Using diatoms and physical and chemical parameters to unveil cow-pasture impact in peat cores from a mountain mire in the south-eastern Alps

Peatland is a major carbon (C) sink, sequestering more atmospheric carbon dioxide (CO 2 ) than any other terrestrial ecosystem. Peatlands, and especially bogs, are typically nutrient-poor environments, extremely sensitive to increases in nitrogen (N) deposition. In fact, increasing N content often causes a shift from a mossto a vascular-plant-dominated vegetation resulting in lower C sequestration rates and/or mobilization of N and C stored in peat by promoting microbial activity. Peatlands are also very selective environments (sub-oxic to anoxic conditions, acidic pH, low N), and thus important habitats for nature conservation because of the occurrence of specifically adapted organisms. Peatlands cover ca. 3% of the world’s land surface but Europe lost >60% of this habitat type in the last decades. Moreover, in Italy they are in a marginal position from the phytogeographical standpoint.