49 Fun Facts About Tundra

What prevents trees from growing in a tundra?

Cold and a very short summer keep trees out: the growing season lasts only about 50 to 60 days, so only dwarf shrubs, sedges, grasses, mosses and lichens survive.

From which language does the word 'tundra' come?

English borrowed 'tundra' from Russian, which took it from the Kildin Sámi word tūndâr, meaning a treeless upland or marshy plain.

Which three regions and types of tundra are recognised?

The three recognised types are Arctic, Alpine and Antarctic tundra; alpine tundra forms on high mountains at any latitude, even near the equator.

What is the name for the boundary between tundra and forest?

Tree line (or timberline) is the boundary beyond which cold and wind prevent trees from growing; the open tundra lies past it.

Which lichen species, nicknamed 'reindeer moss', is a staple winter food of tundra herds?

Cladonia rangiferina, the reindeer lichen or 'reindeer moss', is a pale, branching fruticose lichen that reindeer dig out from under the snow as their main winter food.

Arctic tundra lies north of which forest belt?

The taiga, or boreal forest, is the conifer belt lying south of the Arctic tundra, which stretches across northern Russia, Canada and Alaska.

What grows in permafrost cracks each winter to build the tundra's large polygon networks?

Ice wedges form when intense cold cracks the permafrost and spring meltwater refreezes in the fissure; repeated for centuries, they outline the polygons seen from the air across Arctic lowlands.

Roughly how much precipitation does Arctic tundra receive per year, qualifying it as a polar desert?

Arctic tundra receives only about 150-250 mm of precipitation a year, mostly as snow, yet evaporation is so low that the ground turns to marsh and bog in summer.

How many species of land mammals live in the tundra, according to standard biodiversity counts?

Only 48 species of land mammals are found across the tundra, though millions of migratory birds arrive each summer to nest in its marshes.

Which class of cold-blooded animals is almost entirely absent from the tundra?

The mosquito, by contrast, is one of its most notorious residents.

Labrador tea, a notable Arctic tundra plant, belongs to which genus?

Labrador tea (Rhododendron groenlandicum, once placed in Ledum) now sits in the genus Rhododendron; blueberry and crowberry grow alongside it on the tundra.

Which largely tundra region of Siberia has produced most of Russia's natural gas?

Yamalo-Nenets Autonomous Okrug, home to giant fields such as Urengoy and Yamburg, has produced the bulk of Russia's natural gas for decades.

Under the Köppen climate system, what code denotes a tundra climate?

ET is the Köppen code for tundra: at least one month averages above freezing, but no month is warm enough for trees, while EF denotes a permanent ice cap.

Above what monthly average temperature does a climate stop counting as tundra under the Köppen system?

Under Köppen, a tundra climate requires every month to average below 10 °C; once the warmest month reaches 10 °C it counts as subarctic or temperate instead, roughly the poleward limit of trees.

How many flowering plant species are native to the Antarctic continent?

Two flowering plants are native to Antarctica: Antarctic hair grass and Antarctic pearlwort, both confined to the milder Antarctic Peninsula and nearby islands.

Why does the Antarctic tundra lack large land mammals, unlike the Arctic?

Isolation from the other continents, with Antarctica cut off by the Southern Ocean for tens of millions of years, kept land mammals from reaching it; seals and penguins use only the shore.

What is the name for the stunted, wind-twisted forest found at the edge of alpine tundra?

Krummholz, German for 'crooked wood', names the belt of stunted, wind-twisted trees in the forest-tundra ecotone where upright growth becomes impossible.

At its upper edge, alpine tundra ends at which boundary?

The snow line is the upper limit of alpine tundra; above it, snow and ice persist right through the summer and plant cover gives way to bare rock and ice.

For how long must ground stay below 0 °C to count as permafrost?

Two years or more at or below 0 °C is the definition of permafrost; the oldest known permafrost has stayed continuously frozen for around 700,000 years.

Roughly what share of the exposed land surface of the Northern Hemisphere is underlain by permafrost?

About 15% of the Northern Hemisphere's exposed land surface is underlain by permafrost, including much of Alaska, Canada, Greenland and Siberia.

The deepest permafrost extends to greater than what depth?

The deepest permafrost, in northern Siberia, reaches more than 1,500 m down, while the shallowest is less than a metre thick.

What is the name for the seasonally thawing ground above permafrost in which plant roots can grow?

Active layer is the name for the top of the ground that thaws each summer and refreezes in winter; only there can plant roots take hold above the permafrost.

Which two large cities are the only ones in the world built on continuous permafrost?

Norilsk and Yakutsk, both in Russia, are the only large cities built on continuous permafrost; their buildings stand on piles so heat from them does not thaw the ground.

What are the large ice-cored mounds, up to 70 m high, that form in permafrost regions called?

Pingos are ice-cored hills that grow as groundwater freezes and heaves the surface upward; smaller peaty mounds called palsas form in a similar way in bogs.

Which two greenhouse gases does decomposing biomass release as permafrost thaws?

Carbon dioxide and methane escape as the biomass rots, a climate feedback loop, though not one thought large enough to cause runaway warming.

