| In order to explore the theory and technique of restoring the damaged river bank ecosystem, taking YiTong River as the research subject and applying principles and designs of ecological engineering, we began restoration and construction four years ago. In that process, we analyzed and evaluated the effects of the restoration in the experimental area, mainly from the aspect of vegetative cover, soil organism changes, physical and chemical characters, benthon and corrosion extent of the bank, which collaborately demonstrated the following results:1. Reconstructed experimental area has been restored well. After such a 4-year-succession, the plant population in the experimental area was restored much better than control. (1) reed community grew well near the water: Average height of the stock increased from 1.2m in 2002 to 1.8m of 2006, which covered 95% area; (2) There were 15 herbage species in the experimental river bank whereas only 12 species in the control area. Meanwhile, in the former area, herbage coverage rate, biomass, biodiversity and its corresponding uniformity were also significantly higher than those in the latter one; (3) Arbors and shrub in experimental river bank always grew better than those in control area; (4) A stable arbor-shrub-grass plant community was constructed in the experimental area with a 0.95 crown closure in contrast with 0.25 crown closure in control.2. Experimental area has more kinds of Edaphon than control area. The moisture and soil condition, organizing of the plant community and productivity were all better than those in the control area. Edaphon distribution of the experimental area were developing well.3. In the experimental area, we collected 11 kinds of edaphon, which is contrast with only 7 kinds in the control area. The quantity, biomass, biodiversity, uniformity and dominancy also showed the same phenomena in experimental area. The healthy edaphon community promoted the physical and chemical improvement of the soil, which make the constructed river bank system healthily develop.4. The recovery effects caused by the constructed bank system in the experimental area were more obvious than those in control area. (1) The content of organic matter in the soil layer of experimental area was averagely 18.6% higher than that in control area; (2) The nitrogen and potassium content of every soil layer were all higher than those in control area, which were above 21.7% and 34.1%, respectively; (3) Soil in experimental area contained more water than the control area. However, bulk density in the former area is lower than that in the latter; (4) PH values of the layers in experimental area were much higher than those in the control area, which resulted in higher conductivity in experimental area. The improvement of the soil in physical and chemical aspect provided a positive foundation for the river bank's healthy development.5. The experimental area has been greatly improved in the kinds, quantity and diversity of the benthon compared with the control area. 8 kinds and 4 kinds of benthon were corresponding found in the experimental and control area. In the above areas, oligochaeta hydrodynamic occupied 54% and 77%, respectively. This significant decrease reflected the worse living surrounding in control area with regard to the experimental area.6. The reed- willow- amorpha-weeping elm community structure in the experimental area has gone through the succession process to a system with higher vegetational cover rate and crown density. The erosion extent of the experimental area was also lower than the control area. During the time of May, 2006 to May, 2007, the eroded soil in experimental area was 6315 t·km-2, which was significantly lower than 24608 t·km-2 of the control area. What's more, compared with the latter control area, the former area has fewer phenomena of collapse at the foot of the slope with great resistance to the afflux erosion.
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