Distribution of biogenic silica in Scirpus mariqueter of Chongming eastern tidal flat and its seasonal changes

The content and distribution of biogenic silica (BSi) in salt marsh plants (Scirpus mariqueter) from Chongming east tidal flat were studied by using Na₂CO₃ sequential extraction method. The significant seasonal variations of BSi were observed in Scirpus mariqueter, and BSi in salt marsh plants was characterized by its progressive accumulation in biomass. The contents of BSi ranged from 0.26%~0.93%, 0.31%~0.92% and 0.24%~0.43% in the over-ground biomass, under-ground biomass and fruits, respectively. BSi was mainly deposited in the leaves and significantly affected by the plant (or leaf) age. Significant correlation was found between BSi in rhzioshperic sediments and in salt marsh plants, which indicated that salt marsh plant initiatively absorbed silicon from the sediments. Additionally, there were obvious relationships of BSi in over-ground and under-ground biomass with ON, C/N, sediment temperature, plant height.