Riverine bacterioplankton and phytoplankton assembly along an environmental gradient induced by urbanization

Longitudinal environmental heterogeneity and directionality of the water movement are key features that may exert contrasting forces on riverine plankton assembly. Directionality strengthens dispersal‐driven assembly, but this can be masked by urbanization‐induced environmental heterogeneity along the river continuum. In the light of this contrast, we aimed at delineating the relative importance of assembly processes generating distribution patterns of bacterioplankton and phytoplankton communities in a river draining an urbanizing watershed in Southeast China. We applied variation partitioning analysis, neutral community model, and quantitative process estimate on molecular and morphological plankton data obtained over the years 2012–2016. Despite a relatively short distance between sampling sites (