关键词: 沙地植被, 统计学特征, 沙漠化

Abstract: Statistical properties of the vegetation and its relationship with desertification in Horqin Sandy Land was investigated and analyzed in this paper. The results showed that the frequency curves in the canopy height, plant cover, aboveground biomass and plant evenness all were abrupt single-crest curves, and the curve of plant density appeared a "C" form, the species richness and saturation had a double-crest curve, and the diversity had a parabola curve. In fixed and semi-fixed sandy land, the canopy height of 74.2% samples were ≤18 cm, the cover of 90.9% samples were ≥40%, the plant density of 59.1% samples were 300 n·m^-2, the aboveground biomass of 80.4% samples were from 60 to 210 g·m^-2, richness index of 81.8% samples were ≥10 species, the diversity index of 83.3% samples were 1.5, the evenness index of 56.1% samples were ≤0.2. In shifting and semi-shifting sand lands, the height of 68.8% samples were ≥18 cm, the cover of 68.8% samples were ≤30%, the density of 81.3% samples were 100 n·m^-2, the aboveground biomass of 75.1% samples were ≤90 g·m^-2,the richness of 100% samples were ≤7 species, the diversity index of 75% samples were 1.5, the evenness index of 75% samples were 0.2. Apparently, the desertification resulted in a significantly changes on the vegetation statistics properties, of which changed extent in the height, density and biomass were greater than those in the cover and richness and diversity.

Key words: sand land vegetation, statistical property, desertification