白洋淀菹草不同生长期生物量与水质指标动态变化

Biomass of Potamogeton crispus and dynamic change of water quality on different growth periods in Baiyangdian lake

以白洋淀王家寨淀区菹草为对象,分别在菹草返青期、指数生长期、芽殖体发生期和植株衰亡期,对各采样点菹草的生物量以及该采样点在各时期的水质、底泥和菹草植株中的氮磷含量进行分析。结果表明:菹草指数生长期,生物量增大,淀区水体的溶解氧含量升高,最大值可达9.30 mg/L,化学需氧量、氨氮、总氮、总磷和正磷酸盐含量大幅下降,最大的去除能力分别为:321.7,71.1,108.7,1.9,1.03 mg/(kg.d)。有菹草种群分布的区域各项指标含量明显优于无种群区域。菹草生长吸收底泥中的氮、磷及有机质,并可抑制底泥中污染物质的释放。菹草进入衰亡期后,体内释放出营养盐,造成二次污染,应在5月初,菹草产生芽殖体后,对菹草进行收割,收割的菹草具有广阔的资源化利用空间。

The Potamogeton crispus collected from Wangjiazhai in Baiyangdian Lake was studied in the period of turn green,exponential growing stage,the bud emergence and the decline phase,and its biomass,water and sediment of different sampling points and the content of nitrogen and phosphorus therein were analyzed.The results showed that Potamogeton crispus biomass increased at the exponential growing stage with greater concentration of dissolved oxygen,the largest content being 9.30 mg/L;chemical oxygen demand,ammonia nitrogen,total nitrogen,total phosphorus and orthophosphate levels declined in Wangjiazhai area of Baiyangdian Lake,the largest removal capacity being 321.7,71.1,108.7,1.9,1.03 mg/（kg·d）.The content in the area with Potamogeton crispus was significantly better than the area without Potamogeton crispus.Potamogeton crispus growth absorbed the nitrogen,phosphorus and organic matter from the sediments,and inhibited the pollutants release from the sediment.When Potamogeton crispus enters into the decline phase,the nutrients release from the body,causing secondary pollution.During the budding process,the Potamogeton crispus should be harvested for wider application.