Study On The Correlation Between The Diversity Of Plankton Algae And Macrobenthos And Environmental Factors In The Yong'an River Basin,Changzhou City,Jiangsu

In this study,10 sampling points were set up in the Yong'an River Basin in Wujin District,Changzhou City,Jiangsu Province.Water samples and sediment samples from the study area were collected in March,August,November,and February 2019,and were measured Physical and chemical factors of the water body,monitoring the community composition of plankton algae and macrobenthos,and analyzing aquatic biodiversity.The study aims to explore the response relationship between aquatic biodiversity and environmental factors in the Yong'an River Basin,provide ecological suitability index data for monitoring and restoration evaluation of river ecosystems,and provide a theoretical basis for ecological protection and pollution restoration and management of rivers in Changzhou City.The results of measuring the environmental factors of the Yongan River Basin show that:on the time scale,in March 2018,EC,COD and NH₃-N were higher,and Chl-a was lower;in August 2018,EC and COD were relatively higher Low,TP and Chl-a are higher;TP and NH₃-N are lower in November 2018;NH₃-N is higher in February 2019 and WT is lower.On the spatial scale,Cross River EC,COD and Chl-a are higher,TP and NH₃-N are lower;Tangmenbang TP and NH₃-N are higher,EC,COD and Chl-a are lower.WT has not changed significantly in the three rivers.Pearson correlation analysis shows that NH₃-N and TP have a very significant positive correlation,COD and EC have a very significant positive correlation,and WT and EC have a negative correlation.The results of identification of planktonic algae in the Yong'an River Basin showed that the identified planktonic algae belonged to 8 phyla,11 classes,20 orders,36families and 81 genera.The number of planktonic algae species is relatively small;Cross River,Tangmen Bang and Yong'an River are the most green algae,followed by diatom gate Yong'an River small watershed.The average cell density of plankton algae is 4.039×10⁷ ind./L.The algal cell density is different,and the average cell density of planktonic algae is also different in different rivers.The results of analyzing the biodiversity index of phytoplankton in the Yong'an River Basin show that the average values of the Shannon-Wiener index?H??,Margalef index?H?and Pielou index?J?are all in November 2018.Monthly highest;Shannon-Wiener index?H??:Cross River>Yong'an River>Tangmenbang,Margalef index?H?:Tangmenbang>Yong'an River>Cross River,Pielou index?J?:Cross River>Tangmenbang>Yong'an River.The results of identification and counting of macrobenthos in the Yong'an River Basin showed that the identified macrobenthos belonged to 3 species,4 classes,5 orders,7 families,8 genera and 10 species.There are many species of molluscs,but there are few species of arthropods and arthropods;Glyptotendipes cauliginellus has the largest number in Cross River and Tangmenbang,and there are more Limnodrilus in Yong'an River.The number of macrobenthos is different in each sampling point and different rivers.The average values of H?and H are higher in November 2018 and lower in March 2018;the average value of J is higher in August 2018 and lower in March 2018;H?,H and J:Yong'an River>Cross River>Tangmenbang.The Pearson correlation analysis results of the diversity of planktonic algae and macrobenthos and environmental factors in the Yong?an River Basin showed that planktonic algae H?was significantly negatively correlated with NH₃-N and TP,and J and H were significantly negatively correlated with TP,H?and J are positively correlated with WT,H is negatively correlated with WT;macrobenthos H?is significantly negatively correlated with NH₃-N,J is significantly negatively correlated with NH₃-N,H is correlated with NH₃-N and Chl-a.There is a negative correlation for a,and H?,H,and J are positively correlated with WT.