RESUMEN
The dependence of trans factor of radionuclides on the soil to the vegetation (wood etc.) caused by natural-climatic conditions determine a duration period of the rehabilitation of ecological and social-economic functions of forests landscapes polluted by radionuclides. It firstly allows to classify forest ecosystems by groups of their radioecological stability with division into three appropriate radioecological districts. The forest ecosystems characterized by a rather short-term duration of the rehabilitation period of ecological and social-economic functions after the radiation contamination (till 30 years) are relatively stable in the radioecological reference. They are typical to steppe and forest-steppe zones and appropriate radiological district (related to natural zone). The forests ecosystems with the intermediate-term rehabilitation period after the radiation impact (30-60 years) are weakly stable in the radioecological reference and typical to broadleaved and coniferous-broadleaved forest zones and appropriate radiological district. The forest ecosystems with a long-term rehabilitation period after the radiation contamination (more than 60 years) are characterized as radioecologically unstable. The appropriate radiological district is include north-taiga forests and pre-tundra open woodlands.