PARENT SESSION
Oral Session #10: Paleoecology. Presiding: S. Hotchkiss.
Monday, August 6, 2001. 8:00 AM to 12:00 PM. Hall of Ideas J.
Dark and light taiga history since the last glacial around Lake Baikal.
TAKAHARA, HIKARU1, OGURA, AKIRA1, KRIVONOGOV, SERGEY2, BEZRUKOVA, ELENA3, MIYOSHI, NORIO4, HASE, YOSITAKA5, KAWAMURO, KIMIYASU6, NAKAMURA, TOSHIO7, MORITA, YOSHIMUNE4, SHICHI, KOJI6, SHINOMIYA, YOSHIKI6, TAKEHARA, AKIHIDE8, UCHIYAMA, TAKASHI9, 1 2 3 4 5 6 7 8 9
ABSTRACT- Dark taiga in the southern area of Lake Baikal is mainly composed of Abies sibirica, Picea obovata and Pinus sibirica. In light taiga around the northern area of Lake Baikal, Larix gmelinii is predominant. Palynological studies on the sediment samples from 16 bogs and 5 outcrops have revealed the history of the dark and light taiga forests. These sediment samples were taken from the southeastern to northeastern shore areas of Lake Baikal. We have also studied relationships between pollen assemblage and vegetation on all study sites. Both in the southeastern and in the northeastern shore areas, spruce became dominant from the late-glacial to the early-Holocene. From the early to mid-Holocene, in the southeastern shore areas, fir increased, while in the northeastern shore areas, larch became a dominant component of the forests. In the mid-Holocene, pine trees (P. sibirica and P. sylvestris) were widespread in both areas. On the other hand, in the northeastern inland region of Lake Baikal, larch has been a main component of the forests since the early-Holocene. The differences of the Holocene vegetation history among these areas are considered to be due to retreat of permafrost from south to north. In the southeastern shore areas, where permafrost retreated in the Holocene, dark taiga was developed. In the northeastern inland region, where the continuous permafrost has existed, light taiga has been persisted since the early-Holocene.
KEY WORDS: Lake Baikal, Taiga, permafrost, since the last galcial