The Role of Microsites in the Natural Regeneration of Trees in Boreal Tall-Herb Dark Coniferous Forests of the Northern Urals

Abstract

This paper presents the results of research into the role of various types of microsites (flat under- and intercrown areas, stumps, fallen logs, mounds, and pits) in the natural regeneration of trees in uneven-aged dark coniferous boreal tall-herb spruce–fir forests of the northern Urals. Areas of microsites of various types have been identified; a general description of natural tree regeneration is provided; the association of undergrowth of various tree species with different microsites was determined; and the undergrowth distribution by ontogenetic states has been assessed. The lowest undergrowth density was registered on flat sites occupying the major part of the community area, while the highest density was detected on elevated microsites (fallen logs, stumps, and mounds) the total area of which is pretty small. The highest density of the undergrowth of all species was observed on stumps. On mounds and fallen logs, it was 4.3 and 3.0 times lower, respectively. It is shown that elevated microsites (stumps, fallen logs, and mounds) are required for successful survival of the undergrowth of various tree species in boreal tall-herb forests.