Foliar chemical composition of two oak species grown in a free-air enrichment system with elevated O3 and CO2

Abstract

Ground level ozone (O3) is rapidly increasing in Asia and penetrates plants via stomata. Atmospheric carbon dioxide (CO2) has also been increasing in global and in short term may promote plant growth via photosynthetic enhancement. Oaks are representative deciduous broadleaved trees native to northeastern Asia. In this study, we focused on the effects of elevated O3 and/or CO2 on leaf nutrients status (phosphorous, nitrogen, potassium, magnesium, etc.) of two oak species: Konara oak (Quercus serrata) and Mizunara oak (Quercus mongolica var. crispula) to assess their function. We investigated foliar starch and sugar contents and nutrients composition of leaves of 2-year-old oak seedlings grown under elevated O3 and/or CO2 in a free air enrichment system. From elements concentration, nitrogen and magnesium may become the major indices in assessing the O3 effects on these species, and investigation of both of them would be of use in field studies to discriminate O3 and CO2 effects, especially under the projected elevated CO2 levels.