A new grassland community in the Eastern Alps (Austria): Evidence of environmental distribution limits of endemic plant communities
Dirnböck, Thomas; Dullinger, Stefan; Grabherr, Georg
Peculiar distribution patterns of many plant species and plant communities in the Alps are traditionally explained assuming significant impacts of historic hazards during the ice ages. However, the trade-off between historic and present environmental constraints of plants is largely unknown. This study investigates habitat characteristics of an endemic grassland community to explore the extent to which environmental conditions limit its distribution. The association which is described for the first time, i.e. the Cerastio carinthiaci-Festucetum brachystachyos, occurs at sunlit, wind-prone scree slopes in the lower alpine zone of the eastern edge of the Northern Calcareous Alps. Standard relevé data is used to describe the species composition which is closely related to the widely distributed alpine grassland association Caricetum firmae and the Caricetum mucronatae. The Festuca grassland is subject to severe water loss. Potential evaporation is significantly higher compared to habitats of the Caricetum firmae. Intensified water shortage may improve the competitiveness of the Festuca species against Carex firma, the common key-species of alpine grasslands and may at least partly explain the limitation of the Cerastio carinthiaci-Festucetum brachystachyos to this area of cold steppe conditions of the continental fringe of the Alps.