| Desert steppe is a kind of grassland with the strongest aridity.In order to improve the influence of unfavorable factors on the ecological environment,Caragana korshinskii has been widely planted in desert steppe.Reasonable configuration mode of Caragana korshinskii shrub forest plays an important role in soil and vegetation restoration and reconstruction.In this study,Caragana korshinskii shrub forests with different spacing in Wukehudong Town,Damao Banner,Baotou City,Inner Mongolia Autonomous Region were taken as the research object.In 2021,field vegetation survey and indoor experimental analysis were carried out on the soil,herbaceous vegetation and soil seed bank between Caragana korshinskii shrub forests.The changes of soil physical and chemical properties,vegetation community characteristics and soil seed bank characteristics among the forest belts of Caragana korshinskii were analyzed,and the principal component analysis and canonical correlation analysis of soil,vegetation and soil seed bank factors were carried out.Based on the fuzzy comprehensive evaluation method,the band spacing suitable for the rational planting of Caragana korshinskii shrubs in the study area was preliminarily proposed.The conclusions are as follows:（1）The soil moisture content of Caragana korshinskii shrub land in the study area ranged from 3.62%to 4.92%,and the soil p H value ranged from 8.33 to 8.67.The changes of soil physical and chemical properties between Caragana korshinskii shrub belts with different belt spacing showed that the position near the Caragana korshinskii forest belt was better than the middle position of the forest belt,and the surface soil quality was significantly higher than the lower soil.The soil quality of Caragana korshinskii shrublands with three spacings was lower than that of the control plot,indicating that the soil between Caragana korshinskii shrublands was still in the recovery stage.（2）The herb biomass between Caragana korshinskii shrub belts was between18.16～24.77 g·m-2.With the increase of belt spacing,the microclimate in Caragana korshinskii shrub belt changed.The Margalef richness index and aboveground biomass of herbaceous vegetation in Caragana korshinskii shrub forest with 1.5m belt spacing were significantly higher than those in Caragana korshinskii shrub forest with 3m belt spacing.（3）In all plots of the study area,there were 11 species of plants in the soil seed bank germination,belonging to 5 families and 10 genera.The species composition of the soil seed bank of Caragana korshinskii shrubs with different band spacing was basically the same.The 1.5m Caragana shrub forest had a significant effect on the enrichment of seeds in the soil seed bank.The number of germinated seeds in the soil seed bank was CK（1152.07 grains）>1.5m（978.32 grains）>2.5m（738.54 grains）>3m（580.83grains）,and the soil seed bank was mainly enriched in the surface layer（0～2cm）.From the comprehensive analysis of the species diversity index of the soil seed bank,the Simpson diversity index,Shannon-Wiener diversity index,Pielou evenness index and Margalef richness index of the seed bank between the 3m strip spacing Caragana shrubbery are greater than 2.5m and 1.5m Caragana shrubbery.（4）The canonical correlation between soil,vegetation and soil seed bank in different spacing of caragana shrub belts is inconsistent.According to the index system of soil,vegetation and soil seed bank in different spacing of caragana shrub belts,the comprehensive evaluation results show that the restoration degree of soil,vegetation and soil seed bank in caragana shrub belts with spacing of 1.5m,2.5m and 3m is 83.52%,74.47%and 73.18%of the current control sample,respectively,indicating that planting caragana shrub with spacing of 1.5m in the study area has better effect on soil and vegetation restoration. |
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