Photosynthesis and carbon sequestration efficacy of Conocarpus erectus L. (Combretaceae) grown under elevated CO2 atmosphere

Quantification of carbon sequestration is highly essential to assess the photosynthetic performance of tree species in the context of rising atmospheric CO2 and global warming. In the present study, we investigated the photosynthesis and carbon sequestration potential of Conocarpus erectus L. (Combretaceae), a semi—arid tree species, under present (400 µmol mol−1) as well as elevated [CO2] (550 µmol mol−1) levels. Elevated [CO2] significantly enhanced light saturated photosynthesis, water use efficiency, apparent quantum efficiency and maximum quantum yield of PS-II as compared to their ambient [CO2] counterparts demonstrating significantly enhanced photosynthetic performance. Further, plants grown under elevated [CO2] for 180 days, sequestered 33.73 kg [CO2] tree−1 while the same in ambient [CO2] was 12.89 kg [CO2] tree−1 which also resulted in 70% greater biomass yields. Our data clearly demonstrate the superior photosynthesis associated with extremely high biomass yields in Conocarpus erectus.