Ecology of SO resistance: II. Photosynthetic changes of shrubs in relation to SO absorption and stomatal behavior.

In an effort to predict SO sensitivity of plants from their morphological and physiological features, the effects of SO on photosynthesis were partitioned between stomatal and nonstomatal components for a drought deciduous shrub, Diplacus aurantiacus, and an evergreen shrub, Heteromeles arbutifolia. As predicted, the drought deciduous shrub had the higher gas conductance, and hence SO absorptance. However, nonstomatal components also play a role in determining SO sensitivity. Apparently a plant with a high intrinsic photosynthetic capacity will be more sensitive to SO than one with a lower capacity.