| Based on the observation in the typical hilly and gully region on the Loess Plateau-Wuqi county, the changes of soil water-stable aggregates of different abandoned times? different types of vegetation and different restoration measures during vegetation restoration in abandoned lands were studied. The results showed that the content of >0.25 mm soil water-stable aggregates increases with the increasing of the abandoned time within the depth of 0~60 cm; the content of arbor lands is relatively higher and grassland is relatively lower, bush land is in the middle; For the restoration types, the content of natural restoration is bigger than that of natural restoration with artificial measures, and that of artificial restoration is lower, the cropland is the lowest. The increasing degree of the content of soil water-stable aggregates at the depth of 0~20 cm is bigger in the first stage of vegetation restoration, and lower in the later stage; the changes at the depth of 40~60 cm are on the contrary; The content of >0.25 mm soil water-stable aggregates of the same vegetation land is decline with the depth, the decreasing degree of shrub lands is relatively bigger in shallow layer, and the decreasing degree of arbour lands is relatively bigger in deep layer; soil water-stable aggregates are transformed from bigger particles to smaller ones by means of human interference, and this transformation is more obvious in deeper layer; soil anti-erodibility of arbour lands with longer restoration time is stronger;the natural with artificial restoration not only shorten the restoration time, but also increase the content of soil water-stable aggregates,so the soil structure is improved. |