Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai-Tibet Plateau: importance of source and permafrost degradation

doi:10.5194/bg-15-6637-2018

	Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai-Tibet Plateau: importance of source and permafrost degradation
	Wang, Yinghui 1; Spencer, Robert G. M.; Podgorski, David C.; Kellerman, Anne M.; Rashid, Harunur ; Zito, Phoebe 4; Xiao, Wenjie 1; Wei, Dandan ; Yang, Yuanhe5 ; Xu, Yunping
	2018
发表期刊	BIOGEOSCIENCES
ISSN	1726-4170
卷号	15 期号:21 页码:6637-6648
摘要	The Qinghai-Tibet Plateau (QTP) accounts for approximately 70% of global alpine permafrost and is an area sensitive to climate change. The thawing and mobilization of ice-rich and organic-carbon-rich permafrost impact hydrologic conditions and biogeochemical processes on the QTP. Despite numerous studies of Arctic permafrost, there are no reports to date for the molecular-level in-stream processing of permafrost-derived dissolved organic matter (DOM) on the QTP. In this study, we examine temporal and spatial changes of DOM along an alpine stream (3850-3207 m above sea level) by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), accelerator mass spectrometry (AMS) and UV-visible spectroscopy. Compared to downstream sites, dissolved organic matter (DOM) at the headstream site exhibited older radiocarbon age, higher mean molecular weight, higher aromaticity and fewer highly unsaturated compounds. At the molecular level, 6409 and 1345 formulas were identified as unique to the active layer (AL) leachate and permafrost layer (PL) leachate, respectively. Comparing permafrost leachates to the downstream site, 59% of AL-specific formulas and 90% of PL-specific formulas were degraded, likely a result of rapid in-stream degradation of permafrost-derived DOM. From peak discharge in the summer to low flow in late autumn, the DOC concentration at the headstream site decreased from 13.9 to 10.2 mg L-1, while the C-14 age increased from 745 to 1560 years before present (BP), reflecting an increase in the relative contribution of deep permafrost carbon due to the effect of changing hydrological conditions over the course of the summer on the DOM source (AL vs. PL). Our study thus demonstrates that hydrological conditions impact the mobilization of permafrost carbon in an alpine fluvial network, the signature of which is quickly lost through in-stream mineralization and transformation.
学科领域	Ecology ; Geosciences, Multidisciplinary
DOI	10.5194/bg-15-6637-2018
收录类别	SCI
语种	英语
WOS关键词	SOLID-PHASE EXTRACTION ; MOLECULAR-WEIGHT ; CHEMICAL-COMPOSITION ; CARBON DOC ; MASS ; PERSISTENCE ; RESOLUTION ; CLIMATE ; THAW ; SOIL
WOS记录号	WOS:000449542900002
出版者	COPERNICUS GESELLSCHAFT MBH
文献子类	Article
出版地	GOTTINGEN
EISSN	1726-4189
资助机构	National Basic Research Program of ChinaNational Basic Research Program of China [2014CB954001] ; China Scholarship CouncilChina Scholarship Council ; NSFNational Science Foundation (NSF) [DMR-1157490]
作者邮箱	ypxu@shou.edu.cn
作品OA属性	gold, Green Submitted
引用统计	被引频次：18[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ibcas.ac.cn/handle/2S10CLM1/20475
专题	植被与环境变化国家重点实验室
作者单位	1.Shanghai Ocean Univ, Coll Marine Sci, Shanghai Engn Res Ctr Hadal Sci & Technol, Shanghai 201306, Peoples R China 2.Peking Univ, Coll Urban & Environm Sci, Key Lab Earth Surface Proc, Minist Educ, Beijing 100871, Peoples R China 3.Spencer, Robert G. M.; Kellerman, Anne M.] Florida State Univ, Natl High Magnet Field Lab, Geochem Grp, Tallahassee, FL 32306 USA 4.Spencer, Robert G. M.; Kellerman, Anne M.] Florida State Univ, Dept Earth Ocean & Atmospher Sci, Tallahassee, FL 32306 USA 5.Univ New Orleans, Pontchartrain Inst Environm Sci, Dept Chem, New Orleans, LA 70148 USA 6.Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change, Beijing 100093, Peoples R China
推荐引用方式 GB/T 7714	Wang, Yinghui,Spencer, Robert G. M.,Podgorski, David C.,et al. Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai-Tibet Plateau: importance of source and permafrost degradation[J]. BIOGEOSCIENCES,2018,15(21):6637-6648.
APA	Wang, Yinghui.,Spencer, Robert G. M..,Podgorski, David C..,Kellerman, Anne M..,Rashid, Harunur.,...&Xu, Yunping.(2018).Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai-Tibet Plateau: importance of source and permafrost degradation.BIOGEOSCIENCES,15(21),6637-6648.
MLA	Wang, Yinghui,et al."Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai-Tibet Plateau: importance of source and permafrost degradation".BIOGEOSCIENCES 15.21(2018):6637-6648.

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