The structure (by tree species and age classes) of protective forests in the Karelian part of the Green Belt of Fennoscandia (GBF) was analyzed using a division into subzones with different natural and climatic conditions. Pine forests (82-89 %) dominate in the northern taiga subzone, and young stands prevail (45 to 56 %). Approximately 1/3 of the area is under mature and overmature stands. In the middle taiga subzone, spruce stands and pine stands occupy nearly equal shares (40 %). Mature and overmature stands there occupy about half of the total area. The contributions of young, middle-aged and ripening stands are roughly equal (13-17 %). Long-term ecological and economic sustainability of the Fennoscandian Green Belt requires that a forest management system is introduced in these forests, which ensure connectivity between protected areas. Taking into account the species and age structure, and using the results of long-term studies in sample plots, a system of fellings has been suggested that would help improve the stand quality and enhance the ecological functionality of the protective forests. The suggested thinning programs are designed to promote the robustness of the protective forests according to site conditions and the growth features of commercially valuable species. Felling programs recommended for mature and overmature stands, which prevail in the GBF forest fund, include guidelines on the removal rate (25-30 %) and rotation period (25-30 years). The forest management system suggested for the GF protective forests will provide for a long-term sustainable supply of various ecosystem services both at the local and regional levels, and from the global perspective.