Hydrological changes regulate fish metacommunity structures and β-diversity patterns in the floodplain lake, China

•Temporal metacommunity dynamics in a floodplain lake were tested using complementary methods.•Fish metacommunity displayed similar idealized patterns across three hydrological periods.•It occurred a humped relationship between fish β diversity and the water level gradients.•The relative roles of environmental and spatial factors depended on hydrological conditions.