The alpine tundra domain occurs at altitude in the high mountains in Europe. It is an important reservoir of freshwater and provides habitat to unique species. The treeline, which is below the domain, represents the forest limit. About 98% of Europe's alpine tundra domain is in the Pyrenees, Alps and Scandes. In a 3°C warming scenario, the natural climatic treeline is projected to move vertically upwards and the domain could shrink significantly over Europe. Adaptation is challenging because of the unique topographic, soil and climatic characteristics of high mountain systems.