Middle- and late-Holocene environments and vegetation history of Kunashir Island, Kurile Islands, northwestern Pacific

Natural middle- and tate-Holocene environmental development of Kunashiri Is land reflects global climatic changes and the migration of warm and cold cu rrents. Dry and cool climate changed to warm and moist about 7000-6500 BP, later than on Hokkaido Island. At this time Kuroshio Current system became more active. On Kunashir Island birch assemblages were replaced by cool-tem perate broadleaf forests in the south and mixed coniferous/broadleaf forest s in the north. The highest sea-level position reached 2.5-3 m above PSL ab out 6500-6300 BP. Cooling about 4700-4500 BP island vegetation weakly chang ed that connected with warm current influence. Major regression at this per iod led to formation of extensive coastal dunefields. The warming at the be ginning of the late Holocene was almost similar to the Holocene Optimum. Tw o minor transgressions are recorded about 4010-3400 and 2950-2620 BP. Activ e entrance of detrital material to the coastal zone resulted in growth of a ccumulative landforms. Vegetation changes and climatic deterioration took p lace in the second half of the late Holocene. Coniferous and mixed conifero us/broadleaf forests shifted southward and occupied a large part of the isl and. During cooling at 1700-1300 BP the isthmus area increased, coastal wet lands with lakes and coastal dunes were formed, and grassland and swamp lan dscapes developed. Late-Holocene warming was not intensive. Active aeolian accumulation took place during the 'Little Ice Age' cooling and regression.