水体氮磷营养负荷对苦草净化能力和光合荧光特性的影响  

Effect of Nutrient Loadings on the Regulation of Water Nitrogen and Phosphorus by Vallisneria natans and Its Photosynthetic Fluorescence Characteristics

作　　者：周裔文 许晓光 韩睿明 周晓红 冯德友 李致春 王国祥 

机构地区：[1]江苏大学环境与安全工程学院,镇江212013 [2]南京师范大学环境学院,南京210008

出　　处：《环境科学》2018年第3期1180-1187,共8页Environmental Science

基　　金：江苏省水利科技项目(2016050);国家自然科学基金项目(41403064);江苏省教育厅基础研究计划(自然科学基金)青年基金项目(BK20140922);江苏省教育厅高校自然科学研究项目(14KJB610007);江苏省科技厅科技支撑重点项目(BE2016324)

摘　　要：以沉水植物苦草(Vallisneria natans)为对象,通过室内控制实验,研究营养盐负荷对苦草净化水体氮磷能力的影响;利用水下饱和脉冲荧光仪(Diving-PAM)研究营养盐负荷对苦草光合荧光特性的影响.结果表明,在本实验设置的氮磷浓度范围内(TN≤12 mg·L-1,TP≤1.0 mg·L-1),随营养盐浓度的升高,苦草对水体氮磷的净化能力逐渐增强:在高浓度营养盐组(TN=12 mg·L-1,TP=1.0 mg·L-1),水体氮磷去除率可达95%以上,当铵态氮含量较高时,苦草优先吸收铵态氮;中高浓度营养盐组(TN:8~12 mg·L-1,TP:0.6~1.0 mg·L-1)对苦草叶片Fv/Fm无显著影响;低浓度营养盐组(TN=3 mg·L-1,TP=0.3 mg·L-1)能够提高苦草叶片的Fv/Fm,有利于苦草生长.在本实验条件下,水体氮磷营养盐浓度越高,对苦草叶片的光合活性和光耐受能力抑制作用越明显;随着水体营养盐逐步下降,苦草叶片的光合活性逐渐恢复,捕光能力无明显变化.Submerged macrophytes are an important component of aquatic ecosystems. During the growing period, submerged macrophytes can absorb nitrogen and phosphorus nutrients to reduce pollution loadings. Shoots of submerged macrophytes can also promote the adhesion of suspended substances in water,reducing the turbidity. The release of nutrients in sediments can be suppressed by its root system,and the resuspension of sediments caused by disturbance of winds and waves can also be resisted. The role of submerged macrophytes in ecological restoration of eutrophic lakes has attracted widespread attention. In 1960,the submerged plants Vallisneria natans and Potamogeton malaianus had been the dominant species in East Taihu. However after 2002,Nymphoides peltatum,Elodea nattalii,P. malaianus,etc. have gradually taken over the dominant roles along with significant elevations of nitrogen and phosphorus levels. Nutrients in water are not the only key factors causing eutrophication of water bodies; the nutrient source for submerged plant growth affect both the purification efficiency and the photosynthetic characteristics of submerged macrophytes.Excessive nitrogen and phosphorus concentrations can inhibit the photosynthetic physiological activities of submerged macrophytes,affecting the succession of aquatic vegetation. In addition,under high nutrient conditions,the competition from periphytic algae and planktonic algae may also directly poison submerged macrophytes,leading to its degradation and disappearance. Systematic studies on the regulation and photosynthetic fluorescence response mechanism of submerged macrophytes to varied nutrient loadings are helpful in revealing their relationships. The seedlings of submerged macrophyte V. natans were transplanted in a laboratory mesocosm to study the effect of nutrient loadings on its regulation of water nitrogen and phosphorus. Three nitrogen and phosphorus loadings from low,medium,and high levels derived from nitrate,ammonium,and phosphate were setup as the aquatic medium for the p

关 键 词：水体氮磷 营养盐负荷 苦草 光合荧光特性 

分 类 号：X171[环境科学与工程—环境科学]