Invasive species of the flora of transformed sections of railway tracks in the bottom of the Dnister–Tiligul river

In order to study invasive species as dangerous elements of foreign flora, modern monitoring studies are needed under the conditions of various ecotopes of a wide range of their transformation. According to the «Strategy of biosecurity and biological protection», alien species are a threat to biodiversity at its various levels. Taking into account that railway tracks are one of the main ways of penetration and initial establishment of synanthropic species in new territories, in 2018–2021, the flora of the tracks in the areas of the Dniester floodplain was studied. 34 invasive species from 14 families were noted, they included Asteraceae (26.47% of species), Brassicaceae and Poaceae (17.65% each), Amaranthaceae (8.82%) and others. The majority of species (55.88%) grows both on track sections and (in addition) next to ruderalized sections of overburden. Another 11 species (32.35%) can be found on tracks, ruderalized areas of overburden and on the roadsides of the nearby highway. Only two species (5.88%) are cultivated. Two more species such as Amaranthus powellii S.Watson, Oxybaphus nyctagineus (Michx.) Sweet are noted only on railway tracks and sections of railway infrastructure. According to the life form, nine species (26.47%) are hemicryptophytes. 23 ones are therophytes (67.65%). Two species are fanerophytes (5.88%). According to the chronotype, 41.18% of the species are aschaeophytes. Kenophytes make 58.82%. Among archaeophytes, most plant species have a frequency of occurrence — «scattered» and «abundant» (35.71% each). Among the kenophyres, there are the most species whose plants were «scattered» (40.00%). In general, the majority of invasive species, by frequency of occurrence, belong to the «scattered» (38.25%) and «abundant» (23.53%) categories. Also there are «single» (17.65%), «usually» (11.77%), «single locality» (8.82%). Most species (70.60%) are represented by wide ranges: cosmopolitan (and hemi-cosmopolitan) make 44.12%, Eurasian form 14.71%, Euro-American make 11.77%. Eight species (23.53%) are particularly dangerous for the environment, as they are transformers of local growth. Most of the plants of invasive species of railway tracks were also found on adjacent ruderalized areas. Therophytes, kenophytes and species with a wide range prevail. They are found, mostly «scattered» and «abundant». Eight species (23.53%) are the most dangerous for environment, because they transform ground place (Ambrosia artemisiifolia, Centaurea diffusa, Conyza canadensis, Grindelia squarrosa, Iva xanthiifolia, Elaeagnus angustifolia, Anisantha tectorum, Setaria glauca).