Fig. 3. The factors influencing global variation of critical soil moisture threshold (θ_crit).

a The importance of climatic, biotic and edaphic variables in controlling θ_crit. Aridity index is defined as the ratio of mean annual potential evapotranspiration to precipitation. b–g Partial dependence plots of the top six predictors. The Y-axis is SHAP value for corresponding predictor (X-axis). The partial dependence plots indicate the effects of individual variables on the response, without the influence of the other variables (Methods).