Compositions of stable organic carbon and nitrogen isotopes in wetland soil of Poyang Lake and its environmental implications
WANG Mao-lan, LAI Jian-ping, HU Ke-tu, ZHANG Ding-ling
Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
Fifteen wetland soil samples were collected from the Poyang Lake area and its main tributaries (Ganjiang River, Fuhe River, Xinjiang River, Xiushui River and Raohe River). Contents of carbon and nitrogen isotopes in these samples were quantified to identify the sources of organic matter and nitrogen in the wetland soil. The results showed that the total organic carbon (TOC) and the total nitrogen (TN) contents in the Poyang Lake area were in the ranges of 0.45%~1.58% and 0.06%~0.17%, respectively. The TOC and TN contents in its major tributaries were in the ranges of 0.41%~1.18% and 0.05%~0.13%, respectively. The organic carbon isotope composition (δ13C) ranged from -28.35‰ to -18.58‰, while the nitrogen isotope composition (δ15N) was from 3.27‰ to 6.84‰ in the Poyang Lake area wetland soils. In the main tributaries wetland soils, the δ13C and δ15N values ranged from -25.93‰ to -22.66‰ and 2.97‰ to 5.41‰, respectively. The C3 plants were the main sources of the wetland soil organic matter in Poyang Lake area and its main tributaries; however, C4 plants were the main sources in lake entrances. The sources of nitrogen in the wetland soils were mainly from domestic sewage in the Poyang Lake area, except in Wucheng, which was mainly from synthetic fertilizer there. For the major tributaries, the primary sources of nitrogen included domestic sewage, synthetic fertilizer and industrial sewage.
王毛兰, 赖建平, 胡珂图, 张丁苓. 鄱阳湖湿地土壤有机碳氮同位素特征及其环境意义[J]. 中国环境科学, 2016, 36(2): 500-505.
WANG Mao-lan, LAI Jian-ping, HU Ke-tu, ZHANG Ding-ling. Compositions of stable organic carbon and nitrogen isotopes in wetland soil of Poyang Lake and its environmental implications. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(2): 500-505.
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