中国48个水体象鼻溞夏季种群结构及其与环境因子的相关性

Population Structure and Relations with Environmental Factors in Water Fleas Bosmina in 48 Waters in China in Summer

2017年夏季(7月和8月)定量分析了东部平原(EPR)、蒙疆高原(MXP)、东北地区(NCR)、云贵高原(YGP)和青藏高原(QTP)的48水体中象鼻溞属(Bosmina)及其它浮游甲壳动物的种群结构,同时测定了水温(WT)、溶氧(DO)、pH、透明度(SD)、氨态氮(NH4+-N)、亚硝酸氮(NO2--N)、总氮(TN)、总磷(TP)和叶绿素a(Chl.a)等9个水质理化因子,分析了象鼻溞属各种类与环境因子的相关性。结果表明,本次调查在QTP的10个水体中未发现象鼻溞属的任何种类,且在EPR、MXP、NCR和YGP的35个水体中也未发现简弧象鼻溞(Bosmina coregoni),只发现长额象鼻溞(B. longirostris)和脆弱象鼻溞(B. fatalis)。Pearson相关性分析、多元逐步回归分析和RDA排序的分析均显示,长额象鼻溞(B. longirostris)丰度与叶绿素a(Chl.a)和桡足类丰度呈显著负相关(P<0.05),而脆弱象鼻溞(B. fatalis)与Chl. a和桡足类丰度呈显著正相关(P<0.05),这表明Chl.a和桡足类是影响长额象鼻溞(B. longirostris)和脆弱象鼻溞的重要环境因子。该研究结果有助于深入理解不同地区淡水生态系统夏季象鼻溞属种群特征及其与环境因子的关系,为中国夏季水体的生物监测提供参考。

The population structure and relationships with environmental factors were investigated in water fleas Bosmina collected from 48 water bodies in the eastern plains region(EPR),Mongolian plateau(MXP),northeast China region(NCR),Yunnan-guizhou plateau(YGP)and Qinghai-Tibet plateau(QTP)in summer(July and August)of 2017,and water temperature(WT),and levels of dissolved oxygen(DO),pH,transparency(SD),ammonia nitrogen(NH4+-N),nitrite nitrogen(NO2--N),total nitrogen(TN),total phosphorus(TP)and chlorophyll a(Chl.a)were also measured.Then,correlation analyses were conducted between various species of Bosmina and environmental factors(including other crustacean zooplankton density and 9 physicochemical factors)to understand the effects of various water environmental factors on water fleas in geneus Bosmina in different regions and to provide scientific basis for the monitoring of freshwater ecosystems in summer.The results showed that no Bosmina were found in 10 water bodies in QTP,and no Bosmina coregoni except two species(i.e.B.longirostris and B.fatalis)were investigated in 35 water bodies in EPR,MXP,NCR and YGP.Pearson correlation analysis,multiple stepwise regression and RDA analysis revealed that the B.longirostris density was negatively correlated with Chl.a concentration and copepods density(P<0.05),while B.fatalis was positively correlated with Chl.a concentration and copepods density(P<0.05),indicating that Chl.a and copepods were two important environmental factors af-fecting B.longirostris and B.fatalis.The findings help to further understand the summer population characteristics of Bosmina in fresh-water ecosystems and its relationship with environmental factors,so as to provide reference with the biological monitoring of water quality in summer in China.