Difference of Tidal Flat Microbial Ecosystem Based on Community Construction from the Huaihe Estuary to the Yangtze River Estuary

Abstract

Tidal flats are one of the most active areas of geochemical material circulation, which not only regulates the ecological environment of the coastal zone, but also provides rich ecological and economic value for human beings. In this study, the tidal flats and coastal seas between the estuaries of typical large river basins are taken as the research area, and the water ecological status of typical tidal flats along the eastern coast of China is studied through field sampling, numerical simulation, and high-throughput sequencing. The results showed that due to the differences in water quality and total pollutant discharge of different rivers entering the sea, the study area could be divided into subregions with significant differences in microbial community characteristics. The microbial community construction showed that homogenous selection dominated, with a ratio of 62%. In general, the process of microbial community construction tends to be consistent, and microbial community was determined by deterministic process, especially environmental selectin. Due to the differences in gross and characteristics of pollutants discharged into the sea from the Huaihe River and the Yangtze River, the wetland microbial community is mainly affected by the pollutants from the Yangtze River. The wetland zone was affected by nitrogen pollutants from the Yangtze River and denitrification mainly occurred in the wetland zone,indicating that the nitrogen pollutants from the Yangtze River are conducive to the occurrence of denitrification microorganisms and denitrification reactions in the Wetland zone. The study established the ecological relationship between the river and the sea, and proposed new ideas for watershed management and coastal tidal flat ecological protection.

Keywords: seagoing rivers, tidal flat, microbial community assembly, Aquatic ecosystem