Habitats of the east European tundra and their accordance by the Eunis categories on the Nenetsky reserve example

A classification of habitats is proposed, which is based on the topographic position of biotopes and the territorial units of vegetation that diagnose them (TUV). Units represent by phytocenoses (for many of them the syntaxonomic status of the association and below rank is established), ecological or ecological-genetic series and complexes. Any landscape with this approach is considered as a complex of territorially related habitats. Four categories of habitats of the first level, 15 - of the second and 38 - of the third are allocated for the Nenetsky Reserve territory. The definition of habitats of the first and second levels is based mainly on their topographic position, of the third - TUV is well diagnosed. "Zakharyin shore" cluster of nature reserve is characterized by the largest (28) diversity of biotopes of the second and third levels, and "Bolvanskiy" is smaller (20). Seven categories of habitats out of 22 in the "Islands" cluster are characteristic only of Dolgiy, Matveyev, Bolshoi and Malyi Zelentsy Islands, where carbonate rocks and rocky and pebble shores exist on the surface. It is in these biotopes that the largest number of species of rare plant objects that are included in the Red Book of the Nenets Autonomous Okrug is concentrated. For most categories of the proposed classification, their correspondence with the categories of European Union Nature Information System (EUNIS) is established. EUNIS is a pan-European integrating habitat system and, despite its shortcomings, serves as a standard ensuring the comparability of national and international classifications.