新疆表层土壤粒径分形特征及驱动因素分析OA

Xinjiang,an ecologically fragile region in China that is prone to aeolian desertification,has a surface-soil particle composition that plays a critical role in regional ecosystem stability.This study analyzed the particle composition of surface soils collected from 180 sampling points across 60 plots in Xinjiang,China.Using the aridity index,sampling sites were classified into semi-arid,arid,and hyper-arid plots to examine the fractal char-acteristics of soil particle-size distributions across drought gradients and to assess how environmental factors in-fluence these fractal properties in surface soils.The results demonstrated that(1)With increasing aridity,the sur-face-soil particle-size distribution became progressively coarser and showed clear transitional features.Semi-arid and arid plots were dominated by silt,whereas hyper-arid plots were dominated by sand,with very fine and fine sand together accounting for 53.48%.(2)Overall,the soils exhibited poor sorting.Particle dispersion decreased with increasing aridity,resulting in progressively narrower size distributions,and the fractal dimensions ranged from 1.98 to 2.47.(3)The fractal dimension was strongly influenced by clay content,showing positive correla-tions with clay and silt and a significant negative correlation with sand.Furthermore,the model-fitting perfor-mance of the fractal dimension in plots under different aridity gradients followed the order:hyper-arid>arid>semi-arid.(4)The factor detector results indicated that mean annual precipitation(MAP),mean annual temperature(MAT),soil type,and parent material had strong explanatory power for the soil fractal dimension.Structural equa-tion modeling further showed that,among the continuous variables examined,climatic factors had a significant in-fluence on the surface-soil fractal dimension in Xinjiang.Specifically,MAP and wind speed exerted positive ef-fects,whereas MAT had a negative effect.This research provides a scientific basis for regional soil use and eco-logical management,supporting soil and water conservation,vegetation restoration,and ecosystem stability in Xinjiang.