2.2.1 Experimental plots
Ten hillslope plots (sizes between 800-4000 m2, and elevation from 2595-2683 m) were established along two orientations (horizontal or vertical axis) transect in the Dahuang Mountain Forest Reserve between July and August in 2014 (Fig. 2). Two plots were on the north-facing slope, and others on the west/east-facing slopes, and all of the plots were characterized by heterogeneity of land uses. Basic characteristics of the ten plots are shown in Table 1. The primary landcover types were grass, brush-grass, planted forest, planted-natural mixed forest, and natural forest, representing all stages of landcover changes during plantation restoration in this region. Plots along the horizontal axis (#6, #7 and #8) were used to determine the relationship between landcover and SWC for which can exclude differences in SWC caused by slope position; plots along the vertical axis (#1, #2, #3, #4, #5, #9 and #10) were used to analyze spatial heterogeneity of SWC and landcover types. Five spatial sampling intervals (5, 6, 7, 8, and 10 meter) were used for the investigation, all sampling retained a consistent interval distance at each transect to satisfy the theoretical model of semivariance analysis. Four replicates of SWC records were taken at each sampling point, and the average value was taken for the point after the outliers were removed. In addition to supporting materials, the SWC survey, stand structure investigation, soil texture, and landcover species were also surveyed synchronously.