Temporal variation of plankton and zoobenthos communities in a freshwater reservoir: Structure feature, construction mechanism, associated symbiosis and environmental response

Phytoplankton, zooplankton and zoobenthos, due to their tiny size and high reproductive efficiency, usually hold an essential position in freshwater reservoir biomes. Understanding their community traits and symbiosis mechanism is crucial for determining the nature of water ecological environment and the water ecosystem's evolution. However, the dynamics of interspecific and environmental interactions, as well as community-building processes, are currently unclear. Here, the structure feature, construction mechanism, associated symbiosis and environmental response of plankton and zoobenthos communities were studied in a freshwater reservoir. The features of phytoplankton, zooplankton, and zoobenthos communities varied significantly by season. Dispersal limitation played an important role in the construction of phytoplankton, zooplankton and zoobenthos communities, and the influence degree decreased in order. Phytoplankton communities showed a stronger distance-decay of similarity than zooplankton communities, while zoobenthos communities did not exhibit any discernible distance-decay of similarity. Co-existence network displayed primarily positive interactions between phytoplankton, zooplankton and zoobenthos all year round (92.23% positive in summer, 86.36% positive in autumn, 100% positive in winter and 67.35% positive in spring). Variation partitioning analyses showed that geographical variables had a stronger influence on community distribution than environmental factors. Mantel test revealed that the communities diversity was significantly associated with temperature, dissolved oxygen, nutrients N and nutrients P. Temperature exhibited the highest explanation rate for seasonal variation in phytoplankton (11.48%, p < 0.001) and zooplankton (16.22%, p < 0.001), according to redundancy analysis. These findings provide a thorough comprehension of the biological communities' dynamic equilibrium in a freshwater reservoir aquatic systems.