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.