{“_”：“侵蚀对辽西北草原土壤团聚体稳定性和抗侵蚀性的影响。”，“i”：[“牡荆”]}

摘要(中文译文)

近年来，辽西北地区灌木密度逐年增加并侵入草地，加剧了灌木 encroachment（灌木入侵）。为探究灌木入侵对草地土壤稳定性及抗侵蚀性的影响，本研究在辽西北地区选取未入侵草地及轻度、中度、重度入侵草地4种草地类型，分析土壤理化性质、团聚体稳定性变化以及土壤可蚀性及其影响因素。结果表明：随着灌木入侵程度加剧，土壤孔隙度和土壤有机质显著增加，分别由未入侵草地的26.0%和14.89 mg·kg升至重度入侵草地的45.8%和33.15 mg·kg；相反，土壤团聚体平均重量直径和几何平均直径显著降低，分别由未入侵草地的1.55 mm和1.34 mm降至重度入侵草地的0.92 mm和0.63 mm。重度入侵草地土壤可蚀性因子（K值）较未入侵草地显著提高93.1%，表明灌木入侵削弱了土壤抗侵蚀能力。结构方程模型分析表明，灌木入侵对土壤K值具有显著的直接正向效应，并通过调控土壤有机质含量间接影响K值，从而降低辽西北草地土壤抗侵蚀性。

Abstract

In recent years, the density of shrubs in Northwest Liaoning has increased year by year and invaded grassland, aggravating the shrub encroachment. To explore the effects of encroachment on soil stability and erosion resistance of grasslands, we selected four grassland types including non-encroached grassland and lightly, moderately and severely encroached grasslands in Northwest Liaoning. We analyzed the changes in soil physicochemical properties, and aggregate stability, as well as soil erodibility and its influencing factors. The results showed that with the intensification of shrub encroachment, soil porosity and soil organic matter increased significantly. They rose from 26.0% and 14.89 mg·kg in non-encroached grassland to 45.8% and 33.15 mg·kg in severely encroached grassland, respectively. By contrast, the mean weight diameter and geometric mean diameter of soil aggregates decreased markedly, declining from 1.55 mm and 1.34 mm in non-encroached grassland to 0.92 mm and 0.63 mm in severely encroached grassland, respectively. Soil erodibility factor ( value) in severely encroached grasslands was significantly 93.1% higher than that in non-encroached grasslands, indicating that shrub encroachment weakened soil erosion resistance. Structural equation model analysis revealed that shrub encroachment exerted a significant direct positive effect on soil value, and indirectly affected the value by regulating soil organic matter content, thereby decreasing soil erosion resistance of grasslands in Northwest Liaoning.

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