Initiated by the Swiss Academy of Sciences and founded in Glion, Switzerland in 1999, the Global Mountain Biodiversity Assessment, is one of the internationally acting key networks of DIVERSITAS (Paris). It was established in fulfillment of Agenda 21 and deals with the biological richness, its function and change at the high elevation end of the biosphere. Steep terrain and mountain climate in combination with severe land use pressure cause mountain ecosystems to rank among the most endangered landscapes in the world. Switzerland has initiated the now existing chapter on mountains (Chapter 13 of the Agenda 21) in the protocoll of the UN conference in Rio de Janeiro, and has, since then, been acknowledged as “leading nation” in mountain issues. The main goal of GMBA is synthesis of often hidden and fragmented results of research and establishing an international research community. It is actively exploring and explaining the great biological richness of the mountains of the world and its responses to global change. A central paradigm is that functional insight and theory will only emerge from large-scale comparisons. These include crosscontinental comparisons of the upper montane zone, the treeline ecotone and the alpine regions, as well as elevational transects. GMBA is dedicated to shape a global corporate identity in the widely scattered research community, which will also help to increase the visibility of mountain biodiversity issues. GMBA advocates studies on the human influence on natural and cultural landscapes in the mountains to encourage sustainable development of rural upland areas (e.g. a recent and ongoing project is on “High mountain biodiversity and sustainable land use in the tropics/subtropics” with two workshops in Africa and the Andes, supported by the Swiss Agency of Development and Cooperation).