Tree line in the context of "Inuvialuit Settlement Region"

In physical geography, a tundra (/ˈtʌndrə, ˈtʊn-/) is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: Arctic, Alpine, and Antarctic.

Tundra vegetation is composed of dwarf shrubs, sedges, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating a feedback cycle that contributes to climate change.

Alpine climate is the typical 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.

An alpine lake is a high-altitude lake in a mountainous area, usually near or above the tree line, with extended periods of ice cover. These lakes are commonly glacial lakes formed from glacial activity (either current or in the past) but can also be formed from geological processes such as volcanic activity (volcanogenic lakes) or landslides (barrier lakes). Many alpine lakes that are fed from glacial meltwater have the characteristic bright turquoise green color as a result of glacial flour, suspended minerals derived from a glacier scouring the bedrock. When active glaciers are not supplying water to the lake, such as a majority of Rocky Mountains alpine lakes in the United States, the lakes may still be bright blue due to the lack of algal growth resulting from cold temperatures, lack of nutrient run-off from surrounding land, and lack of sediment input. The coloration and mountain locations of alpine lakes attract lots of recreational activity.

Alpine lakes are some of the most abundant types of lakes on Earth. In the Swiss Alps alone, there are nearly 1,000 alpine lakes, most of which formed after the Little Ice Age. As global temperatures continue to rise, more alpine lakes will be formed as glaciers recede and provide more run-off to surrounding areas, and existing lakes will see more biogeochemical changes and ecosystem shifts. An alpine lake's trophic state (i.e., level of biological productivity) progresses with age (e.g., low productivity after formation and increased productivity with vegetation and soil maturity in the surrounding watershed), but anthropogenic effects such as agriculture and climate change are rapidly affecting productivity levels in some lakes. These lakes are sensitive ecosystems and are particularly vulnerable to climate change due to the highly pronounced changes to ice and snow cover. Due to the importance of alpine lakes as sources of freshwater for agricultural and human use, the physical, chemical, and biological responses to climate change are being extensively studied.

Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level and merges with polar tundra.

The high elevation causes an adverse climate, which is too cold and windy to support tree growth. Alpine tundra transitions to sub-alpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as krummholz. With increasing elevation it ends at the snow line where snow and ice persist through summer.

The Antarctic Convergence or Antarctic Polar Front is a marine belt encircling Antarctica, varying in latitude seasonally, where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the sub-Antarctic. The line separates the clockwise Antarctic circumpolar current from other oceans. Antarctic waters predominantly sink beneath the warmer subantarctic waters, while associated zones of mixing and upwelling create a zone very high in marine productivity, especially for Antarctic krill.

This line, like the Arctic tree line, is a natural boundary rather than an artificial one, such as the borders of nations and time zones. It not only separates two hydrological regions, but also separates areas of distinctive marine life and climates.

Intermontane is a physiographic adjective formed from the prefix "inter-" (signifying among, between, amid, during, within, mutual, reciprocal) and the adjective "montane" (inhabiting, or growing in mountainous regions, especially cool, moist upland slopes below the timberline).

The corresponding physiographic noun is intermountain, while the noun intermontane is an ecologic noun meaning among, between, amid, or within "flora and fauna of a montane habitat." As an example, an alpine region would be an intermontane for a species that migrates between a glacial region and a subalpine region.

Fell (from Old Norse: fell, "mountain → landscape over the tree line"; cf. Icelandic: fell, Norwegian: fjell, Swedish: fjäll) is a high and barren landscape feature, such as a mountain or moor-covered hill, often mountain landscape over the tree line, etc. The term is most often employed in Fennoscandia, Iceland, the Isle of Man, parts of northern England, and Scotland.

Pinus peuce (Macedonian pine or Balkan pine) (Serbo-Croatian and Macedonian: молика, molika; Bulgarian: бяла мура, byala mura) is a species of pine native to the mountains of North Macedonia, Bulgaria, Albania, Montenegro, Kosovo, the extreme southwest of Serbia, and the extreme northwest of Greece, growing typically at (600-) 1,000-2,200 (-2,300) m altitude. It often reaches the alpine tree line in this area. The mature size is up to 35–40 m height, and 1.5 m trunk diameter. However, the height of the tree diminishes strongly near the upper tree line and may even obtain shrub sizes.

It is a member of the white pine group, Pinus subgenus Strobus, and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. They are 6–11 cm long. Its pine cones are mostly 8–16 cm long, occasionally up to 20 cm long, green at first, becoming yellow-brown when mature, with broad, flat to downcurved scales. The 6–7 mm long seeds have a 2 cm wing and can be wind-dispersed, but are also very often dispersed by spotted nutcrackers.

Junipers are coniferous trees and shrubs in the genus Juniperus (/dʒuːˈnɪpərəs/ joo-NIP-ər-əs) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south as tropical Africa, as far north as the Arctic, and parts of Asia and Central America. The highest-known juniper forest occurs at an altitude of 4,900 metres (16,100 ft) in southeastern Tibet and the northern Himalayas, creating one of the highest tree lines on earth.