模拟酸雨对水芹根部NH_4^+、NO_3^-、H^+离子通量的影响

Effects of simulated acid rain on NH_4^+、NO_3^-、H^+ ion fluxes in roots of Oenanthe javanica

氮素是植物生长发育必需的营养元素,利用水生植物吸收水体中的氮素是富营养化水体生态修复的重要途径。以水芹(Oenanthe javanica)为研究材料,在中富营养和超富营养两种水平下,探讨模拟酸雨对水芹根部H+、NH4+和NO3-离子流及根系活力的影响。结果表明,酸雨对水芹根系吸收水体中氮素产生影响,并随富营养化水平提高其影响加大。分析发现:(1)水芹对NH4+有吸收偏好;(2)与对照相比,模拟酸雨降低了根部H+的外排,相应地减弱了NH4+的内流,增加了NO3-的外排,但对根系活力无显著影响;(3)超富营养水平下,酸雨对水芹离子流的影响增强,并使根系活力显著降低。

Nitrogen is necessary for plant growth of the nutritional elements.To absorb Nitrogen from eutrophicational water by using aquatic plants is important means to ecological restoration.Acid rain has become a serious region environment problem.China is the third acid rain area in the world.It should be further studied that how aquatic plants responded with simulated acid rain,and how acid rain effected on the nutrition cycle of roots.It was significant for the further physiological and ecological studies on the interrelationship between acid rain and aquatic plants in acid rain region.In this study,Oenanthe javanica was selected as research material to study the effects of simulated acid rain on H＋,NH＋4,NO-3 fluxes in the roots and root activity among middle eutropher or hyper eutropher.The results showed：（1）O.javanica preference to absorption of NH＋4.（2）Compared with the contrast,simulated acid rain reduced H＋ effluxes,receded NH＋4 influxes,increased NO-3 effluxes,and no significant effect on the root activity.（3）The effect of simulated acid rain on ion fluxes in the roots was enhanced and the root activity was significant deceased among hyper eutropher.To conclude that acid rain affected the absorption of Nitrogen ions fluxes and advanced eutrophication level would strengthen the influence of acid rain.