Zhejiang University, College of Environmental and Resources Sciences, Hangzhou, Zhejiang 310058, China.
Zhejiang University, College of Environmental and Resources Sciences, Hangzhou, Zhejiang 310058, China.
Environ Pollut. 2014 Sep;192:251-8. doi: 10.1016/j.envpol.2014.04.007. Epub 2014 Apr 30.
River health and associated risks are fundamentally dependent on the levels of the primary productivities, i.e., sestonic and benthic chlorophyll-a. We selected a typical urban river system of the Yangtz delta to investigate nutrient and non-nutrient responses of chlorophyll-a contents and to determine biological thresholds of N and P. Results showed the mean contents of sestonic and benthic chlorophyll-a across all sampling points reached 10.2 μg L(-1) and 149.3 mg m(-2). The self-organized mapping analysis suggested both chlorophyll-a contents clearly responded to measurements of N, P, and water temperature. Based on the chlorophyll-a criteria for fresh water and measured variables, we recommend the biological thresholds of N and P for our river system be set at 2.4 mg N L(-1) and 0.2 mg P L(-1), and these be used as initial nutrient reference values for local river managers to implement appropriate strategies to alleviate nutrient loads and trophic status.
河流健康及其相关风险从根本上取决于初级生产力水平，即浮游植物和底栖叶绿素-a。我们选择了长江三角洲的一个典型城市河流系统，以调查叶绿素-a 含量的营养和非营养响应，并确定氮和磷的生物阈值。结果表明，所有采样点的浮游植物和底栖叶绿素-a 的平均含量分别达到 10.2μg/L 和 149.3mg/m2。自组织映射分析表明，叶绿素-a 含量明显响应于氮、磷和水温的测量。基于淡水的叶绿素-a 标准和实测变量，我们建议将我们河流系统的氮和磷生物阈值设定在 2.4mg N/L 和 0.2mg P/L，作为当地河流管理者实施减轻营养负荷和营养状态的适当策略的初始营养参考值。
