Distribution and ecology of the earthworm Eisenia nordenskioldi pallida (Oligochaeta, Lumbricidae) dominant in southern Siberia and the Russian Far East

A literature review and the results of re-examination of collections of the earthworm Eisenia nordenskioldi are presented. Peculiarities of the geographic and habitat distribution, as well the ecology of the diploid subspecies E. n. pallida, originally described as a non-pigmented form of E. nordenskioldi, are analyzed. E. n. pallida inhabits mainly the south of Siberia and the Russian Far East, penetrating as far northwards as the forest-tundra zone along the valleys of large rivers. It is the most abundant in the low-mountain belt in dark coniferous forests, being the dominant form of Lumbricidae there, but it is quite rare above the timberline. The range of E. n. nordenskioldi, which can be found together with E. n. pallida in the south of the territories studied, is much wider, extending further to the north and including some Arctic islands. In addition, E. n. nordenskioldi is known from the eastern parts of European Russia. Both subspecies show high levels of resistance to unfavorable abiotic factors. Differences in the latitudinal and altitudinal distribution patterns of both subspecies of E. nordenskioldi are determined by their different morpho-ecological forms.