Estimation of CO2 sequestration potential by afforestation in the arid rangelands of Western Australia based on long-term empirical data

Large-scale afforestation is a key measure to mitigate global warming, however, implementation may result in land-use competition with agriculture. To avoid such competition, carbon mitigation methods using arid and semi-arid areas have been proposed, but to our knowledge there is no report of rates of sequestration based on long-term observations from actual experimentation. In this study (1999-2015), in an arid area near Leonora, Western Australia (annual rainfall: 220 mm year(-1); pan evaporation: 3400 mm year (-1)), carbon sequestration was assessed in above and below ground biomass in Eucalyptus camaldulensis under ambient conditions and with active site amelioration (combination of water harvesting with large mounds and hardpan blasting). The carbon sequestration rate was estimated at 7.92 Mg-CO2-e ha(-1) year(-1) for a total carbon sink of 230 Mg-CO2-e ha(-1). Carbon mitigation may thus be a viable option in arid regions, not only in Western Australia but globally, and can be enhanced with active site engineering.