Project category：National Natural Science Foundation of China
Person in charge: Tong Lei
Execution time: 2014.1-2016.12
With the rapid urbanization of our country, O3 pollution has become an increasing serious problem in many cities, where obvious degradation of urban forest caused by high level O3 has been observed. In the meantime, land surface temperature in urban area has increased greatly due to large emissions of greenhouse gases. Many cities have experienced extreme high temperature frequently in recent years. Temperature increases could cause great changes to plant physiology and further alter their responses to O3 stress. Clarifying the interactive effects of elevated temperature and O3 on plant growth is of great significance to O3 risk evaluation and plant protection, but few related researches have been carried out in our country. In this project, an environment with elevated temperature and O3 will be simulated using the open-top chamber system. The injury symptoms, stomatal characteristics, allocation of assimilation products and antioxidant capacity of Cinnamomum camphora cultivated in the chambers will be analyzed, and the influence mechanism of elevated temperature on plant O3 sensitivity will be revealed. Besides, based on the observed data of stomatal conductance (gs) and environmental variables, a set of model parameters for gs forecast of Cinnamomum camphora will be determined, through which the stomatal O3 flux can be calculated and compared among different treatments. Finally, the relationship between Cinnamomum camphora growth and stomatal O3 flux will be analyzed, and the stress risk of O3 pollution on Cinnamomum camphora will be assessed. Based on this project, a scientific basis could be provided to urban greening and O3 pollution control for the southern cities of our country.