Process-based isotope partitioning of winter soil respiration in a subalpine ecosystem reveals importance of rhizospheric respiration

摘要: Deep snow in sub-alpine ecosystems may reduce or eliminate soil freezing, thus contributing to the potential for winter respiration account a significant fraction of annual CO2 efflux atmosphere. Quantification carbon loss from soils requires separation produced by roots and rhizosphere organisms that heterotrophic, decomposer because former does not result net stored carbon. Our objective was quantify rates forest meadow, partition flux into its heterotrophic components. We were particularly interested comparing early late winter/early spring each component previous work has shown consistent increase subalpine systems winter/spring. Field data on total isotope composition coupled with laboratory incubations using novel process-based stable mixing model implemented hierarchical Bayesian framework. found generally increased later greatest mid-summer. After correcting effect wind snowpack δ13C–CO2, δ13C soil-respired varied little over winter, contributions rhizospheric (~35 %) (~65 relatively constant. The significance apparent coupling increases are likely be important predicting changes ecosystems.