The BOREAS TF-4 team measured fluxes of CO2 and CH4 across the soil-air interface in four ages of jack pine forest at the BOREAS SSA during August 1993 to March 1995. Gross and net flux of CO2 and flux of CH4 between soil and air are presented for 24 chamber sites in mature jack pine forest, 20-year-old, 4-year-old, and clear cut areas. The data are stored in tabular ASCII files. Anderson, Dean and Striegl, Robert and Wickland, Kimberly and Hall, Forrest G. (Editor) and Conrad, Sara (Editor) Goddard Space Flight Center NASA/TM-2000-209891/VOL198, Rept-2000-03136-0/VOL198, NAS 1.15:209891/VOL198