Community Structure Characteristics of Macroinvertebrate from Yichang to Wuhan in the Middle Reaches of the Yangtze River

CHEN Xiufen1, XIA Wei2, PAN Baozhu3, XU Xuming1, NI Jinren4,†

1. School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055; 2. Jingjiang Headquarters of Changjiang Waterway Bureau, Jingzhou 434000; 3. Institute of Water Resources and Hydro-electric Engineering, Xi’an University of Technology, Xi’an 710048; 4. The Key Laboratory of Water and Sediment Sciences (MOE), College of Environmental Sciences and Engineering, Peking University, Beijing 100871; † Corresponding author, E-mail: nijinren@iee.pku.edu.cn

Abstract To explore the status of macroinvertebrate communities and the main influencing factors, an investigation was carried out at 29 sampling points (4 sections) and 40 sampling points (5 sections) in the middle reach of the Yangtze River, respectively in April and October in 2014. 34 species were identified in April (spring) and 32 species in October (autumn). Arthropods is the dominant class of macroinvertebrate in both seasons, up to 56% and 35% respectively. Spring’s species abundance, the average density as well as the biomass are the highest in two quarters, and from top to bottom in the middle reach of Yangtze River biomass reduced gradually. The results of functional feeding groups show that collector-gatherers are the main components in the middle reach of Yangtze River in spring (40.25%) and autumn (59.3%). The results of tolerance value show that semi-tolerant to pollution and pollution tolerant organisms are the main components in the middle reach of Yangtze River and Wuhan section has more pollution tolerant organism in the two quarters. The correlation analysis on 5 kinds of functional feeding groups and three kinds of biological standing crop with the 7 environmental factors show that the influence of environmental factors on macroinvertebrate is different in the spring and autumn, TP and TN as

well as particle size are the main environmental factors in spring, while in autumn, the benthic animals are mainly affected by ph, dissolved oxygen and transparency. This study has a comprehensive understanding of the benthic fauna from several aspects and can provide basic information for intensive research of the Yangtze River. Key words middle reach of the Yangtze River; macroinvertebrate; community structure; functional feeding groups; environmental factors