Mountains loom large in some of the world’s most spectacular landscapes. Their unique topography, compressed climatic zones and isolation have created the conditions for a wide spectrum of life forms.

Half of the world’s biodiversity hotspots are concentrated in mountains and mountains support approximately one-quarter of terrestrial biological diversity. Mountains are home to rare species of plants and animals. These include increasingly rare animals such as gorillas, mountain lions, and the majestic tahr or strikingly beautiful plants such as orchids and lobelias.

A large portion of the world's most precious gene pools (for agriculture and medicine) are preserved in mountains. Crops that are important for food security, such as maize, potatoes, barley, sorghum, tomatoes and apples, have been diversified in mountains and an array of domestic animals - sheep, goats, yaks, llamas and alpacas - have originated or been diversified in mountains. Other crops, such as wheat, rye, rice, oats and grapes, have found new homes in the mountains and evolved into many varieties. Coffee and tea, with their roots in Ethiopia and the Himalayan region, are mountain crops as well. Medicinal plants are one of the most valuable resources from high altitudes. This rich biodiversity holds cultural, ecological and economic value. In the Andes, for example, farmers know of as many as 200 different varieties of indigenous potatoes and, in Nepal, they farm approximately 2 000 varieties of rice.

Climate change, poverty, commercial mining, logging and poaching all exact a heavy toll on mountain biodiversity. The sustainable management of mountain biodiversity has increasingly been recognized as a global priority. The Convention on Biological Diversity adopted a Programme of Work on Mountain Biological Diversity in 2004, which includes a set of actions and targets addressing characteristics and problems that are specific to mountain ecosystems.