| 1 | The purification ability of Elodea Canadensis Michx is higher than those of Potamogeton Crispus Linn and Ceratophyllum Demersum Linn. | |
| 2 | Effects of ecological factor such as water depth and light on turion germination of Potamogeton crispus L. had been studied much. | |
| 3 | The effect of dissolved oxygen, temperature and concentration of nitrogen and phosphorus on the germination of turion of Patamogeton crispus L. was investigated at the present study. | |
| 4 | The treatments all caused total phosphorus(TP) , total nitrogen(TN), and content of chlorophyll-a(Chl. A) in the overlying water obviously reduced. | |
| 5 | It is showed that the gradually-submerging bed made of plant fiber, Potamogeton crispus and Elodea nuttallii can grow in low temperature condition in winter. |