Response of Ginkgo biloba growth and physiological traits to ozone stress

Abstract

Ginkgo biloba, the main greening tree species in Beijing, was used to study the effects of elevated ozone (O3) concentrations on physiology and ecology using an open-top air chamber (OTC). We set three O3 concentration gradients (NF: normal atmospheric O3 concentration; NF40: normal atmospheric O3 concentration plus 40 nmol/mol; NF80: normal atmospheric O3 concentration plus 80 nmol/mol). Based on the theoretical basis of the coupling of O3 and transpiration through stomata, the O3 uptake from the leaf surface of G. biloba was studied under artificial control. The results showed that with the O3 concentration increased, the leaves of G. biloba were damaged, stomatal density, stomatal aperture, stomatal size, net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll content decreased, while intercellular CO2 concentrations and relative conductivity increased. The monthly and daily variations in the liquid flow density of G. biloba decreased with the increase in O3 concentration. Similarly, water consumption and the ozone uptake rate (FO3) of G. biloba decreased with the increase in O3 concentration: Water consumption by the entire tree under the NF40 and NF80 ozone concentrations decreased compared to NF, the rates of decline were 68.77% and 78.38%, respectively. The rates of FO3 decrease were 15.48% and 31.04%, respectively.

Keywords

• O3 stress
• Ginkgo biloba
• Physiologico-ecological characteristics
• O3 uptake
• Response and adaptation