Nitrogen concentration response to the decline in atmospheric nitrogen deposition in a hypereutrophic lake.
Nitrogen concentration response to the decline in atmospheric nitrogen deposition in a hypereutrophic lake.
复制标题
DOI：
10.1016/j.envpol.2022.118952
复制
发表时间：
2022-02
影响因子：
8.9
通讯作者：
Xingyu Jiang;G. Gao;Jianming Deng;G. Zhu;Xiangming Tang;Keqiang Shao;Yang Hu
中科院分区：
文献类型：
--
作者：
Xingyu Jiang;G. Gao;Jianming Deng;G. Zhu;Xiangming Tang;Keqiang Shao;Yang Hu
大气氮（N）沉降正成为影响湖泊营养水平的一个越来越重要的因素，特别是考虑到发达地区对外部N输入的长期控制措施。然而，很少有研究探讨了大气氮沉降的影响和富营养化沃茨各自的生态意义。基于2010-2018年高分辨率（周或月）系统观测资料，研究了太湖水体氮素的整体和湿沉降速率以及水体氮素浓度。结果表明，风速的降低和土地利用类型的改变可能会降低氮沉降速率。氮沉积速率从2012年的45.77 kg N ha− 1 yr − 1下降到2018年的22.06 kg N ha− 1 yr − 1，粗略估算，这可以解释太湖氮浓度下降1.01 mg N L− 1，该值接近太湖氮浓度的实际变化。氮浓度与大气沉降通量的相关性强于与河流输入或湖泊储存的相关性，进一步表明大气氮沉降的变化是氮浓度变化的主要原因。太湖氮的直接沉积量分别占河流氮输入量和湖泊氮存量的17.5%和51.4%。此外，大气氮沉降集中在夏季，这是占主导地位的还原氮，这可能是重要的藻类水华的持续时间。因此，应进一步控制包括大气氮沉降在内的外源氮输入，以有效缓解太湖富营养化和水华。
Atmospheric nitrogen (N) deposition is becoming an increasingly important factor affecting the nutrient level of lakes, especially considering the long-term control measures for external N inputs in developed regions. However, few studies have investigated the effects of atmospheric N deposition and the respective ecological significance in eutrophic waters. In this study, bulk and wet deposition rates of all N species and water N concentrations in Lake Taihu were determined based on the long-term (2010–2018) high-resolution (weekly or monthly) systematic observations. The results indicated that the decline in wind speed and change in land-use type likely decreased the N deposition rate. The bulk N deposition rates decreased from 45.77 kg N ha−1yr−1in 2012 to 22.06 kg N ha−1yr−1in 2018, which could account for decrease of 1.01 mg N L−1in the lake N concentrations via a rough estimation, and this value was close to the actual variation in N concentration in Lake Taihu. The correlation between N concentrations and atmospheric deposition fluxes was stronger than that between N concentrations and riverine N inputs or lake storage, which further indicated that change in atmospheric N deposition was the key reason for the variation in N concentrations. The direct bulk N deposition into Lake Taihu accounted for 17.5% and 51.4% of the riverine N inputs and lake N inventory, respectively. Moreover, atmospheric N deposition was concentrated in summer, which was dominated by reduced N, and it may be important for the duration of algal blooms. Therefore, external N inputs, including atmospheric N deposition, should be further controlled for an effective mitigation of eutrophication and algal blooms in Lake Taihu.