Soil CO 2 Uptake in Deserts and Its Implications to the Groundwater Environment

摘要

Recent studies of soil carbon cycle in arid and semi-arid ecosystems demonstrated that there exists an abiotic CO 2 absorption by saline-alkali soils (A a ) at desert ecosystems and suggested potential contributions of CO 2 dissolution beneath deserts to the terrestrial ecosystems carbon balance. However, the overall importance of such soil CO 2 uptake is still undetermined and its implications to the groundwater environment remain unaddressed. In this manuscript, a simple method is proposed for the direct computation of A a from the total soil CO 2 flux (F a ) as well as for the evaluation of A a importance to F a . An artificial soil-groundwater system was employed to investigate the implications to groundwater environment and it was found that soil CO 2 uptake in deserts can contribute a possible influence on the evolution of the groundwater environment, providing that the absorbed CO 2 largely remained in the soil-groundwater system.