The effect of vegetation on soil properties (acidity, C/N ratio, content of exchangeable nutrients) was assessed for the northern and middle taiga forests in the Republic of Karelia. The forests occupy autonomous positions in the landscapes; the soil-forming rocks are diverse. The study objects were Al–Fe–humus soils on Quaternary sediments, common for taiga forests. Albic Podzols predominate among them. The differences in the properties of organic soil horizons (corresponding to the taxonomic levels of forest types and formations) within and between the taiga subzones may be explained by variations in the composition of soil-forming rocks and the amount of precipitation, as well as by the influence of vegetation. It is shown that, along with the quality of plant residues produced by the predominant functional groups, the soil properties depend on the regulation by trees of the amount and composition of precipitation penetrating through their crowns and affecting the intensity of nutrients leaching from the soils.