Montane ecosystems are found on the slopes of

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

s. The

alpine climate Alpine climate is the typical weather (climate) for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate. Definition There are multiple definitions of ...

in these regions strongly affects the

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s are common at moderate elevations, due to moderate temperatures and high rainfall. At higher elevations, the climate is harsher, with lower temperatures and higher winds, preventing the growth of trees and causing the plant community to transition to montane grasslands, shrublands or

alpine tundra Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated alpine climate, harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alp ...

. Due to the unique climate conditions of montane ecosystems, they contain increased numbers of endemic species. Montane ecosystems also exhibit variation in

ecosystem service Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. Th ...

s, which include carbon storage and water supply.

Life zones

As elevation increases, the climate becomes cooler, due to a decrease in atmospheric pressure and the adiabatic cooling of airmasses. The change in climate by moving up 100 meters on a mountain is roughly equivalent to moving 80 kilometers (45 miles or 0.75° of latitude) towards the nearest pole. The characteristic flora and fauna in the mountains tend to strongly depend on elevation, because of the change in climate. This dependency causes

life zone The life zone concept was developed by C. Hart Merriam in 1889 as a means of describing areas with similar plant and animal communities. Merriam observed that the changes in these communities with an increase in latitude at a constant elevation ar ...

s to form: bands of similar ecosystems at similar altitude. One of the typical life zones on mountains is the montane forest: at moderate elevations, the rainfall and temperate climate encourages dense forests to grow. Holdridge defines the climate of montane forest as having a biotemperature of between , where biotemperature is the mean temperature considering temperatures below to be . Above the elevation of the montane forest, the trees thin out in the subalpine zone, become twisted krummholz, and eventually fail to grow. Therefore, montane forests often contain trees with twisted trunks. This phenomenon is observed due to the increase in the wind strength with the elevation. The elevation where trees fail to grow is called the tree line. The biotemperature of the subalpine zone is between . Above the tree line the ecosystem is called the alpine zone or

, dominated by grasses and low-growing shrubs. The biotemperature of the alpine zone is between . Many different plant species live in the alpine environment, including perennial grasses, sedges, forbs, cushion plants,

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es, and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.World Wildlife Fund groups a set of related

ecoregions An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

into the "

montane grassland and shrubland Montane grasslands and shrublands is a biome defined by the World Wildlife Fund. The biome includes high elevation grasslands and shrublands around the world. The term "montane" in the name of the biome refers to "high elevation", rather than th ...

" biome. A region in the Hengduan Mountains adjoining Asia's Tibetan Plateau have been identified as the world's oldest continuous alpine ecosystem with a community of 3000 plant species, some of them continuously co-existing for 30 million years. Climates with biotemperatures below tend to consist purely of rock and ice.

Montane forests

Montane forests occur between the

submontane zone Altitudinal zonation (or elevational zonation) in mountainous regions describes the natural layering of ecosystems that occurs at distinct elevations due to varying environmental conditions. Temperature, humidity, soil composition, and solar radi ...

and the

subalpine zone Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

. The elevation at which one habitat changes to another varies across the globe, particularly by latitude. The upper limit of montane forests, the tree line, is often marked by a change to hardier species that occur in less dense stands. For example, in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

of California, the montane forest has dense stands of lodgepole pine and red fir, while the Sierra Nevada subalpine zone contains sparse stands of whitebark pine. The lower bound of the montane zone may be a "lower timberline" that separates the montane forest from drier

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

region. Montane forests differ from lowland forests in the same area. The climate of montane forests is colder than lowland climate at the same latitude, so the montane forests often have species typical of higher-latitude lowland forests. Humans can disturb montane forests through forestry and agriculture. On isolated mountains, montane forests surrounded by treeless dry regions are typical " sky island" ecosystems.

