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Tundra Environments


The word tundra is borrowed from Russian (тундра), which borrowed it from Finnish (tunturia), which got it from a Lapp word meaning "a barren hill" or "a treeless plain," depending on what source you consult.

It refers to lands, generally lying further north than the steppes, where the sub-soils never thaw (and hence have the name "permafrost," although upper levels, called "active permafrost" soften in summer). Tundra is found around the north pole and extends south until it meets a zone of coniferous forests.

Tundras are inevitably treeless and largely rainless —rainfall is about 5 inches a year on average— but brief summer thawing of the surface often leaves them soggy in that season because the melted surface water cannot seep into the frozen layers below. The result is a swamp or bog(called a "muskeg" or "muskeg swamp" in Alaska and western Canada), made up of the water and dead vegetation, often supporting sphagnum or other mosses on the surface.

Tundra actually is land with soil, even though the permafrost never entirely thaws. Therefore it contrasts with frozen ice on the surface of the sea, which is referred to by the term "glacier" when the ice is more or less permanent (non-seasonal).

Lichens and mosses are capable of growing on tundra land, as are a few quickly growing small flowering plants in the two-month summer growing season.

This vegetation is sufficient that a tundra can support a sparse animal population, including even such large animals as caribou, musk oxen, and polar bears, as well as smaller animals like rabbits, arctic hares, wolves, voles, and lemmings (and in the summer formidable mosquitoes, midges,and flies). But the ecological balance is always precarious.

Unlike steppe land, which can sometimes be farmed, tundra land is ill-suited for most human habitation, the more so since even the vegetation that survives there is rarely edible for humans. Therefore tundra-dwelling peoples (such as the Inuit) must subsist by hunting animals able to live on the tundra vegetation plus, in coastal regions, marine resources such as seal, walrus, salmon, or whale.

With global warming, two peninsulas in the Arctic sea (Yamal and Gydansk) experienced at least 17 violent explosions between 2014 and 2020. These seem to occur when subterranean gasses from ancient decaying organic matter produce increasing pressure when decay resumes with global warming and/or as the ice sheet weakens. Alternatively, or in addition, the explosions may be caused by subterranean, ice-like methane hydrates melting to methane gas underground and and expanding. Either way, methane suddenly breaks through weakened ice layers and permafrost, leaving craters as much as 30 meters deep.

Archaeologically it is sometimes difficult to distinguish former tundra from former steppe lands in the far north, especially in previously coastal areas now below the sea, and there has been some disagreement over the years about whether Beringia, for example, provided largely a steppe or largely a tundra environment.

Click here for More About Steppe Environments.


 

 

Content Revised: 2020-09-06
Software Last Modified: 2020-06-13
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