A new study co-funded by ForestPaths reveals that forest reburns, which are areas that catch fire again within ecologically short intervals, are a defining feature of southern Europe's fire regimes, not a marginal phenomenon. 

Researchers and project partners Alba Viana-Soto and Cornelius Senf, from the Technical University of Munich, used the newly developed European Forest Disturbance Atlas (EFDA), a Landsat-based dataset offering annual, 30-metre-resolution fire data since 1985 to map reburn dynamics across twelve southern European countries for the first time at this scale. 

The study, published in Global Ecology and Biogeography, found that 30.1% of the area burned across southern Europe between 1985 and 2023 (4.24 million hectares) experienced fire more than once. Of these repeated fires, 84.5% recurred within 20 years — a threshold the authors link to the time many tree species need to reach reproductive maturity, such as the 15–20 years required for serotinous cone production in many pine species. 

Reburns were not evenly distributed. The strongest hotspot was the West European Atlantic Coast, particularly the northwest Iberian Peninsula, where reburns accounted for an average of 40.8% of annual burned area, with some areas exceeding 70%. The West Mediterranean followed at 21.1%, while the Central Mediterranean and Dinaric Mountains and Balkans region, often considered less fire-prone, recorded reburn fractions of around 19%. The Aegean Sea and East Mediterranean had the lowest reburn fraction, at roughly 11%. 

Most reburns occurred 10 to 20 years after the initial fire (mean interval: 13.3 years), with fires in the first five years being rare, likely reflecting the time needed for fuel to reaccumulate. Pine-dominated forests showed the highest reburn fractions in western regions, while oak and mixed broadleaf forests were more affected in the Dinaric-Balkan region. 

Although total burned area has declined, reburn proportions show no consistent continent-wide trend since 2005, remaining stable in most regions, falling significantly in the West European Atlantic Coast and rising significantly in the Dinaric Mountains and Balkans. The authors conclude that reburns are integral to southern Europe's fire regimes and may play an increasing role as climate change intensifies fire activity, carrying implications for post-fire forest recovery and management. The EFDA dataset is freely available via Zenodo and through Google Earth Engine, and the study's analysis code is publicly accessible on GitHub. 

Read the full paper here.