Ecology of SO₂ resistance - IV. Predicting metabolic responses of fumigated shrubs and trees

10 broadleafed trees and shrubs native to the mediterranean climactic zone in California were surveyed for their photosynthetic and stomatal responses to SO₂. These species ranged from drought deciduous to evergreen and had diverse responses to SO₂. These results suggest an approach for predicting SO₂ resistances of plants. We found that conductance values of plants in SO₂-free air can be used to estimate the quantity of SO₂ which plants absorb. These estimates are based on conductance values for plants in non-limiting environmental conditions. SO₂ absorption quantities are then used to predict relative photosynthesis following the fumigation. Thus, relative photosynthesis of plants following fumigation can be predicted on the basis of conductance in SO₂-free air. This approach to predicting SO₂ resistances of plants includes analysis of their stomatal responses to fumigation, their characteristics of SO₂ adsorption and absorption, and their change in photosynthesis resulting from SO₂ stress.