Communities of the association Melilotetum albo–officinalis Sissingh 1950 in the European part of Russia and Belarus

The purpose of the study is to revise relevés of synanthropic communities dominated by Melilotus albus and M. officinalis from forest, forest-steppe and steppe zones of the European part of Russia and Belarus and to reveal the variation in their floristic composition in this territory. In the present paper, 66 relevés from 2004 to 2016 are analyzed. As a result of the study, the association Melilotetum albo–officinalis was identified. It includes three subassociations that reflect different ecological conditions and some geographical distribution features of communities. Subass. typicum includes the most typical communities. It has two variants. Communities of var. typica often contain few species due to the strong dominance of Melilotus albus and M. officinalis. Var. Ambrosia artemisiifolia includes early successional phytocoenoses affected by regular disturbances. The mesophytic communities which are rich in mesophilous meadow and ruderal species are assigned to the subass. tussilaginetosum farfarae. They tend to spread in the northwestern part of the study area located in the forest zone. Subass. сarduetosum acanthoidis includes xeromesophytic communities. Its coenoflora contains highly constant species of the order Onopordetalia acanthi and a high proportion of subcontinental and continental species. They are widespread in the eastern part of the study area, in steppe and forest-steppe zones. Еnvironmental differences between habitats of the described communities are shown using targeted ecological indicator values. The highest variability between syntaxa was identified in the levels of moisture in soils and substrates, temperature, continentality and hemeroby. URL: https://www.bz.upjs/thaiszi