Distribution of species of the genus Stipa in Ukraine according to phytosociological databases

The paper presents the current distribution of species of the genus Stipa in Ukraine based on the data from phytosociological databases. The main objectives were to produce maps of distribution and to determine the affinity of Stipa species to EUNIS habitat classification units. We succeeded in selecting the relevés with the participation of 16 out of 27 species of the genus Stipa recognized as a species in the “Nomenclature checklist of higher vascular plants of Ukraine”. A total of 4888 relevés with the presence of Stipa were found. Stipa capillata has the most significant presence in the data set among other species of the genus. It was found in 38.1 % of relevés. This species occupies second place in the analyzed data set by the Percentage Frequency and third place by Average Non-Zero Cover. According to the analysis of the distribution maps, it was established that S. capillata is a widespread species in the Forest-Steppe and the Steppe zones of Ukraine. Stipa lessingiana also has a significant distribution but is limited mainly to the Steppe zone. Both S. borysthenica and S. tirsa are significantly less present in the databases than reported in the literature, particularly in the Red Book of Ukraine and Green Book of Ukraine. Other species of the genus have limited distribution. Analysis of the habitat affinity of Stipa species showed that they occur in ten types of grassland habitats of the third level of the hierarchy according to the new version of the EUNIS classification. The vast majority of species have an ecological optimum in R1B – Continental dry grassland (true steppe). Stipa capillata has the widest amplitude in different habitat types. Also, a wide range of habitat types is characteristic for S. pulcherrima, S. lessingiana, S. pennata, and S. ucrainica. Species that are poorly represented in the dataset (S. zalesskii, S. transcarpatica, S. adoxa, S. asperella, and S. dasyphylla) occur in a few or only one habitat type. Hence, our study shows that the vast majority of Stipa species in Ukraine are rare and need protection at the national level. However, the presence of S. capillata in the sample was very high. It was found in almost all types of dry grassland habitats, as well as in petrophytic, shrub, and even anthropogenic habitats. This is evidence of the high adaptability of the species and its wide ecological and coenotic amplitude. Our study results confirm the idea that S. capillata does not meet the criteria for inclusion to the national protection lists. It also suggests excluding this species from the Red Book of Ukraine, in case if the national legislation will regulate the protection of biodiversity at the superorganism level