Influence of global change on the soil stability of the alpine grasslands:
In historical dimensions, the Alps and with them all Alpine ecosystems are subject to constant change. Soils, as the basis of all terrestrial systems, are shaped by this change. Humans have already influenced alpine forest ecosystems since the early Holocene, but massive deforestation took place between the 10th and 19th centuries, which led to a strong destabilization of soils and slopes. In recent decades, alpine ecosystems are influenced by strong effects of both climate and land use change. We mapped these recent developments with semi-automated image classification by documenting different forms of erosion (landslides, sheet erosion, management effects, livestock trails) over time and space. We find a degradation increase due to land use intensification of grasslands at slopes close to the valley floor, mostly due to sheet erosion, management effects (e.g. use of heavy machinery, fertilization, cutting of the grass before long dry periods) and livestock trails. In contrast, extensification or even abandonment of grassland was documented on higher remote areas. The latter usually leads to shrub encroachment, which, depending on the soil and vegetation, might result in an increase or decrease of landslide activity. Simultaneously, landslide activity that was attributed to climate change effects, increased in high altitudes.