Diversity of Vegetation and Soils of the North-eastern Part of the Island Simushir
Oleg V. Polokhin
1Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS, Vladivostok, 690022, Russia
The main distribution patterns of soil and vegetation northeastern part of Simushir Island were studied. Simushir is an uninhabited volcanic island near the center of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean. Simushir is highly elongated, consisting of a series of stratovolcanoes. At the north end of the island is a half-submerged caldera, Brouton Bay. Four courts measuring 10x10m2 for the description of vegetation and soil cover were selected. The soil profile and morphology characters are described. Vegetation description was given. Different types of vegetation properties upper soil horizons define. Pedogenesis has synlithogenic (volcanic) character.
The first accounting platform for sampling of soils and vegetation was planted on the South-Western coastal slope of the Peninsula the Eastern Klishnia. This site was dominated by mixed grass-meadow vegetation and individual plants Duschekia fruticosa (Rupr.) Pouzar, Rosa rugosa Thunb and Sorbus sambucifolia Cham. et Schlecht.
Under this vegetation dry-peaty volcanic soil was formed.
The second site was located in the Central part of the Caldera, in the North-Eastern slope of the side of the cone, dominated by Betula ermanii Cham. and individual plants: Duschekia fruticosa (Rupr.) Pouzar, Sorbus sambucifolia, Salix udensis Trautv. et C.A. Mey, Sasa kurilensis (Rupr.) Makino et Shibata. Under the birch raw-organic volcanic ocherous soil was formed, with more acidic (pH 5.4 to 5.9) reaction medium, higher (15,3–13,4 %) content of humus in the upper horizons and the presence of a bright buff illuvial-metamorphic horizon BAN, as well as a high content of iron oxides (9-11 %) and aluminium (15-18 %), typical of volcanic soils.