Unlike many other soils, mountain soils often are subjected to strong hillslope processes that distinctly affect their properties. At unstable sites, erosion and other mass movements lead to a continuous rejuvenation of the soil. Under such circumstances weathering rates are kept at high levels, as new parent material is intermittently exposed, leading to the development of a shallow soil cover. Mountain soils are highly dynamic systems that may react sensitively to environmental changes. In addition, they may accumulate a substantial amount of organic carbon. However, the sometimes high C stocks are under threat due to the changing climate and increasing land-use pressures.