宇生賀盆地(山口県)における最終氷期最盛期以降の植生変遷

抄録

This paper deals with pollen analysis of a 520 cm core (34°29'N lat., 131°35'E long.; alt. 390m) collected from the Ubuka sedimentary basin at the western edge of the Chugoku Mountains. The pollen history probably spans back to about 25,000 years B.P., i.e. from the last full-glacial maximum to the present, and would serve as a standard in the region. It is divided into five pollen zones in which seven vegetational stages are recognized. These are : I. Zone FG (ca. 25,000-15,000 years B.P.) 1. Pinus-Abies-Picea-Tsuga Stage (520-290 cm) II. Zone L (ca. 15,000-10,000 years B.P.) 2. Pinus-Abies-Picea-Tsuga-Betula Stage (290-170 cm) III. Zone R I (ca. 10,000-9,000 years B.P.) 3. Betula-Quercus-Pinus-Tsuga Stage (170-150 cm) IV. Zone R II (ca. 9,000-4,000 years B.P.) 4. Fagus-Quercus-Tsuga Stage (150-100 cm) 5. Cyclobalanopsis-Alnus-Abies Stage (100-70 cm) 6. Cyclobalanopsis-Alnus-Cryptomeria Stage (70-30 cm) V. Zone R III (ca. 4,000 years B.P.-Present) 7. Pinus-Cyclobalanopsis-Cryptomeria Stage (30-0 cm).