what is a tundra plz help?

Answer 1

tundra is a name for grasslands that grow on ground that is defrosted on top but frozen below a few inches.

Answer 2

A tundra is an open desert that is cold.

Answer 3

A treeless area between the icecap and the tree line of Arctic regions, having a permanently frozen subsoil and supporting low-growing vegetation such as lichens, mosses, and stunted shrubs.

Answer 4

there are like grass tundras, decidious forest tundra, etc.

a tundra is an ecosystem with plants and different things. its like umm. a grassland, forest and other things. its nature
hope that helpss
best answer please? im new and need points

Answer 5

Cold

Answer 6

Huge areas of freezing uninhabitable flat land

Answer 7

he Tundra


The word tundra derives from the Finnish word for barren or treeless land. The tundra is the simplest biome in terms of species composition and food chains.

Vegetation: lichens, mosses, sedges, perennial forbs, and dwarfed shrubs, (often heaths, but also birches and willows).

Growthforms: typical are ground-hugging and other warmth-preserving forms including:

* tussock-forming graminoids
* mats or cushion plants, often evergreen members of the heath family
* rosettes
* dwarf shrubs, some of which are deciduous in habit

Climate: The high latitude conditions of Koeppen's ET climate type that impact life in this biome include

* extremely short growing season (6 to 10 weeks)
* long, cold, dark winters (6 to 10 months with mean monthly temperatures below 32° F or 0° C.)
* low precipitation (less than five inches/year) coupled with strong, drying winds. Snowfall is actually advantageous to plant and animal life as it provides an insulating layer on the ground surface.

Edaphic controls: Permafrost, not cold temperatures per se, is generally believed to be what prevents tree growth. Furthermore, freeze-thaw activity, a thin active layer, and solifluction during the warmer months contribute to strong controls on vegetation patterns and create a mosaic of microhabitats and plant communities.

Soil: No true soil is developed in this biome due to the edaphic factors mentioned above.

Fauna: Strategies evolved to withstand the harsh conditions of the tundra can be divided among those species that are resident and those that are migratory.

* Among the small number of bird (e.g., ptarmigan) and mammal (e.g., muskox, arctic hare, arctic fox, musk ox) species that reside year-round on the tundra one commonly finds:
Morphological adaptations
+ large, compact bodies following Bergmann's and Allen's rules
+ a thick insulating cover of feathers or fur
+ pelage and plumage that turns white in winter, brown in summer
Physiological adaptations
+ ability to accumulate thick deposits of fat during the short growing season. Fat acts as insulation and as a store of energy for use during the winter, when animal species remain active.
Population adaptations
+ cyclical fluctuations in population size, best seen perhaps in the lemming, a small rodent which is the major herbivore in the tundra's simple food chain. Predator populations and plant populations respond in kind to the peaks and crashes of the herbivore populations.

* Migratory species such as waterfowl, shorebirds and caribou adapt to the tundra by avoiding the most severe conditions of winter. Each year at the end of the short growing season they move southward into the boreal forest or beyond, but return to the tundra to breed.

Aperiodic emigration from the tundra is exhibited by the snowy owl during those years that the lemming populations have crashed. Those winters see snowy owl irruptions as far south as Virginia. Most owls are found with empty stomachs and do not survive to return to the Arctic.

Distribution: The tundra biome is restricted to the high latitudes of the northern hemisphere in a belt around the Arctic Ocean. Many of its species, both plant and animal, have circumpolar distribution areas.

Within the tundra biome a latitudinal zonation of communities is realized:

* High Arctic Tundra: essentially confined to the islands of the Arctic Ocean and characterized by scattered lichens and mosses on care rock surfaces and perennial forbs growing in protected crannies among sharp, ice-fractured rock debris.
* Middle Arctic Tundra: restricted to the Arctic Coastal plain where level terrain, a thin active layer, and freeze and thaw result in patterned ground, or rock polygons. The sorting of particles by freeze-thaw activity results in a waterlogged center to the polygons, a microhabitat conducive to sphagnum moss and sedges; and an outer ring that is drier and provides a microhabitat favorable to forbs and some dwarf heaths.
* Low Arctic Tundra: the majority of the tundra lies on better drained slopes with greater depth to permafrost than is encountered on the Arctic coastal plain. Here there is a greater frequency of woody shrubs: willow, birch, and various berry-bearing members of the heath family. Along streams willows and alders may be 10 feet high. On south-facing slopes needleleaf evergreen trees (spruce and fir) are established and represent the northernmost extensions of the great boreal forest to the south. (Such areas where two biomes interdigitate are known as ecotones.)

