| To investigate the effects of vegetation restoration of the desertification land on microbial contents in the soil, soils underneath three different plant communities including arbor, shrub and grassland restored for 30 years in the south of maowusu sandy land of Yulin psammophyte garden were studied. The resulting effects of restoration on microbial biomass C, N, P, the relationship between them and the soil physicochemical properties were further analyzed. The results showed that vegetation restoration of the desertification land in agro-pastoral transitional zone had a significant promoting impact on microbial biomass C, N, P in the surface soil. The soil microbial biomass C of shrub was 288.35 mg·kg-1, which was the highest. The soil microbial biomass N of shrub was 3.99 and 2.10 times higher than that of arbor and grassland, respectively. Difference of the soil microbial biomass P among these three plant communities was not apparent. The order of soil microbial biomass C/N ratios was as arbor>grassland>shrub. The ratio of soil microbial biomass C/P of grassland was slightly higher than that of arbor and shrub. The correlation analysis results showed that the soil microbial biomass C, N, P had close correlations with soil physical and chemical properties. The soil nutrient mostly showed extremely significant correlation, and the soil bulk density mostly had extremely significant negative correlation, which meant that the soil microbial biomass could be used as a biological index for soil quality evaluation. |