Winter-spring precipitation as the principal control on predominance of C-3 plants in Central Asia over the past 1.77 Myr: Evidence from delta C-13 of loess organic matter in Tajikistan

doi:10.1016/j.palaeo.2005.11.007

	Winter-spring precipitation as the principal control on predominance of C-3 plants in Central Asia over the past 1.77 Myr: Evidence from delta C-13 of loess organic matter in Tajikistan
	Yang, SL; Ding, ZL
刊名	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
	2006-06-14
卷号	235 期号:4 页码:330-339
关键词	carbon isotopes of organic matter C-3 and C-4 plants loess precipitation seasonality climate zones Central Asia
ISSN号	0031-0182
DOI	10.1016/j.palaeo.2005.11.007
文献子类	Article
英文摘要	Although changes in atmospheric CO2 levels are thought to be the major factor driving long-term C-3/C-4 vegetation evolution, recent studies tend to emphasize the effect of regional climate conditions on C-3/C-4 variations. The middle latitudes (30-45 degrees), in which C-3/C-4 plants are highly sensitive to environmental changes, provide an optimal basis for the investigation of the relative impacts of climate and pCO(2) on shifts in C-3/C-4 Cover. In order to assess the factors controlling these shifts as well as the complex interactions between environmental factors, the carbon isotopic composition of bulk organic matter from the Chashmanigar loess section (southern Tajikistan) was measured for the past 1.77 Myr. In general, the delta C-13 record shows mostly negative values throughout the sequence, almost all delta C-13 values falling between - 23 parts per thousand and - 26 parts per thousand, indicating a predominance of C-3 plants in Central Asia over this time period, despite the presence of numerous glacial-interglacial cycles. From 0.85 Myr to the present, the delta C-13 values become increasingly positive, reflecting a growing C-4 signal. However, this C-4 component is not detectable prior to 0.25 Myr, after which minor peaks are evident at similar to 228, similar to 171 and similar to 18 kyr. The delta C-13 record from Chashmanigar indicates that winter-spring precipitation, i.e., Mediterranean climatic conditions, have characterized Central Asia throughout the past 1.77 Myr, leading to the predominance of C-3 vegetation. In the context of glacial-interglacial-scale changes in atmospheric CO2, therefore, it is climate rather than pCO(2) that controls C-3/C-4 variations in Asia's middle latitudes. The gradual increase in the C-4 component since 0.85 Myr, especially the notable peaks after 0.25 Myr, may have been caused by an increase in summer precipitation due to an enhanced southward shift of the climate zones. (c) 2005 Elsevier B.V. All rights reserved.
WOS关键词	ATMOSPHERIC CARBON-DIOXIDE ; GLACIAL-INTERGLACIAL VARIATIONS ; CHINESE LOESS ; DOMINANT CONTROL ; CLIMATE-CHANGE ; ICE CORE ; ISOTOPE ; PLATEAU ; PHOTOSYNTHESIS ; STRATIGRAPHY
WOS研究方向	Physical Geography ; Geology ; Paleontology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000238297900002
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/67078]
专题	中国科学院地质与地球物理研究所
通讯作者	Yang, SL
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Yang, SL,Ding, ZL. Winter-spring precipitation as the principal control on predominance of C-3 plants in Central Asia over the past 1.77 Myr: Evidence from delta C-13 of loess organic matter in Tajikistan[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2006,235(4):330-339.
APA	Yang, SL,&Ding, ZL.(2006).Winter-spring precipitation as the principal control on predominance of C-3 plants in Central Asia over the past 1.77 Myr: Evidence from delta C-13 of loess organic matter in Tajikistan.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,235(4),330-339.
MLA	Yang, SL,et al."Winter-spring precipitation as the principal control on predominance of C-3 plants in Central Asia over the past 1.77 Myr: Evidence from delta C-13 of loess organic matter in Tajikistan".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 235.4(2006):330-339.