芦苇对人工盐碱湿地中Na+的吸收与转运特征

以芦苇为材料,通过构建人工盐碱湿地研究芦苇对Na~+的转运特征及Na~+在湿地系统中的分布特征。实验设置4个处理,CK、T1(浇灌100 mmol·L~(-1)的盐水)、T2(浇灌200 mmol·L~(-1)的盐水)及T3(浇灌300 mmol·L~(-1)的盐水),于不同时间测定各处理下芦苇地上及地下部分Na~+与K~+含量,计算Na~+/K~+及二者的转移系数,从而分析湿地盐分对芦苇体内Na~+、K~+平衡的影响及芦苇对Na~+的转运特征;测定土壤及水体中Na~+与K~+的含量,计算去除率,分析芦苇对湿地的脱盐作用。结果显示:与CK相比,高浓度(T3)Na Cl处理使芦苇地上及地下部分Na~+含量最终分别增加了6.09倍和1.61倍,地上及地下部分K~+含量分别降低了26.88%和18.10%。地上部分Na~+/K~+随处理时间逐渐升高,地下部分则相反。CK及T1的Na~+转移系数为0.30~0.86,随处理时间延长而减小;T2及T3的Na~+转移系数为0.51~0.91,随处理时间延长而增加。芦苇对处理组土壤Na~+及K~+的去除率分别为11.0%~13.4%和3.8%~9.8%,对处理组水体Na~+及K~+的去除率分别为42.7%~51.6%和6.8%~74.2%。研究结果表明,盐胁迫会影响芦苇体内的Na~+、K~+平衡,芦苇能有效地吸收Na~+,将Na~+从植物地下部分转运到地上部分。芦苇对湿地具有一定的除Na~+脱盐作用,且高浓度Na~+的存在会影响芦苇对K~+的吸收及去除。

Characteristics of Na+ absorption and transport of Phragmites communis in artificial saline wetlands

The characteristics of both Na⁺ transport in Phragmites communis and Na⁺ distribution in a wetland system were investigated by constructing an artificial saline-alkaline wetland. Four treatments, namely CK, T1 (irrigation with 100 mmol·L^-1 saline water), T2 (irrigation with 200 mmol·L^-1 saline water), and T3 (irrigation with 300 mmol·L^-1 saline water), were set up for the experiment. The effect of wetland salinity on the balance of Na⁺ and K⁺ in P. communis and its Na⁺ transport characteristics were analyzed via the variation in Na⁺/K⁺ and the former''s Na⁺/K⁺ transfer factor under different treatments in different periods. The removal ratios of Na⁺ and K⁺ from soil and water were calculated to analyze the desalination of wetlands by P. communis. The results indicated that in P. communis treated with high concentrations of NaCl (T3), the Na⁺ content in the aboveground and underground parts of the plants eventually increased 6.09 and 1.61 times, respectively, compared with CK, while the K⁺ content in aboveground and underground parts eventually decreased 26.88% and 18.10%, respectively. The Na⁺/K⁺ in the aboveground parts increased gradually while the opposite trend occurred in the underground parts. The Na⁺ transfer factor of CK and T1 decreased gradually while that of T2 and T3 showed the opposite trend. The removal ratios of Na⁺ and K⁺ from soil in the treatment groups ranged from 11.0% to 13.4% and 3.8% to 9.8%, respectively, and the removal ratios of Na⁺ and K⁺ from water in the treatment groups ranged from 42.7% to 51.6% and 6.8% to 74.2%, respectively. The above results indicated that salt stress affected the balance of Na⁺ and K⁺ in P. communis, and that the plant can effectively absorb and transport Na⁺ from its underground parts to its aboveground parts. In addition, P. communis had a role in removal of Na⁺ and wetland desalination, while the presence of a high Na⁺ concentration had a negative effect on the absorption and removal of K⁺.