Soils of the Krestovsky and Chetyryokhstolbovoy islands in the National Nature Reserve 'Bear Islands' (East Siberian Sea)

This paper presents an investigation of previously unstudied soils of the Arctic islands (Krestovsky and Chetyryokhstolbovoy), which gained the status of a new protected area “Bear Islands” (70°37′–70°60′ N, 160°23′–162°33′ E). Their soils were formed mainly under permafrost conditions (approximately 1 m), with a seasonal thawing depth of 0.3–0.6 cm. The territory of Krestovsky Island is a combination of several landscapes characterized by various types of permafrost soils. Primitive gravelly soils (A–BC(C)) are exposed in mountainous areas. Permafrost tundra low-gley soils (OT–Bg–BCg(C)) are formed on the gentle long slopes under hummocky moss-herbaceous tundra. In natural depressions on cryogenic forms of surface, the soil cover represents a combination of permafrost arctotundra gleyic (O–B–Bg(BC)┴) and humus-gley soils (O–AH–AB–BG┴). Marsh soils (Ad–C(AC)–C′) occur along the low flooded gently sloping coasts of the island. All soils are acidic. Zonal types are characterized by gleying, which brings them closer to the soils of the mainland. The soil cover of Chetyryokhstolbovoy Island, with the most fully developed shrublichen-moss or forb-moss soils, is rather monotonous. Namely it is represented by arctotundra gleyic soils with a profile of the same type in terms of morphological features and physicochemical properties (О–Аd–АВ(g)–Вg(BCg)). The main features of this soil type include the thinness of the surface organogenic horizon, good decomposition of organic matter, high and medium content of humus in the soddy-humus horizon, the absence of surface gleying or its weak severity due to drying out in summer.