text: Elevated soil moisture had little influence on wheat yield, regardless of atmospheric CO 2 and O 3 concentrations. Elevated O 3 concentrations, however, negatively influenced wheat yield at both atmospheric CO 2 concentrations. Nevertheless, grain yield was always higher for plants grown at the elevated CO 2 concentration. Indeed, elevated CO 2 increased grain yield by 21, 7 and 11%, respectively, for each of the three years of the study, indicating that elevated CO 2 concentrations ameliorated some of the negative impacts of O 3 -induced damage on grain yield.