3种水生植物腐解过程中磷营养物质迁移、转化过程研究

室内模拟沉水植物狐尾藻(Myriophyllum verticillatum L)、浮水植物菱角(Trapa bispinosa Roxb)、挺水植物荷花(Lotus flower)在5.7 g·L~(-1)初始生物量密度下的腐解过程,并探究该过程中磷营养物质迁移、转化规律.结果发现,3种植物腐解速率在第2 d上升至最大值(分别为1.075、1.455、1.16 g·d~(-1))后出现下降-上升-下降的变化规律,并且在整个腐解周期内种间差异性显著(p0.01),造成整个腐解周期内狐尾藻、菱角、荷花3种植物平均磷释放速率分别为0.456、0.670、0.537 mg·g~(-1),且以无机磷酸盐为主;水中释放的磷在底泥吸附及其自身沉降等作用下,明显向底泥迁移转化,水中磷含量下降,最终在试验结束时恢复至初始水平(0.5 mg·L~(-1));该研究可为湖泊水生植被系统的修复或重建提供科学参考.

Migration and transformation of phosphorus nutrients in the decomposition process of three aquatic plants

The decomposition processes of submerged plant Myriophyllum verticillatum L, floating plant Trapa bispinosa Roxb and emerged plant Lotus flower were simulated in the laboratory at initial biomass density of 5.7 g·L^-1, and the migration and conversion rules of phosphorus in the process were studied. The results showed that the variation pattern of decreasing, ascending and descending appeared after the decomposition rate increased to the maximum at 2 d(1.075,1.455,1.16 g·d^-1 respectively), and there were significant difference in the whole process of decomposition(p<0.01), while the average phosphorus release rate were 0.456, 0.670, 0.537 mg·g^-1 respectively in the whole decay period respectively for Myriophyllum verticillatum L, Trapa bispinosa Roxb, Lotus flower, and most of all the matter released were inorganic phosphate; The phosphorus released in the water were migrated and converted to the sediment obviously under the action of sediment adsorption and its own sedimentation, and the concentration of phosphorus in the water decreased, and finally turned to the initial level (0.5 mg·L^-1) at the end of the test. This study can provide scientific reference for recovering or rebuilding the aquatic vegetation system in lake.