气候变化领域集成服务门户(CCPortal): Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai-Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions

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DOI	10.5194/bg-12-3141-2015
	Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai-Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions
	Ding, S.; Xu, Y.; Wang, Y.; He, Y.; Hou, J.; Chen, L.; He, J. -S.
通讯作者	Xu, Y (通讯作者)
发表日期	2015
ISSN	1726-4170
EISSN	1726-4189
起始页码	3141
结束页码	3151
卷号	12 期号:11
英文摘要	The methylation index of branched tetraethers (MBT) and cyclization ratio of branched tetraethers (CBT) based on the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGT) are useful proxies for the reconstruction of mean annual air temperature (MAT) and soil pH. Recently, a series of 6-methyl brGDGTs were identified which were previously co-eluted with 5-methyl brGDGTs. However, little is known about 6-methyl brGDGTs in the Qinghai-Tibetan Plateau (QTP), a critical region of the global climate system. Here, we analyze 30 surface soils covering a large area of the QTP, among which 6-methyl brGDGTs were the most abundant components (average 53 +/- 17% of total brGDGT). The fractional abundance of 6-methyl brGDGTs showed a good correlation with soil pH, while the global MBT'(5ME) calibration overestimates MAT in the QTP. We therefore proposed a MBT5/6 index including both 5- and 6-methyl brGDGTs, presenting a strong correlation with MAT in QTP: MAT = -20.14 + 39.51 x MBT5/6 (n = 27; r(2) = 0.82; RMSE=1.3 degrees C). Another index, namely IBT (isomerization of branched tetraether), based on carbon skeleton isomerization of the 5-methyl to 6-methyl brGDGTs, is dependent on soil pH: pH = 6 .77-1.56 x IBT (n = 27; r(2) = 0.74; RMSE = 0.32). Our study suggests that changing the position of methyl group of brGDGTs may be another mechanism for some soil bacteria to adapt to the ambient pH change in addition to the well-known cyclization.
关键词	CHAIN ALKENONE DISTRIBUTIONS GDGT-BASED PROXIES MEMBRANE-LIPIDS LAKE QINGHAI TEMPERATURE SEDIMENTS WATER CALIBRATION UPLIFT RECONSTRUCTION
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Geology
WOS类目	Ecology ; Geosciences, Multidisciplinary
WOS记录号	WOS:000356179800001
来源期刊	BIOGEOSCIENCES
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258449
推荐引用方式 GB/T 7714	Ding, S.,Xu, Y.,Wang, Y.,et al. Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai-Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions[J]. 中国科学院青藏高原研究所,2015,12(11).
APA	Ding, S..,Xu, Y..,Wang, Y..,He, Y..,Hou, J..,...&He, J. -S..(2015).Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai-Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions.BIOGEOSCIENCES,12(11).
MLA	Ding, S.,et al."Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai-Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions".BIOGEOSCIENCES 12.11(2015).