Impact of Elevated CO2 and O3 Concentrations on Biogenic Volatile Organic Compounds Emissions from Ginkgo biloba

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 mu g g(-1) h(-1) in July, and 0.92 mu g g(-1) h(-1) in September. Isoprene and limonene were the most abundant detected compounds. In September, alpha-pinene accounted for 22.5% of the total. Elevated CO2 concentration in OTCs increased isoprene emission significantly in July (p < 0.05) and September (p < 0.05), while the total monoterpenes emission was enhanced in July and decreased in September by elevated CO2. Exposed to elevated O-3 increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 mu g g(-1) h(-1) (in July) and 2.24 mu g g(-1) h(-1) (in September), respectively. The combination of elevated CO2 and O-3 did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Delta 3-carene in September.