Flora of the Trans-Siberian railway station within the nizhny Novgorod region
As a result of a floristic survey of three railway stations of the TRANS-Siberian railway within the Nizhniy Novgorod region, the species composition of local floras was revealed and the characteristic features of their structures were established. A comprehensive study was conducted separately for three ecotopes: 1) inter-rail space, 2) railway embankments, and 3) adjacent territories within the exclusion zone. The largest number of species (97) was registered at the Nizhny Novgorod railway station, while the smallest number was noted at the Semenov railway station (45). Analysis of flora structures by life forms shows that monocarpic grasses predominate at 2 out of 3 railway stations: from 49,5% in Nizhny Novgorod to 54,9% in Dzerzhinsk. Within species studied at different sites by geographical origin, European species predominate, the share of which ranges from 45,0% (Dzerzhinsk) to 69,0% (Semenov). A significant number of species belonging to North American and Mediterranean plants, as well as floristic findings of new species for the Nizhny Novgorod region, made by the authors, indicate a fairly high potential of the studied railways for intensive migration of plants along them and the dynamism of the studied flora. It is established that the structure of the studied railway flora complexes differs significantly within the transverse profile. Within the inter-rail space, the most important role in plant communities is played by monocarpic grasses, in particular, annual species of European, North American and Mediterranean origin, as well as in most railway floras of other regions of the world. On the slopes of railway embankments and adjacent territories, grassy polycarpics take the first place in the structure of flora complexes. Drainage ditches are often occupied by hydrophilic communities.