The muskox is most closely related to which animals?

Sheep and goats are the muskox's nearest kin, hence its genus name Ovibos, Latin for 'sheep-ox'.

What does the muskox's Inuktitut name, umingmak, mean?

The bearded one is the meaning of umingmak, a reference to the muskox's long, shaggy guard hairs; the English name refers instead to the strong odour of rutting males.

Muskoxen introduced to which European country wandered over the border to found a small herd in Sweden?

Norway received muskoxen from Greenland in the Dovrefjell mountains; in 1971 a few wandered across the border into Sweden's Härjedalen and founded a small herd there.

The Arctic fox's tail makes up roughly what fraction of its total length?

One third of the Arctic fox's total length is tail: about 30 cm of brush on a 55 cm body, which the fox curls over its face for warmth when sleeping in snow.

What is the maximum litter size recorded for the Arctic fox, the largest in the order Carnivora?

A litter of 25 is the record for the Arctic fox, the largest in the order Carnivora; litter sizes track the lemming population, which peaks every three to five years.

The blue colour morph of the Arctic fox is most common in which country?

Iceland is where the blue morph dominates, making up the majority of the island's Arctic foxes, whereas the white morph prevails almost everywhere else.

Reindeer are unique among deer for what reason?

Females may grow antlers only in reindeer, the one deer species where both sexes are antlered; it is also the only deer semi-domesticated on a large scale.

What is the wild Rangifer tarandus called in North American English?

Caribou is the North American name for wild Rangifer tarandus, while the domesticated animals, introduced to Alaska from Siberia in the 1890s, are called reindeer.

Which Siberian tundra reindeer herd has ranged between 400,000 and a million animals?

The Taimyr herd, migrating across central Siberia's Arctic peninsula, has varied between 400,000 and a million animals, for decades the largest wild reindeer herd on Earth.

Which is the smallest subspecies of reindeer?

Svalbard reindeer are the smallest subspecies: short-legged, stocky and isolated on their high-Arctic archipelago, whereas Osborn's, of British Columbia, is the largest.

Lemmings, voles and muskrats together make up which rodent subfamily?

Arvicolinae, the vole subfamily of the Cricetidae, includes lemmings, voles and muskrats; its members are the primary prey for most Arctic carnivores.

Which 1958 Disney film faked footage of lemmings leaping off a cliff, cementing the mass-suicide myth?

White Wilderness staged the scene: the crew herded lemmings off a cliff using a turntable, as a 1982 CBC investigation revealed, yet the film won the Academy Award for Documentary Feature.

Which predator's numbers may drive lemming population cycles more than the lemmings themselves?

The stoat, a specialist hunter of lemmings, was found in a Greenland study to drive the four-year lemming cycle, its own numbers lagging a year behind its prey's.

What is unusual about the snowy owl's daily habits compared with most owls?

It is often active by day, unlike most owls, because it breeds in the Arctic summer's near-constant daylight; its breeding success tracks the abundance of tundra lemmings.

Into which genus, shared with the eagle-owls, did DNA studies move the snowy owl?

Bubo is the genus the snowy owl joined after mitochondrial DNA showed it is closest to the horned and eagle-owls; it had long sat alone in the genus Nyctea.

The snowy owl is the only owl with what characteristic?

Mainly white plumage is unique to the snowy owl; males are purer white while females carry more dark brown flecks.

How fast can an Arctic hare run?

An Arctic hare can reach 60 km/h in a sprint; fat makes up close to 20% of its body and it digs holes under the snow to keep warm.

The ptarmigan's genus name Lagopus means 'hare-foot' in Greek, referring to what?

Its feathered feet and toes, insulated like a hare's furry paws, earned the ptarmigan the Greek-derived genus name Lagopus, 'hare-foot'.

Where does the silent 'p' at the start of 'ptarmigan' come from?

A false belief in a Greek origin added the 'p': early naturalists assumed a link to Greek pteron, 'wing', though the name is really Scottish Gaelic tàrmachan, 'croaker'.

What is the pale colour of the ptarmigan's winter plumage useful for?

Blending into snow is the point of the white winter coat, which even extends to the flight feathers, a rarity since melanin makes feathers stronger and most white birds keep dark wingtips.

How large an area of Alaskan tundra burned in a single 2007 wildfire north of the Brooks Range?

About 1,039 km² of tundra burned in the 2007 Anaktuvuk River fire on Alaska's North Slope, sparked by lightning in an unusually warm, dry summer; such fires both result from and add to warming.

Research in Alaska found tundra wildfires typically return to a site every how many years?

150 to 200 years is the typical fire return interval, with drier lowland areas burning more often than wetter highlands.

Roughly how many species of vascular plants grow in the tundra?

1,700 species of vascular plants grow across the tundra, a low total for so vast a biome, yet millions of birds migrate to its marshes every summer to breed.

Which penguin species is endemic to the Antipodes Subantarctic Islands tundra ecoregion?

Royal penguin colonies exist only on Macquarie Island and its outlying islets, placing the species entirely inside the Antipodes Subantarctic Islands ecoregion, which also hosts the Antipodean albatross.