Figure 2.

Relationship between the values of photosynthetic parameters at a leaf temperature of 25 °C and leaf N concentration (N_a) across the different experiments and N treatments studied. Linear relationships were found for $V_{\mathrm{cmax}}^{25}$ (A, $V_{\mathrm{cmax}}^{25}=53.03{\text{N}}_{\mathrm{a}}-14.74$, r² = 0.86), $J_{\max }^{25}$ (B, $J_{\max }^{25}=90.91{\text{N}}_{\mathrm{a}}-13.83$, r² = 0.83), TPU²⁵ (C, TPU²⁵ = 6.72N_a − 0.72, r² = 0.78) and $R_{\mathrm{d}}^{25}$ (D, $R_{\mathrm{d}}^{25}=0.69{\text{N}}_{\mathrm{a}}-0.005$, r² = 0.77), respectively.