%0 Journal Article
%T Effects of water depth and sediment nutrients on Vallisneria spinulosa in Lake Poyang
%A Caixia Kang
%A Xingzhao Dai
%A Yunlu Shen
%A Zhengong Tong
%J Journal of Freshwater Ecology
%D 2019
%R https://doi.org/10.1080/02705060.2018.1559243
%X Abstract Poyang Lake, the largest freshwater lake in China, has experienced a large decrease in wetland area due to long-term overutilization and especially after the hydrological drought events from 2003. This outdoor study was conducted to elucidate the impacts of drought and high concentrations of N on Vallisneria spinulosa. Compared with the 60£¿cm water depth, the 30£¿cm water depth caused no difference except lower leaf weight and greater winter bud number per plant growing in the sediment from Poyang Lake. After 400£¿mg/L NH4+-N was added to the sediment, the leaf weight, root weight, root length, winter bud number, ramet number and stolon weight of V. spinulosa declined greatly. The high NH4+-N content in sediment increased the influence of low water depth on V. spinulosa expressed as the relatively light fresh weight per winter bud of 0.11£¿g. The results indicated that both a low water depth in spring and high N concentration impacted V. spinulosa and the high concentration of NH4+-N limited the adaptation of V. spinulosa to the decline in water depths. Thus, besides water-level management, nutrient control is also required to protect and restore aquatic macrophytes in Poyang Lake
%U https://www.tandfonline.com/doi/full/10.1080/02705060.2018.1559243