Phytoplankton Functional Group Characteristics And Eutrophication Evaluation In Jiuli Lake National Wetland Park

The functional group of the Jiuli Lake National Wetland Park is divided.Eight sampling points are set up in the Jiuli Lake National Wetland Park,and they are evenly distributed on the lake surface of the Jiuli Lake National Wetland Park.Degree,phytoplankton community succession process,functional group division.The fuzzy comprehensive evaluation method,BP neural network method and nutrient index method were used to study the eutrophication of Jiuli Lake.Provide certain information and reference for the management and development of Jiuli Lake National Wetland Park.(1)A total of 106 species(genera)of phytoplankton were identified in 7 phyla,among which 43 species were detected in chlorophyta,21 species in diatom,22 species in euglenophyta,accounting for 20.75% of the total phytoplankton,18 species in cyanophyta and 2 species in dinoflagellates.(2)The main dominant species were Arthrospira maxima,Pseudoanabaena sp.,Eerismopedia punctata,and Tetraedron regulare.Pseudoanabaena sp.,Arthrospira maxima,Schroederia sp.,Scenedesmus acuminatus,Scenedesmus armatus var.boglariensis f.bicaudatus,Trachelomonas,Euglena oxyuris.The dominant species in autumn were Pseudoanabaena sp.and Arthrospira maxima.Schroederia sp.,Scenedesmus acuminatus,Scenedesmus armatus var.boglariensis f.bicaudatus,Euglena oxyuris.The dominant species in winter were Pseudoanabaena sp.,Arthrospira maxima,Eerismopedia punctata and Ankistrodesmus angustus.(3)The phytoplankton in jiuli lake are mainly green algae,diatoms,euglenophytes and blue algae.The average density fluctuation range is 5828135-26689915.05 ind./L(4)According to the FG functional area classification method,Jiuli Lake can be divided into 15 functional areas,among which the phytoplankton functional group in spring is mainly D,MP,Y,X1,X2,and W2,and the summer phytoplankton functional group is C,D,Lo,X1,X2,S1,H1,J,W2.The important phytoplankton functional groups in autumn are D,P,S2,Lo,H1,W1,W2,X1,X2,J,S1.Phytoplankton functional groups in winter are B,MP,D,C,X1,J,X2,X1,W1.The only functional group that appears in winter is B.(5)The eutrophication status of Jiuli Lake was evaluated by fuzzy comprehensive evaluation method,BP neural network method and comprehensive nutrient index method.The overall eutrophication of Jiuli Lake water body is relatively high,and the monitoring stations are generally in the middle eutrophic to eutrophic state.(6)Based on the PCA principal component analysis of the succession of phytoplankton functional zones and water physicochemical factors in Lake Jiuli,the relationship between the succession of phytoplankton functional groups and water physicochemical factors in Lake Jiuli is affected by the seasons.