Effect of Different Type Sediments on Transformation of Phosphorus Forms and Growth of Myriophyllum spicatum
不同类型沉积物磷形态转化及其对狐尾藻生长的影响

The changes of the different phosphorus (P) forms in sediments, overlying water and the diversity of dry weight and root forms of Myriophyllum spicatum were studied using different type sediments under simulating condition. The characteristic of transformation of P forms and growth of submerged plant Myriophyllum spicatum were illustrated. The results indicated that the P release was promoted by adding the silver sand in sediment, and their P concentrations in the overlying water were increased. The chemical characteristic of the sediments were changed by adding NH4Cl, which restrained the P release from their sediments and decreased the P concentration in their overlying water. About 49%, 107% of their plant, root dry weight and 19% root length ofMyriophyllum spicatum from different treatments were raised by adding silver sand in sediments. The root growths of the Myriophyllum spicatum from different treatments were restrained and their agings were promoted by adding NH4Cl in sediments. The P release from sediments were accelerated by the growth ofMyriophyllum spicatum,and the early decay of Myriophyllum spicatumcan increase the P accumulation in sediment. The changing trend of different P forms in the sediments decreased firstly, and then increased with the Myriophyllum spicatum growthing, their contents of Fe/Al-P form in sediments varied greatly (41%-57%). The P release and adsorption in sediments were mainly affected by their root length index of Myriophyllum spicatum from different treatments. The P release in sediment was accelerated through their changing penetrate capacity by root diameter increasing.