Fig. 1

The composite resource availability indicator (CRAI), soil fertility index (SFI), biodiversity, functional trait stability, and their relationships between low and high resource availability environments. a The differences of CRAI between low and high resource category at each sampling site. b The differences of SFI between low and high resource environments at each sampling site. c, d Comparisons of biodiversity and functional stability at each sampling site. Asterisks denote significant differences between metrics for low and high resource availability soils within each site (n = 6) (Wilcoxon rank-sum test, *, P < 0.05; **, P < 0.01). e The linear relationships between belowground biodiversity and functional trait stability. The blue and black solid lines represent the significant relationships in low-resource sites and all sampling sites, respectively. No significant relationship was found in high resource availability soils