tundra

(redirected from Arctic tundra)
Also found in: Dictionary, Thesaurus, Medical.
Related to Arctic tundra: alpine tundra

tundra

(tŭn`drə), treeless plains of N North America and N Eurasia, lying principally along the Arctic Circle, on the coasts and islands of the Arctic Ocean, and to the north of the coniferous forest belt. The tundra area is widest in N Siberia on the Kara Sea and reaches as far south as 60° N at the neck of the Kamchatka peninsula. Although sometimes called the Arctic steppe and situated mainly within the Arctic Circle, it reaches southward into the Scandinavian, Timan, and Ural mts. For most of the year the mean monthly temperature is below the freezing point; winters are long and severe. The summers are short and relatively warm, but even in July the mean monthly temperature does not rise above 50°F; (10°C;). Although high temperatures may be reached during a summer day, the subsoil is perpetually frozen. During summer, sedges, mosses, and lichens appear in abundance, along with some flowering plants. Among the few large animal species found in the tundra are the caribou, the arctic fox, the snowshoe rabbit, and occasionally the polar bear. Precipitation is spread evenly during the year and is slight, varying from 8 to 12 in. (20–30 cm). Evaporation is low, and much of the flat ground in areas of poor drainage becomes swampy during the summer months. Because there are very few species of flora and fauna, the destruction of the tundra is a simple process. The elimination of a single species or the disruption of the permanently frozen subsoil (permafrost) may severely damage this fragile ecosystem. Russia's tundra supports a small human population mostly consisting of the Nensty (Samoyedes) and the Komi. Eskimos inhabit the North American tundra.

Bibliography

See E. Bowen, Grasslands and Tundra (1985).

The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/

Tundra

An area supporting some vegetation beyond the northern limit of trees, between the upper limit of trees and the lower limit of perennial snow on mountains, and on the fringes of the Antarctic continent and its neighboring islands. The term is of Lapp or Russian origin, signifying treeless plains of northern regions. Biologists, and particularly plant ecologists, sometimes use the term tundra in the sense of the vegetation of the tundra landscape. Tundra has distinctive characteristics as a kind of landscape and as a biotic community, but these are expressed with great differences according to the geographic region.

Characteristically tundra has gentle topographic relief, and the cover consists of perennial plants a few inches to a few feet or a little more in height. The general appearance during the growing season is that of a grassy sward in the wetter areas, a matted spongy turf on mesic sites, and a thin or sparsely tufted lawn or lichen heath on dry sites. In winter, snow mantles most of the surface. By far, most tundra occurs where the mean annual temperature is below the freezing point of water, and perennial frost (permafrost) accumulates in the ground below the depth of annual thaw and to depths at least as great as 1600 ft (500 m).

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Tundra

 

a type of vegetation characteristic of the arctic region, bounded on the south by forests and on the north by arctic wastelands. The tundra is associated with a cold climate and with cold soils, under which lies, as a rule, permafrost. Mountain tundras are encountered in Scandinavia, the Ural region, Siberia, Alaska, and northern Canada.

Perennial plants predominate in the tundra: mosses, lichens, herbaceous hemicryptophytes and chamaephytes (cespitóse, rhi-zomatous, cushion, semicushion, rosette, and semirosette plants), deciduous chamaephytic dwarf shrubs (for example, Salix polaris), dwarf evergreen shrubs (Empetrum hermaphrodi-tum and Ledum decumbens), and deciduous low-growing nano-phanerophytic shrubs (Betula nana, Betula exilis, and Salix lanata). Annuals (Koenigia islándica) and bulbous geophytes (Lloydia serótina) are rare. The tundra is characterized by poly-dominance (there are several dominant species belonging to various life-forms in each plant community) and mosaic structure. The latter is a result of the cryogenic microtopography, represented by hillocks and small hollows. Often the dense plant cover is interrupted by spots of bare ground.

