What does the oxygen budget of a peatland tell us about global carbon budgets?

The oxidative ratio is a fundamental property of an environment and at global scale controls the magnitude of the terrestrial biosphere carbon sink. The oxidative ratio of the terrestrial biosphere is defined as the ratio of the O2 released to the CO2 adsorbed by a terrestrial environment. It has proved difficult to estimate the OR of environments. This study proposed that the OR of an ecosystem could be calculated from the organic matter budget of a peatland environment constrained by stoichiometry and thermodynamics of the organic matter transfers. This study used the detailed stoichiometry of the organic matter reservoirs of a peatland. The IPCC estimates global OR = 1.1; and this study showed that OR = 0.88. The OR of the study environment is independent of many of the organic matter transfer pathways but dependent on the initial fate ot primary productivity and the N cycle within the environment. The calculated OR is consistent with disproportionation of C occurring in the environment with a reduced component being accumulated into the terrestrial biosphere while an oxidised component of organic matter is lost to the atmosphere.  The method is transferrable to other environments where there is elemental analyses of the organic matter cycle. The implication of OR < 1 is that the magnitude of the carbon sink has been over-estimated.