Phytogeographic features of the north forest-tundra in the south-eastern Yamal Peninsula

摘要

The general character and landscape differentiation of the forest-tundra local flora (LF) (south-eastern Yamal) are considered. This flora is compared with 7 southern local floras in neighbouring regions of Arctic and with other local floras of Yamal. LF stands out among other Yamal local floras due to its high species diversity: 223 species and subspecies of 107 genera and 45 families. This flora is similar to the East European forest-tundra floras in its taxonomic and geographic structure, but index of similarity is higher, there prevail families characteristic of boreal floras, the boreal geographic fraction dominates whereas participation of the arctic fraction is small. Participation of families Brassicaceae, Saxifragaceae, Caryophyllaceae is reduced as compared with the Siberian floras. Analysis of floras of large landscape units (at the macro- and mesoecotope levels) showed the heterogeneity of LF. The richest in the species of vascular plants is delta of the Ob' River, the poorest are watersheds with tundra vegetation. The last ones contain the maximum number of euritopic species and the highest shares of species of arctic fraction. Analysis of the species activeness showed an absolute predominance of low and nonactive species in the LF and in its united partial floras.