Fig. 3: The correlation between Jmax and Vcmax for leaves with different leaf P concentrations.
From: Convergence in phosphorus constraints to photosynthesis in forests around the world
The colour scheme indicates low leaf Pmass in purple shades with increasing Pmass corresponding to progressively lighter shades of purple to plum. Each points is a species-site mean. The lines shown are for the two end-member leaf Pmass classes: mean low Pmass of 0.44 ± 0.11 (s.d.), and mean high Pmass of 1.76 ± 0.55 (s.d.). The OLS regressions shown are: Jmax = 17.5 + 1.52* Vcmax for low Pmass (r2 = 0.82), and Jmax = 12.8 + 1.79* Vcmax for high Pmass (r2 = 0.71), with P < 0.0001 for both regressions. Vcmax and Jmax are temperature-normalised to 25 °C (see methods). The slope terms of the lines are significantly different at P = 0.0355 using Pmass class as a categorical variable in interaction with the independent variable.
