Montane ecosystems

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Montane ecosystems are found on the slopes of mountains. Montane ecosystems_sentence_0

The alpine climate in these regions strongly affect the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. Montane ecosystems_sentence_1

Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall. Montane ecosystems_sentence_2

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. Montane ecosystems_sentence_3

Life zones Montane ecosystems_section_0

As elevation increases, the climate becomes cooler, due to a decrease in atmospheric pressure and the adiabatic cooling of airmasses. Montane ecosystems_sentence_4

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. Montane ecosystems_sentence_5

The characteristic flora and fauna in the mountains tend to strongly depend on elevation, because of the change in climate. Montane ecosystems_sentence_6

This dependency causes life zones to form: bands of similar ecosystems at similar altitude. Montane ecosystems_sentence_7

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. Montane ecosystems_sentence_8

Holdridge defines the climate of montane forest as having a biotemperature of between 6 and 12 °C (43 and 54 °F), where biotemperature is the mean temperature considering temperatures below 0 °C (32 °F) to be 0 °C (32 °F). Montane ecosystems_sentence_9

Above the elevation of the montane forest, the trees thin out in the subalpine zone, become twisted krummholz, and eventually fail to grow. Montane ecosystems_sentence_10

Therefore, montane forests often contain trees with twisted trunks. Montane ecosystems_sentence_11

This phenomenon is observed due to the increase in the wind strength with the elevation. Montane ecosystems_sentence_12

The elevation where trees fail to grow is called the tree line. Montane ecosystems_sentence_13

The biotemperature of the subalpine zone is between 3 and 6 °C (37 and 43 °F). Montane ecosystems_sentence_14

Above the tree line the ecosystem is called the alpine zone or alpine tundra, dominated by grasses and low-growing shrubs. Montane ecosystems_sentence_15

The biotemperature of the alpine zone is between 1.5 and 3 °C (34.7 and 37.4 °F). Montane ecosystems_sentence_16

Many different plant species live in the alpine environment, including perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. Montane ecosystems_sentence_17

Alpine plants must adapt to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, and a short growing season. Montane ecosystems_sentence_18

Alpine plants display adaptations such as rosette structures, waxy surfaces, and hairy leaves. Montane ecosystems_sentence_19

Because of the common characteristics of these zones, the World Wildlife Fund groups a set of related ecoregions into the "montane grassland and shrubland" biome. Montane ecosystems_sentence_20

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. Montane ecosystems_sentence_21

Climates with biotemperatures below 1.5 °C (35 °F) tend to consist purely of rock and ice. Montane ecosystems_sentence_22

Montane forest Montane ecosystems_section_1

Montane forests occur between the submontane zone and the subalpine zone. Montane ecosystems_sentence_23

The elevation at which one habitat changes to another varies across the globe, particularly by latitude. Montane ecosystems_sentence_24

The upper limit of montane forests, the tree line, is often marked by a change to hardier species that occur in less dense stands. Montane ecosystems_sentence_25

For example, in the Sierra Nevada 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. Montane ecosystems_sentence_26

The lower bound of the montane zone may be a "lower timberline" that separates the montane forest from drier steppe or desert region. Montane ecosystems_sentence_27

Montane forests differ from lowland forests in the same area. Montane ecosystems_sentence_28

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. Montane ecosystems_sentence_29

Humans can disturb montane forests through forestry and agriculture. Montane ecosystems_sentence_30

On isolated mountains, montane forests surrounded by treeless dry regions are typical "sky island" ecosystems. Montane ecosystems_sentence_31

Temperate climate Montane ecosystems_section_2

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. Montane ecosystems_sentence_32

The trees are, however, often not identical to those found further north: geology and climate causes different related species to occur in montane forests. Montane ecosystems_sentence_33

Montane forests outside Europe tend to be more species-rich, because the major mountain chains of Europe are oriented east-west. Montane ecosystems_sentence_34

Montane forests in temperate climate occur in Europe (the Alps, Carpathians, Caucasus and more), in North America (Cascade Range, Klamath-Siskiyou, Appalachians and more), south-western South America, New Zealand and the Himalayas. Montane ecosystems_sentence_35

Mediterranean climate Montane ecosystems_section_3

Montane forests in Mediterranean climate are warm and dry except in winter, when they are relatively wet and mild. Montane ecosystems_sentence_36

These forests are typically mixed conifer and broadleaf forests, with only a few conifer species. Montane ecosystems_sentence_37

Pine and juniper are typical trees found in Mediterranean montane forests. Montane ecosystems_sentence_38

The broadleaf trees show more variety and are often evergreen, e.g. evergreen oak. Montane ecosystems_sentence_39

This type of forest is found in the Mediterranean Basin, North Africa, Mexico and the southwestern US, Iran, Pakistan and Afghanistan. Montane ecosystems_sentence_40

