Mountain ecosystems

About mountain ecosystems

“Forests and water” and “watershed management” are embedded in sustainable development and, in particular, in sustainable mountain development (SMD). This explains the complementarities of these topics and the strong linkages that the Forests and Water programme maintains with “mountain” colleagues within and outside FAO.

Since the beginning of the 1990s, FAO Forestry Department staff has been part of a multi-disciplinary global community of mountain stakeholders. Research findings and exchange have resulted in a number of flagship publications such as for example several issues of ”Mountains of the World” (1997, 1998, 1999, 2000, 2001, 2002)and the recent book entitled “Global change and mountain regions” (2005). All these publication have been instrumental to the mainstreaming of mountain issues in the international sustainable development agenda.

from 2001 to 2005, FAO Forestry Department staff participated in drafting the Mountain Chapter of the Millennium Ecosystem Assessment (MEA’s Chapter 24). The MEA is a major research exercise on the current situation and future trends of planet ecosystems, which was called by UN Secretary Kofi Annan speech: “We the Peoples: the role of the United Nations in the 21st Century” (2000). MEA’s four volumes report, issued in 2006, summarizes the current understanding of the situation of the planet, and of actions needed to manage major risks and threats. In the next lines a glance at mountain ecosystems is provided, based on MEA’s Chapter 24 (the full-text version is downloadable from the link at the bottom of this page).

Based on the definition by the United Nations Environment Programme World Conservation Monitoring Centre (which was also adopted by the MEA study and which uses elevation and slope as the main criteria), about 23% of the global land surface can be considered mountain areas.

According to altitude, three belts can be distinguished for mountain regions where latitude and precipitation regimes allow forest or shrubs growth:

• the montane belt which extends from the lower mountain limit to the upper limit of forest;
• the alpine belt which is the treeless region between the natural climatic forest limit and the snow line;
• the nival belt which is the area above the snowline.

Slope and altitude determine many of the characteristics of mountain environments. However, latitude and distance from oceans affects local climate, making some mountains almost permanently wet, others dry, and some highly seasonal. Geological substratum adds a further dimension of geo-diversity and influences soil type, erosion processes, and vegetation cover.

In many parts of the world’s mountains, physical processes, in large part related to gravity, such as erosion, landslides, mud flows, avalanches, and rock fall determine life conditions. These physical phenomena become enhanced when volcanic or seismic activity comes into play, which is particularly the case in geologically young and thus steep mountains (like the Alps or the Himalaya).

Vegetation on lower mountain slopes may be broadly similar to that of surrounding lowlands. However, within an elevation range of 1,000 meters, altitude-related temperature change is enough to cause a full bioclimatic vegetation belt to be replaced by another (montane forest by alpine, for example).

Because of the compression of climatic zones along an elevation gradient, biodiversity in mountains commonly exceeds that in the lowlands. Thirty-two percent of all protected areas in the world are located in mountainous regions, providing habitats for rare, relict, and endangered plants and animals.

Twenty percent of the world’s population - about 1.2 billion people - live in mountains. Most of them inhabit lower elevations. Most of the 90 millions people living above 2,500 meters live in poverty and are considered highly vulnerable to food insecurity.

There are many historical examples of flourishing mountain economies and societies. However, special efforts and techniques are required to sustain agricultural production at altitudes close to the upper tree line level. Subsequently, lowland economies and societies have generally dominated mountain ones. Although there are some exceptions, very seldom exploitation of mountain resources (land, rangeland, timber, minerals, leisure sites, etc) benefits local communities.