| 夏季太湖草/藻型湖区N2O生成与迁移特征及其影响因素 |
| 摘要点击 1935 全文点击 717 投稿时间：2017-09-24 修订日期：2017-11-11 |
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| 中文关键词 水生植物 水-气界面 水-土界面 N2O通量 影响因素 太湖 |
| 英文关键词 aquatic plants water-gas interface sediment-water interface N2O flux influencing factors Taihu Lake |
| 作者 | 单位 | E-mail | | 郑小兰 | 中国科学院大学, 北京 100049
中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008 | zxlan7182@163.com | | 文帅龙 | 中国科学院大学, 北京 100049
中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008 | | | 李鑫 | 中国科学院大学, 北京 100049
苏州科技大学环境科学与工程学院, 苏州 215000 | | | 龚琬晴 | 中国科学院大学, 北京 100049
中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008 | | | 刘德鸿 | 中国科学院大学, 北京 100049
南京师范大学地理科学学院, 南京 210023 | | | 钟继承 | 中国科学院大学, 北京 100049 | jczhong@niglas.ac.cn |
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| 中文摘要 |
| 多生态类型湖泊N2O生成与排放的空间异质性给准确地估算湖泊N2O通量及评估湖泊N2O排放的重要性带来了很大的不确定性，有关多生态类型湖泊N2O生成与排放特征及内在机制的研究相对较少.本研究对夏季太湖典型草/藻型湖区水-气界面N2O通量、水体溶存浓度以及水-土界面N2O通量进行了原位观测及室内分析，并针对影响N2O生成与排放的主要环境因子进行了室内微环境实验.结果表明，夏季水-气界面N2O通量、水体溶存N2O浓度及水-土界面N2O通量大致上呈现为挺水植物湖区 > 藻型湖区 > 沉水植物湖区，水-气界面通量分别为（115.807±7.583）、（79.768±1.842）和（3.685±0.295）μmol·（m2·h）-1；水体溶存N2O浓度分别为：（0.051±0）、（0.029±0.001）和（0.018±0）μmol·L-1，水-土界面通量分别为：（178.275±3.666）、（160.685±0.642）和（75.665±1.016）μmol·（m2·h）-1；空间差异原因可归结为生长的植物以及水体中无机氮浓度的差异.水-土界面微环境实验结果表明，外加硝酸盐及有机碳源可以显著增加沉积物N2O生成潜力，而上覆水中高浓度NH4+-N会抑制沉积物N2O生成，随温度升高，沉积物N2O生成速率显著增加，这表明夏季水-土界面N2O的生成与排放主要受硝酸盐及有机碳的限制，同时也受温度的影响. |
| 英文摘要 |
| Spatial heterogeneity of N2O generation and emissions in multi-ecotype lakes limited the accurate estimation of the N2O fluxes in lakes, but few studies on the characteristics of N2O generation and emissions have been conducted. In this study, N2O flux at the water-gas interface, dissolved N2O concentration in the water column, and N2O flux at the sediment-water interface in typical grass-type and algal-type zones of Taihu Lake were analyzed during summer, and indoor micro-environment experiments were conducted to illustrate the main factors affecting the generation and emissions of N2O. The results showed that the N2O fluxes at the water-gas interface, dissolved N2O concentration, and N2O fluxes at the sediment-water interface of the emergent macrophyte type area was higher than the algae-type area and submerged macrophyte area during the summer., with N2O fluxes at the water-gas interface of (115.807±7.583), (79.768±1.842), and (3.685±0.295) μmol ·(m2 ·h)-1, respectively. The dissolved N2O concentration in the water column were (0.051±0), (0.029±0.001), and (0.018±0) μmol ·L-1, respectively; and the N2O fluxes at the sediment-water interface were (178.275±3.666), (160.685±0.642), and (75.665±1.016) μmol ·(m2 ·h)-1, respectively. The spatial difference could be attributed to dominant plants and the concentration of inorganic nitrogen in the water column. The results of micro-environment experiments showed that nitrate and organic carbon sources could significantly increase the N2O production potential of sediments, the high concentration of NH4+-N in the water column might inhibit the N2O production in sediments, and the production rates of N2O in the sediment increased remarkably when the incubation temperature increased, suggesting that the generation and emissions of N2O were mainly restricted by nitrate, organic carbon, and temperature in summer. |
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