Community Structure Characteristics and the Maximum Biomass Estimation of Submerged Macrophytes in Erhai Lake

In this study,Erhai Lake in Yunnan province was chosen as the research object to evaluate the biodiversity,biomass,and vertical distribution pattern of submerged macrophytes in the growing season (September,2017). The results showed that there were 13 submerged macrophytes species in Erhai Lake,belonging to 8 genera,6 families,including Potamogetonaceae (5 species),Hydrocharitaceae (3 species),Najadaceae (2 species),other species accounted for 23. 1% of submerged macrophyte species. The absolute dominant species in the lake wereCeratophyllumdemersum (37. 74%), Potamogetonmaackianus (21. 87%) and Vallisnerianatans (16. 70%). The biodiversity of submerged macrophyte species varied with water depth,which was 2. 0 ～ 4. 0 m (12 species) >0. 0 ～ 2. 0 m (11 species) >4. 0 ～ 6. 1 m (8 species). The biomass of submerged macrophtyes reached its maximum value in water depth between 2. 0 and 4. 0 m. There are 3 submerged macrophyte communities according to the dominant species and their community,which are communities of Ceratophyllumdemersum +Potamogetonmalaianus + Hydrillaverticillata,C. demersum + P. maackianusand C. demersum. The total biomass (fresh weight) of the whole lake was about 160,900 tons. This research showed that the species abundance of submerged macrophyte in the lake was relatively abundant with relatively higher biomass. However,in order to prevent its degradation in the further,the change dynamic of submerged macrophytes in this lake should be paid more attention to.