Forest landscapes are not homogenous, but consists of a mosaic of well, moderately, and poorly drained soils determined by topography. Variation in topography and drainage classes influences biogeochemical controllers of N₂O and CH₄ fluxes from soils such as moisture, N mineralization and production and decomposition of organic carbon. We measured N₂O and CH₄ fluxes from two deciduous forests near Montreal, along transects running from high-elevation, well-drained to low-elevation, poorly-drained soils. One site is an old-growth and the other, a mature-managed forest. In-situ gas fluxes were measured bi-weekly using static chambers. When averaged from May to December, 2006, upland soils emitted 7.8, while low-elevation wetland soils emitted 15.2 ug N₂O-N m^-2 h^-1. On certain sampling dates, upland soils in the old-growth forest consumed atmospheric N₂O at rates ranging from -0.14 to -7.8 ug N₂O-N m^-2 h^-1. CH₄ is consumed in upland soils (-1.9 mg CH₄ m^-2 day^-1) and is produced in wetland soils (5.8 mg CH₄ m^-2 day^-1). Rates of CH₄ consumption were more than twice as large in the upland old-growth forest than in the managed forest. Soil C:N ratio, moisture and CO₂ production rates accounted for 38%, while soluble organic C, total N and temperature accounted for 83% variability in N₂O emissions from wetland and upland soils, respectively. CH4 fluxes are regulated mainly by soil moisture, temperature and CO₂ production rates, which accounted for 75% variability in CH₄ fluxes both in the upland and wetland soils. As soil moisture, aeration status and organic C accumulation rates are regulated by topography, therefore, it is important to integrate topographic features of a forested landscape while quantifying and modeling the fluxes of greenhouse gases. The data also shows that N₂O consumption by forest soils is a significant component of atmospheric N₂O exchanges with forest soils.