Temperate climate

Montane forests in temperate climate are typically one of temperate coniferous forest or temperate broadleaf and mixed forest, forest types that are well known from Europe and northeastern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. The trees are, however, often not identical to those found further north: geology and climate causes different related species to occur in montane forests. Herbst am Watzmann

Montane forests outside Europe tend to be more species-rich, because the major mountain chains of Europe are oriented east–west. Montane forests in temperate climate occur in Europe (the Alps, Carpathians, Caucasus and

more More or Mores may refer to: Computing * MORE (application), outline software for Mac OS * more (command), a shell command * MORE protocol, a routing protocol * Missouri Research and Education Network Music Albums * ''More!'' (album), by Booka ...

), in

(

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

, Klamath-Siskiyou, Appalachians and more), south-western South America, New Zealand and the Himalayas. Climate change is predicted to affect temperate montane forests. For example, in the Pacific Northwest of North America, climate change may cause "potential reduced snowpack, higher levels of evapotranspiration, increased summer drought" which will negatively affect montane wetlands.

Mediterranean climate

Montane forests in Mediterranean climate are warm and dry except in winter, when they are relatively wet and mild. Montane forests located in Mediterranean climates exhibit towering trees alongside high biomass. These forests are typically mixed conifer and broadleaf forests, with only a few conifer species. Pine and

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

are typical trees found in Mediterranean montane forests. The broadleaf trees show more variety and are often evergreen, e.g. evergreen oak. This type of forest is found in the

Mediterranean Basin In biogeography, the Mediterranean Basin (; also known as the Mediterranean Region or sometimes Mediterranea) is the region of lands around the Mediterranean Sea that have mostly a Mediterranean climate, with mild to cool, rainy winters and w ...

, North Africa, Mexico and the

southwestern US The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, N ...

, Iran, Pakistan and Afghanistan.

Subtropical and tropical climate

Forest on Gunung Batu Brinchang, Malaysia

In the tropics, montane forests can consist of broadleaf forest in addition to coniferous forest. One example of a tropical montane forest is a

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

, which gains its moisture from clouds and fog. Cloud forests often exhibit an abundance of

es covering the ground and vegetation, in which case they are also referred to as mossy forests. Mossy forests usually develop on the saddles of mountains, where moisture introduced by settling clouds is more effectively retained. Depending on latitude, the lower limit of montane rainforests on large mountains is generally between while the upper limit is usually from . Tropical montane forests might exhibit high sensitivity to climate change. Climate change may cause variation in temperature, precipitation and humidity, which will cause stress on tropical montane forests. The predicted upcoming impacts of climate change might significantly affect biodiversity loss and might result in change of species range and community dynamics. Global climate models predict reduced cloudiness in the future. Reduction in cloudiness may already be affecting the Monteverde cloud forest in

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

Subalpine zone

The subalpine zone is the

biotic zone The life zone concept was developed by C. Hart Merriam in 1889 as a means of describing areas with similar plant and animal communities. Merriam observed that the changes in these communities with an increase in latitude at a constant elevation a ...

immediately below the tree line around the world. In tropical regions of Southeast Asia the tree line may be above , whereas in Scotland it may be as low as . Species that occur in this zone depend on the location of the zone on the Earth, for example, Pinus mugo (scrub mountain pine) in Europe, snow gum in Australia, or

subalpine larch ''Larix lyallii'', the subalpine larch, or simply alpine larch, is a deciduous, coniferous tree native to northwestern North America. It lives at high altitudes, from , in the Rocky Mountains of Idaho, Montana, British Columbia, and Alberta. Ther ...

, mountain hemlock and subalpine fir in western North America. Trees in the subalpine zone often become krummholz, that is, crooked wood, stunted and twisted in form. At tree line, tree seedlings may germinate on the lee side of rocks and grow only as high as the rock provides wind protection. Further growth is more horizontal than vertical, and additional rooting may occur where branches contact the soil. Snow cover may protect krummholz trees during the winter, but branches higher than wind-shelters or snow cover are usually destroyed. Well-established krummholz trees may be several hundred to a thousand years old. Meadows may be found in the subalpine zone. Tuolumne Meadows in the

of California, is an example of a subalpine meadow. Example subalpine zones around the world include the French Prealps in Europe, the

and Rocky Mountain subalpine zones in North America, and subalpine forests in the

eastern Himalaya ] The Eastern Himalayas extend from eastern Nepal across Northeast India, Bhutan, the Tibet Autonomous Region to Yunnan in China and northern Myanmar. The climate of this region is influenced by the monsoon of South Asia from June to September. It ...

