Invasive Plant Species of Recreational Zones of Kharkiv (Ukraine) ^†

The formation of synanthropic flora of any territory occurs in two ways-due to the penetration of anthropophytes (anthropophytization, adventization) and the transition of native plant species from natural phytocenoses to anthropogenic ecotopes (apophytization). The article highlights the results of the study of synanthropic flora and vegetation of recreational zones of Kharkiv (abandoned parks, recreational areas, green areas) for 2018–2020. The classification of synanthropic vegetation was performed on the basis of processing geobotanical descriptions in programs Turboveg 2.91 and Juice 7.0.127. Ecological amplitudes of syntaxons were determined by ecological scales of Ya.P. Didukh. The study of invasive plant species was carried out according to the classification of D. Richardson et al. As part of the synanthropic vegetation of recreational zones of Kharkiv, we have found 15 invasive plant species. Most of them, according to the degree of invasive potential, belong to the group with high invasive capacity (11). Among them there are dominate species of the family Asteraceae (8), therophytes (8), mesophytes (14), species of North American origin (13), kenophytes (15), xenophytes (6) and ergasiophytes (5), epecophytes (7). Woody phytocenoses of the class Robinietea are sensitive to soil acidity and carbonate content in soil, thermal and cryo-climate. In their composition we have found 8 invasive species. In plant communities of herbaceous annual vegetation of classes Bidentetea and Galio-Urticetea, which are adapted to the variability of damping and nitrification of the edaphotope, 9 invasive plant species grow. Ruderal phytocenoses of classes Artemisietea vulgaris and Stellarietea mediae are formed with the participation of 10 invasive plant species. These communities are sensitive to the variability of damping, soil acidity, total salt regime, nitrogen content in soil, thermal climate, humidity, as well as to the continentality of climate.