Figure 7
Regression analysis of gm (mesophyll conductance) with the PNUE (photosynthetic nitrogen [N] use efficiency) in the seedling leaves of four tree species following exposure to different soil N treatments. The determination coefficients (R2) and P-values are shown. The lines fitted for the N-fixing and non-N-fixing trees are significantly different (P < 0.05) according to the results of a one-way analysis of covariance (ANCOVA) with the PNUE as a dependent variable, whether it could fix nitrogen as a fixed factor, and gm as a covariate.
