Pioneers communites flood plain her rivers of Desna in the Southern Nechernozemie region of Russia

Results of floristic classification pioneers communities riverside vegetation the rivers of Desna. 4 new associations, distributed in the Southern Nechernozemie of Russia, are for the first time with of the Braun-Blanquet approach: Achilleo salicifoliae-Petasietum spurii, Agrostio giganteae-Sedetum thelephii, Xanthio albino-Eragoristietum albensis, Agrostio giganteae-Salicetum acutifoliae. The new alliance Salicion acutifoliae al. nov. The diagnostics species Salix acutifolia (dom.). Flood plain is and a habitat invasion species: Bidens frondosa, Conyza canadensis, Erigeron septentrionalis ssp., Eragrostis albensis, Oenothera biennis. Are most active Bidens frondosa and Eragrostis albensis. Both species quite often dominate in communities. The received materials are interesting at studying of dynamics of riverside vegetation.