MOSSES OF THE WESTERN PART OF THE CHUKCHI HIGHLANDS. 1. DISTRIBUTION BY HABITAT TYPES, AND ACTIVITY OF SPECIES

Abstract

The analysis of the distribution of mosses in the landscape of the western part of the Chukchi Highlands served as the basis for distinguishing 12 types of habitats, which differ in a number of abiotic (altitude above sea level, slope exposure, steepness, degree of surface moisture) and biotic (composition of dominant species, cover of mosses and vascular plants, percentage of ground area free of vegetation) parameters. The vast majority of habitat types are the slopes of various steepness (including accumulative slopes – plumes with runoff hollows), which are characterized by active movement of solid matter. Each habitat type is characterized by its own moss composition, or bryocenotype. The species richness in the bryocenotypes varies from 23 (mountain slopes with moving scree) to 65 (sloping valleys of plumes with reservoir runoff), the lowest average number of species was found in the tormer bryocenotype – 2.63, the highest – 6.67 – was noted in floodplain terraces. Based on 322 geobotanical relevés, there were identified 12 bryocenotypes, i.e. aggregates of moss species of the same habitat type. Five classes of species activity have been distinguished, based on 3 parameters: the number of habitat types where the species has settled, the constancy of the species in one type of habitat, the cover of the species. Of the 122 moss species noted in geobotanical relevés, 5 oned are classified as especially active (Aulacomnium palustre, A. turgidum, Dicranum elongatum, Distichium capillaceum, Hylocomium splendens, Sanionia uncinata, Tomentypnum nitens), 11 are highly active, 24 are medium-active, 30 are low-active and 52 are inactive.