崇明东滩海三棱藨草生物硅分布及季节变化

利用Na2CO3连续提取法,分析了崇明东滩海三棱藨草(Scirpus mariqueter)体内生物硅(BSi)含量与分布特征.结果表明,BSi在海三棱藨草体内的分布存在明显的季节变化差异,在生物体中连续积累是BSi的一个主要特征.地上部分BSi含量变化范围为0.26% ~ 0.93%,地下部分为0.31% ~ 0.92%,果实中则为0.24% ~0.43%.地上部分含量明显高于其他部分,说明BSi主要沉积在蒸发强烈的叶片中,植株个体生长阶段是决定地上部分BSi含量的主要因素.统计分析显示,根际沉积物BSi和植物各器官BSi相关性均显著,说明海三棱藨草依从主动吸硅机制,从根际沉积物获取所需的Si.地上、地下部分BSi含量与有机氮(ON)、C/N、土壤温度、植株高度也存在明显的相关性.

Distribution of biogenic silica in Seirpus mariqueter of Chongming eastern tidal fiat 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.