Exploring the influence of climatic and environmental factors on the distribution of Alpine peatlands

Peatlands cover approximately 3% of the global land area and are currently of interest for their function as carbon sinks. However, they offer a series of other essential ecosystem services that make them valuable and therefore protected by EU’s Habitats Directive (92/43/CEE). Alpine peatlands, the focus of this study, are mostly important for their role in the water regulation system and preservation of high-altitude biodiversity. However, being mostly small and scattered, peatlands are highly undocumented and unrecognised. This study aims to understand the variables influencing the presence of peatlands in the Italian Alps with the objective of improving their recognition and protection through habitat suitability mapping. Moreover, it aims to create the first comprehensive dataset of all charted peatland sites in the Italian Alps. To achieve this, 69 habitat databases were filtered in QGIS using specific Natura 2000 codes and strings of text to extract all peatlands and merge them to create a comprehensive database of peatlands in the Italian Alps. A series of bioclimatic and topographic raster variables were then taken into consideration: elevation, slope, topographic wetness index, mean annual temperature, mean precipitation, precipitation seasonality and pH. Using Maxent, a distribution modelling software, peatlands’ points and variables were interpolated. The most important drivers of peatland distribution resulted in being elevation and slope, accounting for 73.4% of test gain, with the other variables playing secondary roles. A focused analysis on Trentino Alto-Adige revealed that variable importance slightly varied among habitat types. These results provide new insights on the importance of the environmental drivers, while generating suitability maps helps to further investigate areas with a high probability of peatland occurrence, thereby optimizing research efforts and potentially increasing the number of recognized sites that warrant protection.