| Macrobenthos can influence the material circulation,energy flow and information transfer in water bodies and is a key member in maintaining a healthy ecosystem of water bodies.Macrobenthos can promote the decomposition of organic matter in the sediment through its own ingestion,accelerate the migration and transformation of pollutants,enhance the self-purification of water bodies,and enable macrobenthos to be used as food by other organisms.Therefore,it is of great significance to study the structure of macrobenthic community and its relationship with water environmental factors to understand the structure and function of macrobenthos in lakes and to rationally use lake water resources and biological resources.Chagan Lake is located in the western part of Jilin Province,where the Nenjiang River and the Huolin River meet,and is composed of lakes,swamps,meadows,and other ecological systems.It is also an important fishery base in Jilin Province,China.One of the top ten freshwater lakes.It is also a national nature reserve and it is of great significance to the ecological stability in the west of Jilin Province.Domestic research on Chagan Lake macrobenthos is rare.In this study,Chagan Lake was used as the study area.Samples of water samples and macrobenthos were collected from mid April to September 2017.Statistical methods such as field sampling,monitoring,and clustering were analyzed.Characteristics of community structure,dominant species,diversity,and community structure of macrobenthos community,and their correlation with water environmental factors.The specific results are as follows:?1?The t-test analysis showed that there were significant differences in water-environmental factor between the rainy season and the intermediate season of Chagan Lake in Jilin Province.In 2017,the total organic carbon?TOC?rainy season in Chagan Lake was significantly lower than that in the intermediate season?p<0.001?,the rainy season in phosphate was significantly lower than that in the intermediate season?p=0.007?,and the nitrite nitrogen abundance was significantly lower.During the water level of Yu Ping?p<0.001?,the pH of the rainy season was significantly higher than that of the intermediate season?p<0.001?,and the abundance of dissolved oxygen was significantly higher than that of the intermediate season?p<0.001?.The rainy season was significantly higher than the intermediate season?p<0.001?.?2?During the study period,184 large macrobenthos species were identified in Chagan Lake,which was subordinated to 3 species,3 classes,5 orders,9 families,18 genera,and 24species.The main sites were molluscs and arthropods,among which were arthropods.5genera and 5 species,accounting for 20.83%;molluscs,12 genera and 18 species,accounting for 75%;1 species of annelids is 1 species.The average density in the intermediate season was 93.71 ind·m-2,and the average density in the rainy season was 69.71 ind·m-2.There was no significant difference in the density of macrobenthos between rainy season and the intermediate season?p=0.637?.The dominant species in the intermediate season are Limnodrilus helveticus,Procladius choreus,Valvata cristata,and Valvata sibirica;the dominant species in the rainy season is Limnodrilus helveticus,Gyraulus albus and Valvata cristata.?3?A spatial analysis of the benthic diversity index in the rainy season and the intermediate season in the study area was conducted.During the rainy season and the intermediate season,the macrobenthos biological index in the central region was in a relatively high state and the eastern part was in a low state;the macrobenthos in the west was diverse.The western macrobenthos diversity index was at a relatively high level in the intermediate season and low in the rainy season.Based on the cluster analysis of Bray-Curtis similarity calculations,we can see that the types of macrobenthos in Chagan Lake have different spatial agglomeration characteristics during the rainy season and the intermediate season,which may be related to the change of water quality during the rainy season and the intermediate season and the change of habitat environment.?4?Correlation analysis showed that the Shannon-Wiener diversity index of macrobenthos was significantly and positively correlated with nitrite nitrogen in the f intermediate season.Margalef species richness index and Shannon-Wiener diversity index of macrozoobenthos in the rainy season were positively correlated with temperature.The results of correlation analysis showed that the Shannon-Wiener diversity index of macrobenthic was positively correlated with nitrite nitrogen?r=0.84,p=0.037?in the rainy season,and the Margalef species richness index?r=0.957,p<0.001?and Shannon-Wiener diversity index?r=0.894,p=0.024?was significant positive correlation with temperature.The research aimed at the actual needs of Chagan Lake ecological protection in Jilin Province.The research on the macrobenthos community structure and water quality in Chagan Lake of Jilin Province can provide important basis for the scientific and efficient implementation of the western ecological water supply project and the protection of the Chagan Lake ecosystem.At the same time,there are relatively few such studies on Chagan Lake,and the research results have certain reference significance for the development of related research in Chagan Lake. |
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