Library Index :: Science Encyclopedia :: Depletion and Conservation of Natural Resources - The Economic Value Of The World's Ecosystems—how Much Is Nature Worth?, The Role Of Forests And Habitat
 

Depletion and Conservation of Natural Resources - Mountains

Mountains are one of Earth's most important features. They span one-fifth of the landscape and house one-tenth of Earth's population. Roughly two billion people live downstream from mountains and depend on the water, hydropower, grassland, timber, and mineral resources generated by those mountains.

What Is a Mountain?

A mountain is a landmass that projects conspicuously above its surroundings and is higher than a hill, generally at least 985 feet (300 meters) in height. An additional criterion is that a mountain's rise creates climates, soils, and vegetation distinct from those in surrounding lowlands. Mountains share common physical attributes of steepness, instability, and ecology that create natural hazards, micro-climates, niches of biodiversity, and inaccessibility. The collision of tectonic plates produces mountain uplift and numerous physical hazards, such as earthquakes, volcanic eruptions, landslides, avalanches, and floods. The slope and altitude of mountains create variations in climate—temperature, radiation, wind, and moisture—over very short distances.

Mountains function as the Earth's water towers by attracting much of its precipitation—they are the predominant and most dependable source of fresh water for humankind. A diversity of wild plants makes mountain ecosystems vital sources of food and pharmacological benefits for humans.

A Naturally Vulnerable Resource

A distinguishing feature of mountains is vulnerability to disturbance, largely due to the vertical dimension (height and slope). Because a doubling in water speed magnifies the size of materials that water can transport, the erosive power of rapid runoff from mountains is immense. Unlike lowland environments, mountain ecosystems are typically less able to recuperate from disruptions such as soil erosion or loss of vegetation; soils are usually thin and poorly anchored, and gravity-powered erosion speeds silt and sediment movement. Also, many mountains are still growing and are less geographically stable than flatter landmasses. Seven of the world's 14 tropical "hotspots" for plants threatened by destruction have at least half their area in mountains, and 131 of the world's 247 bird habitats are in tropical mountains.

As studies seem to confirm the warming of Earth's environment, experts predict that such warming will proceed too fast for many ecosystems to adapt. Austrian researchers have found that nine plant species typical of the nival zone (above alpine grasslands) are migrating to higher altitudes at one meter per decade, but will have to move eight to ten meters per decade to keep up with the current rate of warming.

Impacts on Mountain Ecology

Mountains face threats from poor land use patterns, resource extraction, and mass tourism and recreation. Half of U.S. rangeland, most of it in the mountainous West, is now considered severely degraded, with its livestock-supporting ability reduced by 50 percent. The FAO reports that hill and mountain forests are more susceptible to ecological damage from excessive population densities than are lowland forests. Because their slopes permit gravity to increase the power of flowing waters, mountains attract most of the Earth's hydroelectric projects and irrigation reservoirs.

Of all the economic activities in the world's mountains, nothing rivals the destructive power of mining. Environmental impacts include habitat destruction, erosion, air pollution, acid drainage, and metal contamination of water bodies. The result is often denuded forests, eroded hillsides, and dammed or polluted rivers.

TOURISM AND RECREATION.

Many lowlanders feel that mountains are a refuge from modern life, but problems—environmental ones—are following them up the slopes. In slick ads and commercials, images of pristine mountain wilderness lure multitudes for respite and sport. In industrial countries mass tourism and recreation are fast becoming the largest threats to mountain environments.

Since 1945 visits to the ten most popular mountainous national parks in the United States have increased 12-fold. Infrastructure for leisure and recreation in the mountains can be exorbitant. In 1990 there were 100 Alpine golf courses; by the end of 1996, 500 existed. Thundering helicopters bring skiers to untracked slopes not only in the American Rockies but worldwide. The populations of many small ski towns, like Vail, Colorado, have more than doubled since 1980, causing new home construction and retail sales to grow at double or triple the national average. White-water rafters and mountain climbers prowl the slopes in numbers some consider dangerous. A generation ago conquering Mount Everest was considered an unimaginable feat; today, dozens of climbers reach the peak every month, leaving behind trash—even the bodies of climbers that die on the dangerous climb are sometimes left behind. The interference of trash and excess traffic has become a serious problem on the mountain.

Depletion and Conservation of Natural Resources - Erosion [next] [back] Depletion and Conservation of Natural Resources - Wetlands—fragile Ecosystems

User Comments Add a comment…