To clarify the impact of water quality and social activity in the Baiyangdian wetland on the biological community, the change characteristics of bacterial, fungal, and archaeal communities in different areas of the Dian District were studied. Samples were collected at the entrance of Fuhe District (NBB), tourist areas with frequent human social activities (NBD), residential breeding areas (NBX), and village sparse areas (NBN). The physical and chemical characteristics and biological communities of the samples were evaluated. The results of the study show that the COD concentration of organic pollutants in the NBB was 12.35 mg·L-1, and the total nitrogen concentration was 10.12 mg·L-1, that the concentration was highest. Moreover, the water quality in NBD and NBX was better than that of NBB. The NBN area exhibited the best water quality, with COD and total nitrogen concentration values of 6.9 mg·L-1 and 1.82 mg·L-1, respectively. Many types of NBB bacteria were recorded, with a diversity index of 5.86, and NBN diversity index exceeding 4.78. The dominant bacterial flora in all samples was the Proteobacteria, which accounts for 68.8% of the total bacterial communities in NBN samples. The diversity index of fungi in NBB was only 2.14. There were many types of fungi in NBN, with a diversity index of 3.23. Chytridiomycota was found in the NBD and NBN, accounting for 5.4% and 9.8% of the total number of fungi, respectively. The Chytridiomycota was main decomposer of hard to degrade organic carbon. The diversity of archaea of NBN was the lowest among all the samples. Crenarchaeota was the dominant phylum, which accounts for 39.0%, 51.9%, 47.3%, and 30.1% of NBB, NBD, NBX, and NBN samples, respectively. The number of Halobacterota was lower than Crenarchaeota. The main factor of eutrophication and microbial community changes in Baiyangdian wetland was the results of the combined action of external and internal pollution. Both external and internal pollution increased the organic matter, nitrogen and phosphorus content in the water, and the microbial community structure has changed significantly. The contents of organic matter, nitrogen, and phosphorus in water were increased and the microbial community structures were changed significantly by the increase of both external and internal pollution.
Keywords: Baiyangdian; microbial community; social activities; water supply quality; wetland.