Estimation of stomatal ozone uptake of deciduous trees in East Asia

Abstract

To assess ozone risks to temperate deciduous forest trees in East Asia, the stomatal ozone uptake was estimated based on a flux-based modeling approach. In this model, key parameters were obtained from scientific literatures on deciduous tree species in East Asia. In addition, regional characteristics of the leaf duration were estimated using a phenological model. The result showed a difference in spatial pattern between AFst0 (accumulative stomatal ozone uptake) and AOT40 (accumulative exposure above a threshold concentration of 40 ppb during daylight hours). Although most of the areas of high ozone concentration corresponded to humid climate areas, not only the ozone concentration, but also the length of the leaf duration and the species-specific stomatal response to environmental factors, limited AFst0 in East Asia. These results suggested that an approach based on stomatal ozone uptake would be a useful tool for ozone risk assessment in East Asia.