Fig. 2.

Physiological traits in different taxonomic groups: a stomatal conductance (g _s) at ambient [CO₂]; b net photosynthetic rate at 280 µmol mol⁻¹ intercellular [CO₂] (A _n280); c maximum rate of carboxylation (V _cmax); d maximum rate of electron transport (J _max); e short-term g _s response to increased [CO₂] (600 vs. 400 μmol mol⁻¹); f g ₁ (see Eq. 3); g water use efficiency (WUE); and h leaf area-specific plant hydraulic conductance (K _p). Each data point represents the mean value of a species and thick black lines represent mean values of the taxonomic groups. GYM gymnosperms; MON monocots; ROS rosids; and AST asterids