Local and regional factors influencing historical forest fires in eastern Fennoscandia

We aimed at disentangling the role of different local and regional controls influencing fire occurrence in two geographically distinct forest reserves in Finland. We used dendrochronological data to reconstruct fire histories and, using survival analysis, analysed fire occurrence as a function of forest stand (mesic and xeric site type, topographical wetness index) and landscape characteristics (stand area, neighbouring stand identity and shared border length), and the study region. In total, we dated 182 fires between 1574 and 1921. Fires were the most active during 1712-1887, several fires burning up to 10% of the area, and have been absent since the early 1900s. Regardless of the site type, one of the reserves had a higher probability to burn than either site type in the other, showing the importance of larger-scale spatial variation. Also, site type of the neighbouring stand played a role, with a mesic neighbour decreasing the probability of fire in a xeric stand. We highlighted the importance of regional context (e.g. differences in human use of forests) and landscape structure, which may play as a determinant of historical fire regimes.This article is part of the theme issue 'Novel fire regimes under climate changes and human influences: impacts, ecosystem responses and feedbacks'.