浅水富营养水库中藻类生物量与营养盐的关系

Links Between Algae Biomass and Nutrients in a Eutrophic Shallow Lake

在解释为什么蓝藻在淡水藻类群体中会异军突起成为优势种的主要假设中,1983年由Smith提出的'氮磷比理论'可能是最流行的,然而一些质疑的观点也逐渐出现.因此,以天津市于桥水库为例,分析了降雨水文过程与营养盐负荷之间的关系,确定了点源和面源污染对水库富营养化的影响及水库的污染源类型.探讨了氮磷比以及无机氮源与藻类生长之间的关系.主要得出如下结论:于桥水库污染源属于面源污染型,夏季第1场降雨来临的时间决定了夏秋季水库中藻类暴发的时间和程度;水库中充足的营养盐是藻类暴发的诱导因子,低氮磷比不是藻类增殖的条件,而是藻类增殖的结果;叶绿素a(Chl-a)质量浓度与ρ(NH3-N)∶ρ(3NO--N+2NO--N)值呈显著正相关关系,藻类生长大量消耗的无机氮源为3NO--N.

Of the major hypotheses that explain the dominance of blue-algae in fresh water system,the most preva-lent hypothesis might be the rule of the ratio of TN and TP raised by Smith in 1983. However,this hypothesis is also questioned by other researchers. This paper discussed the relationship between precipitation and nutrient loading by using Yuqiao reservoir as an example,and identified the impact of the point and non-point pollution sources on the eutrophication of reservoir and the pollution type of reservoir. It also analyzed the relationship between inorganic ni-trogen and algae growth. This paper drew the following conclusions：The major source of pollution comes from non-point source pollution in the case of Yuqiao reservoir and the timing of first storm in summer is the main forcing factor in determining the time and the extent of an algae bloom;The algae bloom is induced by sufficient nutrient supply in the reservoir,and low the ratio of TN and TP is not the cause for algae bloom but the result of algae growth;The concentration of chlorophyll has a very strong relationship withρ（NH3-N）∶ρ（ 3NO--N＋ 2NO--N）; 3NO--N is the major source of inorganic nitrogen for algae growth.