Parameterization of the dynamics of the COLPOS model through chronosequences of land use and vegetation change

Abstract

The modeling of soil organic carbon (SOC) dynamics is a critical step to analyze CO2 emissions projections associated with changes in land use and vegetation (USyV). The COLPOS model was developed to estimate the distribution of SOC associated with physical soil fractions, but it was not extended to a dynamic version. This paper presents the development of the dynamic COLPOS model, generated from a review of the solutions of the ordinary differential equations of the SOC dynamics models with two stocks, one active and the other inert. With the use of chronosequences of USyV changes, where the decomposition and absorption processes of COS were separated by using techniques that use a stable isotope (13C), an adjustment of the developed model was carried out, obtaining satisfactory results (R2 > 0.9). The COLPOS dynamic model only has one adjustment parameter and was formulated based on measurable laboratory data, so its operational use is viable.