滆湖底质特性对菹草(Potamogeton crispus)和伊乐藻(Elodeanattalii)生长的影响

摘要

通过模拟试验,研究滆湖3种沉积物(表层湖泥、硬底湖泥、表层覆岸泥)对菹草和伊乐藻生长的影响.结果表明,生长于表层湖泥、硬底湖泥、表层覆岸泥的菹草和伊乐藻生物量分别为4.07、1.98、3.69kg/m2和1.86、1.27、1.74kg/m2,表层湖泥较适合这两种沉水植物生长.3种沉积物对菹草和伊乐藻的干湿比影响显著,硬底湖泥>表层湖泥>表层覆岸泥.在表层覆岸泥和表层湖泥中,两种沉水植物的叶绿素含量均较高,伊乐藻在不同沉积物中差别最大,叶色区别明显.丙二醛的测定结果进一步表明硬底湖泥不适宜植物生长.试验结果表明菹草和伊乐藻在滆湖不同的沉积物上能够正常生长,表现出良好的适应性,菹草适合在表层湖泥中生长,伊乐藻更适合在表层覆岸泥中生长,通过对涌湖不适宜的底质环境进行改造,以利于沉水植物的生长繁殖,为滆湖生态修复中的基质修复与沉水植被重建提供理论指导.%Using mesocom experiment, this paper studied the effects of three different sediments ( surface mud, hard mud and surface mud of bank sediment) of Lake Gehu on the growth of two submerged macrophytes, Potamogeton crispus and Elodea nattalii.When grown on surface mud, hard mud and surface mud of bank sediment, the mean biomass of P. crispus and E. nattalii were 4.07,1.98,3.69 kg/m2and 1.86,1.27,1.74 kg/m2, respectively. All the tested species grown on hard mud had the lowest biomass and shoot height. The wet and dry ratio of P. crispus and E. nattalii was affected significantly by the sediments followed with an order of hard mud ＞ surface mud ＞ surface mud of bank sediment. The contents of chlorophyll-a and chlorophyll-b on the surface mud with bank sediment and surface mud were both higher than those cultured on the hard mud. The difference of leaf colour of E.nattalii between the three sediments was remarkable. The measurement of malondialdehyde further suggested that hard mud was not good for the growth of the two submerged macrophytes. Finally the results showed that the two submerged macrophytes were able to gow normally under conditions of different sediments from Lake Gehu. P. crispus grew well on surfurce mud while E. nattalii was more adapted to surface mud of bank sediment. Sediment rehabilitation should be made in order to facilitate the growth of submerged macrophytes of Lake Gehu and give a guide on sediment rehabilitation and the submerged macrophytes restoration of Lake Gehu.