Assessing the impacts of rising concentration of surface ozone on agricultural production in East Asia: 2. A model of ozone absorption by leaves in crop canopy

Research Project , Research Report 2006

Kazuhiko KOBAYASHI Dept. of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, Univ. of Tokyo
Stephen P. Long Dept. of Crop Sciences and Plant Biology, Univ. of Illinois
Hiroki OUE Dept. of Bioresources, Ehime University

Abstract

The rapid increase in energy production in East Asia has brought the increase in the emission of nitrogen oxides, which caused the rise of the surface ozone concentration in this region. Ozone is one of the most damaging air pollutants to vegetation, and its increase at the surface poses a serious threat to the ecosystems and agricultural production in East Asia. Since ozone is absorbed via stomata in plant leaves before exerting any effects on plant tissues, it is crucial to be able to estimate the amount of ozone absorption by plants when predicting the impacts of ozone on vegetation. In this study, we conducted observation of stomatal conductance in the soybean fields with and without ozone elevation at the Soy-FACE (free-air controlled environment) facility of the University of Illinois, USA, and developed a sub model of stomatal uptake of ozone. We then incorporated the stomatal sub model into a multi-layer model of energy and mass transfer in crop canopy, which compared well with the observations with respect to the vertical profile of ozone concentration in the soybean fields. We also conducted a preliminary observation in the wheat field at the Rice-wheat FACE facility in Jiangdu, China.

Keywords:

Ozone, soybean, wheat, model, absorption