Effects of elevated CO2 on growth and capacity of photosynthetic assimilation of carbon in Ginkgo biloba

To study the impact of elevated tropospheric CO2 concentrations on growth and capacity of photosynthetic assimilation of carbon of trees, growth parameters, leaf area index (LAI) and diurnal variation of net photosynthesis rate under different weather were primarily analyzed in leaves of Ginkgo biloba exposed in open-top chambers at either ambient ( approximately equals 350μmol · mol-1) or elevated (700μmol · mol-1) CO2 concentrations in urban area for a growing season. The results show that elevated CO2 exposure induced, growth parameters, leaf area index and net photosynthesis rate were increased. The diurnal variation of net photosynthesis rate on a fine day revealed two maxima, while single maximum on a cloudy day, which was similar to ambient CO2. As a result, the capacity of photosynthetic assimilation of carbon in Ginkgo biloba was enhanced relatively by 119.5% on fine day, while 175.4% on cloudy day.