العربية  |  English  |  Español  |  Français  |  Русский

Sectoral issues

  • Agriculture

    Human managed agro-ecosystems in mountainous areas have been a part of the mountain biome for centuries. Their heterogeneous conditions have led to the evolution of a tremendous diversity of agricultural varieties that are adapted to a wide range of environmental conditions and human needs. Mountains extend over large parts of the five principal centres of early agricultural development, and several crops – maize, potatoes, barley, sorghum, tomatoes, apples – originated in mountains. A large portion of domestic mammals – sheep, goats, domestic yak, llama and alpaca– also stem from mountain regions. Over centuries, the genetic diversity of domesticated mountain plants and animals has been increased, perhaps associated with cultural diversity and extreme variation in local environmental conditions. Some high altitude communities in the Andes maintain more than 150 distinct potato varieties, and mountain farmers in Central Africa cultivate beans as mixed populations of up to 30 varieties.

    This part of the mountain biodiversity is threatened by a continued modernization of agricultural production leading to an impoverishment of the agro-ecosystem through the use of fewer and genetically less diverse varieties. The expansion of agricultural production into formerly uncultivated mountain lands reduces the habitats for other species and leads to a deterioration of ecosystems, particularly where the lands are only marginally suitable for agriculture.

  • Forests

    The great majority of the world’s mountains include forest ecosystems in the lower to medium high altitudes. Mountain forests provide a range of services to mountain communities and to people in lowland areas, and have a key role in maintenance of biodiversity. These forest ecosystems are threatened by the expansion of agriculture and unsustainable methods of timber harvesting, such as clear cutting and the establishment of forest monocultures.

    Evergreen tropical montane cloud forests (TMCF) occur on mountains where there is frequent cloud or mist. They are characterized by the presence of tree ferns and an abundance of mosses, orchids and other plants growing on every trunk and branch (epiphytes). TMCFs are of global importance because they contain exceptionally high levels of endemic species (for example in Mexico, TMCF covers less than one per cent of the country but contain 3000 species or 12% of the country’s flora, of which up to 30% are endemic to the country).

  • Tourism

    Tourist activities in mountain areas such as winter sports and outdoor activities have been increasing at a fast rate in recent years. The result is an expansion of tourist infrastructures into mountain areas, providing access to remote and fragile ecosystems. The transformation of mountain slopes for skiing and other winter sports has strong impacts on the integrity of mountain ecosystems and can lead to their complete deterioration while the provision of tourist infrastructure induces the urbanization of mountain areas.

  • Hydropower

    Mountains and mountain lakes are frequently used to generate electricity through hydropower. While providing a renewable source of energy, hydropower projects can have severe impacts on the rivers and surrounding ecosystems. The creation of artificial lakes and the altering of the water household can modify the habitats, ecosystems, entire valleys and neighbouring ranges.

  • Mining

    The extraction of minerals, metals and other resources from mountain areas has severe impacts on the habitats in the mining area and can cause severe problems of water pollution that affects downstream areas.

  • Climate change

    Global warming has serious impacts on mountain ecosystems as it causes the retreat and sometimes the disappearance of the alpine life zone. Species that are endemic in these areas can become “trapped” on the summits and will disappear as their habitat is reduced. Changes in the precipitation patterns and rising temperatures result in the shrinking of glaciers and snow-covered areas, which reduces the water holding capacity of the mountain range. The modified water household affects ecosystems in lower ranges as well as in downstream lowlands.

  • Air pollution

    High precipitation rates make mountain ranges the primary depository for medium and long range air pollutants. In many cases pollutants accumulate in the snow cover or the soils of mountain areas, which can have long-term effects on ecosystems and especially on species that are susceptible to toxics. The dying of trees due to acid rain is only one example of the consequences of air pollution on montane forest areas. Many impacts are less visible and require intense research and careful monitoring of the deposited pollutants and their emission sources.

  • Invasive species

    Mountains are characterized by a high number of isolated habitats that are similar but separated through summits or valleys. Species that are introduced into a habitat from other mountain habitats can replace endemic species in an area. However, mountain ranges serve as natural barriers to the expansion of alien species from lowland habitat to another.

  • United Nations
  • United Nations Environment Programme