| 引用本文: | 张程,黄文峰,李瑞,杨惠杰,赵雯,林战举.盐度对湖冰冻结过程中氮磷营养盐排出效应的影响.湖泊科学,2022,34(4):1186-1196. DOI:10.18307/2022.0412 |
| Zhang Cheng,Huang Wenfeng,Li Rui,Yang Huijie,Zhao Wen,Lin Zhanju.The effect of salinity on the exclusion of nitrogen and phosphorus nutrients during freezing. J. Lake Sci.2022,34(4):1186-1196. DOI:10.18307/2022.0412 |
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| 盐度对湖冰冻结过程中氮磷营养盐排出效应的影响 |
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张程1,2, 黄文峰1,3, 李瑞1,2, 杨惠杰1,2, 赵雯1,2, 林战举3
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1.长安大学旱区地下水文与生态效应教育部重点实验室, 西安 710054;2.长安大学水利与环境学院, 西安 710054;3.中国科学院西北生态环境资源研究院冻土工程国家重点实验室, 兰州 730000
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| 摘要: |
| 伴随结冰过程的盐分排出是驱动冰封浅湖营养盐动态变化的关键过程,影响湖泊水质、环境与生态演变.为探究湖冰冻融过程如何改变寒区浅湖营养盐条件,采用自制定向冻结装置开展了无机氮磷营养盐溶液(NH3-N、NO-2-N、NO-3-N、PO3-4-P)的室内冻结试验,结合现场采样分析评估了冻结排出效应对典型浅湖氮磷营养盐的影响.结果表明:营养盐浓度、盐度(以NaCl表征)是影响冻结排出效率的关键因素;随营养盐浓度的升高,冰内营养盐浓度升高,但冻结分离系数减小;若盐度升高,冰内营养盐浓度和分离系数均增大,主要与未冻卤水泡的形成有关;3种形态的无机氮、磷酸根的分离系数均存在明显差异.将试验结果应用于内蒙古乌梁素海结冰期氮磷营养分析,计算表明湖冰冻结排盐过程不仅造成湖水各类营养盐浓度升高,同时改变无机氮素构成、氮磷比等营养结构状态;特别是若湖泊盐度发生变化,氮磷营养盐的冻结排出效率及其差异性均会显著改变,增加冰封期湖泊营养条件的时空变异性.本文结果可广泛应用于定量评价冰层冻融过程对冬季湖泊营养条件的影响,有助于理解冰封期浮游植物群落演变的内在驱动力. |
| 关键词: 湖泊 冰封期 营养盐 盐度 冻结排盐效应 |
| DOI：10.18307/2022.0412 |
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| 基金项目:国家重点研发计划政府间国际科技创新合作重点专项(2019YFE0197600)、冻土工程国家重点实验室开放基金(SKLFSE201813)和中央高校基本科研业务费项目(300102299103,300102291507)联合资助. |
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| The effect of salinity on the exclusion of nitrogen and phosphorus nutrients during freezing |
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Zhang Cheng1,2, Huang Wenfeng1,3, Li Rui1,2, Yang Huijie1,2, Zhao Wen1,2, Lin Zhanju3
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1.Key Laboratory of Subsurface Hydrology and Ecological Effects(the Ministry of Education), Chang'an University, Xi'an 710054, P. R. China;2.School of Water and Environment, Chang'an University, Xi'an 710054, P. R. China;3.State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Ecology, Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
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| Abstract: |
| The salt exclusion during water icing is one of the key processes that drive the dynamic changes of nutrient salts in frozen shallow lakes, and also affect the lake water quality, environment and ecological evolution. In order to explore how the lake freezing and melting processes change the nutrient conditions in the cold region shallow lakes, indoor freezing experiments of inorganic nitrogen and phosphorus nutrient solution (NH3-N, NO-2-N, NO-3-N, PO3-4-P) were carried out. With the help of field sampling analysis, the effect of the freezing exclusion was estimated on nitrogen and phosphorus nutrient conditions in a typical shallow lake. The results show that the nutrient concentration and salinity (characterized by NaCl) are key factors affecting the efficiency of freezing exclusion. As the nutrient concentration increases in the freezing water, the concentration in the ice increases and the freezing separation coefficient decreases. If the water salinity increases, both the nutrient concentration in the ice and the freezing separation coefficient increase, which is mainly related to the formation of unfrozen brine channels and pockets. There are remarkable differences in the separation coefficients of the three forms of inorganic nitrogen and phosphate. The experimental results were used to analyze the dynamics of nitrogen and phosphorus nutrients in Lake Wuliangsuhai during the freezing period. The calculation indicated that freezing exclusion does not only increase the concentration of nutrients, but also changes the nutritional structure such as inorganic nitrogen composition and nitrogen-phosphorus ratio. Especially if the lake salinity (salt content) changes, the freezing exclusion efficiency of nitrogen and phosphorus nutrients and their difference will change significantly, and the spatiotemporal variability of lake nutrient conditions will increase during the ice-covered period. These results benefit quantifying the changes in winter nutrient conditions induced by lake ice freezing and melting and help understanding the inner regime of phytoplankton community changes during the ice-covered period. |
| Key words: Lakes ice-covered period nutrients salinity salt exclusion of freezing |
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