Flora of the Student Square of Cheboksary of Chuvash Republic

Student Square was opened on September 1, 2007 at the intersection of the busy Moscow Avenue and K. Ivanov Street. The total area is 2,5 hectares. The predominant tree species are Tilia cordata Mill., Betula pendula Roth and Acer platanoides L. In 2016, the first inventory of the square flora was carried out, 94 plant species from 79 genera and 37 families were identified. Pinopsida are represented by 4 cultivated introducents. Only 6 species from the Poaceae are monocotyledons. The systematic diversity of the flora is very low. Virtually every genus is represented by only one species. The average level of species wealth in one family is 2,54. The number of families with one species is 21 (56,8%). The top ten in the number of species families are concentrated by 63,8% of the species. The spectrum of the leading families of the flora of the Student Square indicates its thermophilic appearance. The share of synanthropic species in the flora as a whole is 53,2%. The index of synanthropization (Is) of the square flora is 1,14 and emphasizes the anthropogenic nature of the landscape. The aboriginal fraction of the flora is strongly altered (Is = 0,48). In the ecologo-cenotic spectrum, there is a preponderance towards plants of open habitat types, among which weed species predominate (34%), among which 4 are malignant invasive species: Acer negundo L., Conyza canadensis (L.) Cronq., Lepidotheca suaveolens (Pursh) Nutt., Xanthoxalis stricta (L.) Small. On the second place is a group of meadow plants (16%). The distribution of other coenotic groups in general is consistent with the regional spectrum of the flora of Chuvashia. The hygromorph spectrum is dominated by mesophytes (71,3%), followed by xeromesophytes (16%), the share of the remaining groups varies from 1,1 to 6,4%. The trofomorph spectrum is dominated by mesotrofs (62,8%) and megatrofs (36,2%). Aliens fraction is 30,9% of the square flora. 17 species (58,6%) are cultivated introducents, and the rest – weed plants. Kenophytes (75,9%) predominate, ergasiophytes and ergasiofigophytes (24,1% each), epekophytes and agrio-epekophytes (65,5%), North American (31%) and Iranian-Turanian (20,7%) species.