Study On The Temporal And Spatial Variation Phytoplankton Community And Their Correlation With Environmental Factors In Muye Lake And Inflow Rivers

Muye Lake is an artificial lake which was made through widing the WeiHe river by artificial inXinxiang.Built in2009. built in2009,with a total area of2.23×105m2, shoreline length of2700m, anaverage depth of3.5m, water5.0×105m3, is a typical urban shallow lakes.Muye Lake is also the mainplace for residents of Xinxiang’s entertainment, but also has some ecological functions.So we want toimplement the lake water quality and phytoplankton community structure features in water survey, forscientific and reasonable on lake management, prevention and control of eutrophication state, isparticularly necessary. Physical and chemical characteristics of water in the Muye lake have beenanalyzed through the sampling analysis of5samples which were picked from September,2012toAugust,2013.S1located in the upstream channel,was designed with samples which located in the lake ascontrols;S2is located in the lake inlet.S3,S4are located at the lakeshore and the center of the lake,S5islocated in the lake outlet. During the trial we identified the types and numbers of phytoplankton,and usingthe diversity index of water body to classify the eutrophication status of Muye lake.the main result showedthat:1.We have identified phytoplankton72genera146species during the survey. Among them, theCyanophyta13genera and18species, which account for the total number of kinds of12.33﹪,Bacillariophyceae14genera and29species, which account for the total number of kinds of19.86﹪,Euglenophyta5genera and23species, which account for the total number of kinds of15.75﹪,Chlorophyta26genera and58species, which account for the total number of kinds of39.37﹪, Chrysophyta3generaand4species,Xanthophyceae4genera and5species,Cryptophyta5genera and6species, Pyrrophyta2genera and3species.2. The variation of species density of phytoplankton in Muye Lake showed,Chlorophyta(55.25%)> diatoms (23.48%)> Cryptophyta (10.13%)> Cyanophyta (5.51%)> Euglenophyta (3.55%)>Xanthophyta (1.04%)> Chrysophyta (0.96%)> dinoflagellates (0.09%).The minimum value ofphytoplankton density was3.91×106cells/L appear in March, the highest value is8.09×107cells/L appeare in August.3. The classification and identification of the dominant species of phytoplankton in Muye Lakeshowed that: there are31dominant species of phytoplankton in the entire sample period,the maindominant species in the lake are cyanobacteria and algae, including a total of17chlorophyta,5cyanophyta,3diatoms,3Cryptophyta,2Euglenophyta,1Xanthophyta.4. Spatial and temporal variation of phytoplankton: total number of species of phytoplankton wasminimum in December,38species, the highest values occur in September,110species. Several species ofphytoplankton in different seasons are: Fall (average86kinds)> summer (average64kinds)> spring(average53kinds)> winter (average51kinds). Every point of the total number of species of phytoplanktonare as follows:5sample114species with the most species of phytoplankton,110kinds of sample2times,sample no.3, there are108species,4sample only at least101kinds of phytoplankton species quantity.5. Physical and chemical indicators of water: the average temperature in the lake of each sampleis17.48℃in spring,29.13℃in summer,14.93℃in fall,in the winter the temperature is3.63℃.Transparency throughout the year fluctuated between40-210cm.DO change range from1.2to1.2mg/L,the average oxygen was11.3mg/L.CODCr of the average content of change are:49mg/L in the fall and46mg/L in the winter,32mg/L in spring and summer of75mg/L, the average content of CODCris50.5mg/L.TN content fluctuation between2.28~9.8mg/L, the average content of TN is4.8mg/L.TP contentfluctuation between0.05~2.41mg/L, the average content of TP is0.65mg/L.6. The average density of phytoplankton has a significant positive correlation with CODCr、WT（p<0.05）.It also has certain positive correlation with TN、TP、NH4+-N, but did not reach significant leveland has certain negative correlation between NO-3-N, but did not reach significant level.7. According to the diversity index of phytoplankton. Water quality of each sampling pointsthroughout the year are in the moderately polluted or heavily polluted state.