Plant community characteristics and functional traits may respond to soil erosion due to their high plasticity in varied environments. However, the linkages between plant functional traits and soil properties under erosion stress remain poorly understood, despite the fundamental role they play in controlling soil erosion. Here, we selected 50 plots on degraded land caused by long‐term water erosion representing three degrees of erosion that differed in terms of soil profile and erosion landform. We measured aboveground plant characteristics, root functional traits, and soil properties to explore their responses to the degree of erosion and to identify the main factors mitigating soil erodibility (K _r). The results showed that vegetation cover and root length density (RLD) were the plant variables that were most sensitive to the erosion stress. Topographic parameters strongly affected plant community characteristics (vegetation cover and litter mass) by favouring thicker soil layers and lower bulk densities, and soil texture strongly affected root functional traits (root mass density [RD] and RLD) by favoring lighter soils. Importantly, plant community characteristics and root functional traits were the main drivers of K _r mitigation through their mediation effects on a range of soil properties (e.g., soil organic matter, aggregate stability, and shear strength) during the restoration, and vegetation can still be efficient in maintaining and restoring soil functions, even on severely degraded land. Overall, these findings could guide restoration practices to meet soil conservation and ecosystem function goals in degraded ecosystems.

中文翻译：

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植物群落特征和功能性状是沿土地退化梯度减轻土壤侵蚀性的驱动力

植物群落的特征和功能性状可能因土壤在各种环境中的高可塑性而对土壤侵蚀作出反应。然而，尽管它们在控制土壤侵蚀中起着基本作用，但在侵蚀胁迫下植物功能性状与土壤特性之间的联系仍然知之甚少。在这里，我们选择了由长期水蚀引起的退化土地上的50个样地，代表了三个侵蚀程度，这三个侵蚀程度在土壤剖面和侵蚀地貌方面有所不同。我们测量了地上植物的特性，根系功能性状和土壤特性，以探讨其对侵蚀程度的响应，并确定减轻土壤可蚀性的主要因素（K _r ）。结果表明，植被覆盖度和根长密度（RLD）是对侵蚀胁迫最敏感的植物变量。地形参数通过偏爱较厚的土壤层和较低的堆积密度而强烈影响植物群落特征（植被覆盖度和凋落物质量），而土壤质地则通过偏爱较轻的土壤而强烈影响根系功能性状（根系密度[RD]和RLD）。重要的是，植物群落特征和根部功能性状是K _r的主要驱动力。 在恢复过程中，通过其介导作用对一系列土壤特性（例如，土壤有机质，团聚体稳定性和抗剪强度）的缓解，即使在严重退化的土地上，植被仍然可以有效地维持和恢复土壤功能。总体而言，这些发现可以指导恢复实践，以满足退化的生态系统中的土壤保持和生态系统功能目标。