Effects of sediment burial on seed germination and seedling establishment of Vallisneria natans

Burial of seeds by sediment often happens in lakes. Laboratory experiments were conducted to investigate the effects of burial by river sand and fishpond sediment on seed germination and seedling establishment of Vallisneria natans at depths of 0, 1, 3, and 5 cm. Sediment type had significant effects only on dry weight and total leaf area of the seedlings and did not interact with burial depth. In contrast, a significant negative correlation was observed between burial depth and all of the variables, including seed germination rate, seedling emergence rate, shoot length, dry weight, leaf number, total leaf area, root number, and total root length. Moreover, no seedlings emerged above the sediment surface in the 5 cm depth treatment in either sediment, even though seed germination was observed. In addition, the results showed that fishpond sediment was more effective than river sand in accumulation of dry matter and increase of leaf area. Therefore, taking measures to accelerate seed germination and seedli...