Water-holding capacity of surface soils of different land-use patterns in the rocky desertification area of the peak cluster depression

The purpose of exploring the differences in water holding capacity of surface soil and the factors affecting it under different land uses in the peak cluster depression of the rocky desertification area is to improve the water holding capacity of its soil. In this study, three natural ecosystem land use modes (abandoned land, shrub land and natural forest) and four artificial ecosystems (artificial forest, Zea mays land, Juglans regia forest, and Actinidia chinensis) were taken as the objects of the study, and the characteristics of soil water-holding indexes (maximum water holding capacity, capillary water holding capacity and field water holding capacity) and soil properties were measured to investigate the differences in soil water-holding capacity among different land use modes of the peak cluster depression of the rocky desertification area. The results showed that (1) the soil properties of natural ecosystems were better than those of artificial ecosystems. In particular, the soil physico-chemical properties (bulk density, porosity and organic matter), fractal dimension and enzyme activity of the irrigated grassland and maize land were better than those of the other land uses in the system, respectively. (2) Natural ecosystem had a greater water-holding capacity than artificial ecosystem. The soil water-holding characteristics of natural ecosystem all showed shrub land>abandoned land>natural forest; the soil water-holding characteristics of artificial ecosystem all showed Zea mays land>artificial forest> Juglans regia forest>Actinidia chinensis. (3) The results of correlation analysis showed that the bulk density, the total porosity, organic matter content, particle composition and soil enzyme activities all affect soil water-holding; and the results of principal component analysis showed that the cumulative contribution of clay, sand, sucrase, urease, phosphatase, dehydrogenase, maximum water holding capacity and capillary water holding capacity to soil water-holding capacity was 83.901%. In order to improve the water-holding capacity of the soil in the peak cluster depression of the rocky desertification area, man-made disturbance should be reduced in disturbed abandoned land, shrub land, artificial forests and natural forests, which have less man-made disturbance; and man-made disturbance should be reduced in the case of Zea mays land, Juglans regia forest and Actinidia chinensis, which had more man-made disturbance, on the one hand, and vegetation cover can be increased on the other hand. On the whole, in the process of restoration and management of rocky desertification areas in the peak cluster depression, shrub land can be the preferred land use mode.