Regional Mountain Conference

Snowbeds represent a unique habitat for specialist plant species characterised by a relatively good water and nutrient supply but a short growing season due to the long-lasting snow cover. Consequently, snowbed vegetation is expected to be strongly affected by ongoing changes in temperature and precipitation regimes. In this study, we assessed the development of six snowbed species (Achillea atrata, Achillea clusiana, Arabis caerulea, Gnaphalium hoppeanum, Saxifraga stellaris and Sedum atratum) over a period of 20 years in 210 snowbed patches of four mountains in the northeastern Calcareous Alps of Austria. The eclined significantly for all species except for the endemic A. clusiana, with small populations being most at risk of extirpation. Consistently, a substantial reduction in population sizes was observed for all species apart from A. clusiana. Thereby, A. caerulea completely disappeared from the observed snowbeds. These patterns were primarily driven by declining snow cover and increasing vegetation density (NDVI). Conversely, the establishment of. Without effective mitigation of climate change, the observed massive population decline is likely to be intensified in upcoming decades, posing a severe threat to specialist snowbed plants because upward migration is impeded by the restricted altitudes of the northeastern calcareous Alps.