Toward an impact assessment of ozone on plant carbon fixation using a process-based plant growth model: A case study of Fagus crenata grown under different soil nutrient levels

Abstract Ozone (O3) in the troposphere, an air pollutant with phytotoxicity, is considered as a driver of global warming, because it reduces plant carbon fixation. Recently, a process-based plant growth model has been used in evaluating the O3 impacts on plants (Schauberger et al., 2019). To make the evaluation more rigorous, we developed a plant growth model and clarified the key factors driving O3-induced change in the whole-plant carbon fixation amount (Cfix). Fagus crenata seedlings were exposed to three O3 levels (charcoal-filtered air or 1.0- or 1.5-folds ambient [O3]) with three soil fertilization levels (non-, low-, or high-fertilized), i.e., a total of nine treatments. The Cfix was reduced in non- and low-fertilized treatments but was unaffected in high-fertilized treatment by O3 fumigation. Our plant growth model could simulate Cfix accurately (