A Case Study On Sandy Desertification And Vegetation Succession In Hulunbeier Grassland

The Hulunbeier sandy land is our country one of four big sands. Recent year, because natural environment's worsening adds fells, opens up wasteland, herds, excavates and excessively human's unreasonable activity caused the Hulunbeier sand big area pasture to the sandy land to desertification. It's the only expanding land in china. Combat desertification becoming more and more important in china. This paper choose Chenbaerhu Banner as the trail area based on almost 20 year's climate'date and vegetation date to investigate the reason of desertification, the vegetation constructs and sandy land restored method. Through this research the main purpose of this paper is to give the effective suggestion on restores with the reconstruction degeneration ecosystem. The main conclusion is as follows:1. The Hulunbeier sand's desertification is created together by the natural factor and the human factor. The temperature continues to elevate with the precipitation reduction, the climate is getting drier, along with local population's increase, as well as resource demand's expansion has put more and more tremendous pressure to the land, which accelerated the desertification advancement.2. There are 54 families, 146 genera and 199 species seed plants in the research area. The dominant genera are Artemisia of Asteraceae family, Stipa, Cleistogenes, Achnatherum, Puccinellia, Calamagrosti, Leymus, Phragmites of Gramineae family, Caragana, Oxytropis, Hedysarum of leguminosae family,Suaeda of Chenopodiaceae family, Carex of sedge family and Iris of Iridaceae family.3. In plant's retrogression of succession, the plant community species composition changed. Species decreased from 31 to 2, coverage from 61% to 8%, species richness in shifting sandy land is 0.25 times of that in semi-fixed sandy land, 0.065 times of that in fixed sandy land. diversity index in Fixed sandy land, semi-fixed sandy land ,shifting sandy land are 2.464, 1.584 and 0.554.diversity index in Fixed sandy land was the biggest which is 4.45 times of that in shifting sandy land. Species evenness is 0.497, 0.528 and 0.554. Species evenness in shifting sandy land is the biggest which is 1.11 times of that in fixed sandy land. At the same time, the biomass also assumes the decreasing progressively tendency, the dominant species and constructs the group kind to occur alternates, the community structure tends to be simple.4. Manual intervention in the restoration of state in succession, the progress of succession law: annual species such as Agriophyllum squarrosum as the dominant species in vegetation community. Cleistogenes squarrosa as the dominant species with another Perennial Grass in this kind of transition vegetation community Agropyron cristatum and Cleistogenes squarrosa together as the dominant species in the transition vegetation community Leymus chinensis and Artemisia frigida together as the dominant species in the metastable vegetation community. At the same time, the soil structure, improve physical and chemical properties.Plant's progression of succession rule is: the stage of Agriophyllum squarrosum & Corispermum stauntonii -> the stage of Agropyron cristatum & Artemisia frigida -> Caragana microphylla & Stipa grandis & Cleistogeness quarrosa -> Carex rigescens & Agropyron cristatum. Meanwhile, the soil structure, the physics and chemistry nature are improved.