forest, wetland, and aquatic ecosystems. The flora of this park was shaped by the combined influence of natural components of the northern mixed (oak-pine) forest and forest-steppe zones, which makes it unique compared to other nature protected areas in the region. The study revealed the presence of 851 species and subspecies of vascular plants on this territory, of which 684 are native and 167 are alien. For the first time, alien plant species Rubus balticus has been included in the list of the flora of Ukraine. The most representative families are Asteraceae, Poaceae, Cyperaceae, Rosaceae, Caryophyllaceae and Lamiaceae. The most species-rich genera are Carex, Veronica, Trifolium and Pilosella. Geographic analysis of the flora indicates the dominance of widespread species (48.6 %) among native plants, as well as European (17.8 %) and Euro-Mediterranean (13.4 %) zonal elements. In contrast, the alien fraction is mainly represented by species of Mediterranean (46.7 %) and American (23.4 %) origin. The biomorphological structure of the native flora is characterized by a predominance of perennials (65.2 %), whereas the alien fraction includes a larger proportion of annuals, biennials and short-lived (60.5 %). Meadow-steppe, forest, and wetland plant communities play a crucial role in shaping the floristic composition of the park. The highest species richness is observed in pine forests, meadow steppes, and in riparian ecosystems. The flora of the park has significant conservation value, as 107 rare and endangered species have been identified, 25 of which are listed in the Red Data Book of Ukraine. At the same time, 35 invasive species have been recorded, such as Acer negundo, Asclepias syriaca, Solidago canadensis and Robinia pseudoacacia, which pose a threat to natural plant communities.