Study On The Temporal And Spatial Variation Zooplankton Community And Their Correlation With Environmental Factors In Muye Lake And The Upriver River Channel

Muye Lake is an artificial lake which was made through widing the WeiHe river by artificial during2009-2010in Xinxiang, and it also has many functions, such as controlling flood and so on. In order tounderstand comprehensive conditions of Muye Lake ecological system and provide scientific evidence forintegrated management and controlling of eutrophication. We made the point sampling survey from July2011to June2012on Muye Lake and the upriver river channel. We set of5samples, from upstream todownstream, S1（Upriver river channel, Labor Bridge）, S2（Upriver river channel, Check sluice）, S3（Themain lake watershed）, S4（The middle of lake）, S5（The middle of second phaselake）. We discussed deeplythe dynamic change of physical and chemical indicators about Muye Lake, community characteristics,dominant species, abundance and abundance index of zooplankton, and analyzed the correlationrelationship of zooplankton abundance and environmental factor, chlorophyll a and environmental factor.The main result showed that:1. We have identified zooplankton （mainly refers to Rotifer, Cladocera, Copepods, the article only dothe number of measurement to Protozoa）23genera43species during the survey. Among them, the Rotifer15genera and26species, which account for the total number of kinds of60﹪, Cladocera5genera and11species, which account for the total number of kinds of26﹪, Copepods6genera and6species, whichaccount for the total number of kinds of14﹪. Dominance analysis showed that Rotifera pot of arm tailwheel bug, needle cluster much limb rotifer, calyx flower arm tail wheel bug, cornu arm tail wheel wormare the main dominant species. The monthly average abundance size of all kinds of group of zooplankton inMuye Lake performanced that Protozoa> Rotifer> Cladocera> Copepods. The monthly averageabundance of protozoa accounted for83%of the total average abundance, zooplankton abundance arealways the most important contribution type. The mean monthly occupancy of abundance of Rotifer is14%and Cladocera, copepods occupies2%and1%respectively.2. The seasonal variation of species number of zooplankton in Muye Lake ranged from3to29, therule of seasonal changement for the performanced that summer> spring> autumn> winter. The spatialchangement showed that S3> S4> S2> S5. Zooplankton abundance index of each sample in Muye Lakeand upriver river channel into the lake ranges from0to2.155. Seen from seasonal distribution, zooplankton abundance index of every point during the late summer is bigger, and it began to decline entering autumn,reaching to the minimum in the winter. As for as the space distribution, the species of centrol lake （S3, S4）are abundant which has one big species richness index.However, the index of rivers into the lake （S2） issmaller, as well as S5.3. There are certain temporal and spatial change in zooplankton abundance of Muye Lake. Theseasonal change of Zooplankton average abundance shows: summer> spring> autumn> winter, besides, itis evedent for the seasonal difference by univariate analysis （p＜0.01）. Also,the spatial variation foraverage total zooplankton abundance shows S3>S2>S5>S4. It conclude by variance analysis that there issignificant difference （p<0.01） among total zooplankton abundance of each point. The environmentalfactors are the important ones that affect zooplankton abundance of Muye Lake, which have certainrelevance with zooplankton abundance. The zooplankton total average abundance of Centrol Lakes has asignificant positive correlation （p<0.01） with chlorophyll a, WT and CODcr, while significantly negativecorrelation with NO₃-N （p=0.006）, SD （p=0.018）. The zooplankton average abundance of Rivers into thelake has significant positive correlation with chlorophyll a, WT.But it has significant negative correlationwith SD, nitrate nitrogen.4. During the investigation, the chlorophyll-a content of all sampels of different season rangs from1.28mgï¹'m^-3to167.44mgï¹'m^-3. Seen from the seasonal changes the chlorophyll-a average concentrationshows that summer> spring> autumn> winter and all points average concentration order shows that S4>S3> S5> S1>S2. The relationship of Chlorophyll-a with environmental factors demonstrate as follows:significant positive correlation with WT and CODcr, significantly negatively correlated with NO₃-N.5. The water quality of Muye Lake and upriver river channel were in severe eutrophication state insummer, autumn, in light-moderate eutrophication state during the whole winter. The water eutrophicationstatus in spring displays obvious changes process from mild, moderate to severe eutrophication. And everysample’s TSI was higher than54, which were close to each other, and they orders S5> S2> S4> S1> S3.It is conclued that the whole lake water was in the eutrophication state.