Abstract:Taking the Wind-breaking and Sand-fixing Forest System in Jilantai Salt Lake as the object, the physical and chemical properties of soil in different parts were investigated to evaluate the effect of the Wind-breaking and Sand-fixing Forest System, and provide a theoretical basis for vegetation restoration in arid areas. The results showed that:(1) After 35 years of construction of the Wind-breaking and Sand-fixing Forest System in Jilantai Salt Lake, the original quicksand texture changed significantly under the joint effect of intercepting wind erosion material and vegetation improvement. Compared with the moving dune, the contents of fine sand and powder in the targeted soil increased significantly (30.55% and 500.00%, respectively), while the coarse sand contents decreased by 27.00%. (2) The soil organic matter, available nitrogen and total nitrogen contents in the shelterbelt were very high, which was 252%, 665% and 1 466% of the moving dune. The difference of total phosphorus was not obvious. The contents of available phosphorus and available potassium in the lake were the highest, which were 276% and 202% of the moving dune, respectively. The highest total potassium content was observed in the transition zone with white thorn bushing, which was 153% of the moving dune. In general, the nutrient contents showed a positive correlation with medium sand, fine sand, very fine sand and powder. (3) Soil organic matter, total available nitrogen, and potassium could comprehensively reflect the soil quality improvement effect of the shelterbelt system, and the soil in the shelterbelt had the highest comprehensive soil nutrient contents. After 35 years of development, the soil available nitrogen, total nitrogen and organic matter in the shelterbelt increased by 204.20%, 90.63% and 94.11%, respectively, indicating that the Wind-breaking and Sand-fixing Forest System had an obvious improvement effect on soil. These research results could provide data support for evaluating the protection benefits of the wind-fixing and sand-fixing forest system in Jilantai Salt Lake.