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The zoobenthos is an important part of the aquatic ecosystem, an irreplaceable important role in the material circulation and energy flow, and to a large extent reflects the health of aquatic ecosystems. Usually serious pollution of aquatic ecosystems, the benthic community structure tends to be relatively simple, the partial loss of function. The richness of the macrobenthic community can be reflected by the degree of interference with the health status of aquatic ecosystems. Thus, through the study of the ecology of benthic animals can understand the level of contamination of water, to grasp the main factors of the Gan River Basin aquatic ecosystem health, help build the Gan River Basin aquatic ecosystem health assessment and evaluation criteria, and final evaluation of the Gan River Basin water ecosystem health, and to provide a scientific basis for human scientific and rational development of the Gan River Basin, and provide scientific and technological support to protect watersheds biodiversity, habitat and healthy water ecosystem. This paper studies relying on the national \studies, mainly discussed the benthic community structure, functional feeding groups as well as the impact of environmental factors on the benthic fauna, and provide a reference for the Gan River Basin Pollution Prevention and governance, as well as the river ecosystem assessment. The main contents of the thesis and the results obtained are as follows: (1) Ganjiang benthic fauna survey found a total of annelids, mollusks, arthropods and linear animal categories, including 27 families and 73 species, respectively, under the vermiculite Gang Oligochaeta, Polychaeta, Malacostraca and Insecta, gastropods, Lamellibranchia and Nematoda, three water regime (wet period, the dry season, flat water period) mollusks are dominant. Wet period, 18 families and 44 species; dry season, 20 families and 44 species; collected 20 families and 48 kinds of normal water. The wet period dominant species in the the patina Bellamya; dry season the dominant species of freshwater mussel; flat water period, the dominant species of river clams. Sensitive indicator species including China new rice shrimp, Gammarus, Macrobrachium Romantic and Uncontrolled semisulcatus curled, ephemera, arrows dragonfly, freshwater shell dishes, show that the the Gan River water quality has been a certain degree of pollution. (2) Gan River Basin benthic fauna functional feeding groups: scraping eater and filter feeders dominant, followed by collectors, and predators, tore the second. On dynamic analysis of functional feeding groups of benthic animals space, each functional feeding groups reflect the ecological characteristics of the spatial sequence resource sites, the limit of its distribution characteristics significantly affected by a bit of space resources. (3) Based on the impact of environmental factors on the benthic fauna, the use of a model of correspondence analysis (CCA) to analyze the environmental factors affect the benthic fauna of the Gan River Basin, the study found that the wet period of the main environmental factors affecting the distribution of macrobenthic community Pb, Zn, and sulfides of heavy metals in the water level, watershed latitude and longitude, velocity, water column, watershed latitude and longitude to the major environmental factors that affect the distribution of macrobenthos density water column, Cr6, Pb, Zn, fecal coliform, sulfide, and water column Cu; dry season The main environmental factors that affect the distribution of macrobenthic community watershed latitude and longitude, the water level, the F-, water column Zn and flow rate, the main environmental factors affect the density distribution of benthic fauna latitude for the basin, wc Zn, phenol, water column Cu and BOD5. To arrive at the benthic animals and environmental factors have a high correlation coefficient, and species composition of benthic fauna, the correlation between the density of the main environmental factors are strong.
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