, Western Himalayan subalpine conifer forests, western Himalaya, and Hengduan mountains of Asia.

Alpine grasslands and tundra

Alpine grasslands and tundra lie above the tree line, in a world of intense radiation, wind, cold, snow, and ice. As a consequence, alpine vegetation is close to the ground and consists mainly of perennial grasses, sedges, and forbs. Annual plants are rare in this ecosystem and usually are only a few inches tall, with weak root systems. Other common plant life-forms include prostrate shrubs;

tussock Tussock may refer to: * Tussock grass, a group of species in the family Poaceae *Floating island * Lymantriinae, called tussock moths or tussocks See also * Hassock (disambiguation) Hassock may refer to: * Kneeler, a cushion or a piece of f ...

-forming

graminoid In botany and ecology, graminoid refers to a herbaceous plant with a grass-like morphology, i.e. elongated culms with long, blade-like leaves. They are contrasted to forbs, herbaceous plants without grass-like features. The plants most ofte ...

s; and cryptogams, such as

bryophytes The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited i ...

and lichens. Plants have adapted to the harsh alpine environment. Cushion plants, looking like ground-hugging clumps of moss, escape the strong winds blowing a few inches above them. Many flowering plants of the alpine tundra have dense hairs on stems and leaves to provide wind protection or red-colored pigments capable of converting the sun's light rays into heat. Some plants take two or more years to form flower buds, which survive the winter below the surface and then open and produce fruit with seeds in the few weeks of summer. Non-flowering

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.algal cells can photosynthesize at any temperature above , and the outer fungal layers can absorb more than their own weight in water. The adaptations for survival of drying winds and cold may make tundra vegetation seem very hardy, but in some respects the tundra is very fragile. Repeated footsteps often destroy tundra plants, leaving exposed soil to blow away, and recovery may take hundreds of years. Alpine meadows form where sediments from the weathering of rocks has produced soils well-developed enough to support grasses and sedges. Alpine grasslands are common enough around the world to be categorized as a biome by the World Wildlife Fund. The biome, called "Montane grasslands and shrublands", often evolved as virtual islands, separated from other montane regions by warmer, lower elevation regions, and are frequently home to many distinctive and endemic plants which evolved in response to the cool, wet climate and abundant sunlight. The most extensive montane grasslands and shrublands occur in the Neotropical

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower ...

of the

Andes Mountains The Andes, Andes Mountains or Andean Mountains (; ) are the List of mountain ranges#Mountain ranges by length, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range i ...

. This biome also occurs in the mountains of east and central Africa, Mount Kinabalu of Borneo, highest elevations of the Western Ghats in South India and the Central Highlands of New Guinea. A unique feature of many wet tropical montane regions is the presence of giant rosette plants from a variety of plant families, such as '' Lobelia'' ( Afrotropic), ''

Puya Puya may refer to: * ''Puya'' (plant), in the family Bromeliaceae * Puya (river), in Russia * Puya, a variety of Guajillo chili * ''Puya'' (Meitei texts), traditional or mythological texts of the Meetei people * ''Culoepuya'' or ''Culo'e Puya'', V ...

'' (

Neotropic The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

), '' Cyathea'' ( New Guinea), and '' Argyroxiphium'' ( Hawaii). Where conditions are drier, one finds montane grasslands, savannas, and woodlands, like the Ethiopian Highlands, and montane

s, like the steppes of the Tibetan Plateau.

References

External links

*
Tree cover map for mountain forests – UNEP Map 2011
{{Subject bar, auto=1, wikt=montane, Mountains, Ecology Forest ecology