CO2 production and the priming effect in different ecosystems

These data are from laboratory incubations of soils collected from the Merriam Powel Elevation Gradient Climate Change Experiment plots (only warming treatments). The soil was put in jars, and either had 13C-labeled glucose added or not, and CO2 production was measured over a several week period. The isotope composition of the CO2 released during the incubation was measured. This allowed us to partition CO2 production derived from the new C input (13C labeled glucose) and that from older soil organic matter (not labeled) along with CO2 concentration. From this information, priming (change of soil organic matter turnover in response to a C input) is calculated.