Holocene vegetation dynamics and its climatic implications inferred from pollen record in Boseong area, South Korea

摘要

To investigate the Holocene vegetation and climate changes, pollen analysis performed on swamp deposits of the Boseong area, South Korea. From ca. 11,800 to 10,500 cal. yr BP, a cool temperate deciduous broadleaved forest dominated by Alnus and Quercus (Lepidobalanus) occupied the study area, indicating climatic warming during the Preboreal (earliest Holocene). A remarkable decrease in riparian Alnus and an increase in xerophytic Artemisia from ca. 10,500 to 8,400 cal. yr BP suggest open woodland with herbaceous understory reflecting a cool and dry condition. The expansion of deciduous broadleaved forest combined with rise in evergreen broadleaved taxa and the retreat of grassland between ca. 8,400 and 3,700 cal. yr BP indicate a vegetation shift from open woodland with herbaceous understory to warm temperate evergreen and deciduous broadleaved forests, resulted from climate amelioration during the Holocene climatic optimum. A warm and humid condition during this period is also evidenced by high values of pollen concentration. Vegetation change controlled by human impact occurred from ca. 3,700 to 2,900 cal. yr BP, as indicated by a rise in Pinus and Polypodiaceae and by high sedimentation rate. Along with the late Holocene climatic cooling, human impact brought about the development of Pinus dominated open woodland with a fern (Polypodiaceae) understory in the Boseong area.