| 外源营养盐输入后水体中营养盐浓度的时空变化 |
| 摘要点击 1750 全文点击 1068 投稿时间：2013-08-02 修订日期：2013-09-17 |
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| 中文关键词 外源营养盐 富营养化 氮循环 水污染 时空变化 |
| 英文关键词 exogenous nutrient eutrophication nitrogen circulation water pollution spatial and temporal variations |
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| 中文摘要 |
| 在温室内的水泥沟渠中人工构建6种不同的植物镶嵌群落，通过人工添加营养盐的方式模拟外源营养盐输入，并持续测量单次营养盐添加后22 d内水体表层、中层和底层可溶性总氮（DTN）、可溶性总磷（DTP）、氨氮（NH4+-N）、硝氮（NO3--N）以及亚硝氮（NO2--N）浓度变化情况，以揭示单次外源营养盐输入后水体营养盐浓度的时空变化过程. 结果表明：1不同水深和测量时间下各形态营养盐浓度有显著差别，植物群落类型对不同形态营养盐浓度影响不显著；2外源营养盐进入表层水体后扩散到中层水体的过程较为缓慢，在本实验条件下需要6 d；3实验过程中底层水体NO2--N以外的其它营养盐浓度均无显著变化，外源营养盐输入仅影响表层和中层水体营养盐浓度；4单次外源营养盐输入一定时间后DTP和NH4+-N浓度逐渐下降到输入前水平，本实验条件下这一过程需要22 d，DTN和NO3--N浓度则下降非常缓慢；5外源营养盐输入水体后不同深度水体中NO2--N浓度均呈上升趋势，一方面说明外源营养盐输入后，水体N循环过程中的硝化作用和反硝化作用加强，另一方面也说明外源营养盐输入除危害水生生态系统健康以外更会直接危及人类自身的健康. |
| 英文摘要 |
| In order to study the spatial and temporal variations of nitrogen (N) and phosphorous (P) nutrition in artificial wetlands after a single exogenous nutrient input, 6 mosaic communities of 7 plant species were set up in a cement channel in the greenhouse. After the addition of N and P nutritional solutions, the concentrations of dissolved total nitrogen (DTN), dissolved total phosphorous (DTP), ammonia nitrogen (NH4+-N)、nitrate nitrogen (NO3--N) and nitrite nitrogen (NO2--N) in the surface, middle, and bottom layers of the bulk water were determined regularly within 22 days. The results show that: 1the water depth and measuring date have significant effects on nutritional contents while the type of plant communities have no such an influence; 2the diffusion of nutrient from surface to the middle water layers is relatively slow, which costs 6 days under the current experimental condition; 3in the bottom water layer, nutritional concentrations had no significant changes except for NO2-N, thus the exogenous nutrient input mainly affects the nutrient contents of surface and middle-level bulk water; 4DTP and NH4+-N contents gradually decline to similar levels that before the nutritional input event until the end of experimental period, though DTN and NO3--N content decrease much more slowly; 5the fact that NO2--N contents rise in water layers of all depths demonstrates that nitrification and denitrification in the process of N circulation are enhanced. It is concluded that exogenous nutrient inputs not only harm aquatic ecosystems but also directly threat human health. |
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