Ozone fluxes to tobacco and soil under field conditions

Abstract

The flux densities of ozone to tobacco plants grown on the north shore of Lake Erie were measured using a micrometeorological (Bowen ratio) technique and were predicted from measurements of leaf diffusion resistances. Ozone flux densities to the soil below the crop were also estimated using a soil boundary layer resistance. About 40–50% of the total ozone flux density from the atmosphere entered the plants during the day, the rest going to the soil. The leaf resistance technique provides a better estimate of the ozone flux densities to leaves than does the micrometeorological method. This is because the latter provides the combined flux density to the soil and the plants, and the partitioning between these sinks for ozone is variable, and often unknown.