Microscopic morphology of surface sediments and its related causes in Jiulongjiang estuary wetland

To explore the microscopic morphology of surface sediments and its related causes in Jiulongjiang estuary wetland,the surface area(SA) and surface fractal dimension(SFD) of different sediments,from the different vegetation,water disturbance and chemical clean,were determined based on the adsoption-desorption curves of nitrogen.For all sediments,SA of sediments from bare flat(A sample site) was the lowest with 17.07 m2/g,and the SFD(2.5177) was also the lowest.The following was spartina sediment(E sample site),which was 20.82 m2/g for the SA and 2.5354 for SFD.While SA and SFD of the sediments from the mangrove(D),spartina(B) and the mix of spartina with mangrove(C) were much greater than that of the sediments from A and E sites.The reasons were possible that the space fill capacity of the sediment from A and E sites was weakened,resulting in the decreases of SA and SFD,due to the sediments were near to the river,subsequently much more influenced by the disturbance and pollution from the tides and rivers.The Pearson correlation showed that sediment SD and SFD were positively correlated to inorganic nitrogen and phosphorus,indicated that the sediment with the lower SD and SFD could not have high adsorption capacity for nitrogen and phosphorus due to the subsequent decreases of the space fill capacity of the sediments.Additionally,the disturbed sediments by the tides and rivers showed lower SA and SFD,while the less contaminated sediment showed greater SA and SFD.Therefore,the changes in the microscopic morphology of the different sediments would suffer from the disturbance and contamination from tides and rivers.