Relationship Between Plankton Community Characteristics And Hydrological Connectivity In The Yellow River Delta And Its Application In Wetland Restoration

Due to climate change,human activities and other reasons,the hydrological connectivity of the Yellow River Delta has been seriously affected,and the ecological functions and biodiversity of wetlands are declining.Therefore,research on hydrological connectivity and biodiversity restoration measures is necessary.This study explored the relationship between plankton community and hydrological connectivity of the Yellow River Delta wetland.The results showed that the IIC and PC values of the Yellow River Delta wetland were 0.08 and 0.10,respectively.Comparing the hydrological connectivity of each region,it was found that the hydrological connectivity of the recovery zone is higher than that of the tidal zone.The phytoplankton community in the study area was dominated by diatoms,green algae and cyanobacteria,and the zooplankton community was dominated by rotifers.The results of CCA analysis showed that EC,TP,DO,TN and water depth were the main factors affecting the growth of phytoplankton and zooplankton.The density and biomass of phytoplankton and the diversity of zooplankton in all regions showed the law of recovery zone>tidal zone,which was consistent with the regularity of hydrological connectivity.The similarity of plankton community has a certain characterization of hydrological connectivity.The more similar the community composition of each node,the greater the possibility of hydrological connectivity between nodes.The fitting results of plankton biodiversity and hydrological connectivity showed that when 0.04<hydrological connectivity<0.14,plankton biodiversity could reach the average level within the study area.Based on this result,the tidal zone and the recovery zone of the Dawenliu was selected as the priority recovery region,and at the same time,under the condition that the important level of water patch reached medium and above,and the species diversity and similarity index of the plankton community was less than average,14 hydrological nodes that need priority recovery were selected,including 6 priority recovery nodes and 8 secondary priority recovery nodes,and corresponding restoration measures were proposed.The results of this study provide a theoretical basis for further understanding of the hydrological connectivity of the Yellow River Delta wetland,and provide a reference for the restoration of plankton biodiversity and ecosystem of the Yellow River Delta wetland.