北方景观水体中生态浮床的植物筛选与水质净化效果

以千屈菜(Lythrum salicaria L.)、黄菖蒲(Iris pseudacorus L.)、鸢尾(Iris tectorum Maxim.)3种植物为对象,研究了北京市朝阳区景观水体中生态浮床的植物筛选与水质净化效果.结果显示,千屈菜、黄菖蒲、鸢尾均生长迅速,且千屈菜表现最佳;移栽4个月后,3种植物的生物量分别较初始增加了15.9、8.5和13.1倍,达到945.5、489.2和585.0 g/m2.千屈菜对水体氮、磷的吸收去除能力显著(P<0.001)高于黄菖蒲和鸢尾,其总氮、总磷吸收量分别为黄菖蒲的2.2倍和2.3倍,为鸢尾的2.1倍和1.9倍.生态浮床的水质净化效果总体良好,运行60 d后,水体总氮、总磷浓度分别从16.28和0.27 mg/L降低至5.70和0.18 mg/L,二者去除率分别为65.0%和35.0%.研究表明,千屈菜、黄菖蒲、鸢尾在营造景观和净化水质方面协同作用良好,其中千屈菜表现尤为突出,可作为北方地区生态浮床的首选植物.

Plants screening of ecological floating bed and its effects on water quality purification in an artificial lake in Northern China

Three kinds of plants, including Lythrum salicaria L., Iris pseudacorus L., and Iris tectorum Maxim., were introduced as floating bed plants, and their water quality purification effects were studied in a artificial lake in Beijing, China. The results showed that the three kinds of plants, especially L. salicaria, grew rapidly. The biomass of L. salicaria, I. pseudacorus, and I. tectorum were 945.5, 489.2, and 585.0 g/m2 (increased by 15.9, 8.5, and 13.1 times), respectively, within 4 months. The L. salicaria had significantly (PI. pseudacorus and I. tectorum. The total nitrogen (TN) and phosphorus (TP) uptaken by the L. salicaria were 2.2 and 2.1 times of that by the I. pseudacorus, and were correspondingly 2.3 and 1.9 times of that by the I. tectorum. After 60 days, the TN and TP concentrations in the artificial lake decreased from 16.28 and 0.27 mg/L to 5.70 and 0.18 mg/L, respectively; while the removal rates of TN and TP by the ecological floating beds were 65.0% and 35.0%, respectively. To summarize, the ecological floating beds constituted by the L. salicaria, I. pseudacorus, and I. tectorum played very well in both building landscape effects and purifying water quality. In the three kinds of tested plants, L. salicaria performed the best and should be adopted preferentially in constructing ecological floating beds in Northern China.