Atmosphere-biosphere exchange of carbon dioxide in boreal forests

An ecophysiological model of photosynthesis and respiration by forest ecosystems was used to examine CO₂ fluxes in 23 mature boreal forests near Fairbanks, Alaska. The boreal forests of Alaska play an active role in the seasonal dynamics of atmospheric CO₂ at Barrow. Only one of the 23 stands was a source of CO₂, and the 23 stands absorbed (mean ± SE) 1173 ± 211 g CO₂ m^-2 yr^-1. Observed productivity in these forests spans the range of productivity in the circumpolar boreal forest, suggesting the simulated CO₂ fluxes are representative of the circumpolar boreal forest. If so, metabolic activity in the circumpolar boreal forest results in a significant annual uptake of CO₂. -from Author