The vegetation and climate change during Neocene and Early Quaternary in Jiuxi Basin, China
Sporopollen record in the Laojunmiao Section at Yumen in the Hexi Corridor foreland depression at the northern margin of the Tibetan Plateau revealed that during the period of 13.0―11.15 Ma the ecological environment of the Jiuxi Basin is characterized by steppe vegetation and a semi-moist climate. During 11.16―8.60 Ma prevailed forests of cypress and a still warmer, moister climate; steppe vegetation and dry climate began probably at about 8.6 Ma. Although aridification had been relaxed time and again during 8.40―6.93 Ma (forest-steppe, warm-semi-moist), 6.64―5.67 Ma (open-forest and steppe, warmer-semi-moist) and 5.42―4.96 Ma (steppe, semi-arid), the climate in the region became drier and drier in response to the frequent occurrence of aridity during 6.93―6.64 Ma (steppe, semi-arid), 5.67―5.42 Ma (desert-steppe, arid), 3.66―3.30 Ma (desert-steppe, arid) and 2.56―2.21 Ma (desert, arid). Perhaps the important findings of our study are the notable expansion of drought-enduring plants during 3.66―3.30 Ma and about 2.56 Ma and the replacement of vegetation by vast arid desert.
作 者： Ma Yuzhen FANG Xiaomin LI Jijun Wu Fuli ZHANG Jun 作者单位： Ma Yuzhen,LI Jijun,Wu Fuli,ZHANG Jun(Key Laboratory of Western China's Environmental Systems and College of Resources and Environment, Lanzhou University, Lanzhou 730000, China)FANG Xiaomin(Key Laboratory of Western China's Environmental Systems and College of Resources and Environment, Lanzhou University, Lanzhou 730000, China;State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China)
刊 名： 中国科学D辑（英文版） SCI 英文刊名： SCIENCE IN CHINA SERIES D(EARTH SCIENCES) 年，卷(期)： 2005 48(5) 分类号： P5 关键词： Tibetan Plateau Hexi Corridor sporopollen record ecological environment vegetation evolution aridification