Poplar forests of the Ob River near Kolpashevo town, Tomsk Region, Russia
Georgy S. Taran
Abstract
Natural poplar (Populus nigra, Populus alba) forests of the Ob River were studied on the northern border of south taiga subzone (vicinities of the Kolpashevo town, Kolpashevo district of Tomsk Region, 58º18′ N, 82º54′ E) on the floodplain segment formed in 1890–1970. They belong to association Anemonidio dichotomi-Populetum nigrae Taran 1993 (Equiseto hyemalis-Populion nigrae Taran 1997, Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958) and 2 subassociations: Anemonidio dichotomi-Populetum nigrae typicum Taran 1993 and Anemonidio dichotomi-Populetum nigrae rubetosum saxatilis Taran subass. nov. Poplar forests of the Kolpashevo Meander of the Ob are examined from stage of young high black poplar (Populus nigra) to stage of its total declining. General direction of the poplar forest succession is expressing in a replacement of black poplar coenoses by birch ones. At the most sandy soils, black poplar stands are changed by small-sized Scotch pine stands. On the middle stages of the succession, white poplar (Populus alba) plays the important part, sometimes together with Populus ×canescens. However, near Kolpashevo town, white poplar doesn’t form stable coenoses as it grows at the northern border of its areal in Western Siberia. In studied poplar forests, mean species saturation with vascular plants is 42,4, with mosses – 14,4 species per 100 m2, total number of species of vascular plants is 123, mosses – 34.