Vegetation and climate history since the last interglacial in Kurota Lowland, western Japan

The pollen record of a long core from the Kurota Lowland of central Honshu in western Japan provides a continuous vegetation and climate history from beyond 120,000 to 25,000 yr BP. The chronology is based on widely dispersed tephra and six conventional 14C dates. Prior to 120,000 yr BP, forests were composed predominantly of Abies, Tsuga, Picea and Pinus (Haploxylon) which indicate a cold climate probably corresponding to oxygen isotope stage 6. During the last interglacial around 120,000 yr BP, Cryptomeria japonica was dominant in forests with a small amount of evergreen oaks. The early stage of the last glacial period is characterised by dominance of C. japonica with two increases (at 105,000 and 90,000–80,000 yr BP) of pinaceous conifers and cool-temperate deciduous broad-leaved trees. Between 70,000 and 60,000 yr BP, pinaceous conifer vegetation developed indicating a dry and cold climate and this was succeeded by a cool-temperate deciduous broad-leaved forest composed mainly of Fagus crenata and deciduous oaks indicating a wet and cool/cold climate. From 55,000 to 40,000 yr BP, temperate coniferous forests composed of C. japonica and Cupressaceae, associated mainly with Tsuga and deciduous oaks, occurred. After 40,000 yr BP, mixed forests of C. japonica, Tsuga and cool-temperate deciduous broad-leaved trees such as Fagus crenata and deciduous oaks prevailed in a wet and cool climate. At 28,000 yr BP, an abrupt decrease of C. japonica and development of forests composed of Tsuga, Pinus (Haploxylon) and Betula with some deciduous broad-leaved trees imply climatic deterioration to the LGM. The vegetation history since the LGM has been revealed previously at Iwaya site in Kurota Lowland. Time series of these pollen records can be correlated with the marine oxygen isotope stages 1 through 6.