【作者】 刘月敏；

【导师】 汤纯鹏；

【作者基本信息】 天津大学 ， 环境工程， 2007， 博士

【摘要】 河岸带水陆交互的边际效应决定了整个流域的多样性相对丰富,影响着整个流域的水和营养平衡,起到物理缓冲器及生物缓冲器的作用。河岸植被作为河岸带重要的组成因素日益受到各国学者的关注。自然状态及人工管理下河岸的特征不同,对整个河流流域起到的作用也有明显差别。人为管理下的河岸土壤盐分含量相对较高,河岸植物的种类与自然状态下河岸的植物有所差异。本文选取自然河岸带常见物种柽柳及人工管理河岸下的常见物种紫穗槐和黑麦草,测定其在不同NaCl浓度下的生长和生理状况及对富营养化水体的净化效果。为水质净化及防止河岸水土流失、护岸护坡的生态工程设计提供理论依据。研究结果表明:(1)长期浸泡条件下,适量NaCl均能促进柽柳和紫穗槐的生长。两植物生长的最适NaCl浓度分别为6 g·l-1和3 g·l-1。最适NaCl浓度下紫穗槐的生长速度大于柽柳。(2)与盆栽试验相比,长期浸泡条件下柽柳的耐盐能力明显下降,NaCl浓度为15 g·l-1时,部分单株出现死亡。本试验条件下柽柳的耐盐性能优于紫穗槐。(3)柽柳和紫穗槐叶片中MDA含量及抗氧化酶活性与其生长状况呈现一定相关性。MDA含量及SOD酶活性随NaCl浓度升高均明显增大;(4)适量浓度的NaCl可促进柽柳和紫穗槐对无机氮的吸收,所有NaCl处理柽柳水培液中硝态氮浓度的下降速度均大于紫穗槐。无论NaCl存在与否,两植物对硝态氮的利用效率高于氨氮;(5)紫穗槐根部和叶片的钠离子含量均随NaCl浓度的增大而增加。不同NaCl处理中,紫穗槐根部的钠离子含量大于叶片。柽柳根部和叶片的钠离子含量呈现不同的变化规律,根部钠离子含量随水培溶液中NaCl浓度增大未发生明显变化,叶片中钠离子含量随NaCl浓度增大迅速增加。相同NaCl处理下,柽柳叶片的钠离子含量均大于紫穗槐;(6)温度和NaCl的交互作用和明显影响黑麦草的发芽进程和发芽率。(7)黑麦草叶片中抗氧化酶活性及叶绿素、MDA含量的变化与其生长状况基本一致。30℃时黑麦草的抗NaCl性能明显下降。(8)在NaCl浓度为0.6%和1.2%的水培液中黑麦草的生长均明显受抑;(9)黑麦草对富营养化水培液中不同形态氮和总磷的净化效率均随NaCl浓度的升高而降低。更多还原

【Abstract】 Being an interface between the catchment area and the aquatic environment, the biodiversity was relatively high in riparian area, due to the marginal utility of it, and the balance of water and related chemical fluxes of surface water systems was influenced. And riparian area acted as physical buffers as well as biological buffers. As an important ecological factor, riparian vegetation was paid more attention to by scholars in all countries increasingly. The characteristics of riverbank were different at nature and human management, the function of riverbank was different obviously. In this study, saltscedar (Tamarix chinensis), a familiar species in nature riverside, and Amorpha fruicosa L. and ryegrass (Lolium L.), the familiar species in the riverside at human’s management, were selected. The growth, the physiological condition and the purified effect to water at different NaCl concentration were determined, to provide theory basis for water purification, prevent riverside from soil erosion, and the design of ecological engineering of retaining wall. The results showed: (1) The growth of saltscedar and Amorpha fruicosa L could be accelerated by optimum NaCl, yet the optimum concentration of NaCl were different, 6 g·l-1 and 3 g·l-1 respectively. And the growth speed of Amorpha fruicosa L. was higher than saltscedar at optimum NaCl concentration; (2) The capability of salt tolerance debased obviously dipped in chronically. Capacity of salt tolerance of saltscedar was higher than that of Amorpha fruicosa L. (3) Antioxidant enzyme activity and malondialdehyde (MDA) content in leaves of Amorpha fruicosa L. and saltscedar were correlated with their growth status, the integrated change of antioxidant enzyme activity and MDA content can indicate the damage to above plants of NaCl stress; (4) The absorption of Amorpha fruicosa L. and saltscedar to inorganic nitrogen could be accelerated by appropriate NaCl concentration. And the descending speed of nitrate nitrogen in culture solution of saltscedar was higher than that of Amorpha fruicosa L. at different NaCl concentration. And the utility nitrate nitrogen by two plants to was higher than that of ammonia nitrogen in spites of the existence of NaCl; (5) Na+ both in roots and in leaves of Amorpha fruicosa L. increased with NaCl concentration increasing, and Na+ in roots was always higher than leaves of Amorpha fruicosa L. Yet, Na+ variation in roots and leaves of saltscedar was different from that of Amorpha fruicosa L. with NaCl increasing, Na+ in roots had not obvious variance while Na+ content in leaves increased rapidly with NaCl increasing. Na+ content in leaves of saltscedar was always higher than that of Amorpha fruicosa L at same NaCl treatment; (6) The interaction of NaCl and temperature affected the germinating progress and germinating rate of ryegrass evidently. The growth status of ryegrass at 10℃and 20℃had not significant difference with control expriment, as NaCl concentration lower than 0.9%. Yet, ryegrass at 30℃showed shorter figure, and thinner leaves, and so on. So, the capacity of salt tolerance of ryegrass at 30℃declined markedly; (7) The variety of antioxidant enzyme activity, chlorophyll and MDA content was accordance with growth status. Nevertheless, the capacity of salt tolerance of ryegrass debased clearly; (8) The growth of ryegrass was repressed in the culture solution at 0.6% and 1.2% NaCl concentration; (9) The purification efficiency of ryegrass to both inorganic nitrogen and total phosphate in eutrophic culture solution decreased with NaCl increasing. The antagonism of various factors should be considered as designing of ecological engineering to sewage purification.更多还原