Aspects of spatial and temporal aggregation in estimating regional carbon dioxide fluxes from temperate forest soils

We examine the influence of aggregation errors on developing estimates of regional soil‐CO 2 flux from temperate forests. We find daily soil‐CO 2 fluxes to be more sensitive to changes in soil temperatures (Q 10 = 3.08) than air temperatures (Q 10 = 1.99). The direct use of mean monthly air temperatures with a daily flux model underestimates regional fluxes by approximately 4%. Temporal aggregation error varies with spatial resolution. Overall, our calibrated modeling approach reduces spatial aggregation error by 9.3% and temporal aggregation error by 15.5%. After minimizing spatial and temporal aggregation errors, mature temperate forest soils are estimated to contribute 12.9 Pg C yr −1 to the atmosphere as carbon dioxide. Georeferenced model estimates agree well with annual soil‐CO 2 fluxes measured during chamber studies in mature temperate forest stands around the globe.