The new associations of anthropogenic vegetation of the classes Sisymbrietea Gutte et Hilbig 1975 and Digitario sanguinalis–Eragrostietea minoris Mucina, Lososová et Šilc in Mucina et al. 2016 in the Republic of Bashkortostan

Abstract

Being one of the most characteristic types of plant communities found within settlements, the synanthropic communities of the Republic of Bashkortostan (RB) have been studied since the end of the XX century (Ishbirdin et al., 1988; Ishbirdinа, Anischenko, 1989; Sachapov et al., 1990; Anischenko, 1995; Ryabova, 1996, etc.). At the beginning of the XXI century geobotanical research was actively continued, while significant attention was paid to phytocenoses located within the towns and villages of the republic (Govorov, 2004; Edrenkina, 2005; Yamalov et al., 2008; Yamalov, Suyundukova, 2008; Usmanova et al., 2013, 2014). Urban vegetation is most fully presented in the series of publications on the classification of vegetation of towns of the Southern industrial zone (Golovanov, Abramova, 2012, 2013; Golovanov et al., 2017). The given article presents results of the long-term (2005-2018) research of vegetation of the towns of Bashkir Pre-Urals, as well as rural settlements of Trans-Urals. 63 complete relevés of new communities for RB included in the geobotanical base of synantropic vegetation of the Southern Urals were used. The geobotanical database was implemented using the TURBOVEG software (Hennekens, Schaminée, 2001). The area of relevé depended on the community size and homogeneity. Classification is carried out according to Braun-Blanquet method using the JUICE software (Tichý, 2002). The identification of new syntaxa was carried out in accordance with the “International Code of Phytosociological Nomenclature. 4th edition” (Theurillat et al., 2021). The names of the higher syntaxa are given by “Vegetation of Europe...” (Mucina et al., 2016). The ecological conditions were assessed with use of average values of E. Landolt (1977) ecological scales and processed by IBIS software (Zverev, 2007). Average values are calculated on the following scales: humidification (M), acidity (R), soil richness with mineral nutrition elements (N), humus (H) content, mechanical composition and soil structure (D), illumination (L). At the beginning of the 2010s prodrome of synanthropic communities of RB, included 7 classes, 12 orders, 17 alliances and 61 associations (Yamalov et al., 2012). Currently, the synthaxonomy of the synanthropic vegetation of the study area requires adjustment in accordance with the modern state of European synthaxonomy. Special geobotanical studies of recent years have allowed expanding the synthaxonomic scheme of synanthropic vegetation of the region. Earlier, data have already been published on new associations for the region of the classes Artemisietea vulgaris and Galio-Urticetea (Golovanov, 2017). This article extends our research. This article considers the synanthropic vegetation of two synanthropic classes — Sisymbrietea and Digitario sanguinalis–Eragrostietea minoris. These classes are first given for the territory of the RB. The article contains their regional diagnostic species. Previously, they were a part of the wider class — Stellarietea mediae, combining annual weed and ruderal vegetation. For the class Sisymbrietea, three synthaxa are given: the associations Descurainietum sophiae and Poo annuae–Stellarietum mediae and the subass. Malvetum pusillae urticetosum urentis. The last two synthaxa are new. They unite nitrophilic communities of low-growth annuals along the house walls, fences, shoulders and other disturbed habitats both in rural settlements and in towns. Association Descurainietum sophiae unites communities found in various disturbed habitats: landfills, deposits, as well as near buildings. They occur mainly within the small settlements of the Bashkir Trans-Urals, less often in the Bashkir Cis-Urals. A comparison of the coenoflora of communities described in territory of RB and in other regions of Europe (Table 2) showed that the composition of diagnostic species groups is quite similar. The greatest similarity is with the communities located in the Czech Republic. Association Malvetum pusillae, subass M. p. urticetosum urentis (Table 3). holotypus: Table 3, relevé 2, the Republic of Bashkortostan, Khaibullinsky district, Stepnoe, along the wall of the building, 51.81988° N, 58.15081° E, 14.06.2005, author — G. Ya. Suyundukova. We compared communities dominated by Urtica urens described in territory of RB with the closest associations of the Malvion neglectae alliance of Eastern Europe (Table 4). Significant differences are visible both in the almost complete absence of main diagnostic species, and in the features of coenoflora. The cenoses described in the Czech Republic are characterized by the high constancy of Malva neglecta, completely absent in the Southern Urals, as well as the significant presence of species resistant to trampling. This indicates the different nature of environmental conditions in the compared syntaxa. Comparison with other syntaxa of the Malvion neglectae alliance in RB (Table 6) showed that the floristic composition and ecology of the Urtica urens dominated communities and the ass. Malvetum pusillae cenoses are very similar. Thus, we consider the specific subass. M. p. urticetosum urentis as part of the above association. Its physiognomy is characterized by the dominance of Urtica urens. Basically, communities are found within the rural settlements of the Bashkir Trans-Urals in the steppe and forest-steppe zones. Association Poo annuae–Stellarietum mediae (табл. 3; Fig. 1). holotypus: Table 5, relevé 1, Republic of Bashkortostan, town district Salavat, boulevard Salavat Yulaev, d. 17, house plot, 10.08.2008, 53.34177° N, 55.93038° E, author — Ya. M. Golovanov. Communities dominated by Stellaria media in Eurasia were described as a rule within the framework of weed vegetation. The closest in ecology are the cenoses of the Euphorbia peplus–Stellaria media community described within the alliance Malvion neglectae in Poland (Ratynska et al., 2010). In the ruderal communities described by us, species of the alliance Malvion neglectae and other classes of synanthropic vegetation occur with high constancy. Association communities are found near the building walls of shadow expositions, along the edges of abandoned palisades in the towns of the Bashkir Cis-Urals. Compare to other syntaxa of the Malvion neglectae alliance in the territory of RB (Table 6), the ass. Poo annuae–Stellarietum mediae occupies the most humidified habitats on slightly less rich substrates. At the same time, such communities have the richest coenoflora due to the presence of species of the classes Molinio-Arrhenatheretea and Epilobietea angustifolii. Communities of subassociation Malvetum pusillae urticetosum urentis are similar in coenofloras and occupy similar habitats. The ass. Eragrostio–Amaranthetum albi within the class Digitario sanguinalis–Eragrostietea minoris is firstly identified. It combines specific synanthropic communities of railway embankments with predominance of annual species. Associations with the dominance of Eragrostis minor of the Digitario sanguinalis–Eragrostietea minoris class in different regions were compared (Table 8, Fig. 2). Significant similarity of the cenoses described in the republic with the communities of the ass. Eragrostio–Amaranthetum albi located in Kursk was revealed. Differences are probably due to the nature of the use of railway embankments within stations, as well as the accidental drift of certain species.