不同底泥处理对软叶丁香蓼去除水体中氮素的影响

选用沉水植物软叶丁香蓼(Ludwigia hyssopifoliaExell)为材料,结合不同的底泥处理,在人工模拟条件下研究了水体中几种氮形态变化的影响.结果表明,开始阶段因裸露底泥处理会向水体中释放出不同形态的氮素,使水体总氮含量有所增加.但试验的后期因软叶丁香蓼对铵态氮,尤其是对硝态氮的吸收作用,以及底泥中大量硝化和反硝化菌参与的硝化反硝化作用,会使软叶丁香蓼配合裸土的处理加快水体中氮的去除.在处理50 d后,软叶丁香蓼 裸露底泥(植物裸土)的处理和软叶丁香蓼 包裹底泥(植物包土)的处理对氮素的去除已经没有显著差异,说明在一定条件下底泥对水质的影响并非总是负作用,尤其在与一些高等水生植物组成的生态系统中能起到营养物质"库"的作用.

Effects of SuBmerged Macrophyte on Water Nitrogen in Ludwigia hyssopifolia Exell Combined with Sediments

In our experiment,we chose the submerged macrophyte Ludwigia hyssopifolia Exell combined sediment as different treatments.Under artificial condition,we studied the change of different forms of nitrogen.The results indicated that: at the beginning of experiment with the exposed sediment treatment,several forms of nitrogen released from the sediment,perhaps disturbed by planting submerged macrophyte,but with the time passing,submerged macrophyte absorbed more NO-3-N,and through the nitrification and denitrification supported by sediment, more nitrogen will be removed.At 50 days,between first treatment and second treatment there was no significant difference for the nitrogen removal.So we concluded that under a certain condition,sediment may have positive effect on the nitrogen removal,especially on the eco-system consisting of macrophyte.