Climate and vegetation changes around Lake Baikal during the last 350,000 years

Abstract

We conducted particle size and pollen analyses on two cores extracted from Lake Baikal to investigate the response of vegetation to climate change and to assess the differences in vegetation changes between the northern and southern regions of Lake Baikal over the last 350 kyr. Vegetation changes in the Lake Baikal region corresponded well to the fluctuations in median particle size, which are indicators of the climate changes in this region. Forest, which was mainly composed of Pinus and Picea, spread widely during the interglacials/interstadials of MIS 9, 7, 5, and 1, and open forest or desert covered most areas during the glacial/stadial substages. However, the responses of vegetation to climate changes differed between the northern and southern regions. Generally, vegetation expansion was restricted around the northern region. During the interglacial substages equivalent to MIS 9.3, 7.5, and 5.5, forest spread widely around both the northern and southern regions. However, sparsely vegetated (poor) desert/open forest covered the northern region during MIS 5.3 and 5.1, while forest extended around the southern region in these substages. Moreover, during glacial periods, open forest, composed mainly of Artemisia, Chenopodiaceae/Amarantaceae , Betula, and Alnus, covered the southern region, while poor desert/open forest covered the northern region. These different vegetation responses are considered to have been caused by the geographical characteristics of the regions, i.e., the mountains around the northern region and the plains around the Selenga River in the southern region.