Practice of Establishing Aquatic Vegetation in Lake Lianhuahu in Wuhan,China

Lake Lianhuahu locates in Wuhan city,which is in the middle reach of Yangtze River.It is a hypereutrophic,small and shallow lake,which consists of Lake Small Lianhuahu and Lake Large Lianhuahu.The water quality of it was worse than Class Five(water quality standard of China).Within 2-3 years pioneer submersed plant community dominanted by Elodea nuttallii was established by sewage interception,fish removing,phytoplankton controlling and transplanting submersed plants etc.in Lake Small Lianhuahu.In the springs of 2004 and 2005,the coverage of submersed vegetation was 98% and 95%,respectively.Water bloom was controlled,and the water quality was improved.To transplant Elodea nuttallii,Potamogeton crispu in winter when water level is lower and its transparence is higher than other season is an effective way to establish pioneer submersed plant community.Due to the pioneer community dominanted by submersed macrophytes E.nuttallii or P.crispu was unsteady,it is necessary to improve the structure of plant community and enhance the stability by enriching the species of established community.In the early time after the establishment,plant community was very weak that strong fluctuations of major environment factors could easily destroy the community.So it is necessary to keep the factors steady,such as forbidding breeding aquatics fish,preventing the abruptly increase of sewage load and stabilizing water level etc.