沉水植物苦草对上覆水各形态磷浓度的影响

沉水植物是影响湖泊磷营养状态的重要因素。在室内模拟了"水-苦草-沉积物"生态系统,在沉水植物苦草生长过程中分析上覆水中的总磷(TP)、溶解性总磷(TDP)、溶解性有机磷(DOP)、溶解性活性磷(SRP)、颗粒态总磷(PP)的变化,探讨了苦草对上覆水磷赋存形态的影响。结果表明,苦草在生长过程中减缓了沉积物磷的相对释放速率使上覆水中TP、SRP、DOP、PP均呈现不同程度的下降。上覆水TP、SRP、DOP、PP分别下降了37.5%、74.6%、42.0%、19.5%;苦草主要通过吸收上覆水和间隙水中的磷及对环境因子的影响,使得上覆水中各形态磷浓度保持在较低的水平,降低沉积物向水体释放磷的速率。

Effect of submerged macrophyte vallisneria natans on concentrations of different phosphorus species in overlying water

Submerged macrophytes are the key factor determining nutritional status of phosphorus in a lake.A water-vallisneria natans-sediment ecosystem was established indoors.Changes of total phosphorus（TP）,total dissolved phosphorus（TDP）,dissolved organic phosphorus（DOP）,soluble reactive phosphorus（SRP）,and particulate phosphorus（PP） in overlying water were monitored and analyzed during the vallisneria natans＇s growing period.The effect of vallisneria natans on phosphorus species in overlying water was investigated.The submerged macrophyte reduced the relative phosphorus release rate of the sediment,and the concentrations of TP,SRP,DOP,and PP in overlying water decreased by 37.5%,74.6%, 42.0%,and 19.5%,respectively,during the growth period.Uptaking phosphorus from overlying water and interstitial water,vallisneria natans maintained the concentrations of phosphorus at a low level in overlying water and reduced the phosphorus release rate of the sediment.