Fig. 7.

Typical responses of species with active (black line and black data points) and passive (grey line and grey data points) physiological stomatal behaviour to a a transition from light to dark and b a step increases in [CO₂] from 200 to 2000 μmol mol⁻¹ (G_s is expressed as a percentage relative to the point where illumination was ended at time 0 and G_s at 400 μmol mol⁻¹). The relative change in epidermal and stomatal morphological parameters in plants grown in ambient (400 μmol mol⁻¹) and extremely elevated (1500 or 2000 μmol mol⁻¹) [CO₂] versus the physiological G_s response to darkness (darkness ∆G_s) or a change in [CO₂] from 400 to 2000 μmol mol⁻¹ ([CO₂] ∆G_s): c) ∆A_% versus darkness ∆G_s (linear regression P = 0.0007.517 × 10^–4; F_1,19 = 16.067; R² = 0.458); d ∆A_% versus [CO₂] ∆G_s (linear regression P = 5.718 × 10^–5; F_1,19 = 26.502; R² = 0.582); e ∆SD versus darkness ∆G_s (linear regression P = 2.489 × 10^–6; F_1,19 = 43.771; R² = 0.697); f ∆SD versus [CO₂] ∆G_s (linear regression P = 7.053 × 10^–6; F_1,19 = 37.383; R² = 0.663); g ∆SI versus darkness ∆G_s (linear regression P = 7.754 × 10^–7; F_1,19 = 51.812; R² = 0.7316), and; h ∆SI versus [CO₂] ∆G_s (linear regression P = 2.455 × 10^–5; F_1,19 = 30.608; R² = 0.617). Presented as in Fig. 2 (data from Haworth et al. 2013, 2015; Elliott-Kingston et al. 2016).