Extended Data Table 1.

Unstandardized coefficients of CUE-SOC relationship in the mixed-effects model with meta-analysis data

CUE, depth and mean annual temperature (MAT) were set as the fixed effects to both logarithmic and original SOC content. The study source was set as the random effect. We explored different structures of the mixed-effects models (i.e., random intercepts with common slopes or random intercepts with random slopes) to test the CUE-SOC relationship. The interaction between CUE and MAT was also considered. Only results of model structures that converged in regressions are presented. The total observation size $n_{\mathit{sample}}$ = 132; the random effects size $n_{\mathit{study}}$ = 16. The variance inflation factors for the main effects model were all low.