The attempt to assess the fire risk of non-forest terrestrial ecosystems of Biebrza National Park – A case study

Abstract On 19th April, the largest wildfire of the entire history of Biebrza National Park broke out and consumed 5526 ha, mostly overdried grassland with sedges and reeds of Biebrza marshes. The very rapid spread of the fire in the open space, with the blowing wind changing directions and the inaccessibility of the area for fire-fighting vehicles were the main reasons of this third largest wildfire in Poland, after the tragic forest fires in Kuźnia Raciborska (9060 ha burnt) and Potrzebowice (5600 ha burnt) in the memorable year of 1992. After this event, activities were undertaken to develop a fire protection plan for the Biebrza National Park. It took into account an innovative approach during the analysis of the existing fire risk, primarily regarding the non-forest terrestrial ecosystems composed of herbaceous vegetation, which constitutes as much as 61.2% of the park’s area, and to propose protection methods adequate to the threat. The work was completed in the framework of the project entitled ‘Development of the method for assessing the fire risk of non-forest ecosystems and the principles of fire protection for the Biebrza National Park – stage I,’ commissioned for the Forest Research Institute by the Biebrza National Park, financed by the State Forests from the forest fund, in accordance with the contract EZ.0290.1.24.2020. The article presents a preliminary method of classifying the fire risk of non-forest ecosystems, considering the occurrence of the fires in the Biebrza National Park in the years 2007–2020 and the type of vegetation burnt. This method, after supplementary field tests planned in 2021, will enable evaluation of the fire risk, which shall be a premise for the development of a fire protection plan.