Assessing wildfire vulnerability of vegetated serpentine soils in the Balkan peninsula

Abstract

The endemic vegetation on serpentine soils is remarkably diverse and usually of low productivity and recovers slowly after major disturbances like wildfires and subsequent runoff, erosion, and landslides. Climate change and anthropogenic factors may increase the vulnerability of these ecosystems to disturbances with social and ecological consequences. The assessment of wildfire risks of these habitats is crucial for a targeted management to protect ecological, agricultural, and urban systems. The major goal of this study is to highlight the importance and utility of wildfire risk assessment for sustainable management of serpentine soils and the related vegetation cover. In this paper we present an example from Albania where the coverage of serpentine soils (11.2%) is about four times higher than the global average (3%). We used the wildfire ignition probability index (WIPI) and wildfire spreading capacity index (WSCI) as wildfire risk indicators. WIPI values were more evenly distributed while higher WSCI values were mostly concentrated in remote, high-elevation areas. The inner areas within serpentine soils were at lower risk regarding wildfire ignition, while higher values were found at the borders of serpentine soils that are closer to urban and residential areas. The distribution of normalized wildfire risk indices by vegetation type showed that overall habitats covered by sclerophyllous vegetation had the highest risk for wildfire ignition, followed by forested areas, while moors and heathland had the lowest risk. On the other hand, the WSCI was higher for forested areas, especially broad-leaved, coniferous, and mixed forests. Higher WIPI and WSCI values were associated with municipalities with less resources to mitigate the consequences for wildlife and implement preventive measures. According to our study, considerable surfaces of vegetation covering the serpentine soils in Albania are exposed to significant wildfire ignition and spreading risks. We argue that these areas need to be considered for a special protection status. This would facilitate a proper management of this unique soil type and improve the conservation of these fragile ecosystems.