Fig. 6.
Instantaneous and intrinsic water use efficiency [WUE, mean Pnet/mean transpiration under ambient light (A, B); and mean maximum net photosynthetic rate/mean maximum conductance (Psat/gs) under saturating light (C, D), respectively] of Quercus ilex (A, C) and Arctostaphylos uva-ursi (B, D) in sun and shade habitats. Data are given for the three campaigns (May, July and August 2005) with reliable data for the two species. Error bars indicate the 95 % confidence intervals for the mean; thus, non-overlapping bars reveal significant differences (ANOVA, Fisher l.s.d. post hoc test).