Millennial-scale vegetation and climate changes in the Sea of Japan region over the last 120 kyr inferred from marine sediments

Abstract

Records of vegetation and climate changes in northeast Asia do exist in abundance. However, continuous dated evidence of regional environmental changes is a rarity, but are very important for comparison with global climate events on a millennial scale. We presented a millennial-scale reconstruction of vegetation changes in the southern part of the Russian Far East during the Last Interglacial, Last Glaciation, and Holocene. The reconstruction is based on analyses of the pollen record from deep-sea sediment core from the Sea of Japan (SJ) and then it was corresponded with the previously constructed by Gorbarenko team age model. We compared vegetation changes with published data on productivity changes and sedimentation in the SJ and with the variability of the East Asian Summer Monsoon (EASM) over the last 120 kyr to determine the dynamics of climate relationships between land and sea on the millennial scale. The oak and other thermophilic species dominated in the region during the strongest Dansgaard–Oeschger (DO) interstadials (DOIs) 24, 23, 18, 17, 14 and 8, indicating warm and wet climate conditions because of rapid climate changes and high activity of EASM. Simultaneously, the surface water primary productivity increased, contributing to the dark layer formation on the bottom. The shrubby alder and cold-hardy birch species spread in the adjacent land during the cold Heinrich stadials (HS) and Dansgaard–Oeschger stadials (DOS) in response to cold conditions because of global climate changes and weak intensity of EASM. The primary productivity mostly decreased in response to climate cooling, favorable to light layers formation in the JS.