Fig. 2: Driving factors for the spatial distribution of trends in βSOT.
From: Accelerated land surface greening caused by earlier permafrost thawing
Grouped bar plots of six key environmental factors, i.e., Mean SOT (A), mean temperature (B), temperature trend (C), mean start of autumn permafrost frozen (SOF) (D), kNDVI trend (E), and mean shortwave radiation (Srad) (F), across regions with increased and decreased βSOT trends. Box plots show medians (center lines), interquartile ranges (boxes), and whiskers extending to 1.5×IQR; crosses indicate means. The numbers in brackets represent the number of pixels. G The relative importance of environmental factors controlling the spatial variability of trends in βSOT, determined by a random forest model using mean absolute SHAP values. The six most important variables, ranked highest in importance, correspond to (A–F). H All factors were aggregated into five categories: permafrost, climate, hydrology, vegetation and soil nutrition, for comparison of their relative importance (Methods). Tmin minimum air temperature, ALT active layer thickness, SOC soil organic carbon, POS peak of growing season; DFS, the autumn date of foliar senescence. Source data are provided as a Source Data file.
