Kaybasovo Poplar Forests (the Ob River, Tomsk Oblast, the Southern Taiga Subzone)

Abstract

The Ob River basin is the last large fragment of the range of native Euro-Siberian poplar (Populus nigra, Populus alba) forests where these forests remain intact. The taiga section of the Ob River is occupied by the association Anemonidio dichotomi-Populetum nigrae Taran 1993, and the subtaiga, forest-steppe, and steppe sections are occupied by the association Equiseto hyemalis-Populetum nigrae Taran 1997. The purpose of the study is to determine the syntaxonomic status of poplar forests growing at the junction of the southern taiga and subtaiga subzones and to provide a detailed bryofloristic characterization thereof. Based on the Braun-Blanquet approach, we studied poplar forests located near the south border of the Ob River southern taiga section (Krivosheinsky district, Tomsk Oblast, Russia, surroundings of the Kaybasovo research station, 57º14′44″N, 84º11′05″E). In the forests, average species saturation by vascular plant species is 32.3 species per 100 m2, and its range is 13–56 species/100 m2. Moss flora includes 51 species. Average species saturation by mosses is 15.4 species per 100 m2, and its range is 10–21 species/100 m2. Based on the new data, total moss flora of the Ob poplar forests has increased from 73 species to 86 species and 1 variety (by 19 %), moss flora of the poplar forests of the taiga zone – from 59 species to 81 species and 1 variety (by 39 %). We identify Kaybasovo poplar forests as the new variant, Stellaria bungeana, of the subassociation Equiseto hyemalis-Populetum nigrae betuletosum pubescentis Taran 1997 (Equiseto hyemalis-Populion nigrae Taran 1997, Salicetalia purpureae Moor 1958, Salicetea purpureae Moor 1958)