论文部分内容阅读
对河北坝上康保地区天然草地、人工林、农田和退耕地四种土地利用方式的输沙量、风速廓线以及土壤的理化性质进行观测和分析。结果显示:天然草地的地表硬度最大,输沙量最小,表层土壤粗颗粒含量最低;农田地表含水量和硬度最小,输沙量最大,有机质含量最低,表层土壤粗颗粒含量最高;人工林地土壤水分含量较高,输沙量较低,有机质含量较高;退耕还灌木地表层含水量较低,地表硬度和空气动力学粗糙度较大,输沙量大于林地,有机质含量低于林地。表明土壤风蚀受地表含水量、硬度以及空气动力学粗糙度的共同作用影响,三者均不同程度受地表植被的影响,反映了地表植被类型对土壤风蚀的潜在影响。因此,在优先保护原生植被的前提下,重视植被生态恢复建设,着重提高地表植被覆盖度,以改善土壤结构,提高土壤有机质含量,增强土壤抗风蚀能力。
The sediment discharge, wind speed profile and soil physical and chemical properties of four kinds of land use patterns of natural grassland, plantation, farmland and cropland in Hebei Bashang Kangbao area were observed and analyzed. The results showed that the natural grassland had the highest surface hardness, the least amount of sediment, the lowest content of coarse soil in the surface soil layer. The surface water content and hardness of farmland were the lowest, the sediment content was the highest, the content of organic matter was the lowest, and the content of coarse particle in surface soil was the highest. Higher sediment content, lower sediment concentration and higher organic matter content. Surface water content of returned farmland to shrubs is lower, surface hardness and aerodynamic roughness are larger, sediment load is higher than forest land, organic matter content is lower than forest land. It shows that the wind erosion is affected by the combined effect of surface water content, hardness and aerodynamic roughness. All three are influenced by the surface vegetation to some extent, reflecting the potential impact of surface vegetation on soil erosion. Therefore, on the premise of protecting native vegetation, priority should be given to the ecological restoration and construction of vegetation, with emphasis on improving the coverage of surface vegetation so as to improve soil structure, increase soil organic matter content and enhance soil erosion resistance.