Figure 3.

Seasonal contrasts in leaf gas exchange between C₃ and C₄ PACMAD grasses in a common garden experiment at Grahamstown, Eastern Cape of South Africa, between November 2008 and April 2009. (a,b) Net CO₂ assimilation, A; (c,d) stomatal conductance to H₂O, g_s; (e,f) transpiration, E. Experimental plots were rain-fed (a,c,e) or given supplemental water (b,d,f). Points represent pooled means and lines 95% confidence intervals for 4–6 species, values are back-transformed from the log-transformed scale used for statistical analysis. Differences between photosynthetic types and months in the experiment are highlighted by the grey-filled areas. Photosynthetic type comparisons for which confidence intervals indicate significance at the P < 0.05 level are highlighted by * within each pane. Significant differences within photosynthetic types that resulted from watering are indicated by + below the relevant means in (b), (d) and (f).