Aboveground and below-ground carbon allocation of summer rape under elevated CO2 and air temperature
In studies on plant responses to climate change more attention has been given to aboveground processes although carbon input by plants into the soil is a major flux in the global carbon cycle. The objective of study was to investigate the effects of elevated CO2 and temperature on carbon allocation and partitioning in different parts of plant, soil, and microbial biomass. An experiment was conducted on summer rape (Brassica napus L.) under increased levels of air temperature and atmospheric CO2 in controlled environment chambers. Results showed that the amount of leaf, stem and root carbon statistically significantly increased under elevated CO2 and temperature conditions. Microbial biomass carbon significantly increased by 11.2% and 13.5% under elevated CO2 and elevated CO2 and temperature, respectively, although soil carbon under both treatments decreased. It is concluded that carbon allocation is controlled under different climate conditions; however, elevated CO2 and temperature together will have a more significant effect for carbon allocation to different plant parts and microbial biomass carbon compared to elevated CO2 alone.