Palynological reord of paleovegetation change during holocene at north tumd plain in inner mongolia, China

摘要

In this paper, the Holocene paleoenvironment change sequence in middle Inner Mongolia was primarily re- constructed on the basis of palynological analysis at the resolution of 70 years profile, which was located in the northern part of Tumd Plain with its oldest age of 9100 a. B.P.As the consequence indicated, the Holocene climate change in the middle Inner Mongolia had undergone cool→temperate→warm→temperate→cool series, and the history could be divided in to 7 epochs: 9100-7400 a B.P., with slightly arid and cold climate; 7400-5000 a B.P., transitory climate with dynamic fluctuation, earlier period temperate and slightly arid, and later temperate and slightly hu- mid; 5000-4100 a B.P., with warm and humid climate; 4100-1350 a B.P., with transitory climate getting arid, as the result of human being's growing influence; 1350 a B.P.-present, with temperature and slightly arid climate, under strong influence of human being. The warm period of Holocene occurred in 7400-4000 a B.P., while the optimal period occurred in 5000-4100 a B.P.