Investigation of endemic plants of calcareous scree slopes in Gesäuse National Park in Austria

Master thesis Endemic species are essential for identifying biodiversity hotspots and conservation priorities. In the Eastern Northern Calcareous Alps an important glacial refuge calcareous scree slopes form a dynamic habitat that hosts highly specialised vegetation. This study examines four calcareous scree slopes in Gesäuse National Park Haindlkar, Gseng, Langgries and Kühgraben. Vegetation surveys were conducted in 22 m plots arranged along transects, recording all vascular plant species and relevant environmental parameters. For endemic species, fitness traits were measured for all individuals found in the plots, and occurrences were additionally mapped via GPS. The vegetation on the scree slopes was shaped by multiple environmental drivers, most particularly altitude, grain-size distribution, and total vegetation cover. Eleven endemic plant species were recorded, whose abundance was strongly related to altitude and the proportions of different debris fractions. Fitness patterns were primarily determined by altitude, grain size and slope exposure. Across the study area, three broad vegetation domains could be distinguished, structured mainly by grain size, substrate movement, altitude and radiation. The endemic species exhibited characteristic morphological and biological adaptations that enabled them to occupy specific microhabitats within this extreme environment. Overall, the results provide novel insights into the fitness determinants and microhabitat preferences of endemic vascular plants on calcareous scree. The findings highlight that these species persist within narrow ecological niches and are highly specialized, emphasising their vulnerability and the importance of targeted conservation efforts.