Abstract
Due to the coupling effects of runoff and tidal currents, the carbon cycle process of tidal wetlands in the Yangtze River estuary is extensively influenced by both hydrodynamic and environmental factors. In this study, samples of particulate organic carbon (POC) and dissolved organic carbon (DOC) in water, and total organic carbon (TOC) in surface sediments were taken at sites Sanjiagang (SJG) and Nanhui (NH) along the Yangtze River estuary (YRE) in December 2022 to investigate the tidal variation of organic carbon distributions. The results showed that the concentrations of organic carbon, including POC, DOC and TOC were higher at SJG than at NH. According to the Pearson correlation analysis, the concentrations of POC and TOC were positively correlated at NH, and tidal elevation had a positive effect on TOC concentrations. Organic carbon concentrations and water physicochemical properties (salinity, dissolved oxygen, temperature, turbidity and pH) had strong relevance. Results in this paper can provide a scientific basis for the assessment of regional and global carbon balance in coastal wetlands.
