Community characteristics of benthic macroinvertebrates and identification of environmental driving factors in rivers in semi-arid areas - A case study of Wei River Basin, China

The characteristics of the benthic community structure can effectively reflect the health status of the river ecosystem and the quality of the river ecological environment. It is of great significance to identify the limiting factors of benthic community structure for the maintenance of river ecosystem health. As a typical semi-arid ecological fragile area, the eco-environmental problems in the Wei River basin have become increasingly prominent. The benthic community structure is affected by multiple stresses such as habitat degradation and water quality deterioration. In this study, 18 national monitoring stations were selected to investigate the ecological environment and benthic invertebrate community characteristics in the Wei River basin in October 2019. W-statistics, Shannon-Winer index, Pielou index, Margalef index, and B-IBI index were selected to evaluate the community characteristics of benthic macroinvertebrates from three aspects of the community stability, community diversity, and community integrity. Principal component analysis, Pearson correlation analysis, and canonical correspondence analysis were used to analyze the correlation and variability between zoobenthos community index and environmental factors. The results showed that the spatial difference of benthic community structure in the Wei River basin was not significant, and the Sal, NH3-N, Tub, DO in water environment and heavy metals in sediment were the main environmental factors affecting the community structure of benthos. Improving water quality and controlling pollution were the main strategies to improve benthic biodiversity and promote sustainable development in the Wei River basin.