| Sediment burial often happens in water bodies. This experiment investigated the effects of river sand burial and pond sediment burial on seed germination and seedling survival of Vallisneria natans at depth of 0, 1, 3 and 5 cm. The seed emergence rate, seedling survival rate, height and dry weight of seedlings decreased significantly with the increase of burial depth. No seed emergence was observed and no seedlings could survive when the burial depth was 5 cm. Compared with the control, seedling survival rates decreased less than seed emergence rates at burial depth of 1 cm and 3 cm, and no significant decrease was observed in seedling survival rates at burial depth of 1 cm. At burial depth of 3 cm, the seed emergence rate and seedling survival rate reduced more seriously by pond sediment than river sand. Average height, average dry weight and average root/shoot ratio were all apparently higher in pond sediment than river sand at burial depth of 0, 1 and 3 cm. This indicated that sediment burial had more negative effects on seed emergence than seedling survival, and pond sediment was more beneficial to the growth of V. natans than river sand, although it decreased seed emergence rate and seedling survival rate more significantly than river sand. |
