Extended Data Fig. 7: Influence of soil and climate on growth-trait relationships in the European Atlantic Network.

Linear regressions between growth rate and trait value were fitted for each site of the European Atlantic Network (see panels abc of Extended Data Fig. 6 for three examples of SLA-growth relationships). The correlation values (r) were then regressed to site productivity (i.e. the mean value of growth per site; Fig. 2). The fitted linear regression between site productivity and r values was finally used to draw the graph: for instance, the correlation between growth and trait value was systematically negative for wood density (WD; fitted linear regression in Fig. 2a), but switched from being negative at low productivity sites to positive at high productivity sites for SRL (Fig. 2d). Functional traits: Max height = tree species maximum height (m); A_max = maximum photosynthetic capacity (µmol g⁻¹ s⁻¹); SLA = specific leaf area (mm² mg⁻¹); SRL = specific root length (m g⁻¹); WD = wood density (mg cm^-3); Leaf N, Leaf P, and Root P = organ content in nitrogen or phosphorus (mg g⁻¹).