白洋淀围隔中不同生物组合调控水质实验

In situ Enclosure Experiment on Influence of Different Biological Combination on Water Quality in Baiyangdian Lake

在白洋淀建成10个原位围隔,研究穗花狐尾藻(Myriophyllum spicatum)、金鱼藻(Ceratophyllum demersum)、圆顶珠蚌(Unio douglasiae)和圆顶珠蚌+金鱼藻等不同生物组合在调控水体富营养化方面的效能与稳定性。在围隔中,分别种(投)入密度为10株/m2穗花狐尾藻、20株/m2金鱼藻、195 g/m2圆顶珠蚌和20株/m2金鱼藻+195 g/m2圆顶珠蚌。结果表明,穗花狐尾藻和金鱼藻能有效控制浮游植物的生物量,并改善水体透明度,使水体中总氮含量和总磷含量明显下降,透明度增加,浮游植物多样性明显增加,水体富营养化指数明显下降;圆顶珠蚌对水体中的总氮、总磷和叶绿素a有一定的去除作用,但对水体透明度、氨氮含量和营养状态影响不大;金鱼藻和圆顶珠蚌组合的水体净化效果要优于单一种植金鱼藻和穗花狐尾藻。

In Baiyangdian Lake, 10 situ enclosures （9 m2 each） were constructed, which were selected for Myri- ophyllum spicatum, Ceratophyllum demersum, Unio douglasiae and the combination of the last two species be- ing planted with different density （10 individual/m2, 20 individual/m/, 195 g/m2, 20 individual/m2＋ 195 g/m2）, respectively. As a result of 6 weeks＇ observations, the biomass of phytoplankton decreased and the transparen- cy of water improved in enclosures. Especiallly the enclosures with 10 individual/m2 of Myriophyllum spica- turn and 20 individual/m2 of Ceratophyllum demersum were improved well, of which total nitrogen and total phophorus contents decreased significantly, the water transparency and the biodiversity of phytoplankton in- creased distinctly. The enclosure with 195 g/m3 of Unio douglasiae removed total nitrogen, total phophorus and chlorophyll-a with some degree, but had no effect on water transparency, nitrate nitrogen and comprehen- sive nutrition state index. Combined with Unio douglasiae and Ceratophyllum demersum could maintain water transparency in an optimum condition, and the purification effect brought by the combination was better than that with only submerged macrophytes.