摘要
为了研究水生植物荷花(Nelumbo nucifera)治理水体富营养化的效果,在白洋淀建成18个围隔,种植不同密度的荷花,研究荷花种植密度对富营养化的影响。荷花种植密度分别为0株/m2、1株/m2、2株/m2、3株/m2、4株/m2和5株/m2,考察荷花在水华爆发前后70d内对水质的调控效果。结果表明,当荷花种植密度为3株/m2时,总体水质改善效果最好,水体中的总氮、总磷和氨氮的平均去除率分别为47.11%、49.14%和42.88%,优势藻从绿藻(Chlorophyta)和蓝藻(Cyanophyta)转变为绿藻和硅藻(Bacillariophyta)。绿藻细胞生物量的抑制率为44.46%。白洋淀荷花种植区域的水体富营养化程度从重度转为中度。荷花种植密度低于3株/m2,对水体中营养盐的吸收效果较差;荷花种植密度高于3株/m2,主要伴生种金鱼藻(Ceratophyllum demersum)光合作用受阻而大量死亡,腐败的植物会造成水体中的氮、磷含量升高。因此合理的荷花种植密度有利于治理白洋淀水体富营养化。
Eighteen enclosures, 4 m2 each, with different plant densities of Nelumbo nucifera were established in Baiyangdian Lake to investigate the effects of plant density on the eutrophication control. The plant densities of Nelumbo nucifera were 0 individual/m2, 1 individual/m2, 2 individuals/m2, 3 individuals/m2, 4 individuals/m2 and 5 individuals/m2, respectively. The main water quality indexes such as total nitrogen（TN）, total phosphorus（TP）, ammonia nitrogen（NH3-N） in 70 days （before algae bloom） were chosen to analyze. The results showed that different plant densities of Nelumbo nucifera could improve water quality to some degree. When the density of Nelumbo nucifera was 3 individuals/m2, the average removal efficiencies of TN, TP and NH3-N in water were 47.11%, 49.14% and 42.88%, respectively, and the removal ratio of algal biomass was up to 44.46%. The dominant green algae （Chlorophyta） and blue-green algae （Cyanophyta） turned into green algae and diatoms before and after the experiment. And the eutrophication levels of the water were from severe to moderate. Of all the enclosure experiments, the density of 3 individuals/m2 got the best removal of nutrients and algal biomass. When the density was less than 3 individuals/m2, the absorption of nutrients in water was less effective, and when the lotus density is higher than 3 individuals/m2, the photosynthesis of major associated species Ceratophyllum demersum reduced, leading to a large number of deaths. And the plant corruption caused the total nitrogen and total phosphorus contents increased in the water column. It is concluded that reasonable Nelumbo nucifera plant could contribute to water quality improvement and reduce the occurrence of eutrophication in Baiyangdian Lake.
出处
《湿地科学》
CSCD
北大核心
2013年第2期282-285,共4页
Wetland Science
基金
国家水体污染控制与治理科技重大专项项目(2009ZX07209-008和2012ZX07101-002)资助
关键词
荷花
围隔实验
富营养化治理
Nelumbo nucifera
enclosure experiment
eutrophication control
