SFI research plots, in particular the Rajhenavski Rog forest, represent an important source of information on processes and changes in forest soils. On the above-mentioned plots we continuously monitor the parameters of the dynamics of the development and decay of the roots, the growth of the mycelium of fungi in the soil and the dynamics of degradation of the plant detritus, in order to study the processes in the soil, the anthropogenic and environmental influences on them, for the needs of analyzes of carbon cycling in forest ecosystems and modeling in several mathematical models that simulate the effects of forest soils.