The Use of Natural and Anthropogenic 14 C to Investigate the Dynamics of Soil Organic Carbon

Abstract

Radiocarbon has been measured in two soil profiles, one of which has been covered by a building since 1956. A comparison of the Δ 14 C values in horizons of each profile gives an estimate of the total input of atom bomb 14 C into the soil profile. From the Δ 14 C and carbon density profile data, the carbon input rates, respiration rates, and diffusivity are calculated. The lack of vegetation on one soil affects the mobility and the respiration rate of the soil carbon in that soil. The data from this soil profile are also used to check the assumption, used in previous analyses, that there is a uniform distribution of ‘old’ carbon down the soil profile. The input rate, turnover time, and diffusivity parameters determined from the Δ 14 C profiles in these soils are compared with other published data on pasture and forest soils.