荷花覆盖度对衡水湖叶绿素a含量变化的影响

Effect of Lotus Coverage on Chlorophyll-a Content in Hengshui Lake

在衡水湖选取5个荷花样区,在每个样区选择生长状况相对一致的低覆盖度、中覆盖度和高覆盖度位点。2019年5—9月,每月采集水样一次,分别测定叶绿素a含量。结果表明:衡水湖叶绿素a含量变化与荷花覆盖度有关;合适的覆盖度(中覆盖度)对叶绿素a的合成有明显抑制作用;荷花覆盖度对衡水湖叶绿素a含量变化的影响有明显的季节性,6、7月份影响较大,这与荷花及藻类的生长规律有关;6、7月份温度适合荷花的快速生长,对浮游植物藻类的生长形成一个天然的遮光屏障,藻类日照时数降低从而叶绿素a含量也呈现相应变化。加强荷花的科学管理,根据荷花的生长状况及时调整荷花的植株密度和盖度,与此同时,加强湖泊水质的综合管理,预防藻类水华的危害。

Five lotus plots were selected in Hengshui Lake,and low coverage,medium coverage and high coverage sites with relatively consistent growth status were selected in each plot.From May to September in 2019,water samples were collected once a month to determine chlorophyll a content.The results showed that the change of chlorophyll-a content in Hengshui Lake was related to the coverage of lotus.The suitable coverage(medium coverage)could significantly inhibit the synthesis of chlorophyll-a.The effect of lotus coverage on chlorophyll-a content in Hengshui Lake was seasonal.In June and July,the effect is greater,which is related to the growth of lotus and algae.The temperature in June and July is suitable for the rapid growth of lotus,which forms a natural shading barrier for the growth of phytoplankton and algae,and reduces the sunshine hours of algae,resulting in the corresponding change of chlorophyll-a content.It is necessary to strengthen the scientific management of lotus,timely adjust the plant density and coverage of lotus according to the growth status of lotus,and at the same time,strengthen the comprehensive management of lake water quality and prevent the harm of algae bloom.