Alpine Tundra
Many tundra species can be found at high elevations in the mountains of the northern hemisphere. The arctic-alpine lifezone of high elevations experiences a different climate--in terms of daylength and seasons--than does the true tundra of the Arctic. However, thin soils and cold temperatures create an environment that many middle latitude trees cannot tolerate and thus allow tundra species to invade and thrive.

In the tropics, the climate of very high elevations is extremely different than that of the Arctic. Freeze-thaw, instead of following a seasonal cycle, follows a diurnal cycle. Also, the peaks are isolated from the Arctic tundra. Often endemic species derived from a tropical flora or from Antarctic flora create the unique communities of tropical high mountain tops. See Tropical Lifezones for additional information and some photographs of the giant lobelias and groundsels of Mt. Kenya.

Return to biome page
Created by SLW, September 30, 1996

Answer 8

it's an ecozone characteristic of the far north.

Very low-growing plants, very cold, windy.

Answer 9

limited growth

Answer 10

Tundra
From Wikipedia, the free encyclopedia
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For other uses, see Tundra (disambiguation).

In physical geography, tundra is an area where the tree growth is hindered by low temperatures and short growing seasons. The term "tundra" comes from Kildin Sami tūndâr 'uplands, tundra, treeless mountain tract'. There are two types of tundra: Arctic tundra (which also occurs in Antarctica), and alpine tundra[1]. In tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.
Arctic tundra on Wrangel Island, Russia, a World Heritage Site
Arctic tundra on Wrangel Island, Russia, a World Heritage Site[2]
Contents
[hide]

* 1 Arctic tundra
* 2 Antarctic tundra
* 3 Alpine tundra
* 4 Climatic classification
* 5 References
* 6 See also
* 7 External links

[edit] Arctic tundra
Tundra in Greenland
Tundra in Greenland
Map of arctic tundra
Map of arctic tundra
Tundra coastal vegetation in Alaska, during the summer
Tundra coastal vegetation in Alaska, during the summer

Arctic tundra occurs in the far Northern Hemisphere, north of the taiga belt. The word "tundra" usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil. (It may also refer to the treeless plain in general, so that northern Sápmi would be included.) Permafrost tundra includes vast areas of northern Russia and Canada [1]. The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area (and the Sami in Sápmi).

The Arctic tundra is a vast area of stark landscape, which is frozen for much of the year. The soil there is frozen from 25-90 cm (9.8-35.4 inches) down, and it is impossible for trees to grow. Instead, bare and sometimes rocky land can only support low growing plants such as moss, heath, and lichen. There are two main seasons, winter and summer, in the polar Tundra areas. During the winter it is very cold and dark, with the average temperature around -28 °C (-18.4°F), sometimes dipping as low as -50 °C (-58°F). However, extreme cold temperatures on the tundra do not drop as low as those experienced in taiga areas further south (for example, Russia's and Canada's lowest temperatures were recorded in locations south of the treeline). During the summer, temperatures rise somewhat, and the top layer of the permafrost melts, leaving the ground very soggy. The tundra is covered in marshes, lakes, bogs and streams during the warm months. Generally daytime temperatures during the summer rise to about 12°C (53.6°F) but can often drop to 3°C (37.4°F) or even below freezing. Arctic tundras are sometimes the subject of habitat conservation programs. In Canada and Russia, many of these areas are protected through a national Biodiversity Action Plan.

The tundra is a very windy area, with winds often blowing upwards at 48–97 km/h (30-60 miles an hour). However, in terms of precipitation, it is desert-like, with only about 15–25 cm (6–10 inches) falling per year (the summer is typically the season of maximum precipitation). During the summer, the permafrost thaws just enough to let plants grow and reproduce, but because the ground below this is frozen, the water cannot sink any lower, and so the water forms the lakes and marshes found during the summer months. Although precipitation is light, evaporation is also relatively minimal.

The biodiversity of the tundras is low: 1,700 species of vascular plants and only 48 land mammals can be found, although thousands of insects and birds migrate there each year for the marshes. There are also a few fish species such as the flat fish. There are few species with large populations. Notable animals in the Arctic tundra include caribou (reindeer), musk ox, arctic hare, arctic fox, snowy owl, lemmings, and polar bears (only the extreme north) [3].

Due to the harsh climate of the Arctic tundra, regions of this kind have seen little human activity, even though they are sometimes rich in natural resources such as oil and uranium. In recent times this has begun to change in Alaska, Russia, and some other parts of the world.

