Holocene Vegetation and Climate Changes in the Huangqihai Lake Region, Inner Mongolia  

作　　者：TIAN Fei WANG Yong ZHAO Zhili LI Yang DONG Jin LIU Jin LING Yuan YUAN Lupeng YE Mengni 

机构地区：[1]Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [2]China Solibase Engineering Co.,Ltd.,Beijing 101300,China [3]School of Civil and Architecture Engineering,Xi'an Technological University,Xi'an 710021,China

出　　处：《Acta Geologica Sinica(English Edition)》2020年第4期1178-1186,共9页地质学报（英文版）

基　　金：funded by the Geological Survey Projects of China(Grant Nos.DD20190370 and DD20190009);supported by Natural Science Foundation of Shaanxi Province,China(Grant No.2019JQ-835);Research Foundation of Education Bureau of Shaanxi Province,China(Grant No.2019JK-0404)。

摘　　要：A consensus on Holocene climate variability at the modern northern fringe of the East Asian summer monsoon(EASM) region remains elusive. Here, we present a pollen-based reconstruction of vegetation history and associated climate variations of a sediment core from Huangqihai Lake, central Inner Mongolia. During 10.7 to 8.8 cal kaBP, typical steppe with small patches of forest dominated the lake area, suggesting a moderately wet climate, followed by ameliorating climatic conditions until 8.0 cal kaBP as deduced by the expansion of forest. Typical steppe recovered the lake area between 8.0 and 7.2 cal kaBP, reflecting a deterioration of climatic conditions;in combination with other proxy records in the study region, we noticed that severe aridity was prevailed in the lake area between 8.0 and 7.6 cal kaBP. During 7.2 to 3.2 cal kaBP, abundant tree pollen indicated dominance of forest-steppe around the lake, marking regionally wet conditions. A notable absence of broadleaved trees after 5.2 cal kaBP reveals a slight drying trend, and climate deterioration from 4.5 to 4.1 cal kaBP might be linked to the 4.2 ka event. After 3.2 cal kaBP, a transition to steppe was associated with dry conditions in the region. Based on our pollen record and prior paleoclimatic reconstructions in the Huangqihai Lake region, there was a generally-accepted, stepwise shift to a wet climate during the early Holocene, an overall humid climate from 7.2 to 3.2 cal kaBP, and then severe drought for the rest of the Holocene. Moreover, regional comparisons among pollen records derived from lakes situated in the temperate steppe region suggested a roughly synchronous pattern of vegetation and climate changes during the Holocene and demonstrated an intensified EASM during the middle Holocene.

关 键 词：POLLEN PALEOVEGETATION HOLOCENE East Asian summer monsoon Huangqihai Lake 

分 类 号：P532[天文地球—古生物学与地层学] Q948[天文地球—地质学]