Spatial distribution and sources of organic carbon in the surface sediment of Bosten Lake, China
Z. T. Yu1,2,3,X. J. Wang1,4,5,E. L. Zhang6,C. Y. Zhao1,and X. Q. Liu7Z. T. Yu et al. Z. T. Yu1,2,3,X. J. Wang1,4,5,E. L. Zhang6,C. Y. Zhao1,and X. Q. Liu7
1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 830011 Urumqi, China
2College of Resources and Environmental Sciences, Xinjiang University, 830046 Urumqi, China
3University of Chinese Academy of Sciences, 100049 Beijing, China
4College of Global Change and Earth System Science, Beijing Normal University, 100875 Beijing, China
5Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, USA
6State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 210008 Nanjing, China
7College of Resource Environment and Tourism, Capital Normal University, 100048 Beijing, China
1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 830011 Urumqi, China
2College of Resources and Environmental Sciences, Xinjiang University, 830046 Urumqi, China
3University of Chinese Academy of Sciences, 100049 Beijing, China
4College of Global Change and Earth System Science, Beijing Normal University, 100875 Beijing, China
5Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, USA
6State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 210008 Nanjing, China
7College of Resource Environment and Tourism, Capital Normal University, 100048 Beijing, China
Received: 09 Jul 2015 – Discussion started: 25 Aug 2015 – Revised: 05 Nov 2015 – Accepted: 10 Nov 2015 – Published: 19 Nov 2015
Abstract. Lake sediment is an important carbon reservoir. However, little is known on the dynamics and sources of sediment organic carbon in Bosten Lake. We collected 13 surface (0–2 cm) sediment samples in Bosten Lake and analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon isotopic composition in TOC (δ13Corg), and grain size. We found a large spatial variability in TOC content (1.8–4.4 %) and δ 13Corg value (−26.77 to −23.98 ‰). Using a three-end-member mixing model with measured TOC : TN ratio and δ13Corg, we estimated that 54–90 % of TOC was from autochthonous sources. Higher TOC content (> 3.7 %) was found in the east and central-north sections and near the mouth of the Kaidu River, which was attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively. The lowest TOC content was found in the mid-west section, which might be a result of high kinetic energy levels. Our study indicated that the spatial distribution of sediment TOC in the Bosten Lake was influenced by multiple and complex processes.
Bosten Lake is the largest inland freshwater lake in China, which has been impacted by land use changes, with implications for carbon burial. Our study showed a large spatial variability in total organic carbon (TOC) (1.8–4.4%); 54–90% of TOC was from autochthonous sources. Higher TOC content was found in the east and central-north sections and near the mouth of the Kaidu River, which was attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively.
Bosten Lake is the largest inland freshwater lake in China, which has been impacted by land use...
