Assembly 1 Assembly process 1 Bacteria 1 Bacteria (microorganisms) 1 Bacterial community 1 Bacterioplankton communities Bacterioplankton community 1 Bacterioplanktons 1 Biodiversity 1 Biogeography 1 Co-occurrence networks 1 Co-occurrence relationships 1 Ecosystems 1 Exact sequencing variant 1 Exact sequencing variants 1 Han River [Hubei-Shaanxi] 1 Han river 1 Neutral community model 1 Random processes 1 Rivers 1 Stochastic systems 1 Stochastics 1 Topology 1 assessment method 1 bacterioplankton 1 biodiversity 1 economic diversification 1 environmental gradient 1 microbial activity 1 microbial community 1