Figure 3. The quantitative limitation of A_n (net CO₂ assimilation rate, μmol CO₂ m⁻² s⁻¹) for Schima superba (Ss) and Pinus massoniana (Pm) during drought stress.

The stomatal limitation (S_L, red area), mesophyll conductance limitation (MC_L, yellow area) and biochemical limitation (B_L, green area) are shown. The total diffusional limitation (D_L = S_L + MC_L, blue area) and the non-stomatal limitation (NS_L = MC_L + B_L, sky blue area) are also indicated.