Alpine grazing is part of the cultural history of Europe, but with serious consequences. Sheep, goats and cattle keep the alpine meadows open, but weaken the stability of the ground underneath them. Add the weather extremes of rapid increasing temperatures, heavy rainfalls, and disappearing permafrost, and you find unstable slopes with high risk of landslides.
Mountain slopes often used to be covered with trees and shrubs, especially the Scots pine (Pinus sylvestris) and the Mountain pine (Pinus mugo). Both species grow well at higher elevations and on nutrient poor soils. Many Scots pine trees disappeared rapidly from the mountains, as the tree became important for forestry and timber industry. The Mountain pines were damaged by alpine herds that strip the bark. Active removal by foresters and herders lead to the disappearance of Mountain pines in many places.
A cascade of effects
Areas that preserved the Scots pine, often held livestock in the same area. Bark stripping occurred mainly on younger trees, and we are now dealing with the consequences. The stripping of bark removes the tree’s protective layer around the stem. This wound weakens the stem, but also exposes it to fungal infections and desiccation. Most of the trees will survive the bark stripping, but it is likely to cause staining and stem rot. This lowers not only timber quality, it weakens the stability and strength of the tree. Many pine trees in Austria indicate staining and stem rot, caused by the livestock debarking from 60-80 years ago.
About 30% of Austrias forests are so-called protective forests. The protective forests function to stabilise slopes and reduce risk of landslides. Historical heavy browsing in these alpine forests weakened the forest stability. A proper storm could easily blow over many trees. As a result, artificial measures are needed to minimise the impact on human infrastructure.
Looking at the current developments and occurrence of landslides, it is more important than ever to support the return of the Scots and Mountain pines to mountain slopes. Yes, alpine meadows will become smaller for sheep and goat herds, but that would be in the best interest for all of us. Let nature do her thing and support our projection from future landslides.