Ecological Protection Effects Provided by Sand Barriers in a Grassland Mining Area

[Objective] The wind protection effectiveness of different sand barriers and their effects on surface soil particle size composition, soil nutrients and vegetation growth werer studied in order to provide a theoretical basis for the optimal selection of sand barriers for dump slopes in grassland mining areas. [Methods] Reed curtain sand barriers and Salix psammophila sand barriers having different specifications (0.5 m×0.5 m, 1.0 m×1.0 m, and 1.5 m×1.5 m) were set up on a dump slope in the study area. Wind protection effectiveness, soil particle size composition, soil nutrients, and vegetation growth were used to evaluate the ecological protection effects of different sand barriers on the dump slope. [Results] ① The sand barrier reduced the surface wind speed, and the wind protection effectiveness of the 0.5 m×0.5 m reed curtain sand barrier was the highest at the height of 10 cm (84.30% efficiency). The overall wind protection effectiveness of the sand barriers followed the order of 0.5 m×0.5 m > 1.0 m×1.0 m > 1.5 m×1.5 m. ② The content of silt, very fine sand, and fine sand in the surface soil of the 0.5 m×0.5 m reed curtain sand barriers accounted for 58.28% of the total particle size fractions. Soil moisture content, organic matter, total nitrogen, and total phosphorus content were the highest for this treatment, and were 29.72%, 29.69%, 22.22% and 83.33%, respectively, greater than the values observed for the control treatment. The total potassium content of the soil with the 0.5 m×0.5 m S. psammophila sand barrier was the highest (8.80% greater than observed for the soil from the control treatment. ③ The placement of sand barriers promoted the establishment of herbaceous plants, resulting in an increase in the number of plant species in the sand barrier plots, and a greater number of plant species in the small-size sand barriers than in the large-size sand barriers. [Conclusion] Sand barrier construction is beneficial to the ecological restoration of dump slopes. These results suggest that the construction of 0.5 m×0.5 m reed curtain sand barriers during the early restoration of dumps in grassland mining areas.