Fig. 3: Relationships between ectomycorrhizal (EcM) tree dominance and carbon stocks with climate (CL), different successional stages (SUS), or different species richness (SR) were examined.

Panels (a), (d), and (g) illustrate tree, soil and forest carbon stocks with changes in climate; panels (b), (e), and (h) depict tree, soil and forest carbon stocks with changes in successions; while panels (c), (f), and (i) show tree, soil and forest carbon stocks with changes in tree species richness. To meet the normality assumption, all carbon stock components are ln-transformed. Each dot on the plots represents a single plot. Mixed-effects models were fitted to test whether relationships between EcM tree dominance and different carbon storage components changed along the species-richness gradient, across successional stages, or with climate changes (see Supplementary Table S1 for statistical results). EcM × SR, EcM × SUS, and EcM × CL represent the interactions.