A severe threat to the tundras, specifically to the permafrost, is global warming. Permafrost is essentially a frozen bog - in the summer, only its surface layer melts. The melting of the permafrost in a given area on human time scales (decades or centuries) could radically change which species can survive there[4].

Another concern is that about one third of the world's soil-bound carbon is in taiga and tundra areas. When the permafrost melts, it releases carbon in the form of carbon dioxide, a greenhouse gas. The effect has been observed in Alaska. In the 1970s the tundra was a carbon sink, but today, it is a carbon source[5].

[edit] Antarctic tundra
Tundra on the Péninsule Rallier du Baty, Kerguelen Islands
Tundra on the Péninsule Rallier du Baty, Kerguelen Islands

Antarctic tundra occurs on Antarctica and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and the Kerguelen Islands. Antarctica is mostly too cold and dry to support vegetation, and most of the continent is covered by ice fields. However, some portions of the continent, particularly the Antarctic Peninsula, have areas of rocky soil that support plant life. The flora presently consists of around 300-400 lichens, 100 mosses, 25 liverworts, and around 700 terrestrial and aquatic algae species, which live on the areas of exposed rock and soil around the shore of the continent. Antarctica's two flowering plant species, the Antarctic hair grass (Deschampsia Antarctica) and Antarctic pearlwort (Colobanthus quitensis), are found on the northern and western parts of the Antarctic Peninsula[6] In contrast with the Arctic tundra, the Antarctic tundra lacks a large mammal fauna, mostly due to its physical isolation from the other continents. Sea mammals and sea birds, including seals and penguins, inhabit areas near the shore, and some small mammals, like rabbits and cats, have been introduced by humans to some of the subantarctic islands.

The flora and fauna of Antarctica and the Antarctic Islands (south of 60° south latitude) are protected by the Antarctic Treaty.[7]

Tundra also occurs on Tierra del Fuego and southern Argentina.[8] Notable plant and lichen species of this tundra include Neuropogon aurantiaco, Azorella lycopodioides, Marsippospermum reichei, Nardophyllum bryoides, and Bolax gummifera.

[edit] Alpine tundra
Hikers traversing the Franconia Ridge in the White Mountains of New Hampshire, much of which is in the alpine zone.
Hikers traversing the Franconia Ridge in the White Mountains of New Hampshire, much of which is in the alpine zone.

Alpine tundra is an ecozone that does not contain trees because it has high altitude. Alpine tundra occurs at high enough altitude at any latitude on Earth. Alpine tundra also lacks trees, but the lower part does not have permafrost, and alpine soils are generally better drained than permafrost soils. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz. Alpine tundra occurs in an alpine zone.

Alpine tundra does not map directly to specific World Wide Fund for Nature ecoregions. Portions of Montane grasslands and shrublands ecoregions include alpine tundra.

Because alpine tundra is located in various widely-separated regions of the Earth, there is no animal species common to all areas of alpine tundra. Some animals of alpine tundra environments include the Kea parrot, marmot, Mountain goats, chinchilla, and pika.

Large sections of the Tibetan Plateau include alpine tundra.

See also: Tree line

[edit] Climatic classification

See also: Alpine climate

Tundra climates ordinarily fit the Köppen climate classification ET, signifying a local climate in which at least one month has an average temperature high enough to melt snow (0°C or 32°F), but no month with an average temperature in excess of (10°C/50°F). The cold limit generally meets the EF climates of permanent ice and snows; the warm-summer limit generally corresponds with the poleward or altitudinal limit of trees, where they grade into the subarctic climates designated Dfd and Dwd (extreme winters as in parts of Siberia), Dfc typical in Alaska, Canada, European Russia, and Western Siberia (cold winters with months of freezing), or even Cfc (no month colder than -3°C as in parts of Iceland and southernmost South America). Tundra climates as a rule are hostile to woody vegetation even where the winters are comparatively mild by polar standards, as in Iceland.

Despite the potential diversity of climates in the ET category involving precipitation, extreme temperatures, and relative wet and dry seasons, this category is rarely subdivided. Rainfall and snowfall are generally slight due to the limited capacity of the chilly atmosphere to hold water vapor, but as a rule potential evapotranspiration is extremely low, allowing soggy terrain of swamps and bogs even in places that get precipitation typical of deserts of lower and middle latitudes. Scarcity of lushness (by polar standards) of native vegetation of tundra regions depends more upon the severity of the temperatures than upon the scarcity or copiousness of precipitation.