The paper deals with the ecological and fire situation in the forest ecosystem of the “Drevlyansky” nature reserve. The relevance of this study is that every year Ukraine's forests suffer from fires that destroy significant areas, and forests with radiation pollution suffer from fires the most. The purpose of the study was to investigate the impact of radiation pollution on the fire situation in the forest ecosystem of the reserve. The main task was to distribute the area of the reserve according to the level of radiation pollution and fire hazard classes with and without taking into account radiation pollution. To achieve the results, the area of the forest ecosystem of the Reserve was distributed according to the levels of radiation pollution. The average fire hazard class between 2008 and 2018 ranged from 2.02 to 2.06, which in turn improves the fire situation. However, since the territory of the reserve has been exposed to radiation pollution, the distribution of areas by fire hazard classes has undergone changes between the years of forest management. Thus, the fire situation, taking into account radiation pollution, has deteriorated compared to the area that was not exposed to radiation pollution, and between 2008 and 2018 it improved and amounts to 1.16 and 1.17, respectively. Consequently, the distribution of area by fire hazard classes depends not only on the level of radiation pollution, but also on the taxational specifications (land category, and in plantations it depends on the type of forest vegetation conditions, age, and tree species). The results of the fire that occurred on the territory of the reserve in the spring of 2020 are shown, along with a map of the fire danger of the forest fund of the “Drevlyansky” nature reserve in 2018. The prospect of further research is to re-conduct a study of the level of radiation pollution and to carry out actual measurements every 10 years, without using calculation methods. This will provide a more reliable distribution of forest fund areas by fire hazard classes and affect the planning of strategic tasks to prevent fires in the reserve

Keywords: radiation pollution, fire situation, fire hazard class, forest ecosystem