洞庭湖湿地植物根系氧化力对氮、磷去除的影响

Effect of Wetland Plant Root Oxidation on Removal of N and P in Dongting Lake

以洞庭湖湿地艾蒿、水芹、苔草、益母草、菖蒲、芦苇等6种典型群落优势湿地植物为材料,测定各形态氮和磷的质量浓度变化及根表面积、根系氧化力等指标,探讨湿地植物根系特征和根系氧化力对氮、磷去除的影响。结果表明:随着培养时间的延长,6种洞庭湖湿地植物培养液中氮和磷质量浓度均逐渐降低后趋于平缓的趋势。6种湿地植物对培养液中氮和磷的去除率比CK分别提高了47.48%~69.89%和44.43%~66.71%,且不同湿地植物对氮和磷的去除效果存在显著性差别(P<0.05)。6种湿地植物体内氮、磷积累量也存在差异,培养期内植物体内氮的积累量为206.57~399.03 mg·株^-1,磷的积累量为27.26~53.78 mg·株^-1,其中,艾蒿、水芹、苔草湿地植物生长量和氮、磷积累量显著高于菖蒲和芦苇。6种湿地植物的根表面积、根系氧化力分别在36.91~58.57 cm 2和4.63~23.57μg·g^-1·h^-1,艾蒿的根表面积和根系氧化能力最大,水芹和苔草次之,芦苇最低。相关关系分析表明,6种湿地植物生物量、根表面积、根系氧化力与氮质量浓度呈极显著正相关,而与磷质量浓度呈显著正相关。

Six typical wetland plants in Dongting Lake,including Phragmites australis,Carex cinerascens,Leonurus Artemisia,Oenanthe javanica,Artemisia argyi and Acorus calamus,were used to measure some indicators such as concentration of N and P,root surface area and root oxidation,and to investigate the effects of root characteristics and root oxidation on removal of N and P in wetland plant.The contents of N and P all showed a trend of gradually decreasing at first and then flattening with the extension of culture time.Compared with the CK,the efficiency of the six wetland plants to remove N and P pollution was improved by 47.48%-69.89%and 44.43%-66.71%,respectively,and there were significant differences in the removal rate of N and P among different wetland plants(P<0.05).The cumulative amount of N and P ranged from 206.57 to 399.03 mg and from 27.26 to 53.78 mg,respectively,and the growth,N and P cumulative amount of A.argyi,O.javanica and C.cinerascens were significantly higher than those in the other wetland plants.The root surface area and root oxidation of the six wetland plants ranged from 36.91 to 58.57 cm^2 and from 4.63 to 23.57μg·g^-1·h^-1,respectively,and the root surface area and root oxidation of A.argyi were the largest,followed by O.javanica and C.cinerascens,and P.australis was the lowest.The correlation among root surface area,root oxidation and N content was the very significant,and the correlation among P content,root surface area and root oxidation was significant in the six wetland plants.