沉水植物对沉积物及土壤垂向各形态无机磷的影响

Effect of inorganic phosphorus forms in the sediment and soil by submerged plant

该研究利用相同区域湖泊沉积物及土壤在室内模拟条件下培养黑藻,运用化学连续浸提法分离不同层次底质中各形态无机磷,并通过对水体中磷质量浓度和Eh值的测定,分析不同层次底质中各形态无机磷质量分数和间隙水中磷质量浓度的变化,揭示在沉水植物作用下淹水土壤和沉积物中不同层次各形态无机磷的迁移转化规律。结果表明,本试验条件下,黑藻主要影响上层和下层(根系所在层)底质中各形态无机磷的迁移转化;黑藻主要吸收利用弱吸附态磷和可还原态磷,并通过改变底质氧化还原环境影响可还原态磷和铁铝氧化态磷的迁移转化;黑藻的生长促进钙结合态磷的释放,但是黑藻的腐烂促进钙结合态磷的沉积;土壤中各形态无机磷比营养水平相当的沉积物中的磷容易迁移转化,黑藻对沉积物中各形态无机磷迁移转化的影响大于土壤。

The changes of the inorganic phosphorus forms in sediments and gap water of the different layer of sediments were studied by culturing submerged plant Hydrilla verticillata under indoors simulating condition. The different inorganic phosphorus forms in the different layers of sediments and soil were separated by the chemical sequential extraction methods, the concentrations and Eh were detenninated. At the same time, the transfer rules of the inorganic phosphorus forms were shown. The results indicate that： Hydrilla verticillata can influences on the transfer of inorganic phosphorus in the superstratum sediments and substrate （layer taken on root tine ） sediments. Hydrilla Verticillata can absorb and utilize labile P and RSP in the sediments. Hydrilla Verticillata effectes the transfer of RSP and Fe/AI-P by changing the oxidation deoxidize circumstances in the different layer sediments. The growth of Hydrilla VerticiUata can promote the CaP release and the rots can promote CaP sediment. The transfer of the inorganic phosphorus forms was easier in the soil than in the sediments for the comparative alimentation level, The influences of Hydrilla Verticillata on the transfer of the inorganic phosphorus forms was great in sediments than in soil.