The extreme topography, climate and remoteness of mountain ecosystems are the origin of high biodiversity and productivity but cause high instability, fragility and sensitivity of the ecosystems. One inherent parameter of ecological stability is the status of soils in the ecosystems. Mountain soils are defined here as soils strongly affected by snow, frost and slope as ecological drivers. Changes in land-use and climate are currently affecting mountain soils thereby changing biogeochemical cycles, slope stability, water budgets, vegetation productivity, ecosystem biodiversity and nutrient production. In the near future, the changes in soil functions might be dramatically affected by global climate change. Until 2100, mean winter temperature in the alpine region is expected to increase at least by 3-5°C, reducing the snow cover period by 70-120 days. These dramatic changes will certainly affect carbon and nutrient cycling in the plant and soil system and increase soil erosion because of strong leaching with no or sparse vegetation cover in late fall and early spring. The session addresses the direct and indirect impact of changes in climate and land-use on the functioning, the degradation, the biogeochemical cycles and the stability of soils.