Environmental variability and human adaptation during the Lateglacial/Holocene transition in Japan with reference to pollen analysis of the SG4 core from Lake Suigetsu

摘要

High-resolution pollen analysis of annually laminated sediments from Lake Suigetsu in Japan revealed that climate amelioration at 16,500 varve years before present (vy BP) triggered the expansion of cool temperate deciduous broad-leaved forest. The oldest pottery appearance in Japan coincided with this climate amelioration. Significant vegetation change occurred from 15,000 to 14,500 vyBP. The period during 15,000-14,500 vyBP was a time of ecological transition from a Glacial-type ecosystem, eventually destroyed by global warming, to a new Postglacial-type ecosystem represented by that in Lake Suigetsu. It is believed that the completion of this ecological transition actually took nearly 500-800 years. This drastic change in the ecosystem had forced people to create a new strategy of adaptation. The Japanese Neolithic Jomon culture, mainly sustained by gathering nuts and fishing, was widely established at this time. On the other hand, the cold period which correlates with the Younger Dryas in Europe had no significant ecological influence on the Japanese ecosystem and human culture.