环境DNA揭示东江流域水生昆虫生物多样性变化及影响因素

Environmental DNA revealed changes and influencing factors of aquatic insect species diversity in Dongjiang River Basin

以东江流域为例,通过环境DNA技术探究了水生昆虫群落的空间分布规律及其环境影响因子。结果显示:1)水生昆虫物种丰富度由高到低顺序为:双翅目(7科)>蜉蝣目(6科)>毛翅目(2科)=蜻蜓目(2科)=鞘翅目(2科)>鳞翅目(1科)。双翅目(84.99%)和蜉蝣目(14.89%)共占总reads数99.88%,摇蚊科(69.20%)、四节蜉科(14.36%)及蚊科(14.26%)三个科合计占总reads数97.82%。2)物种丰富度指数、香农维纳指数、辛普森指数与功能丰富度指数(FRic)、功能离散度指数(FDiv)均与距河口距离呈正相关关系。功能均匀度指数与距河口距离呈负相关关系。3)海拔是影响物种丰富度最重要的环境因子(P<0.01),COD是影响物种丰富度的重要环境因子(P<0.05)。海拔、DO、COD是影响功能丰富度的重要环境因子(P<0.05)。

Taking Dongjiang River Basin as an example,the spatial distribution of aquatic insect community and its environmental influencing factors were explored through environmental DNA technology.The results showed that:1)The species richness of aquatic insects in descending order was Diptera(7 families)>Ephemeroptera(6 families)>Trichoptera(2 families)=Odonata(2 families)=Coleoptera(2 families)>Lepidoptera(1 family).Diptera(84.99%)and Ephemeroptera(14.89%)accounted for 99.88%of the total reads,while Chironomidae(69.20%),Tetrapaetidae(14.36%)and Heliidae(14.26%)accounted for 97.82%of the total reads.2)Species richness index,Shannon Wiener index,Simpson index,functional richness index(FRic)and functional dispersion index(FDiv)were positively correlated with the distance from estuarine.The FEve index of functional evenness was negatively correlated with the distance from estuary.3)Elevation was the most important environmental factor affecting species richness(P<0.01),and COD was the most important environmental factor affecting species richness(P<0.05).Elevation,DO and COD were important environmental factors affecting function richness(P<0.05).