Language: Russian with English contents and 2-page summary
The spatial differentiation of the vascular plants flora in the Kanin-Mezenski region from the Kanin Peninsula (west of the Nenets Autonomous Okrug) to the lower reaches of the river Mezen (north-east of the Arkhangelsk oblast) is considered. The data on the taxonomic diversity and floristic richness of floras of 17 geographical areas studied by the local floras method are reported. The floras located in three zonal types of vegetation: the southern tundra, forest tundra and northem taiga.
The speciﬁc of spatial taxonomic diversity of flora of this region is caused by its location on the northern macro-slope of Russian Plain and depends on both changes in climatic variables from north to south throughout the east-west 500-km-long transect and the differences of relief. In different types of landscapes there are such contrasting elements as rocky outcrops at ridge Kanin Stone, vast lowlands occupied by wetlands, coastal salt marshes, sandy aeolian landscapes of sea coasts, valleys of major rivers, tundra-forest woodlands and wetland complexes on the low plains and others.
Regional flora of postglacial origin is migratory in nature and includes 714 taxa, 296 genera and 86 families. Latitudinal and longitudinal geographic groups, distribution in the geographic regions and in local floras are shown for each taxon. The situation of the southem boundaries of geographical ranges of species belonging to Arctic fraction as well as norther boundary of species belonging to Boreal fraction were analyzed. The results of the analysis of local floras were used in floristic regionalization of the area, where floristic borders of different ranks are found. The region is divided into three circuits and five floristic districts according to species richness, taxonomic structure, the ratio of latitude geographical elements, the species distribution on the profile and the concentration of limits of species areas. The boundary is marked between the Arctic and Boreal floristic regions.
As a result of analysis of taxonomic and systematic indicators of floras 3 districts for monitoring floristic diversity were suggested. The first area is in the mouth of the river Mezen on the border of northern taiga and forest-tundra, the second is north of the mouth of the river Nes near the northern boundary of the forest tundra, and the third is north of the basin of the river Shoina on the border between the stripes of high-shrub dwarf birch and low-shrub dwarf birch tundra.
The problem of conservation of biodiversity in Kanin- Mezenski region is to preserve the species diversity of the gene pool of the flora. The distribution of 94 rare and in need of protection plants included in the Red Data Books of the Nenets Autonomous Okrug and Arkhangelsk oblast was revealed. Many of these species grow outside the protected areas. Ten districts with unique landscapes and the highest concentration of rare species are suggested for the establishment of new protected areas (7 – in rank of botanical sanctuaries and 3 – as “monuments of nature”). The characteristic of the existing and proposed protected areas is given. These protected areas will help to conserve the natural state of the typical and unique natural complexes, which are threatened by economic development connected with production and transportation of hydrocarbons.
Proposals for the protection of natural areas will guarantee conservation of the gene pool of flora and landscape diversity in the Kanin-Mezenski region and may become the part of inter-regional system of protected natural areas in the European North. Data on local floras can be used to monitor changes in vegetation cover and biodiversity of the northem territories in Russian Arctic and sub-Arctic, and lists of species can be used to replenish the data base on “FLORA” problem.