Subarctic tundras (northern and southern) occupy a large part of the tundra zone of the northern hemisphere. At their northern boundaries they are replaced by arctic tundras, where there are no scrub thickets but where arcto-alpine shrubs (Salix polaris, Dryas octopetala), mosses, lichens, and grasses play a major role. In the eastern part of European USSR and in Western Siberia, southern tundras are characterized by large dwarf-birch tundras, with a marked stratum of dwarf birch (Betula nana) and an admixture of willow. Toward the north, the stratum of shrubs becomes sparse, and the shrubs decrease in height. Mosses, dwarf shrubs, trailing shrubs, and sedge (Carex ensifolia ssp. arctisibirica) are common, and there is a significant admixture of Dryas. In Eastern Siberia, where the climate is more continental, the large dwarf-birch tundras are replaced by small dwarf-birch tundras, with a different species of birch (Betula exilis) predominating. In Chukotka and Alaska hummock tundras with cotton grass (Eriophorum vaginatum) and sedge (Carex lugens) predominate; there are hypnum and sphagnum mosses, with an admixture of low shrubs, which diminishes to the north. In the subarctic tundras of Canada and Greenland there is a predominance of eri-coid shrubs (for example, Vaccinium uliginosum ssp. microphyl-lum and Cassiope tetrágono).

Tundras serve as pastures for reindeer, hunting lands, and sources of berries (cloudberry, bog whortleberry, crowberry). It is possible to raise vegetables in the open ground, and methods have been developed for creating high-yield meadows on tundra sites.

REFERENCES

Gorodkov, B. N. Rastitel’nost’ tundrovoi zony SSSR. Moscow-Leningrad, 1935.
Sochava, V. B., and B. N. Gorodkov. “Arkticheskie pustyni i tun-dry.” In Rastitel’nyi pokrov SSSR: Poiasnitel’nyi tekst k “Geobo-tanicheskoi karte SSSR” (m. 1:4,000,000), [part] 1. Moscow-Leningrad, 1956.
Tikhomirov, B. A. “Dinamicheskie iavleniia v rastitel’nosti piatnis-tykhtundr Arktiki.” Botanicheskii zhurnal, 1957, vol. 42, no. 11.
Aleksandrova, V. D. “Printsipy zonal’nogo deleniia rastitel’nosti Arktiki.” Botanicheskii zhurnal, 1971, vol. 56, no. 1.
Khantimer, I. S. Sel’skokhoziaistvennoe osvoenie tundry. Leningrad, 1974.
Iurtsev, B. A. Problemy botanicheskoi geografii Severo-Vostochnoi Azii. Leningrad, 1974.
Knapp, R. Die Vegetation von Nord-und Mittelamerika und der Hawaii-Inseln. Jena, 1965.
Walter, H. Die Vegetation der Erde in ôkologischer Betrachtung, vol. 2: Die gemassigten undarktischen Zonen. Jena, 1968.

V. D. ALEKSANDROVA

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

tundra

[′tən·drə]
(ecology)
An area supporting some vegetation between the northern upper limit of trees and the lower limit of perennial snow on mountains, and on the fringes of the Antarctic continent and its neighboring islands. Also known as cold desert.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

tundra

a. a vast treeless zone lying between the ice cap and the timberline of North America and Eurasia and having a permanently frozen subsoil
b. (as modifier): tundra vegetation
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
The seasonal course of aboveground production and chlorophyll distribution in a wet arctic tundra at Barrow, Alaska.
This volume also deals with a zonal biome, the most northerly of all biomes, the Arctic tundra. The circumpolar maps used to show the location of the phenomena described in this part of the volume clearly show the tundra biome's main feature, its location around the pole.
However, we are not aware of studies that have directly linked the establishment of boreal predators in Low Arctic tundra to specific weather events.
The vast open wildernesses of African savannah, Asian steppe, Arctic tundra and North American prairie are the great plains of the planet.
It's the second half of the show and Moon is in the Arctic Tundra looking for the ruby of Kukunda to revive Shaman Naboo back to life after he was killed by The Hitcher.
"They can be found in Arctic tundra, forests and mountains in Russia, Northern China, Canada, Alaska and Scandinavia.
Locals in Dingle have been taking a gander at the Red-breasted bird, who usually only nests in the Arctic tundra.
This massive volume is global in its scope, featuring 9,850 species of birds that live in locales as extreme as the icy arctic tundra and teeming tropical rain forests.
From the desert and rainforest to the arctic tundra and urban survival, Chris shows how to keep a clear head and develop mental toughness by setting goals and addressing the threats to life.
So it was with some excitement that I dipped into his most recent offering, a coffee-table book full of photographs and explanations on how to survive in six of the most hostile environments on the planet, from the Arctic tundra of Baffin Island to the dense jungles of Indonesia.
The areas of wilderness comprise diverse habitats on every continent, from desolate Arctic tundra to dense Congolese jungle.
In the Arctic tundra, however, several lines of evidence have forced us to question the importance of N mineralization in supplying N to plants: (1) in these soils, there is often net immobilization of N during the growing season (Chapin et al.