サハリン中・北部における第四紀後期の環境変動 Late Quaternary Environmental Change in Central and North Sakhalin, Russia
Pollen and diatom analysis were conducted on sediments in a fossil gully at Schmidt Peninsula, northwest Sakhalin and in a tectonic basin at a western area of central Sakhalin. Between 8, 500 and 7, 400 yBP a taiga dominated with Larix gmelinii and Pinus pumila developed at the Schmidt Peninsula under colder and drier climate than that at present. The paleoenvironment was marine and marine to blackish conditions. After the Betula forest period between 7, 400 and 6, 000 yBP, the present taiga, which was composed of dominant Picea jezoensis, coexisted with Larix and Pinus which developed since 6, 000 yBP under the same climate as that at present. At a western area of central Sakhalin, taiga composed of Picea, Larix and Pinus was distributed under colder and drier climatic conditions than that at present during the interstadial since 37, 000 yBP. In early Holocene, Larix-Pins taiga changed to Picea-dominated taiga due to a recovery of the climate. At around 6, 000 yBP the present taiga was established under the same climate as that at present. Larix, which is a good indicator of a cold and dry climate, formed a taiga together with Picea and Pinus in northern and eastern Hokkaido during LGM. During the migration north since Lateglacial, Larix formed taiga in Sakhalin. However, it decreased in the western area of central Sakhalin during early Holocene, and also decreased in the northwest at around 7, 400 yBP.
地學雜誌 109(2), 165-173, 2000-04-25
Tokyo Geographical Society