Biota and Environment of Natural Areas

Lyashchevskaya M.S. , Ganzei K.S., Makarova T.R.

Paleogeographical Reconstruction for Stenina Island (Sea of Japan) during Middle-Late Holocene

Year: 2017, Number: 2, Pages: 3-20

On the basis of complex landscape and paleogeographical investigations executed in 2015 stages of Stenina Island environment development in the Middle-Late Holocene are analyzed. Based on relief and underwater coastal slope digital model modeling of coast changes depending on sea level fluctuations is executed. It is established that around 6000 14С years ago on the island prevailed broad-leaved with oak and horn-beech. Presence shells in a sea mud with domination marine and brackish-water diatoms show the existence of shallow bay or lagoon on Stenina Island. About 1920–1820 14С years ago lowering of sea level was resulted of lagoon separation by accumulative form (a pebble offshore bar) with formation of the lake. Gittja pack at a section with pollen of a water plants and absence of marine and the brackish-water diatoms show the lake stage of lagoon evolution. The climatic cooling at the beginning of the Late Holocene has led to distribution of the oak and birch forests with coniferous trees and underbrush with lespedeza. Lagoon lake gradually became bogged up and grew over, being reduced to the present size. Formation of a modern vegetation cover of the Stenina Island has happened not earlier than the middle of the XIX-th century after the end of Little Ice Age and steady increase of average annual temperature. That was expressed in increase area of broad-leaved forests, especially an oak (Quercus mongolica) and horn-beech (Carpinus cordata) on Stenina Island and all islands of Peter the Great Bay.

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