A theoretical analysis of carbon isotope evolution of decomposing plant litters and soil organic matter

摘要: [1] Systematic variations in the carbon isotopes of soil organic matter (SOM) have been observed a variety ecosystems. Such may provide important insights into physical and biological processes that mediate storage, nutrient availability, trace gas emissions. To study cycles using isotopes, it is to link isotope systematics with dynamics models, so can be interpreted context rates fluxes transport This paper presents theoretical analysis, which isotopic evolution decaying modeled for system rate litter or decomposition controlled by substrate quality microbial growth rate. The model examines two mechanisms controlling one-time input: kinetic fractionation microbes differential decomposition. produces several characteristics SOM decomposing system: (1) single population matter, carbon-13/carbon-12 ratio increases increasing loss as result respiration; (2) given factor, enrichment relative original material rate; (3) containing multiple components having different qualities compositions (e.g., cellulose lignin), temporal reflects competing dominance preferential reservation one more components.