Tundra
- Highly polar lichen and moss tundra ( 10 - 80% vegetation cover )
- Low polarity dwarf shrub & meadow tundra (> 80% vegetation cover )
- Subpolar mountain tundra
- Bergtundren temperate and alpine azonal Mats & Gentiles
- Similar tundra bogs, heaths and meadows of the Subantarctic
- ( Note: Click on the link for a great view of the original map "Vegetation zones " ")
Typical dwarf shrub tundra ( here northern Swedish Fell )
~ 20 % largely to nature <20% of anthropogenic overprinted
Laponian (SWE ) 9400 km ² Bolshoy Arktichesky (RUS ) 41,692 km ² Hemis (IND ) 4100 km ² Heard Island (AUS) 368 km ²
Tundra: Climate diagrams
Tundra ( also cold steppe ) is a term used in geography and describes in general terms the type of landscape of the global scale level.
From the perspective of Geobotany ( Plant Geography ) the Tundra is a natural type of vegetation is mainly produced under the conditions of Tundrenklimas. In their erdumspannenden ( geozonalen ) expansion, the Tundra is among the vegetation zones. In addition, comparable plant formations are found worldwide in alpine altitude level of the mountain, which can be as non- zonal vegetation types assigned to the tundra.
From the perspective of ecology the tundra [Note 2] is a global ecosystem, which is referred to as either biome or ecoregion. , Which in turn subdivide the globe for seamless Polar Zonobiom or the Polar / Subpolar ecozone.
Characteristic of the various forms of the tundra is an open, treeless landscape (mostly ) over permafrost, which is dominated depending on the type of lichens, mosses, grasses and deciduous dwarf shrubs.
"Tundra " is a loanword from the same major Russian тундра that from the Finnish Tunturi ' treeless plateau ' or was borrowed from the Kildin - Sami Tūndar.
- 2.4.1 Northern Hemisphere
- 2.4.2 Southern Hemisphere
- 5.1 Additional Classification according to plant formations
- 5.2 Classification according to biomes / ecoregions 5.2.1 WWF ecoregions
Distribution and condition
The northern ( Arctic ) vegetation of the tundra zone extends beyond the polar timberline in their maximum extent about 80 ° north latitude ( on the island of Spitsbergen ) to 55 ° ( on James Bay in Canada). The southern ( Antarctic ) zone extends from 70 ° S latitude ( in Palmer land on the Antarctic Peninsula ) to about 45 ° (on the Crozet Islands in the Indian Ocean).
Because of the few areas of land in the South hemisphere the local tundra accounts for only a tiny fraction of the entire area. "Real" Tundra can be found there is very limited at the edges of Antarctica and on some sub-Antarctic islands. The marshes south of Patagonia ( also referred to as " Magellan Tundra" ), the dwarf shrub heath of the Falkland Islands and the subantarctic meadows of Crozet and Kerguelen Islands in the Indian Ocean and Macquarie Island in the South Pacific soft with a milder climate and a lack of permafrost significantly from the typical tundra from, though the vegetation has quite tundra -like character. The assignment of the vegetation is therefore non-uniform in the literature.
The tundra poleward go into the zone of ice and cold deserts and towards the equator over (on the northern hemisphere ) in the Waldtundren. To temperate rain forest adjoins the tundra -like Moore Patagonia.
The non- zonal Bergtundren, mats and Gentiles are found worldwide in almost all high mountains above the tree line.
The largest undestroyed tundras of Earth lie in the Nunavut Territory and northern Labrador in Canada. But even in the far north of Eurasia are still few significant areas.
Without the influence of the people today would be about 5% of the terrestrial land surface tundra. In fact, the beginning of the third millennium, over 60 % of them in a largely unaffected, natural state. These areas are virtually uninhabited. Around 20 % are still affected to nature and relatively small. These areas are, however, highly fragmented and mostly are consistently changing (either by a steady conversion to farmland or by overexploitation ). With less than 20% the original vegetation cover has been changed extensively and overprinted by anthropogenic landscapes. In these areas, natural tundra landscapes are more than still to be found in small relics. [Note 3]
Characteristics
The Tundra is the result of a high selection pressure by hostile environmental conditions: Plant growth is mainly influenced by the extreme climatic conditions, and (usually ) by the permafrost. In the summer it is due to the waterlogging on frozen ground to very large temporary wetlands. This interplay of frost and moisture is also the cause for the various Moore and soil structures in the tundra landscapes. The plants of the tundra are characterized by low growth forms and great hardiness. Inventory -building plants are mosses and lichens, grasses, alpine herbs and deciduous dwarf shrubs. The branches of these shrubs often remain close to the ground ( espalier growth), the rougher is the microclimate at their location.
