| Vegetation restoration at Waste Sanitary Landfill has become the hot points and focus of many international and multidisciplinary research projects. In this thesis, taking the techniques of vegetation restoration at Liulitun Waste Sanitary Landfill Slope in Beijing as study object, on the basis of vegetation investigation at Liulitun Waste Sanitary Landfill,screening seven kinds of plants with strong resistance used in the test of planting techniques on landfill slope and soil improvement with earthworm. These studies can provide a theoretical basis of vegetation restoration at waste sanitary landfill slope in Beijing. The achievements are as follows:Present vegetation investigation shows that although plants covered almost all the areas in Liulitun Waste Sanitary Landfill, the temporary slope ware still bare. According to the statistical analysis, 32 species and 18 families were found at the landfill site. The herb plants are the main plant ecotype. The wild bushes and arbor ware not found. The dominant population are Echinochloa crusgallii var caudate and Setaria viridis (Linn.) Beauv. Kochia scoparia and Portulaca oleracea were subdominant species. Survey results show that: the wild plant grown at the landfill site is well. They are Widely distributed and have a stronger ability to adapt to the harsh environment. The height of Setaria viridis, Bidens bipinnata and Digitaria sanguinalis is upper than artificial plant. They are all the pioneer species. So at the beginning of the vegetation restoration, Gramineae and Compositae is the best choice. After the pioneer species grow up, plant other wild vegetation. Furthermore, breeding wild plant seed could enhance the process of vegetation restoration.The test of planting techniques on landfill slope shows that: The effect of using spraying and sowing green, spraying and sowing green with non-woven fabrics and vegetation blanket for slope vegetation restoration is better than that of using covering soil with non-woven fabrics and covering soil. The former reduce about 50%soil erosion. The height and the cover rate ware improved 2 to 3 times. But the investment costs also increased about 2 times. Medicago sativa Linn. has the better suitability,compared with Agropyron cristatum(L.)Gaertn and Orychragmus violaceus. Because Medicago sativa Linn. is Nitrogen-Fixing Legume can improve soil fertility. It is the best choice using in the vegetation restoration at landfill site.It is indicated by our environment monitoring that the the impact factor of vegetation restoration are high temperature, landfill gas, leachate, soil physical and chemical properties, soil Thickness , heavy metal accumulation and so on. It is consider that strengthen research in the soil monitor and improvement is necessary.The test of soil improvement with earthworm shows that: The available K,P,K of fertilizers in the wormcast was near to 30 times of that of Refuse Landfill. Soil porosity and water content was near to 2-3 times. Compared with the flowers planting in the landfill soil, flowers of height, cover rate, Pharbitis nil. and water use efficiency planting in the wormcast increased 100%,200%,20%,13%. It is the method of refuse recycling technology and can reduce the cost. So the excrement of earthworm was recommended as covering materials for the ecological restoration of municipal waste landfill sites... |
