关键词: 沙质草甸草原, 地形因子, 植物群落, 优势种, 重要值

Abstract:

A study was carried out on the relationship between the changes of micro-relief and the changes of plant communities as well as their spatial distribution patterns, by systematic sampling in a dry depression and its adjacent flat background grassland in the Hulunbuir sandy meadow grassland, Inner Mongolia, China. It was discovered that the changes of micro-relief has a great influence on the variety, composition, and the distribution pattern of plant communities in the depression. There are significant differences about the species composition, the community biotype and ecotype. Heterogeneity of the dominant species and sub-dominant species in different micro-relief were also observed. Plant community characteristics of coverage, ground biomass, and height were high on lower slopes, medium on the middle of slopes, and low on upper slopes. The important value differentiation of dominant specie at different places on slopes facing different directions was also significant. Overall status of plant community on upper SW slope was the poorest, compared with that on the depression and on background grasslands, coinciding with the mass occurrence of blowouts, which indicated that the poorness of vegetation coverage should be an important reason for the mass development of sandy grassland blowouts on upper SW slope in Hulunbuir sandy meadow grasslands.

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