The transformation of fine minerals (<1, 1–5, and 5–10 μm) separated from the mantle loam and the soils that developed from it during 33 years under forest, grass, and crop communities in a lysimeter experiment is analyzed. The experiment is being performed on 20 trial lysimetric plots, each of them is 9 m² in size and 175-cm deep. Picea abies, Quercus robur, and Acer platanoides seedlings were planted to simulate coniferous, broad-leaved, and mixed forest communities. Phleum pratense together with Bromus inermis and Trifolium pratense represented grassy communities. The crop rotation included summer wheat, potatoes, and barley that are commonly grown in the southern taiga zone. In 30 years, the weakly developed soils have been formed in the lysimeters filled with thoroughly mixed mantle loam. These soils display clear differences in their macro- and microfabrics depending on the character of plant communities. The mineralogical composition of the fraction <1 μm is represented by the smectite phase (58.6±2%), hydromica (32.7±2%), and kaolinite and chlorite (totally, 8.4±0.7%). The smectite phase consists of mixed-layered minerals with a predominance of mica-smectite with a high content of smectite layers. There are also mica-smectites with a low content of smectite layers, chlorite-smectite, and individual smectite. The fraction of 1-5 μm contains quartz (28.5±2.4%), feldspars (27.1±2%), hydromica (31.7±4.1%), kaolinite and chlorite (totally, 9.1±0.3%), and mica-smectite (3.8±1.2%). The fraction of 5-10 μm includes quartz (39.6±2.9%), feldspar (38.4± 2.7%), mica (20.1±1.9%), and kaolinite and chlorite (totally, 1.9±0.2%). The coniferous and broad-leaved woody plantations provided the acid reaction in the soil solution and produced the organic matter with a predominance of fulvic acids. Under these conditions, the content of smectitic phase decreased due to the destruction of individual smectite and mica-smectites with a higher content of smectite layers; the relative accumulation of fine-dispersed quartz and the enrichment of the fraction <1 μm with hydromica at the expense of their mechanical disintegration in the coarser fractions have been registered. In the silty fractions of the topsoil, the amount of feldspars proved to be higher due to the mechanical disintegration of the coarser grains. In the fraction of 5-10 μm, the content of chlorites increased in the upper part of the profile. It is possible that the further evolution of these soil profiles might be directed toward podzolization. In the course of soil formation under the broad-leaved plantations and perennial grasses the smectite phase in the fraction <1 μm was subjected to transformation into the super-dispersed state. Due to this fact, its destruction was intensified in the upper soil horizons; the super-dispersed smectite could also be removed from them in the course of lessivage. The amount of hydromica was higher in the upper horizons due to the active disintegration of mica in the coarser fractions; in the latter, the hydromica content became lower. The upper horizons contained increased amounts of feldspars in the fractions of 1-5 and 5-10 μm, which could be due to the disintegration of coarser grains. The cryogenic factor plays the leading role in the mechanism responsible for such mechanical disintegration. The behavior of soil minerals under the communities of broad-leaved woods and perennial grasses suggests that the development of lessivage is possible in the future. Under the impact of crops, soil tillage, and fertilization, the mineralogical composition of the fine-dispersed fractions in the plow horizon was transformed considerably: the content of smectite phase got sharply decreased, whereas the amount of hydromica increased at the expense of the mechanical disintegration in the coarser fractions and the agrogenic transformation (degradation) of soil mineral upon the nonexchangeable sorption of potassium and ammonium ions introduced with fertilizers. The modeling of soil-forming processes under different plant communities gives us information on the character of soil evolution as dependent on the type of biocenoses.