We evaluated the effect on soil CO 2 efflux ( F CO 2 ) of sudden changes in photosynthetic rates by altering CO 2 concentration in plots subjected to +200 ppmv for 15 years. Five‐day intervals of exposure to elevated CO 2 ( eCO 2 ) ranging 1.0–1.8 times ambient did not affect F CO 2 . F CO 2 did not decrease until 4 months after termination of the long‐term eCO 2 treatment, longer than the 10 days observed for decrease of F CO...

Models predicting ecosystem carbon dioxide ( CO 2 ) exchange under future climate change rely on relatively few real‐world tests of their assumptions and outputs. Here, we demonstrate a rapid and cost‐effective method to estimate CO 2 exchange from intact vegetation patches under varying atmospheric CO 2 concentrations . We find that net ecosystem CO 2 uptake ( NEE ) in a boreal forest rose linearly by 4.7 ± 0.2% of the curren...