Soil pits located in boreal aspen ( Populus tremuloides Michx.), jack pine ( Pinus banksiana Lamb.), and white spruce ( Picea glauca (Moench) Voss) stands were analyzed by horizon for nutrients (Ca, Mg, PO 4P, K, Na, SO 4S, NH 4N, NO 3N), physical properties (horizon depth; silt, clay, and organic content; bulk density, water-holding capacity), and root densities. Two aspen, three jack pine, and one white spruce stand were on aeolian sands with Eutric Brunisolic soils; and two aspen and one white spruce stand were on clay loa, morainal deposits with Gray Luvisolic soils. Stand ages ranged from 19 to 170 years. This study assessed the relationships of root location and density to the above-mentioned edaphic variables. The highest concentration of roots was at the organic/mineral soil interface. Correlation and Principal Components Analysis (PCA) revealed that root densities are negatively correlated with depth, clay content, and bulk density; and positively correlated with soil water-holding capacity and extractable PO 4P. Insufficient phosphorus appears to be an important growth-limiting factor in the study area. PCA ordinations of edaphic variables consistently revealed a cluster of correlated variables composed of organic matter, NH 4, NO 3, and sometimes K content, but none of these was consistently associated with root distributions. Aspen communities appear to be more dependent upon N and other organically bound nutrients than coniferous stands.