Fig. 2
From: The optimal CO2 concentrations for the growth of three perennial grass species
Effects of elevated CO2 concentrations on (a) leaf net photosynthesis rate (An), (b) water use efficiency (WUE), (c) stomatal conductance (gs), and (d) transpiration rate (Tr) of the three grass species. Values given are mean ± standard deviation for n = 4 pots