This study examines the effects of burn severity on patterns of post-fire tree establishment in the boreal forest. We collected data from 5 separate field experiments examining seedling establishment across different severity levels in 4 burns in central Yukon Territory, Canada, and interior Alaska, USA. The experimental studies focus on the germination, survival, and growth responses of four common tree species, trembling aspen (Populus tremuloides), lodgepole pine (Pinus contorta), white spruce (Picea glauca) and black spruce (Picea mariana). Data on the soil organic layer (depth, moisture, bulk density, pH) were also collected at each site. This file contains data on total aboveground dry biomass of germinated seedlings harvested in lat...