| Ecological restoration technology is important to the mining wasteland for soil erosion and water Loss control and fast revegatation. For many years, the destruction of the quarry mountain by disordered quarrying caused serious threat to the regional ecological security. The problem of barren soil, serious water drainage and low survival rate seriously restrict the study of vegetation construction and control of soil and water erosion in this area. In particular, the site environment of the mixture of large loose deposits with different particle diameter gravels by random dumping on the natural slope is the emphasis and difficulty to vegetation construction and control of soil and water erosion.So, based on the artificial preparation condition of the platform and slope of loose accumulation, the author did the field experiment of ecological technology system from the degree of soil, water and revegatation factor in southwest mountain of Fangshan region; and developed the laboratory, pot and farmland experiment research of the ecological technology in Changping region by loose deposits of Fangshan region; and put forward a series of ecological technologies. The results are as follows:1) Through the study, the author found the basic physical and chemical properties of loose deposits were bad, the heavy metal content was very low. By the steeper slope, the condition of soil and water loss was more serious. By the bigger difference in elevation, the phenomenon of water leakage was more obvious.2) The author did a pot, farmland and field experiment to conclude that the maximum dry density was1.95g/cm3and the optimum moisture content was6.1%. With increasing compaction degree, dry density was increased; the water content and the porosity ratio were decreased gradually; the soil saturation (water retention) was an upward trend. The compaction technology could increase the volumetric soil and water content of50%; the two treatments of hydraulic fill of water and the compaction degree of70%were better; the suitable plants were Medicago sativa Linn., Platycladus orientalis and Black Locust. In the same compaction degree of70%, the author proposed the best compaction process of the compaction depth of1-3meters which could grow two plants of Pinus tabulaeformis Carr. and Rhus typhina Nutt.3) The author concluded that the drought resisting water retention bag had the best water absorption and water retention capability. The technology could increase the volumetric soil and water content of23.3%-48.5%, and improving the survival rate of25.6%-69.5%. The author suggested choosing different kinds of resisting water retention bags according to the water condition of the region.4) The author did a pot, farmland and field experiment to conclude that the plastic film mulching was better than the organic waste and gravel mulching treatments in the part mulching condition. With the complete mulching condition, the effect of the organic waste mulching was best. Using the mulching technology could decrease the surface temperature of19.1%, and reducing the soil evaporation of14.8%, and increasing the volumetric soil moisture content of8%-30%, and increasing Pimts armandii biomass of22.8%. The survival rate and the growth index were increased about20%and17.2%-20.3%of Pinus tabulaeformis Carr. and Rhus typhina Nutt, In all, there were there mulching technologies: organic waste mulching+Rhus typhina or Pinus tabulaeformis, gravel mulching+Rhus typhina or Pinus tabulaeformis. and plastic film mulching+Rhus typhina or Pinus tabulaeformis.5) The experiment of loose deposits improvement resource concluded that farmland soil, aged refused humus soil and sewage sludge could provide the necessary chemical nutrients, and adjust the pH of the loose debris effectively. They could improve the volumetric soil and water content, the survival rate and the growth of Platycladus orientalis, Festuca arundinacea and Pinus tabulaeformis. In all, there were the ratio accounted for10%-40%,30%-50%and40%-60%of farmland soil, aged refused humus soil and sewage sludge improving technologies.6) It was found that it could reduce water losses and soil erosion observably with ecological bag technology, and there had good correlation basically with the good effect of reducing runoff and sediment yield and the rainfall intensity and slope. With the increase of rainfall intensity and slope, the values of runoff and sediment with ecological bag technology were lower than the contrast. The effect of reducing runoff was notable with the rainfall intensity of5.1mm/h and the slope of35°. The effect of reducing sediment yield was notable with the rainfall intensity of12.0mm/h and the slope of25°.The value of runoff was higher and the sediment yield was lower by the increasing annual rainfall by using the ecological bag technology.7) The experiment of selection and configuration of the plants concluded that the species numbers were more but little kinds. By the restoration years increased, there were no difference in the species numbers, but had some arbor and shrubs increased. The herb reduced slightly, and the life form diversify, and the perennials plants take advantage gradually. The plants would success from herb layer to herb and shrub layer and arbor, shrub layer. The author summarized two primary plant communities by the method of summed dominance ratio:Rhus typhina-Vitex negundo Linn.-Setaria viridis (Linn.) Beauw; Ailanthus altissima-Astragalus adsurgens Pall.-Setaria viridis (Linn.) Beauv. By the comprehensive analysis of the survival rate and the growth height and coverage, the author screened23strong adaptability dominant plants.By analysis, the conclusions of this study formed a set of perfect ecological restoration technologies in deserted quarry in the mountain of Beijing. |
PDF Full Text Request