The idea of the application of one basic type of forest ecosystem models for different scales is proposed and discussed. The individual-based spatially explicit simulation model of tree/soil system EFIMOD is used for the demonstration of its applicability on forest stand, local (forest unit or landscape) and regional levels. At stand level, the model was implemented for theoretical analysis of the effects of environmental changes on forest ecosystems in West Europe and for the quantification of the efficiency of different types of forest thinning. At local level, the EFIMOD model was applied for the long-term simulation to quantify the difference of various silvicultural regimes at the forest lot with 108 individual stands in Central European Russia. At regional level, the model was implemented for a determination of the role of forest soils in carbon balance at the large territory of Leningrad administrative district in Russia.