The effects of vegetation restoration on soil erosion resistance of gully head, along a revegetation age gradient, remain poorly understood. Hence, we collected undisturbed soil samples from a slope farmland and four grasslands with different revegetation ages (3, 10, 18, 25 years) along gully heads. Then, these samples were used to obtain soil detachment rate of gully heads by the hydraulic flume experiment under five unit width flow discharges (2–6 m3 h). The results revealed that soil properties were significantly ameliorated and root density obviously increased in response to restoration age. Compared with farmland, soil detachment rate of revegetated gully heads decreased 35.5% to 66.5%, and the sensitivity of soil erosion of the gully heads to concentrated flow decreased with revegetation age. The soil detachment rate of gully heads was significantly related to the soil bulk density, soil disintegration rate, capillary porosity, saturated soil hydraulic conductivity, organic matter content and water stable aggregate. The roots of 0–0.5 and 0.5–1.0 mm had the highest benefit in reducing soil loss of gully head. After revegetation, soil erodibility of gully heads decreased 31.0% to 78.6%, and critical shear stress was improved by 1.2 to 4.0 times. The soil erodibility and critical shear stress would reach a stable state after an 18-years revegetation age. These results allow us to better evaluate soil vulnerability of gully heads to concentrated flow erosion and the efficiency of revegetation.

中文翻译：

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黄土高原25年重新植被龄期沟头土壤侵蚀抗力的变化

植被恢复对沿重新植被年龄梯度的沟头土壤侵蚀抵抗力的影响仍然知之甚少。因此，我们从一个坡耕地和四个不同植被年龄（3、10、18、25 年）沿沟头的草地采集了未扰动的土壤样品。然后，这些样品用于通过水槽实验在五个单位宽度流量（2-6 m3 h）下获得沟头的土壤脱离率。结果表明，土壤性质显着改善，根密度随着恢复年龄的增加而明显增加。与农田相比，重新植被的沟头土壤脱离率下降了35.5%～66.5%，沟头土壤侵蚀对集中流的敏感性随着重新植被年龄的增加而降低。沟头土壤脱离率与土壤容重、土壤崩解率、毛细管孔隙度、饱和土壤导水率、有机质含量和水稳性团聚体显着相关。0-0.5和0.5-1.0 mm的根系对减少沟头土壤流失的效益最高。重新植被后，沟头土壤可蚀性降低31.0%～78.6%，临界剪应力提高1.2～4.0倍。土壤可蚀性和临界剪应力经过 18 年的重新植被年龄后将达到稳定状态。这些结果使我们能够更好地评估沟头土壤对集中水流侵蚀的脆弱性和重新植被的效率。有机质含量和水稳性聚集体。0-0.5和0.5-1.0 mm的根系对减少沟头土壤流失的效益最高。重新植被后，沟头土壤可蚀性降低31.0%～78.6%，临界剪应力提高1.2～4.0倍。土壤可蚀性和临界剪应力经过 18 年的重新植被年龄后将达到稳定状态。这些结果使我们能够更好地评估沟头土壤对集中水流侵蚀的脆弱性和重新植被的效率。有机质含量和水稳性聚集体。0-0.5和0.5-1.0 mm的根系对减少沟头土壤流失的效益最高。重新植被后，沟头土壤可蚀性降低31.0%～78.6%，临界剪应力提高1.2～4.0倍。土壤可蚀性和临界剪应力经过 18 年的重新植被年龄后将达到稳定状态。这些结果使我们能够更好地评估沟头土壤对集中水流侵蚀的脆弱性和重新植被的效率。土壤可蚀性和临界剪应力经过 18 年的重新植被年龄后将达到稳定状态。这些结果使我们能够更好地评估沟头土壤对集中水流侵蚀的脆弱性和重新植被的效率。土壤可蚀性和临界剪应力经过 18 年的重新植被年龄后将达到稳定状态。这些结果使我们能够更好地评估沟头土壤对集中水流侵蚀的脆弱性和重新植被的效率。