HISTORY OF LARIX FOREST IN HOKKAIDO AND SAKHALIN, NORTHEAST ASIA SINCE THE LAST GLACIAL

Larix pollen is abundant in the Last Glacial sediments of Sakhalin and Hokkaido islands. To clarify the relation between the pollen percentage of Larix and its stand density, surface samples from tundra, forest tundra and taiga in the Far East Russia were analyzed. On the basis of surface pollen data, vegetation and climate since 30 ka in both islands were reconstructed. Around 30 ka, taiga of dominant Picea coexisted with Larix, Pinus and Abies was distributed in both islands under relatively colder and drier climate than at present. During the LGM, bog and taiga were mainly composed of Larix and Pinus in Sakhalin, which could be correlated to the present northeast Siberian taiga. In Hokkaido, grassland and taiga were mainly consisted of Larix, Pinus and Picea. Climate was colder and drier than that around 30 ka. During Younger Dryas, forest tundra occurred in middle Sakhalin. In Hokkaido, contemporary vegetation was grassland and taiga characterized by the predominance of Larix. Climate was colder and drier than at LGM. Larix began to decrease in both islands at 10 ka. It disappeared till 6 ka in Hokkaido, however it survived in Sakhalin until the present.

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Clc Number:

Q914.87