夏季富营养化滆湖中沉水植物群落重建及水质净化效果

Reconstruction and water purification of submerged macrophytes community in eutrophicated Gehu Lake during summer

通过滆湖原位围隔试验分析了不同单种及混种沉水植物群落随环境变化的生长状况及对水质的净化效果。结果表明:(1)夏季,沉水植物生物量的平均值与透明度/水位存在显著线性相关性,进一步表明沉水植物的生长在很大程度上依赖于光强和水深。(2)各植物区(除马来眼子菜区外)的高锰酸盐指数、TN高于空白对照区。(3)对比空白对照区,苦草区、金鱼藻区、金鱼藻-伊乐藻区对NH3-N、TP、叶绿素a的去除率都在25%以上。对比敞水区,金鱼藻-伊乐藻区、苦草-马来眼子菜区、苦草-伊乐藻区对TP的去除率分别为33.5%、20.8%、9.9%;金鱼藻-伊乐藻区对叶绿素a的去除率为41.4%。(4)TP和叶绿素a存在显著线性关系,反映了沉水植物可通过对TP的去除有效控制藻类的生长。(5)苦草、金鱼藻-伊乐藻群落、苦草-马来眼子菜群落对水体中NH3-N、TP、叶绿素a的平均去除速率(V)都符合V—时间(t)回归方程。(6)在沉水植物群落恢复中可优先考虑金鱼藻-伊乐藻、苦草-马来眼子菜群落等有稳定及较高平均去除速率的沉水植物群落重建形式。

In-situ enclosure experiment was conducted in Gehu Lake to investigate the effect of environmental change on growth and purification performance of different single and mixture submerged macrophytes community.Results showed that the average biomass of submerged macrophytes was significant linearly correlated with transparency and water level,which indicated that the growth of submerged macrophytes was highly dependent on the light intensity and water depth.The permanganate index and TN in test area were higher than that in control area except for the test area planting Potamogeton malaianus.Compared with control area,planting Vallisneria spiralis,Ceratophyllum demersum and Ceratophyllum demersum-Elodea nuttallii could removal more than 25% of NH3-N,TP and chlorophyll-a;Compared with water open area,TP removal rate in test area of planting Ceratophyllum demersum-Elodea nuttallii,Vallisneria spiralis-Potamogeton malaianus,Vallisneria spiralis-Elodea nuttallii was 33.5%,20.8% and 9.9% respectively;Chlorophyll-a removal rate in Ceratophyllum demersum-Elodea nuttallii planting area was 41.4%.There is a significantly linear relation between TP and chlorophyll-a,so submerged macrophytes could effectively control the algae growth through the TP removal.The average removal rate of NH3-N,TP and chlorophyll-a in Vallisneria spiralis,Ceratophyllum demersum-Elodea nuttallii community and Vallisneria spiralis-Potamogeton malaianus community were consistence with V-t regression equation.The communities of Ceratophyllum demersum-Elodea nuttallii and Vallisneria spiralis-Potamogeton malaianus which had perfect stability and water purification efficiency were best for the submerged macrophytes community reconstruction.