| 湖泊基质客土改良的环境效应:对芦苇生长及光合荧光特性的影响 |
| 摘要点击 1763 全文点击 888 投稿时间：2015-01-20 修订日期：2015-07-13 |
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| 中文关键词 基质改良 芦苇 生长 光合荧光 富营养化 湖泊 |
| 英文关键词 substrate amelioration by soil exchange Phragmites communis growth photosynthetic fluorescence eutrophication lake |
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| 中文摘要 |
| 湖泊底质对根着水生植物生长发育有重要的影响,通过滨岸底质植生性改良、重建水生植被被认为是污染湖泊生态修复的重要手段. 本研究模拟5种客土厚度对芦苇生长和叶绿素荧光参数的影响,结果表明,覆盖5 cm处理芦苇总生物量、株高、叶长和叶宽显著大于覆盖18 cm处理(P< 0.01),实验第120 d,地下/地上部生物量和细根/地下部生物量显著大于其他处理(P< 0.05). 表明覆盖18 cm显著抑制芦苇生长,但对照组富营养底质可能对芦苇生长造成轻微胁迫,随覆盖厚度增大,显著降低芦苇的地下部/地上部生物量比值,芦苇优先生长地下部,特别是细根的生物量,以便从底质中吸收更多养分供植物生长. 不同处理芦苇Fv/Fm、Yield、qP和qN变化差异不显著(P> 0.05),覆盖厚度越大,芦苇光合结构PSⅡ更易受到损坏,主要是通过较高的热耗散、降低叶片光合面积与叶片捕光色素含量来维持光合结构PSⅡ保持正常. 就客土改良对芦苇生长与叶绿素荧光参数总体影响而言,覆盖2 cm和5 cm能有效改善基质Eh和营养条件,促进植物生长,其中覆盖2 cm处理能有效地提高芦苇光合利用效率(α)、相对电子传递速率(ETRmax)和半饱和光强(Ek),覆盖18 cm使得芦苇对冬季的低光抑制有更强的适应能力. |
| 英文摘要 |
| Growth of rooted aquatic macrophytes was affected by the nature and composition of lake bottom sediments. Obviously, it has been recognized as an important ecological restoration measure by improving lake substrate and then reestablishing and restoring aquatic macrophytes in order to get rid of the environmental problem of lake. This study simulated five covering thickness to give an insight into the influence of substrate amelioration on Phragmites communis growth and photosynthetic fluorescence characteristics. The results showed that the total biomass, plant height, leaf length and leaf width of Phragmites communis under capping 5 cm were much more significant than those of capping 18 cm (P< 0.01),at the 120 d,the underground: shoot biomass ratio and fine root: underground biomass ratio were also much higher than those of other treatments(P< 0.05),which indicated that capping 18 cm treatment would significantly inhibit the growth of Phragmites communis,but the growth of control group Phragmites communis was slightly constrained by eutrophicated sediment. In addition, as the capping thickness growing, the underground: shoot biomass ratio of the plant would be reduced dramatically, in order to acquire much more nutrients from sediment for plant growing, the underground biomass of Phragmites communis would be preferentially developed, especially, the biomass of fine root. However,PhotosystemⅡ(PSⅡ) photochemical efficiency (Fv/Fm), quantum yield (Yield), photochemical quenching (qP), non-photochemical quenching (qN) of Phragmites communis under different treatments had no significant differences(P> 0.05),furthermore, with much greater capping thickness, the photosynthesis structure of PSⅡ would be much easier destroyed, and PSⅡ would be protected by increasing heat dissipating and reducing leaf photosynthetic area and leaf light-captured pigment contents. In terms of the influence of sediment amelioration by soil exchange on the growth and photosynthetic fluorescence characteristics of Phragmites communis, plant growth could be effectively promoted under capping 2 cm and capping 5 cm by increasing the Eh value and nutrient content, whereas plant under capping 18 cm would be much easier adaptive to low-light stress in winter season, of which capping 2 cm treatment was conducive to enhance the initial slope of RLCs (α), maximum electron transport rate (ETRmax) and minimum saturating irradiance (Ek). With regard to the harness of environmental problem of lake, the eutrophication status of lake will be mitigated by using multi-ecological measures to control the internal nutrients content once the external loading was first effectively controlled. |
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