Abstract
The UN Decade on Ecosystem Restoration 2021–2030 has launched nature conservation, environmental protection, and ecosystem services' restoration on the global environmental policy agenda. However, particularly high mountain habitats being subject to erosion are up to now hardly restorable. Erosion with associated loss of vegetation, soil, and its fertility, is one of the most urgent environmental problems throughout the world. Consequently, we analyzed the soil seed bank of calcareous high-mountain grassland in the European Alps to reveal the natural regeneration potential after shallow erosion events. We applied a chronosequence approach taking recently eroded grassland areas (<5 years) as well as areas with earlier erosion events (>5 up to 10 and >27 years) into account. Our results revealed that the vegetation of old eroded areas was not closely similar to the surrounding intact grasslands. However, it was well differentiated from the initial stages of young and intermediate eroded areas' vegetation and had higher plant cover and species richness. The old eroded areas' seed bank had higher seed density and species richness compared to younger areas. While typical mountain meadow species were present in the seedbank of eroded areas, the assessed indicator species of both, younger and older eroded areas did not resemble the ones of the above-ground vegetation. We conclude that the seed bank has important but limited potential for the restoration of the complete species range of calcareous eroded alpine grasslands. This implies that additional restoration measures are needed to reintroduce species absent from the seed bank.