A comparative characterization of postagrogenic soils under different lithological conditions in the Southern Taiga

The soils under two meadows overgrown by a small-leaved forest that are no longer used for agricultural purposes were studied. The changes in the plant cover resulted in an increase in the soil acidity, a decrease in the humus content, and a transformation of its composition; the content of fulvic acids increased. The most essential modifications to the soils were related to alterations in the density of the birch forest. The degree and rate of these changes depended on the local environmental conditions, such as the soil texture, the depth of the moraine layer, and the dynamics of vegetation. The dynamics of acidity were displayed to a greater degree in the sandy soils, while the dynamics of the humus content and its reserves were evidenced in the heavy-textured soils.