NEW DATA ON THE DISTRIBUTION OF JAPANESE WHITE BIRCH (BETULA PLATYPHYLLA SUKACZ.) IN THE OLYUTORSKY DISTRICT OF THE KORYAK OKRUG (KAMCHATSKY KRAI)

Abstract

New data on the distribution of Japanese white birch (Betula platyphylla Sukacz.) groves in the Olyutorsky District (Koryak Okrug of the Kamchatsky Krai) are presented. The geobotanical description of white-birch forests in the valley of River Kailulovayam, a tributary of River Vyvenka, is given. Using the dominantdeterminant approach the forests were ascribed to the association Betuletum platyphyllae fruticoso-varioherbosum. White-birch forests of the Koryak Okrug grow in the valleys of large rivers in areas away from the influence of the Bering Sea. They occupy above-floodplain terraces with mesic coarse-loam and loamy sand soils underlain by pebbles. The studied community of Betula platyphylla is similar in floral composition and structure to the shrub-forb valley white-birch forests of the Penzhinsky District of the Koryak Okrug. In comparison with Kamchatka analogues, the white-birch forests of Northern Koryakia are characterized by a reduced floral composition. The white birch grove in the Kaylulovayam River valley is the second confirmed location of Betula platyphylla in the Olyutorsky District.