Vegetation changes in western central region of Korean Peninsula during the last glacial (ca. 21.1-26.1 cal kyr BP)

Abstract

Age-controlled pollen record from wetland sediments of Hanam, western central Korean Peninsula (KP), reveals vegetation dynamics response to climate changes during last glacial, 26.1？20.1 cal kyr BP. The Hanam pollen assemblages are dominated by conifers, Picea and Pinus and cold tolerant deciduous broadleaved Betula, together with common xerophytic herb like Artemisia and Gramineae. Principal taxa are similar to those of subalpine forest in modern vegetation of KP. Humidity variation reconstructed by semi aridity index (AI) indicates that, during 26.1？22.7 cal kyr BP, cold and dry conditions were prevailed with an expansion of subalpine coniferous forest and high value of AI. From 22.5 to 20.5 cal kyr BP, cool and wet conditions were reconstructed with low value of AI due to climatic amelioration, enhanced conifers and temperate deciduous broadleaved mixed forests flourished. Between 20.3 and 20.1 cal kyr BP, an abundance of Picea and Betula associated with high value of AI infers that subalpine conifers forest colonized again in hinterland montane along with open, low grassland under colder and drier conditions owing to climatic deterioration. The principal pollen taxa suggest that prevailing climate conditions were annual mean temperature about 5？6 oC colder and annual mean precipitation 40% drier than today.