Fig. 2.
The generality of the stomatal safety-efficiency trade-off. Relationship of maximum stomatal conductance (gmax) and sensitivity to stomatal closure (Ψgs50) for (a) 15 California species grown in a common garden design for this study (r = 0.69; P = 0.005; phylogenetic least squares regression), and in analyses of previous studies of stomatal responses in excised leaves or dehydrating plants of diverse species, measured with different techniques, and under different growing conditions (Pearson correlations): (b) 16 diverse angiosperm species (r = 0.50; P = 0.05)74, (c) 10 Chinese Ficus species32 (r = 0.82; P = 0.003), (d) five European tree species33 (r = 0.79; P = 0.03), (e) five tree species75 (r = 0.95; P = 0.009), (f) eight tree species of Costa Rican dry forest76 (r = 0.55; P > 0.05), (g) four woody species46, (h) two Vitis vinifera cultivars77, (i) two Vaccinium species of subalpine Austria78, and (j) two varieties of a fern species64. The gmax and Ψgs50 values were derived from fitted curves (Supplementary Fig. 1). Lines are standard major axes for log-transformed data, i.e., for power-law fits. Different scales were used in the panels to highlight the generality of the trend across studies of species diverse in stomatal responses to leaf water status. Source data are provided as a Source Data file