| 长江中游浅水湖泊沉积物碳氮同位素特征及其来源分析 |
| Carbon and Nitrogen Isotope Characterization and Source Analysis of Sediments from Shallow Lakes in the Middle of Yangtze River |
| 投稿时间：2017-03-24 修订日期：2018-11-17 |
| DOI：10.15928/j.1674-3075.2018.06.002 |
| 中文关键词:长江中游 湖泊沉积物 草藻型湖泊 碳氮稳定同位素 有机指数 |
| 英文关键词:middle Yantze River lakes lake sediment macrophytic and algal lakes carbon and nitrogen isotopes organic index |
| 基金项目:科技基础性工作专项“中国东部湖泊沉积物底底质点差”课题（2014FY110400-1）；国家自然科学基（31300395）；教育部高等学校博士学科点专项科研基金（2013341820007）；中科院南京地湖所湖泊与环境国家重点实验室开放基金（2014SKL008） |
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| 中文摘要: |
| 通过分析长江中游湖北地区4个浅水湖泊（鲁湖、花马湖、野潴湖、三山湖）沉积物中的有机碳（TOC）、总氮（TN）、碳氮比（C/N）、碳稳定同位素（δ13C）以及氮稳定同位素（δ15N），探究藻型湖泊和草型湖泊沉积物间碳、氮稳定同位素组成差异性，并进行了有机污染评价和有机质与氮素来源分析。结果表明，4个浅水湖泊的有机污染严重，鲁湖、花马湖、野潴湖、三山湖的平均有机指数分别为0.86、1.05、0.53和2.71，均达到了有机污染的程度，平均有机氮污染指数分别为0.34、0.36、0.21和0.54，均达到了有机氮污染程度；藻型湖泊（花马湖和鲁湖）沉积物中δ13C和δ15N的变化范围分别为-3.126%～-2.260%和0.291%～0.731%，均值分别为（-2.885±0.275）%（n=10）和（0.486±0.168）%（n=10）；草型湖泊的δ13C、δ15N变化范围分别为-3.048%～-2.494%和0.411%～0.830%，均值分别为（-2.766±0.213）% （n=10）和（0.617±0.183）%（n=10），藻型湖泊的δ13C要更加偏负，草型湖泊的δ15N更加偏正；利用C/N与δ13C对有机质来源进行定性分析，发现浮游植物的沉积构成了藻型湖泊沉积物有机质的主要成分，而草型湖泊中浮游植物、土壤有机质和维管束植物均有贡献。利用C/N与δ15N对沉积物氮素来源进行半定量分析，发现本研究所选取湖泊的沉积物氮行为与湖泊的草藻形态没有显著相关关系，需更详细的物源信息才可确定氮素来源。 |
| 英文摘要: |
| A Large number of shallow lakes spread over Hubei province from the middle Yantze River. In recent years, the number of macrophytic lakes is decreasing, while the number of algal lakes is increasing. Because macrophytic and algal lakes represent different responses to human activities, an analysis of the differences in sources of organic matter for the two lake types is important for improving both treatment of organic pollutants and lake water quality. In October 2014, we investigated TOC and TN, C/N ratios, δ13C and δ15N values in the sediments of four shallow lakes in Hubei Province (Luhu Lake, Hamu Lake, Yezhu Lake, and Sanshan Lake). The level of organic pollution in each lake, sources of organic matter and nitrogen, and differences in δ13C and δ15N between the macrophytic and algal lakes were analyzed. Luhu Lake and Hamu Lake are phytoplankton-dominated lakes with an aquatic plant covers of 4% and 12%, and phytoplankton densities of 1.88×108 ind/L and 1.77×108 ind/L, respectively. Yezhu Lake and Sanshan Lake are macrophytic-dominated lakes with aquatic plant covers of 73% and 29%, and phytoplankton densities of 1.08×108 ind/L and 1.05×108 ind/L, respectively. Surface sediments were sampled at five sites in each lake. The organic indices (OI) of Luhu Lake, Hamu Lake, Yezhu Lake, Sanshan Lake were, respectively, 0.89, 1.05, 0.53 and 2.71, indicating a high level of organic pollution. The corresponding organic nitrogen indices were 0.34, 0.36, 0.21 and 0.54, all at level Ⅳ nitrogen pollution. The behavior of carbon and nitrogen in the four lakes displayed some similarities. The δ13C and δ15N ranges in the algal lakes were from -3.126% to -2.260% and 0.291% to 0.731%, with average values of (-2.885±0.275)% (n=10) and (0.486±0.168% (n=10). The δ13C and δ15N ranges in macrophytic lakes were from -3.048% to -2.494% and 0.411% to 0.830%, with average values of (-2.766±0.213)% (n=10) and (0.617±0.183)% (n=10). There were high negative δ13C values in algal lakes and high positive δ15N values in macrophytic lakes. Qualitative analysis of organic matter source based on C/N and δ13C indicated that organic matter in algal lake sediments originated primarily from phytoplankton, while the primary sources of organic matter in macrophytic lake sediments was phytoplankton, soil organic matter and macrophytes. Semiquantitative analysis of nitrogen sources based on C/N and δ15N showed no significant correlation between sediment nitrogen and lake type, indicating that tracking sources of nitrogen will require considerably more information. |
| 冀文豪,郭匿春,徐 军,余 辉,牛 远.2018.长江中游浅水湖泊沉积物碳氮同位素特征及其来源分析[J].水生态学杂志,39(6):8-15. |
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