Dry deposition determinations, along with wet deposition and throughfall (TF) measurements, at a spruce fir forest in central Maine were used to estimate the effect of atmospherically deposited nitrogen (N) uptake on forest carbon storage. Using nitric acid and particulate N as well as TF ammonium and nitrate data, the growing season (May--October) net canopy uptake of atmospheric, predominantly anthropogenic, N deposition was found to be 1--5 kgNha-1. The ratio of growing season net canopy N uptake to that of recycled root N uptake (10--30 kgNha-1 during the growing season) suggests a substantial modification of the N cycle at this Maine spruce fir forest over the past decade. The growing season 1--5 kgha-1 canopy N uptake may induce an enhanced annual carbon (C) storage of 250--1350 kgCha-1yr-1. This magnitude of N-stimulated C storage may be compared with measured annual C sequestration of ~2000 kgCha-1 for each of the years 1996--1998 at this Maine site. Consideration of four other eastern U.S. forest sites for which net canopy N uptake data are available suggests that from 285 to 2950 kgCha-1, annual C sequestration may be occurring at these conifer sites, consistent with the Maine site results. ¿ 2000 American Geophysical Union