A Comparative Study on the Growth and Nutrient Uptake Characteristics of Fifteen Wetland Species in Taihu Lake Region of China

Fifteen kinds of local wetland plants in Taihu Lake region of China were investigated on their respective growth conditions, biomass allocations and nutrient uptake capacities. The test plants were cultured in 3 L nutrient solutions for 28 days with NH4 + -N, NO3 - -N and P concentrations of 38.5, 132.8 and 10 mg/L, respectively. Mean species total biomass ranged from 1.2-21.6 g/plant with above/below ground ratios (AG:BG) between 1.7-5.5. Mean NH4 + -N, NO3 - -N and P uptake rates ranged from 3.7-14.3 mg/day (8.0-49.4 % of NH4 + -N supplied), 17.8-59.4 mg/day (17.8-59.6 %) of NO3 - -N supplied and 1.71-4.61 mg /day (24.1-61.5 % of P supplied), respectively. Plant tissue N and P concentrations ranged between 28.2-606.1 mg N /plant and 4.1-53.1 mg P/plant, with AG:BG ratio between 1.7-7.0 and 1.6-4.6, respectively. The accumulation of N and P in plant tissues was significantly correlated with plant biomass and root surface area. Among the different species, C. generalis, T. latifolia, T. dealbata and L. salicaria were better than the other plants in above- and below-ground biomass, root surface area, nutrient uptake and storage rates. T. dealbata and L. salicaria were more suitable for year-round application in this area due to their tolerance of coldness.