Climatic conditions
The tundra of the Earth lie in the sub-polar climate zone and are therefore usually characterized by very cold climates with long, cold winters and short, cool summers. In the coldest month, the average temperatures drop lower than -17 to -40 ° C. In Tierra del Fuego and Patagonia in freezing temperatures stay close, while they can also fall well below -40 ° C in the Bergtundren Siberia. In the "real" tundra is eight to eleven months snow. The warmest month is between -6 to 6 ° C in the polar tundra and well above the freezing point up to 16 ° C in the Bergtundren warmer latitudes. Yet even at high latitudes maximum temperatures of 25 ° C are possible. 's long-standing average temperature is in the Polartundren at ± 0 to -18 ° C on average, while it can vary up to 7 ° C and down to -22 ° C in the other areas. for the polar tundra also is added one aggravating for plant growth, very little sunlight, which is however compensated by the midnight sun, partly in midsummer.
With average values below 200 to 600 mm, the annual totals of precipitation are low to moderate. In the oceanic mountain ranges, values in excess of 1500 mm can be measured. Since they mainly fall as snow, the air is also called nival. The long period of frost and low temperatures lead to a low evaporation rate, so that the climatic water balance on the ground despite the low rainfall vollhumid (very humid) is.
The growing season is short to very short with 30-90 days. This result, however, that the heyday of many plants, which takes place elsewhere at different times, in the tundra arrives at the same time.
After the effective climate classification of Köppen / Geiger is referred to in the aforementioned conditions the so-called tundra ( symbol: ET).
More Features
In the tundras come on rock and sand in the first place CryoSol mineral soils that have arisen under permafrost. Organic Histosol floors from Moostorfen can be used anywhere where tundra bogs have developed. To a far lesser extent also to see Alaska and northern Europe Bergtundren flat ground, Leptosols on rock. [Note 4] It falls to very little leaf litter and the decomposition proceeds very slowly. This is the cause of a massive accumulation ( accumulation ) of raw humus in the flat tundra and for very large, rather uniform ecosystems. On shallow slopes, it also often result in the flow of the soil ( solifluction ).
Pronounced typical of the highly polar tundra landscapes is the restless ground relief that is often characterized by peaks and troughs or network-or ring- like arrangement of walls. These are either polar mire types ( Aapamoore, polygon Moore ) to palsas or Pingos or in drier areas of so-called frost -patterned ground. In essence, the leads up and defrost the soil above the permafrost to these unusual structures.
Through the above-mentioned abiotic factors include the existing amount of biomass is very low (25-30 t / ha of dry matter). Per year occur five to six tonnes / ha new.
Flora
Northern Hemisphere
Only 0.4 % of all vascular plants on earth live in the Arctic. In most areas, all vegetation is (partly to about 90%) made less than 10 species. In addition, the distribution of almost all living species there is not restricted to the tundra. The plant density and diversity decreases poleward. The following plants are typical of the tundra:
Mosses, lichens; large area Sedges, grasses significantly less; Club mosses, dwarf birch, plumbago plants, ferns, Germer plants, Bellflower Family, Ranunculaceae, heather plants, buckwheat family, Asteraceae, Brassicaceae, Poppy Family, Onagraceae, Pink Family, Boraginaceae, rose plants, horsetails, Fabaceae, Broomrapes, Saxifragaceae, water hose plants, plantain plants, shrub -like and dwarf willow family.
Southern Hemisphere
Before man einschleppte a handful of neophytes, grew up in and around the Antarctic only two flowering plants: the Antarctic hairgrass ( Deschampsia antarctica) and Antarctic Perlwurz Dianthus ( Colobanthus quitensis ). By far the largest part of the Antarctic tundra is formed of mosses and lichens. The other areas of the sub-Antarctic tundra (especially fire, Falkland Islands, South Georgia, Kerguelen, Crozet Islands ) have significantly less dwarf shrubs and overall a much lower species diversity than the sub - arctic tundra.
Fauna
Northern Hemisphere
The following mammals are typical inhabitants of the polar tundra: polar bear, musk ox, arctic fox and arctic wolf. Until the Waldtundren common are (Russian ) Tundra Wolf, Arctic hare and mountain hare. From the tundra to the boreal forests following mammals are used: Lemming, Brown Bear, different subspecies of the wolf ( Mackenzie Wolf, Eurasian Wolf), wolverine, reindeer and North American caribou. Typical of the tundra and upland grasslands of the mountains of Central Asia are the Yak and the snow leopard.
