The effect of ground level ozone on vegetation: the case of spatial variability of crops in the People’s Republic of China

This paper aims to show how spatial variability of crops in China could reduce the effect of ozone on crops. The spatiotemporal variations of ozone are simulated using Models-3 Community Multiscale Air Quality modelling system coupled with the Regional Emission Inventory in Asia (CMAQ/REAS). The ozone effect on crops is evaluated based on the AOT40 index (accumulated exposure over threshold of 40 ppb). We find that wheat and soybeans are more sensitive to ozone compared to rice and maize. Assuming no change in field management practices we find that in 2000 there are losses of approximately 30.5%, 10.4%, 2.8%, and 19.0% of total yields for wheat, rice, maize, and soybeans, respectively. Similarly, in 2005 the losses are approximately 47.2%, 12.5%, 5.6%, and 27.1%.

Keywords: AOT40, CMAQ, ground level ozone, REAS, relative yield, China