Disentangling multiple relationships of species diversity, functional diversity, diatom community biomass and environmental variables in a mountainous watershed

Biodiversity and ecosystem functioning (BEF) relationships are important research issues in the context of biodiversity loss. However, most studies only explored BEF using species richness as a proxy for without considering effects evenness importance functional diversity on functioning. In present study, we multiple among in-stream environmental variables, (species evenness), (functional richness, Rao’s quadratic entropy index) biomass benthic diatom communities from Chinese mountainous river network. We tested two hypotheses: (1) affect community independently, (2) directly affects also indirectly by influencing diversity. found that were influenced wetted width, conductivity, pH. Species had positive negative biomass, respectively; while, effect (with pathway coefficient 0.39) was stronger than (−0.28). have not an interaction between structural equation models, indicating independent each other. Both index although other variables blurred relationship modeling. Besides direct effects, affected through index, with (0.27) more twice indirect (0.12). Our findings imply selection played dominant role indicated relationship; meanwhile, complementarity important. The inclusion indices to explore biodiversity-biomass would help provide deeper comprehensive understanding this its driving mechanisms. suggest carrying out streams rivers support protection practices sustaining their functions natural lotic ecosystems.