Flora of the botanical-geographical plot "Steppes of Ukraine" in the M.M. Gryshko National Botanical Garden of the NAS of Ukraine

In 2020–2022, the complete taxonomic composition of the flora for the botanical-geographical plot “Steppes of Ukraine” at the M.M. Gryshko National Botanical Garden of the NAS of Ukraine (NBG) was studied and analyzed. This plot was established at the NBG in 1949 to demonstrate the floristic diversity of the Ukrainian Steppes ex situ. According to the inventory results, 347 species and infraspecific taxa from 196 genera and 53 families of higher vascular plants were recorded in the flora of the plot. The steppic component of this plot joins 213 species and infraspecific taxa (61.38 % of the total number of inventoried taxa) belonging to the collection fund and representing the flora of the Steppes of Ukraine, 126 species and infraspecific taxa (36.31 %) of which are introduced plants and 87 species and infraspecific taxa (25.07 %) are native plants. During the inventory, spontaneously growing plants that are not a part of the collection fund were precisely studied. Among inventoried plants, native non-steppic plants are represented by 46 species and infraspecific taxa (13.26 %); alien plants – by 88 taxa (25.36 %), including ergasiophygophytes (45 taxa, 12.97 %) and xenophytes (43 taxa, 12.39 %). The plants of the collection fund predominate on the plot and form the main vegetation cover. Currently, the taxonomic composition of the plot is similar to the characteristics of regional meadow-steppes. The perennials dominate in the biomorphological structure of the plot’s flora (63.69 %), which is typical for the steppic phytocoenoses. In general, a significant number of trees is present here (5.48 %), which is explained by the forest communities surrounding the plot and, as a result, their active self-sowing. Hemicryptophytes prevail in the plot’s flora (60.52 %). Nevertheless, the collection fund of the plot is distinguished by the absence of trees, a greater number of perennials (79.34 %), and hemicryptophytes (72.77 %). The steppic (33.33 %) and marginal (33.33 %) plants prevail in the collection fund, while the amount of meadow plants (18.78 %) is still significant. In the plot “Steppes of Ukraine”, most of the rare introduced plants formed stable homeostatic introduction coenopopulations. Among them, 15 species and rare infraspecific taxa are listed in the Red Book of Ukraine