Figure 3
Stomatal conductance (gs), mesophyll conductance (gm), CO2 concentration in substomatal cavities (Ci), CO2 concentration at the carboxylation site (Cc), and Ci–Cc in the seedling leaves of the four tree species after exposure to different soil nitrogen (N) treatments. The statistical differences between each characteristic of the different species under the three N treatments (mean ± SE) are the results of a one-way analysis of variance (ANOVA) (n = 7). The CO2 conductance data were measured under light saturated conditions, and the leaf chamber CO2 concentration was 380 μmol mol−1. The lowercase letters indicate significant differences at the 0.05 level between different N treatments, and the uppercase letters indicate significant differences at the 0.05 level between the species under the same N treatment. Control, high N; MN, medium N; and LN, low N.
