Comparison Study On Vegetation And Soil Characteristics In The Different Type Of Grassland

The plant communities and soil physical and chemical characteristics of High grassland and Sandy grassland were investigated in the Baiyinxile of Xilinhot, Inner Mongolia, from May to October in 2008. The main researched contents included characteristics of plant communities, important values, community diversity, above-ground biomass, nutrition contents of forage, soil physical and chemical properties. The main results were shown as follows:1. Leymus chinensis density and Cleistogenes squarrosa coverage in the high grassland were high. C. squarrosa density in the Sandy grassland was low. The coverage of annual forages (Salsola collina and Lappula myosotis) was lower in the High grassland compared with the Sandy grassland.2. Perennial grass possessed an important role in the High grassland and Sandy grassland. The importance value of annual forbs was low, whereas of which annual Chenopod forage and Chenopodium glaucum in July were high in the High grassland and Sandy grassland. The species richness in High grassland was lower than that in Sandy grassland from July to October. The multiplicity and uniformity index of the Sandy grassland were high.3. Above-ground biomass of the Sandy grassland from May to October was high. The content of crude protein decreased, and the content of crude fiber decreased, then increased with the time of vegetation, which were higher in the High grassland compared with the Sandy grassland.4. The trends of total sugar content of perennial grasses were"decrease-increase", while that of perennial bunchgrass (Stipa grandis, C. squarrosa and Agropyron cristatum) were"decrease-increase-decrease".5. The soil moisture content from 10~40cm differ greatly in the High grassland, of which 0~10cm soil layer did not differ. The soil moisture content in High grassland was lower than that in the Sandy grassland, and the soil bulk density was high in the High grassland.6. There was a positive correlation among soil organic matter, available nitrogen, total potassium content and soil depth in the High grassland. The content of available nitrogen, total potassium decreased with an increase of soil depth, while organic matter content increased with an increase of soil depth. There was a positive correlation between the soil nutrition and depth except for the total phosphorus content, and above-ground biomass, soil organic matter and total phosphorus content showed out a positive correlation in the high grassland.