中文摘要：

在野外调查与室内分析的基础上，对黄土丘陵区典型草原带植被自然恢复过程中土壤水稳性团聚体及其主要影响因子的演变规律进行了研究，并用通径分析法对二者的相互关系进行了定量分析。结果表明：随着植被演替。土壤中大粒级水稳性团聚体含量逐步增加，〉5mm粒级团聚体在土壤团粒结构中占主导地位，含量占50％～80％。其次是5～2mm含最，占到10％～15％左右。不同群落之间〉5mm团聚体含量在2m深土层加权平均值比较结果为：大羽茅群落〉长芒草群落〉铁杆蒿群落〉百里香群落〉香茅草群落，其中大羽茅群落是香茅草群落〉5mm团聚体含量的近5倍，长芒草群落也是香茅草群落的近4倍左右。主要影响因子对团聚体直接作用系数的大小为：物理性粘粒〉有机质〉全氮〉全铁〉阳离子交换量〉全量铝〉游离铁〉全磷〉pH值〉粘粒〉碳酸钙。物理性粘粒、有机质和全氮是影响水稳性团聚体含量的主要因子。

英文摘要：

Based on the field investigation and lab analysis, we studied the characteristics of soil water - stable aggregates and soil properties during vegetation rehabilitation in typical grassland of hilly - gullied Loess area, and analyze the relationship between them by path analysis and main component analysis. The results show that： In terms of vegetation succession stages, the contents of big gravel soil water- stable aggregates increased, the 〉5,m aggregate is priority in different layers, about 50% - 80%, The 5 - 2mm aggregate is the second main component. The mean values of 〉 5,m aggregate in 2m layers show that Stipa gradiss. Community 〉 Stipa bungana Trin Community 〉 Artemisia sacrorum Ledeb community 〉 Thymus mongolicus Ronn community 〉 Hierochloe ordorata community. Physical clay, organic matter and total nitrogen are the key factors that influenced the total water - stable aggregates.