About poplar forests of the Tom river upper course, Kemerovo region, Russia

Poplar forests of the Tom River are studied near Mayzas settlement, Mezhdurechensk town district of Kemerovo Region (53°37'48" N, 88°12'25" E). On a base of Braun-Blanquet classification, they are described as Brunnero sibiricae-Populetum laurifoliae ass. nov. attributed to the Populion lauri- folio-nigrae Taran 2015, Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958. Diagnostic species of the association and its typical subasso-ciation are Populus laurifolia, Brunnera sibirica, Carex sylvatica, Milium effusum, Ranunculus mon-ophyllus, Stachys sylvatica, Veratrum lobelianum. Coenoses of the typical subassociation are located on high sites formed by cobblestone-shingly alluvi-um covered by thin layer of a soil. Populus laurifolia dominates in timber layer, Padus avium - in shrub layer, Matteuccia struthiopteris and Brunnera sibiri-ca - in field layer. Total projective cover (TPC) of the timber layer is 60 %, shrub layer - 10 %, field layer - 80 %. Species saturation with vascular plants is 48 species per 100 m2. Forests codomi-nated Populus laurifolia, Populus nigra and Popu-lus x jrtyschensis Ch.Y. Yang, natural hybrid of the two first species, are spread on lower riverside sites of the floodplain. These communities are separated into Brunnero sibiricae-Populetum laurifoliae aconogononetosum alpini subass. nov., its diag-nostic species are Populus nigra, Aconogonon al-pinum, Calamagrostis purpurea, Cardamine mac-rophylla, Pedicularis resupinata, Ranunculus pro-pinquus, Trollius asiaticus. In the subassociation communities, TPC of the timber layer is 35-40 %, shrub layer - 5-15 %, field layer - 50-60 %. Species richness is 76-91 vascular plant species per 100-150 m2.