Benefits And Structure Of The Windbreaking And Fixing Sand Forest In Sandy Desertification Region Along The Great Wall In Northen Shaanxi

Based on theories of landscape ecology, systems engineering and sustainable development, according to combing standard plot investigation and permanent plot observation, single technology and corresponding technology, located observation and experimental analysis, mathematical methods and computer technology, to analyze the structure configuration and ecological function of fixing sand forest in Yulin sandy desertification region along the Great wall in northern Sha'anxi, put forward the reasonable structure and optimize allocation mode for different land site, provide a theoretical foundation and technological support for implementation of anti-desertification project, all these work are very important and have a great significance in guiding the practice for the construction of ecological environment. The main conclusions show as following:(1) The types of sites of Yulin desert were classified. It involved 1 site zones, 3 site areas, 5 site kinds and 16 site types. There are about 10 kinds plant species suited to artificial afforestation, Pinus sylvestrisL. Var. MongoLicaLitvin. Populus opera, Hedysarunlaeve, H. scoparium, Salix psammophila, Caragana korshinskii, Amorpha fruticasaL, Sabina vulgaris, ArtemisiaarenariaDC. Astragalus adsurgens Pall. etc.(2) The reasonable planting density of windproof dune-fixing forest in Yulin sand land is about 3000～3500 strain /hm~2. The suitable cover of windproof dune-fixing forest is about 0.33～0.55. The structure patterns mixture of trees with shrubs and herb may obtain the good protection benefit.(3) The bush dune-fixing forest has the remarkable ecology potency. In the forest, the wind speed was reduced, the Soil nutrient was increased obviously, such as organic matter, total N, available P etc., the nutrient condition obtains improved greatly. It was important for improving the ecological environment of Yulin sand land.