不同基质下菹草的生长及其对水体营养盐的吸收

Growth of Potamogeton crispus L. and its influence on the water quality under different substrate types

设置两组实验分别研究不同基质对菹草生长繁殖的影响以及菹草对不同基质下水体营养盐的吸收净化作用.结果表明:湖泥、混合基质及黄土三种基质对菹草的生物量变化及石芽的形成有比较明显的差别,氮磷养分含量高的湖泥更有利于菹草植株的生长,其生物量增长幅度最大,混合基质次之,氮磷含量最低的黄土最差;黄土基质下菹草石芽产生的时间最早;混合基质下产生石芽数量最多.3、4月份菹草水体中不同形态的氮浓度均低于空白组,最大净化效率达74%,构成水体营养盐氮的汇;菹草对不同基质下水体中氮的净化效率表现为:湖泥>混合底泥>黄土;菹草对水体磷的控制吸收作用不明显,甚至有加快磷转换释放的作用;6月份处于腐败分解阶段的水草组水体营养盐浓度普遍高于对照组,构成水体营养增加的源.

Two groups of experiments were set up to study the growth and reproduction of Potamogeton crispus L.and the absorption of Potamogeton crispus L.to nutrients in the water body on different substrates.The results showed that lake mud,mixed substrate and loess had different effect on the growth of plants.The formation of turion appeared earliest under loess-substrate and the number was highest under mixed-substrate.Different forms of nitrogen concentration in experimental group were lower than the control group,with the largest removal efficiency up to 74% during March and April.The purification efficiencies of water under three kinds of substrates was as follows：lake mud 〉mixed sediment 〉loess.Absorption of phosphorus of P.crispus was not obvious,however,P.crispus speeded up the transformation and the release.Nutrient concentration in the water under experimental groups was generally higher than control groups in the decomposition phase of the group of water plants.