【摘要】 [目的]研究不同放牧强度下草原植物群落根系性状对土壤分离能力的影响以及根系缠绕—固结效应和根系分泌物黏结效应对土壤抗侵蚀能力的相对贡献，为荒漠草原水土流失治理提供科学依据。[方法]以内蒙古希拉穆仁荒漠草原为研究对象，采用土壤分离冲刷试验，系统测定不放牧、轻度放牧、中度放牧及重度放牧4种处理条件下的土壤分离能力，并计算根长密度等根系参数。[结果]随放牧强度增加，禾本科植物植被盖度和生物量降低，0～1 mm径级范围内的细根含量明显减少；重度放牧强度下的土壤分离能力为不放牧样地的2.5～3.1倍；根长密度可表征土壤的分离能力，当根长密度>0.4 cm/cm3且根重密度>0.6 kg/m3时土壤分离能力显著降低；根系缠绕—固结效应和根系分泌物黏结效应在抑制土壤侵蚀中的贡献率比例为0.65∶0.35。[结论]放牧强度显著影响了荒漠草原的土壤分离能力，根系的缠绕—固结效应对土壤分离能力的降低起到了关键作用。更多还原

【Abstract】 [Objective] The effects of root traits of grassland plant communities on the soil detachment capacity and the relative contribution of root winding-consolidation and root exudate bonding effects on soil erosion resistance under different grazing intensities were analyzed in order to provide a scientific basis for soil and water conservation efforts in a desert steppe. [Methods] The Xilamuren desert steppe in Inner Mongolia Autonomous Region was evaluated as the research object. Soil detachment scouring experiments were conducted to systematically measure the soil detachment capacity under four treatments: no grazing, light grazing, moderate grazing, and heavy grazing. Root parameters such as the root length and density were calculated. [Results] As the grazing intensity increased, the vegetation coverage and biomass of gramineous plants decreased, and the content of fine roots(0—1 mm diameter) significantly decreased. The soil detachment capacity under heavy grazing intensity was 2.5—3.1 folds that of no grazing plots. The soil detachment capacity could be characterized based on the root length density; when the root length density exceeded 0.4 cm/cm3 and root weight density exceeded 0.6 kg/m3, the soil detachment capacity significantly decreased. The contribution rates of the root entanglementconsolidation effects and root exudate binding effects on soil erosion inhibition were 0.65∶0.35. [Conclusion] Grazing intensity significantly influenced the soil detachment capacity of the desert steppe, with the root entanglement-consolidation effect playing a key role in this outcome.更多还原