Subtropical and tropical climate Montane ecosystems_section_4

In the tropics, montane forests can consist of broadleaf forest in addition to coniferous forest. Montane ecosystems_sentence_41

One example of a tropical montane forest is a cloud forest, which gains its moisture from clouds and fog. Montane ecosystems_sentence_42

Cloud forests often exhibit an abundance of mosses covering the ground and vegetation, in which case they are also referred to as mossy forests. Montane ecosystems_sentence_43

Mossy forests usually develop on the saddles of mountains, where moisture introduced by settling clouds is more effectively retained. Montane ecosystems_sentence_44

Depending on latitude, the lower limit of montane rainforests on large mountains is generally between 1,500 and 2,500 metres (4,900 and 8,200 ft) while the upper limit is usually from 2,400 to 3,300 metres (7,900 to 10,800 ft). Montane ecosystems_sentence_45

Subalpine zone Montane ecosystems_section_5

The subalpine zone is the biotic zone immediately below the tree line around the world. Montane ecosystems_sentence_46

In tropical regions of Southeast Asia the tree line may be above 4,000 m (13,000 ft), whereas in Scotland it may be as low as 450 m (1,480 ft). Montane ecosystems_sentence_47

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, mountain hemlock and subalpine fir in western North America. Montane ecosystems_sentence_48

Trees in the subalpine zone often become krummholz, that is, crooked wood, stunted and twisted in form. Montane ecosystems_sentence_49

At tree line, tree seedlings may germinate on the lee side of rocks and grow only as high as the rock provides wind protection. Montane ecosystems_sentence_50

Further growth is more horizontal than vertical, and additional rooting may occur where branches contact the soil. Montane ecosystems_sentence_51

Snow cover may protect krummholz trees during the winter, but branches higher than wind-shelters or snow cover are usually destroyed. Montane ecosystems_sentence_52

Well-established krummholz trees may be several hundred to a thousand years old. Montane ecosystems_sentence_53

Meadows may be found in the subalpine zone. Montane ecosystems_sentence_54

Tuolumne Meadows in the Sierra Nevada of California, is an example of a subalpine meadow. Montane ecosystems_sentence_55

Example subalpine zones around the world include the French Prealps in Europe, the Sierra Nevada and Rocky Mountain subalpine zones in North America, and subalpine forests in the eastern Himalaya, western Himalaya, and Hengduan mountains of Asia. Montane ecosystems_sentence_56

Alpine grasslands and tundra Montane ecosystems_section_6

Main articles: Alpine tundra, Montane grassland and shrubland, and Alpine plant Montane ecosystems_sentence_57

Alpine grasslands and tundra lie above the tree line, in a world of intense radiation, wind, cold, snow, and ice. Montane ecosystems_sentence_58

As a consequence, alpine vegetation is close to the ground and consists mainly of perennial grasses, sedges, and forbs. Montane ecosystems_sentence_59

Annual plants are rare in this ecosystem and usually are only a few inches tall, with weak root systems. Montane ecosystems_sentence_60

Other common plant life-forms include prostrate shrubs, graminoids forming tussocks, and cryptogams, such as bryophytes and lichens. Montane ecosystems_sentence_61

Plants have adapted to the harsh alpine environment. Montane ecosystems_sentence_62

Cushion plants, looking like ground-hugging clumps of moss, escape the strong winds blowing a few inches above them. Montane ecosystems_sentence_63

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. Montane ecosystems_sentence_64

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. Montane ecosystems_sentence_65

Non-flowering lichens cling to rocks and soil. Montane ecosystems_sentence_66

Their enclosed algal cells can photosynthesize at any temperature above 0 °C (32 °F), and the outer fungal layers can absorb more than their own weight in water. Montane ecosystems_sentence_67

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. Montane ecosystems_sentence_68

Repeated footsteps often destroy tundra plants, leaving exposed soil to blow away, and recovery may take hundreds of years. Montane ecosystems_sentence_69

Alpine meadows form where sediments from the weathering of rocks has produced soils well-developed enough to support grasses and sedges. Montane ecosystems_sentence_70

Alpine grasslands are common enough around the world to be categorized as a biome by the World Wildlife Fund. Montane ecosystems_sentence_71

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. Montane ecosystems_sentence_72

The most extensive montane grasslands and shrublands occur in the Neotropical páramo of the Andes Mountains. Montane ecosystems_sentence_73

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. Montane ecosystems_sentence_74

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 (Neotropic), Cyathea (New Guinea), and Argyroxiphium (Hawaii). Montane ecosystems_sentence_75

Where conditions are drier, one finds montane grasslands, savannas, and woodlands, like the Ethiopian Highlands, and montane steppes, like the steppes of the Tibetan Plateau. Montane ecosystems_sentence_76

See also Montane ecosystems_section_7

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: ecosystems.