Choosing a suitable epsilon(w-p) by distinguishing the dominant plant sources in sediment records using a new Pta index and estimating the paleo-delta D-p spatial distribution in China

doi:10.1016/j.orggeochem.2018.01.002

	Choosing a suitable epsilon(w-p) by distinguishing the dominant plant sources in sediment records using a new Pta index and estimating the paleo-delta D-p spatial distribution in China
	Cao, Yunning 2; Liu, Hu 1,2; Wang, Zheng 2
刊名	ORGANIC GEOCHEMISTRY
	2018-07-01
卷号	121 期号:1 页码:161-168
关键词	Leaf Delta D-wax Vegetation Effect Pta Index Paleo-delta D-p Reconstruction Arid Semi-arid
DOI	10.1016/j.orggeochem.2018.01.002
文献子类	Article
英文摘要	The hydrogen isotopic composition of plant wax (delta D-wax) inherits the isotopic values of the source water and isotopic fractionation that take place in lipid biosynthesis. The delta D-wax values of n-alkanes or n-acids in sediment records are considered to be effective paleo-delta D for precipitation proxies for different timescales. However, the vegetation effect also contributes substantially to the apparent fractionation values (epsilon(w-p)) between the precipitation and plant. Therefore, a method for evaluating the dominant plant source in the sediment records is key for reconstructing a reliable paleo-delta D-p record. In this study, based on field data from the extremely arid Qaidam Basin and the semi-arid central Chinese Loess Plateau (CLP), a plant type index (Pta), based on the traditional P-aq and n-alkane C-31/C-29 index, was used to evaluate the dominant plant type that contributed to the sediments. In the arid and semi-arid region, the Pta values of the aquatic plants were <90, while the shrub Pta ranged from 90 to 180 and the grass Pta was >180. A test on contemporary soils and surface lake sediments also showed that the Pta index could estimate the regional vegetation distribution in modern environments. We also evaluated the dominant n-alkane source for four sediment records in China during the last millennium and reconstructed a regional paleo-delta D-p by choosing a different epsilon(w-p). The estimated paleo-delta D-p values showed a good correlation with the modern regional summer delta D-p. We suggest that a large number of field studies are needed to improve the Pta index for quantitatively calculating the precise ratios for various plant sources. Such data would play a key role in improving hydrogen isotopic hydroclimatic research. (C) 2018 Elsevier Ltd. All rights reserved.
WOS关键词	HYDROGEN ISOTOPIC COMPOSITIONS ; N-ALKANE DISTRIBUTIONS ; QINGHAI-TIBET PLATEAU ; LAKE-SEDIMENTS ; D VALUES ; TERRESTRIAL PLANTS ; LIPID BIOMARKERS ; AQUATIC PLANTS ; LEAF WAXES ; RECONSTRUCTION
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000434096000015
内容类型	期刊论文
源URL	[http://ir.ieecas.cn/handle/361006/5140]
专题	地球环境研究所_加速器质谱中心
作者单位	1.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, IEE, Xian 710075, Shaanxi, Peoples R China
推荐引用方式 GB/T 7714	Cao, Yunning,Liu, Hu,Wang, Zheng. Choosing a suitable epsilon(w-p) by distinguishing the dominant plant sources in sediment records using a new Pta index and estimating the paleo-delta D-p spatial distribution in China[J]. ORGANIC GEOCHEMISTRY,2018,121(1):161-168.
APA	Cao, Yunning,Liu, Hu,&Wang, Zheng.(2018).Choosing a suitable epsilon(w-p) by distinguishing the dominant plant sources in sediment records using a new Pta index and estimating the paleo-delta D-p spatial distribution in China.ORGANIC GEOCHEMISTRY,121(1),161-168.
MLA	Cao, Yunning,et al."Choosing a suitable epsilon(w-p) by distinguishing the dominant plant sources in sediment records using a new Pta index and estimating the paleo-delta D-p spatial distribution in China".ORGANIC GEOCHEMISTRY 121.1(2018):161-168.