Ecosystem services assessments have the potential to support negotiating the complex trade-offs between conservation goals and other economic, political and social agendas across administrative borders, spatial and temporal scales. While earlier studies showed the global importance of tropical areas in supplying ecosystem services, the specific contribution of mountain areas has not been investigated in details. The degradation of mountain ecosystems driven by climate, demographic and economic changes is however increasingly threatening essential ecosystem services supply to people living in- and outside mountains. In this study, we present an assessment of eight ecosystem services in mountains across the world using high resolution earth observation datasets for 2000 and 2010. We link the ecosystem services supply data with an expert survey dataset to assess ecosystem services demand. We show that most mountain ranges show large patches of decreasing ecosystem services in areas characterized by high population pressure. By comparing ecosystem services supply of and demand for ecosystem services, we highlight the growing scarcity of highly demanded ecosystem services, in particular water, food and forage in mountain areas of Global South. Population growth in mountain regions and surrounding lowlands accentuate this trend and call for urgent solutions to sustainably manage ecosystems in
mountain areas.
