黑藻对沉积物及土壤中不同形态磷的利用与转化

Availability and transferring of phosphorus forms by Hydrilla verticillata in the sediment and soil

利用同一区域湖泊和河流沉积物及土壤培养黑藻,运用化学连续提取法对底质中磷的不同形态进行分离,同时分析黑藻生物量及底质中上覆水和间隙水中磷浓度的变化,并对底质中生物可利用磷进行了估算,揭示沉水植物对底质中不同形态磷的利用与转化规律.结果表明,底质中弱吸附态磷、可还原性磷(RSP)是黑藻利用的主要磷形态;土壤与沉积物相比不利于黑藻生长,营养水平高的河流沉积物有利于黑藻初期生长,但容易使其早衰;沉积物作底质上覆水和间隙水磷浓度主要受底质中RSP含量的控制;土壤作底质上覆水和间隙水磷浓度主要受弱吸附态磷控制;黑藻能促进底质中磷向可利用态转化;黑藻对土壤中生物可利用磷的利用率比沉积物低.

Availability of phosphorus forms of submerged plant in the sediment and soil has been studied using the submerged plant Hydrilla verticillata culturing in different trophic sediments and soil. Different phosphorus forms in sediments and soil were separated by the chemical sequential extraction methods, at the same time the biomass of Hydrilla verticillata, concentrations of phosphorus in overlying water and in interstitial water were also analyzed. Amount of the bioavailable particular phosphorus was estimated by the formula of age available particular phosphorus. The results showed that labile phosphorus （P） and reducible soluble phosphorus （RSP） were the main phosphorus forms for Hydrilla verticillata utilization. The sediment is beneficial for the growth and fade of Hydrilla verticillata at the growth early stage. Phosphorus concentrations of the overlying water and interstitial water were affected mainly by the RSP concentrations in sediments. Phosphorus concentrations of interstitial water in soil were affected mainly by its labile P concentrations. The submerged plant Hydrilla verticillata promoted available phosphorus transforming, and its utilization rate for available particular phosphorus in soil is lower than that in sediments.