Typical tundra birds: ducks, hawks, geese, mergansers, plovers, ravens, herons, terns, gulls and skuas, rough-legged buzzard, snow bunting, snowy owl, ptarmigan, Lapland Bunting, Golden Eagle, Ruddy Turnstone, beach skiers, divers kinds, different bird families: grebes ( Podicipedidae ), loons ( Gaviidae ), Tundra swan
Southern Hemisphere
The fauna of the sub-Antarctic tundra is also significantly poorer in species than the Arctic. All major land-living animals of the Antarctic birds, especially penguins, petrels and Sheathbills. Only in the Magellanic tundra of Tierra del Fuego a few mammals such as the guanaco, the Andean jackal or comb rats occur. In the Falkland Islands, lived a single native land mammal of the Falkland fox, which was eradicated in the 19th century. In many sub-Antarctic islands, inter alia, rabbits, rats, dogs and cats have been introduced that do great harm in some cases the local wildlife. Was deliberately settled the reindeer in South Georgia, the Kerguelen Islands and Tierra del Fuego. The approximately 3000 animals counted population in Georgia is 2011 to 2015 again completely eradicated to prevent further damage to the sensitive tundra vegetation.
Indigenous residents
The polar and subpolar regions are among the most sparsely populated landscapes in the world, although the man already penetrated during the last glaciation in the Arctic. In the remaining tundra close to nature still live indigenous peoples whose lives have been shaped by the peculiarities of their country since time immemorial and are still dependent largely intact ecological conditions of their ancestral home today. Therefore, the following selection takes into account only those nations that have at least some segments of the population have not yet fully adopted the modern Western culture, whose farming practices are predominantly extensive and traditionally a lasting impact and where the cultural identity still a large - often spiritually anchored - connectedness with their natural habitat contains.
However, this should not obscure the fact that it has already changed significantly altered dependencies by the influence of western lifestyle or by different assimilation policy and by decreasing traditional knowledge, the original " natural " way of life of all these people by increasing mechanization, ! While there are many promising approaches to preserve or revive the traditions. However, this relates mostly to language, material culture, tradition or religion. Only in a few cases, these efforts have a cultural ecological background to promote the preservation of traditional farming practices in the tundra.
The original inhabitants of the Eurasian tundra are (from west to east) the Sámi the Fennoscandian Fell areas Nenets, Nganasans, Evenki - all of which are expected to cultural complex "Siberia", as well as the Yukagirs, Chukchi and Koryak the Cultural Center " paleo- Siberia " form. The North Eurasian Tundrenvölker were formerly mostly reindeer nomads. Even today plays reindeer husbandry in most of these peoples a more or less important role. The Nenets have so far preserve their traditional way of life best adapted.
The indigenous people of the great tundras of North America and Greenland, the Inuit peoples ( cultural complex " Arctic " ), some of today from the hunt - especially on marine mammals -. Living in the Bergtundren Alaska and Canada also hunt some Athabascan Indian tribes, especially the Kutchin who continue to live primarily on caribou. the residential area of this strain, however, lies in the forest tundra. For the majority of these ethnic groups hunting and gathering is only a sideline.
Use, development, threat and conservation
Agricultural cultivation is in the tundra not possible because of the climate. Since time immemorial, the large-scale use is therefore limited to the mobile reindeer pastoralism: Previously exclusively nomadic, semi-nomadic and often today using modern methods. Especially in Northern Europe, but also in parts of northern Russia, the proportion of reindeer husbandry in subsistence farming goes in favor of market-oriented livestock production declining steadily. The resulting economic competition often leads to an increase of the herds with the risk of overgrazing. Usually one to seven reindeer on a square kilometer of the border, but which is often exceeded today.
Among the Tundra soils are rich mineral resources, their promotion apart from oil and natural gas, given the huge size of the areas can be referred to as " selective ". The gas and oil production - for example, on the coast Nordalaskas ( Prudhoe Bay Oil field) or in Northern Siberia ( Urengoy gas field ) - is, however, associated with large-scale disturbances and widespread risks to sensitive ecosystems. Soils and vegetation are so sensitive that already seemingly minor injuries due to climatic conditions in the course of time more and more mint (so-called thermokarst ).
Throughout the Antarctic may provisionally take place no resource extraction in the framework of the " World Park Antarctica " until 2048.
The global air pollution has resulted in some tundra to the acidification of waters and damage the sensitive lichens, which are a major food source for many animals. The thinning of the ozone layer caused by humans leads to increased ultraviolet radiation, which in turn can lead to direct damage to plants and animals.
The greatest threat to the tundra resulting from global warming, which is located in the high latitudes of the North, well above the average. The tundra is overgrown with bushes and finally - albeit with a substantial delay - become forest, so this vegetation type along with its typical inhabitants of a day almost entirely concealed.
