Sedge-cottongrass hummocky communities in the north of the Koryak district (Kamchatka territory)

Sedge-cottongrass hummocks formed by Sochava sedge ( Carex lugens subsp . soczavaeana ) and cottongrass ( Eriophorum vaginatum ) are widespread in the extreme Northeast of Asia, in intermountain depressions and river valleys. They are found on sandy loams or loams underlayed by permafrost. Their syntaxonomic position is quite ambivalent and debatable. Some authors refer sedge-cottongrass communities to tundra, others to sphagnum bogs, and others to tundra mires on permafrost. The article presents new data on the vegetation of sedge-cottongrass hummock communities in the North of the Koryak Okrug (Kamchatka Region). Their geographical distribution, species composition, community structure, pyrogenic dynamics, and conditions of formation are discussed. Using the principles of typology of mire massifs elaborated by T. K. Yurkovskaya, it is proposed to classify them as the Type of Sedge-Cottongrass Hummocky permafrost mires, a Group of types of Hummocky Sedge-Cottongrass Northeast Asian mires, and a Class of types of Herb-Lichen-Moss mires.