A simple method for estimating the influence of eroding soil profiles on atmospheric CO2

Although soil erosion has often been considered a net source of atmospheric carbon (C), several recent studies suggest that erosion serves as a net C sink. We have developed a spreadsheet-based model of soil organic C dynamics within an eroding profile (Soil Organic Carbon, Erosion, Replacement, and Oxidation (SOrCERO)) that calculates effects of soil organic carbon (SOC) erosion and altered SOC oxidation and production on the net exchange of C between the eroding profile and atmosphere. SOrCERO suggests that erosion can induce a net C sink or source, depending on management practices, the extent to which SOC oxidation and production characteristics change with erosion, and the fate of eroded SOC. Varying these parameters generated a wide range of C source and sink estimates (maximum net source and sink of 1.1/3.1 Pg C yr(-1) respectively, applying results globally), highlighting research needs to constrain model estimates. We invite others to download SOrCERO (http://www.kbs.ku.edu/people/staff_www/billings/index.html) to test conceptual models and eroding soil profiles of interest in a consistent, comparable fashion.