磁湖叶绿素a时空分布特征及环境因子影响分析

Correlation of Temporal and Spatial Distribution of Chl.a with Environmental Factors in Cihu Lake

2013年分四季监测了磁湖10个位点的水质状况,分析了磁湖叶绿素a的时空分布特点及其与环境因子之间的关系。结果表明,磁湖叶绿素a平均值为14.86μg/L,已处于富营养化状态。不同季节的叶绿素a浓度无显著性差异(P>0.05);叶绿素a浓度呈现空间差异性,南磁湖的水体叶绿素a浓度较高。磁湖水体叶绿素a浓度与TN显著性正相关(P<0.05),与其他环境因子无显著相关性,水体叶绿素a浓度的变化受多种环境因子综合影响。对磁湖与其他富营养化水体的叶绿素a及氮、磷浓度对比,结果表明在富营养水体中氮磷比是影响叶绿素a的重要因子。磁湖水体中Cd、Ni、Fe含量较高,且多种重金属的联合效应抑制了藻类的光合作用,致使水体中叶绿素a含量较低。

Water samples at ten sites in Cihu Lake were collected from April 2013 to December 2013 every season in order to analyze the temporal and spatial distribution of chlorophyll-a in the Lake and its correlation with environmental factors. Results showed that average concentration of Chl.a in the Lake was 14.86 μg/L, which indicated that the water was eutrophic. Chl.a concentrations of various seasons had no significant differences and Chl.a concentration appeared obvious spatial difference from ten sites, with higher values occurred in the south Lake. There was significant positive correlation between the concentration of Chl.a and the concentration of TN, while no significant correlation between the concentration of Chl.a and other environmental factors. By comparing the concentration of Chl.a, TN and TP in the Lake and other eutrophic water bodies, N/P ratio was an important factor affecting the concentration of Chl.a. In addition, high concentration of Cd, Ni, Fe and the joint effect of heavy metals inhibited the algae＇s photosynthesis, resulting in the decrease of Chl.a content in the Lake.