DOI: 10.1016/j.palaeo.2015.01.005
论文题名: Hydrological and ecosystem response to abrupt changes in the Indian monsoon during the last glacial, as recorded by sediments from Xingyun Lake, Yunnan, China
作者: Wu D. ; Zhou A. ; Chen X. ; Yu J. ; Zhang J. ; Sun H.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 421 起始页码: 15
结束页码: 23
语种: 英语
英文关键词: Abrupt change
; Ecosystem
; Indian summer monsoon
; Lake level
; Last glacial
; Xingyun Lake
英文摘要: The Indian Summer Monsoon (ISM) is the major moisture source of precipitation in southwest China and plays an important role in regional environmental change and in economic and social development, since abrupt changes of the ISM can cause crop failures and flooding that impact the livelihood of a large population. However, with the exception of speleothem records, abrupt changes of the ISM during the last glacial are not well documented in terrestrial records. Here we present a sediment record from Xingyun Lake in Yunnan Province, southwest China, spanning the interval 36.4kaBP to 13.4kaBP (1ka=1000cala) which documents the occurrence of a series of millennial-scale episodes which may reflect the abrupt weakening of the ISM. Seven AMS 14C dates from terrestrial wood fragments provide a robust chronology. The results demonstrate that increases in the coarse sediment fraction (>30μm) correspond to increases in the concentration of Pediastrum, the grain size of magnetic minerals, carbonate content and C/N ratios, which together indicate episodes of low lake level. In addition, pollen analysis indicates that Quercus (oak) increased and that ferns decreased during intervals of abrupt weakening of the ISM, indicating a drier environment. Nine abrupt shifts to a low lake level are documented for the studied interval and three of them are correlative with Heinrich events 1 to 3. Our study supports the hypothesis that, in response to the cold events in the North Atlantic associated with massive iceberg influxes and the corresponding slowing down of Atlantic meridional overturning circulation, the mean latitudinal extent of the ITCZ shifted southwards. As a result of an atmospheric teleconnection there was a corresponding decrease in precipitation associated with ISM precipitation, which caused reduced fluvial runoff in Yunnan. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69023
Appears in Collections: 过去全球变化的重建
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作者单位: MOE Key Laboratory of Western China's Environmental Systems, Collaborative Innovation Centre for Arid Environments and Climate Change, Lanzhou University, Lanzhou, China; Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, China; College of Tourism and Geography Science, Yunnan Normal University, Kunming, China
Recommended Citation:
Wu D.,Zhou A.,Chen X.,et al. Hydrological and ecosystem response to abrupt changes in the Indian monsoon during the last glacial, as recorded by sediments from Xingyun Lake, Yunnan, China[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,421