Abstract: Field investigation data in summer from 36 urban rivers in Shanghai  were used to explore the relationship betweenPlanktothricoidesspp., which can form  cyanobacteria bloom, and its environmental factors. The generalized additive model (GAM) results showed that the biomass ofPlanktothricoides spp. significantly increased when the water temperature ranged between 25 and 35 ℃ and the pH values ranged between 6.5 and 9.5. Contrarily, Planktothricoides spp. didn’t show significant correlation with total nitrogen and total phosphorus (P>0.05) when their concentrations ranged from 0.04 to 7.33 mg·L^-1 and from 0.04 to 4.10 mg·L^-1, respectively. It was indicated that the high concentrations of nutrients in Shanghai rivers were no longer the limitation factors for the growth of Planktothricoides spp. Furthermore, significantly positive correlations were observed between the biomass of rotifer, protozoan and cladocera andPlanktothricoidesspp., while the latter showed a negative correlation with copepod biomass. This correlation pattern between zooplankton andplanktothricoidesspp. may be explained by the abundance of small sized edible algae in the water column and the tolerance capability of different sized zooplankton to filamentous cyanobacteria.

Key words: climate change, open-top camber, soil activated carbon, soil activated nitrogen, alpine treeline