黑龙江上游及源头地区大型底栖动物群落结构及其环境影响因素OA

Two investigations were carried out in June(summer)and October(autumn)in 2022 to find out the benthic macroinvertebrates community structure and their water environmental factors in the upper and source of Heilongjiang River and fill the gap of biodiversity data in cold regions of Northeast China..A total of 74 spe-cies of the benthic macroinvertebrates were recorded in this study,belonging to 4 phyla,7 classes,13 orders and 33 families,among which 65 species were aquatic insects,accounting for 87.84%of the total species.The dominant species in summer include Siphlonurus sp.,Ameletus montanus Imanish,Sweltsa sp.,Tadamus sp.,Poly-pedilum laetum Meigen and in autumn were Heptagenia sp.,Siphlonurus sp.,Isoperla sp.,Cinygmula sp.The total aver-age biomass in summer was(4.72±4.43)g/m2 and the total average abundance was(61.71±40.86)ind./m2.However,the total average biomass in autumn was higher than that in summer(10.12±25.82 g/m2),and the total average abundance was(24.71±13.96)ind./m2,which was lower than that in summer.The Shannon-Wiener diversity index(2.66±0.35)and Margalef richness index(2.77±0.69)were higher in summer than in autumn(2.36±1.01)and(2.26±1.24),respectively,while the Pielou evenness index was lower in summer(0.77±0.09)than in autumn(0.84±0.11).The Bioenv analysis showed that the key water environmental fac-tor combinations with the most significant impact on the community structure of benthic macroinvertebrates were COD,TN,and NO3-in summer,and WT and NO3-in autumn.Spearman correlation analysis showed that COD,TN,NH3-N,TP,and other water ecological factors were significantly correlated with the abun-dance of benthic macroinvertebrates,and there were differences among species.The results of this study are helpful to provide an important scientific basis for biodiversity research and rational protection of important food sources for rare cold-water fish species in mountainous rivers.