Community Structure Of Metazoan Zooplankton In Xingkai Lake

The wetland is one of most important and multi-functional ecosystems on the earth, known as "kidney of the earth".The ecological study of zooplankton was conducted on eleven typical sampling stations selected in Xingkai Lake wetland Nature Reserve,in spring,summer and autumn in 2007.Zooplankton communities and biodiversity were examined with multivariate statistic analysis.The Pearson analysis and gray association analysis were used to detect the correlation between zooplankton and environmental factors.The purpose of this paper was to provide a guideline of management and a foundation for the future study in Xingkai Lake wetland Nature Reserve.Total of 17 species were identified,which are cladocerans(4 families 4 species) and copepods(4 families 4 species).The total mean abundance and biomass were 3.9ind./L and 0.268mg/L.Common species of zooplankton throughout the year has Epischura chankensis, Tropocyclop sprasinus breviramus,Eucyclops rerrulatus serrulatus.There were different ranges in different diversity index,Shannon-Veane' index from 2.62 to 3.12,Pielou' index from 0.47 to 0.69 respectively.Seasonal variation of Shannon-Veaner' index were summer＞spring＞autumn and Pielou' index were autumn＞summer＞spring.The hierarchical cluster analysis revealed that the zooplankton community structure were obviously different at different sampling stations in Xingkai Wetland Nature Reserve, and the phytoplankton community structure in Xingkai Lake wetland Nature Reserve was classed three groups,the comparability is high within groups and the great change between groups.The results of nor-matric multidimentional scaling(MDS) was same of the hierarchical cluster analysis,and showed the change was for the change of zooplankton factor and vegetation.Based on Pearson analysis,the results showed that the zooplankton varied with the changes of environmental factors.Water temperature was positively related to the abundance and biomass(p＜0.01,p＜0.05).Correlation between Chla and abundance,biomass was positively significant at 0.01 level and in spring,but in summer and autunm was negatively (p＜0.05,p＜0.01).The phytoplankton abundance and biomass were positively correlated-to transparency in three seasons,and their correlation was not significant(p＞0.05).The relationship between zooplankton abundance,biomass and PH was negatively,and positively significant between PH and zooplankton in spring and summer(p＜0.01).The result of grey relational analysis suggested that the correlation between zooplankton abundance,biomass and various environmental factors were different.The factor which seriously influenced zooplankton density was water temperature in spring and Chla in summer;and the factor which seriously influenced zooplankton biomass was Chla in spring, summer and autumn.