The Adapatility To Riverbank And The Purification To Saliferous And Contaminative Water Of Three Plants

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.