Fig. 4: Correlations between the responses of plant biomass and leaf economics spectrum.
a Principal component analysis (PCA) of leaf functional traits. The trait loadings are delineated by principal component 1 (PC1) and principal component 2 (PC2), with the color gradient of the arrows indicating their contribution to the principal components. b The correlation between the effect sizes (lnRR) and PC1. The correlation was estimated using a linear mixed-effects model with PC1 and ‘study’ as the fixed and random factors, respectively, and is significant at p < 0.05 based on two-sided F-tests with Satterthwaite approximation of degrees of freedom. Rm2 and Rc2 represent the marginal and conditional R2, which are the proportion of variance explained by fixed effects and by both fixed and random effects, respectively. Black lines and gray shaded areas represent the mean and 95% confidence interval of the slope, respectively. PC1 depicting the leaf economics spectrum can be characterized by a single acquisitive-conservative axis. LA leaf area, leaf [C] leaf carbon concentration, leaf [N] leaf nitrogen concentration, leaf [P] leaf phosphorus concentration, SLA specific leaf area, leaf C:N leaf carbon/nitrogen ratio, LL leaf lifespan, leaf Pn leaf photosynthetic rate. Source data are provided as a Source Data file.
