| 引用本文: | 于志同,王秀君,赵成义,兰海燕.基于多指标分析的博斯腾湖表层沉积物有机碳来源.湖泊科学,2015,27(5):983-990. DOI:10.18307/2015.0526 |
| YU Zhitong,WANG Xiujun,ZHAO Chengyi,LAN Haiyan.Source characterization of organic carbon using elemental, isotopic and n-alkanes proxies in surface sediment from Lake Bosten, Xinjiang. J. Lake Sci.2015,27(5):983-990. DOI:10.18307/2015.0526 |
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| 摘要: |
| 通过有机碳稳定同位素(δ13Corg)、有机碳、氮含量及其比值(C:N)的测定,结合已有的正构烷烃空间分布特征数据,对新疆博斯腾湖表层沉积物的有机碳来源进行综合研究. 结果表明:博斯腾湖表层沉积物δ13Corg 值在-26.7‰~-24.1‰之间波动,变幅较小;C:N的波动范围为4.8~8.5,平均值约为7.4;正构烷烃的碳数分布范围为nC13~nC35,所有采样点样品的主峰碳以nC17和nC23为主. 参考博斯腾湖文献调查资料,基于δ13Corg值、C:N及正构烷烃等指标的空间分布状况,发现博斯腾湖表层沉积物中的有机碳主要来自湖泊内部浮游生物的残体;而不同湖区沉积物有机碳的内、外源贡献比例不同,其中陆源碎屑、挺水植物、沉水植物的贡献空间差异较大. 博斯腾湖有机碳来源的空间差异主要表现在湖泊东部近岸水域表层沉积物有机碳主要为外源贡献,中心湖泊东部和西部浅水区表层沉积物有机碳由外源和内源共同贡献,而其余大部分水域表层沉积物有机碳则主要为内源贡献. |
| 关键词: 博斯腾湖 有机碳来源 C:N 有机碳稳定同位素 正构烷烃 |
| DOI：10.18307/2015.0526 |
| 分类号: |
| 基金项目:中国科学院战略性先导科技碳专项(XDA05020202)、中德合作项目(GZ867)和国家自然科学基金项目(41403072)联合资助. |
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| Source characterization of organic carbon using elemental, isotopic and n-alkanes proxies in surface sediment from Lake Bosten, Xinjiang |
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YU Zhitong1,2,3, WANG Xiujun1, ZHAO Chengyi1, LAN Haiyan2
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1.State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, P. R. China;2.College of Resources and Environmental Sciences, Xinjiang University, Urumqi 830046, P. R. China;3.University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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| Abstract: |
| Lake sediment is an important carbon reservoir thus plays a role in the terrestrial carbon cycle. However, little is known on the dynamics and sources of organic carbon in the lake surface sediment from northwest China. In this paper, we applied element analyses, isotopic and n-alkanes approach to study the sources of organic carbon in the Lake Bosten, the largest inland lake in Xinjiang. We found that there was some spatial variability in C:N (4.8-8.5) and stable carbon isotopic composition in δ13Corg values (-26.7‰ to -24.1‰). The carbon numbers of n-alkanes ranged from C13 to C35, with the dominating compounds C17 and C23 in most samples. Further analyses showed that organic carbon in the surface sediments was generally from the autochthonous sources. There existed a relatively large spatial variability in contributions from different sources. According to the lake survey data and the spatial distribution characteristic of C:N, δ13Corg and n-alkanes, we estimated that the organic carbon sources in the east near-shore lake area, central-east section and western shallow lake area, and the other lake parts were mainly attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively. |
| Key words: Lake Bosten sources of organic carbon C:N δ13Corg n-alkanes |
