Grain size analysis of the soil samples was conducted using a particle size analyzer (LS 13 320, Beckman Coulter®).

Soil samples were collected from depths 0–0.1 m, 0.1–0.3 m, 0.3–0.7 m, and 0.7–120 m at all sites except for the Kuke/Ghanzi area, where we have used only soils from the top 10 cm.除库凯（Kuke）/甘齐（Ghanzi）区域外，所有采样点位均采集了0–0.1米、0.1–0.3米、0.3–0.7米及0.7–120米深度的土壤样本；库凯/甘齐区域仅采集了表层10厘米的土壤样本。