Long-term* fire effects on vegetation and topsoil properties in beech forests of Manjaca Mountain (western Bosnia and Herzegovina)

Wildfires are an important driver of land degradation, with detrimental impacts on soil properties, usually leading to decreasing soil fertility and erosion, which affect vegetation recovery. This study investigates the long-term impact of wildfires on topsoil horizons and vegetation in Bosnia and Herzegovina, where land degradation is causing significant economic and ecological losses. Ten years after a wildfire, 12 plots were installed in areas affected by low- and medium-severity fire, and in unburned areas. Morphological, physical and chemical soil properties were explored on each plot, together with vegetation cover (number and cover of species). Soil organic matter, carbon, nitrogen and available phosphorus contents in medium- and low-severity fire affected plots are approximately half of those recorded in unburned plots, showing detrimental long-term impacts on soil fertility. Soil cation exchange capacity, pH and available potassium did not show significant differences between fire- and non-fire-affected plots. The number of plant species in medium-severity fire-affected plots is significantly lower than in low-severity and unburned plots. Differentiated plant groups are led by herbaceous (ground-breaking and weed) species. This study shows that wildfires can have long-term impacts on topsoil horizons and vegetation in limestone areas, threatening the sustainability of forest ecosystems.