Even today, the thawing of permafrost causes serious damage to the environment, but also to roads and buildings. While large amounts of methane may be released over time that might accelerate the heating again drastically. Increasingly, one can observe that the reindeer herds suffering from the consequences of global warming. Warm weather periods in the summer, leading to a weakened immune system, it is still the lesser problem. Thaw in winter leads to that then a layer of ice on the vegetation forms, which greatly complicates the animals access to their food.
The species diversity ( and beyond biodiversity) of the tundra is very low ( 600-1000 species per ha).
According to the IUCN approximately 15 % of the total were 2003 protection. Of these, in turn, accounts for about 74 % in North America.
Referred to in the infobox exemplary large protected areas each contain a maximum share of the vegetation type tundra. Moreover, it is only to areas where the preservation ( or restoration ) of a prospective natural state as possible is paramount and that can be viewed by international standards as strictly protected.
Subdivision
The global vegetation type Tundra must be seen as an umbrella term for a variety of small plant formations, biomes and ecoregions, which can be divided into a different number of steps further down to the level of biotopes:
Further classification according to plant formations
Find similar appearances - and therefore essentially without consideration of the specific types Inventares -, the tundra can further subdivide as follows: (This classification is based on the names of Josef Schmithüsen )
- Highly polar lichen and moss tundra - 10 to 80% of vegetation cover Lichen tundra - occupied predominantly sandy soils and loves dry locations
- Moss tundra - occurs on moist soils
- ( Arctic ) dwarf shrub tundra
- Sub-Antarctic cushion hard formations - the West Antarctic Islands
- Tundra Moor - from mosses, cotton grass and sedges consisting
- Meadow tundra - with Schmielen, fescue grasses and riding; in some places mix crowberry and bearberry and dwarf birch among the grasses; Meadows or tundra grass grows mainly on loamy soils in the oceanic version of the sub-polar climate
- Mountain tundra - Fell Swedish, Norwegian Fjell, Fjall Icelandic, Finnish Tunturi is called the mountain tundra in northern Europe
- Alpine mats - the Wiesentundren above the tree line in the mountains
- Mountain vegetation above the tree line - mainly dwarf shrubs
- Hart and thorn -cushion mountain formations - the central Andes
- Sub-Antarctic dwarf shrub heath - mainly on the islands of the South Atlantic
- Sub-Antarctic meadows - mainly on the islands of the southern Indian Ocean
- " Magellan raised bog " - on the southernmost islands off Tierra del Fuego
Classification according to biomes / ecoregions
In the further subdivision can be accessed from the global perspective on the scale level of the regions. At this level priority entire ecosystems are considered and not only the vegetation. One speaks of the biomes and / or ecoregions.
WWF ecoregions
The WWF U.S. has made an exemplary global classification by ecoregions. The boundaries of these regions are based on a combination of different biogeographic concepts. They are particularly well suited to the purposes and objectives of nature conservation. [Note 5]
The term tundra is used by the WWF - categories for one of 14 main biomes ( "Major habitat types" ), which roughly corresponds to the polar Zonobiom. For the purposes of this main biomes the cold desert the azonal Bergtundren but is expected to tundra, no. 37 ecoregions ( " Ecoregions " ) subdivide this major biome.
Gallery
Mountain tundra in the Arctic Alaska
Muskoxen in the autumn tundra of Alaska
Landscape in the Northwest Territories of Canada
Aerial view of tundra in Kivalliq, Nunavut
Abandoned huts in ( Ukkusiksalik National Park ), Nunavut
On Nachvak Fjord in the Torngat Mountains National Park Labrador
Tundra at Sydkap, Kangertittivaq (East Greenland)
Meadow tundra at Iceland's Landmannalaugar
Svalbard reindeer on the island of the same name
Moss tundra on Franz Josef Land
Mountain tundra ( Fell ) in Northern Sweden
Mountain tundra in the Urals
Tundra landscape in the European part of Russia
In the lower reaches of the Kara River in Russia
Tundra at Dudinka the Yenisei in Siberia
Frost pattern ground in the alpine zone of the Swiss Alps
Tundrenartige mountain vegetation in the Himalayas
Antarctic tundra similar Moor on the islands south of Tierra del Fuego
Sub-Antarctic tundra meadows and on the Kerguelen
Purple saxifrage
Lapland Alpenrose
Mammoth bones from the tundra at Ust- port on the Yenisei
Kittiwakes on the cliffs of Cape Graham Moore ( southeast tip of Bylot Island to Baffin Bay)
Two Magellanic Penguins in the Falkland Islands
King Penguins in the südgeorgischen meadow tundra
CO ² - gassing experiment the Science Station Abisko ( Northern Sweden ) in a tundra bog at Tornetrask