Tundra is cold, treeless land where the growing season is too short and cool for trees. In the Arctic it usually lies over permafrost and is covered with low shrubs, grasses, sedges, mosses and lichens.

Why don't trees grow on the tundra?

Summers are too short and cold for trees to grow and reproduce, strong winds dry and damage anything that sticks up, and the frozen ground below limits roots and drainage.

Permafrost is ground that stays frozen for at least two years in a row. Only the top layer thaws in summer, and the frozen ground below can be hundreds of metres thick.

Which animals live on the Svalbard tundra?

The native land mammals are Svalbard reindeer, Arctic foxes and polar bears. Many birds, including geese, waders, terns and gulls, come to breed in summer, and the rock ptarmigan stays all year.

Is the tundra changing?

Yes. The Arctic is warming several times faster than the global average, which is thawing permafrost, shrinking sea ice and glaciers, and changing which plants and animals can thrive.

A treeless land of permafrost, moss and reindeer on the edge of the Arctic Ocean

Arctic tundra

3D landscape · Adventdalen, Svalbard, Norway

Land here and explore →

The Arctic tundra rings the Arctic Ocean across northern Russia, Scandinavia, Greenland, Canada and Alaska, north of the line where trees can no longer grow. In this app you can land in Adventdalen, a broad valley on Svalbard near the town of Longyearbyen, and explore it in interactive 3D: a braided river plain, scree slopes and flat-topped mountains, with mats of dwarf willow, cushions of moss campion, tufts of cotton grass and pale reindeer lichen underfoot.

Svalbard reindeer graze the slopes, Arctic foxes trot across the valley, gulls drift over the fjord and, far off, a polar bear may be walking the shore. Life here has only a few weeks of warmth each year, and every plant and animal is built to make the most of them.

Key facts

Model setting: Adventdalen, Svalbard (Norway)A wide valley of river gravel, tundra and flat-topped mountains near Longyearbyen, about 78°N
What makes it tundra: Too cold for treesSummers are too short and cool for trees; the ground below is permanently frozen
Permafrost: Ground frozen for 2+ yearsOn Svalbard it can reach down hundreds of metres; only the top metre or so thaws in summer
Midnight sun: About 19 April – 23 AugustAt Longyearbyen the Sun does not set for roughly four months
Polar night: About late October – mid FebruaryThe Sun stays below the horizon for around three and a half months
Typical plants: Dwarf willow, mountain avens, moss campion, cotton grassMost grow only a few centimetres tall, hugging the ground for warmth
Svalbard reindeer: A small, short-legged subspeciesFound only on Svalbard; they live without predators other than the occasional polar bear
Polar bears: Roam the whole archipelagoSvalbard and the Barents Sea hold an estimated few thousand bears; people outside settlements must be prepared for them
Warming: Among the fastest on EarthSvalbard has warmed several times faster than the global average in recent decades

Where tundra is found

Arctic tundra covers a broad belt around the Arctic Ocean: the northern coasts of Russia and Siberia, northern Scandinavia, Iceland's highlands, Greenland's ice-free margins, and Arctic Canada and Alaska. Its southern edge is the tree line, where the boreal forest thins out into scattered stunted trees and then open land. Similar treeless landscapes high on mountains are called alpine tundra.

Svalbard is a Norwegian archipelago roughly halfway between mainland Norway and the North Pole. About 60 percent of it is covered by glaciers, and the tundra lies in the ice-free valleys and along the coasts. Adventdalen, just outside Longyearbyen, is one of the most visited and studied tundra valleys in the High Arctic.

Climate: cold, dry and lit by the midnight sun

Svalbard is warmer than its latitude suggests because the last branch of the North Atlantic Current carries warm water up its west coast. Even so, the average temperature in Longyearbyen's warmest month is only around 6 to 7 °C, and winters average around −12 to −16 °C, with much colder spells. Precipitation is very low, often around 200 mm a year, so much of the High Arctic is technically a polar desert.

Light shapes the year. From late April to late August the Sun circles the sky without setting, and plants grow around the clock. From late October to mid-February it never rises at all, and the only light comes from the Moon, the stars and the aurora.

Permafrost and patterned ground

Permafrost is ground that stays at or below 0 °C for at least two years in a row. Under Svalbard's valleys it can extend tens to hundreds of metres down. Each summer only a shallow 'active layer', usually around a metre thick, thaws. Water cannot drain through the frozen ground below, so the tundra is often boggy in summer even though little rain falls.

Repeated freezing and thawing sorts stones and soil into striking shapes: polygons, circles and stripes of stones known as patterned ground. Ice wedges grow in cracks in the frozen ground, and pingos, mounds pushed up by ice beneath them, rise from some valley floors in Svalbard.

A landscape shaped by ice

Adventdalen's broad, flat floor is filled with gravel brought down by glacier rivers. These braided rivers change course every summer, and in dry, windy weather silt blown off the riverbeds can form dust clouds across the valley.

Plants that hug the ground

Tundra plants are small, slow-growing and mostly perennial. Staying low keeps them inside the thin layer of warmer, calmer air just above the ground and under protective snow in winter. Polar willow and net-leaved willow are true woody shrubs, yet they creep along the surface and rarely rise more than a few centimetres. Moss campion forms dense cushions that trap heat and covers itself with pink flowers in summer. Arctic cotton grass grows in wet hollows, its white seed heads nodding in the wind.

Mosses and lichens are everywhere. Reindeer lichens and other lichens are a key winter food for reindeer, while mosses build thick, spongy carpets around streams and bird cliffs, where droppings from seabirds fertilise surprisingly green slopes.

Animals of the Svalbard tundra

Only three land mammals are native to Svalbard: the Svalbard reindeer, the Arctic fox and the polar bear (which spends much of its life on sea ice). Svalbard reindeer are short-legged and round-bodied, with thick winter coats, and they build up fat during the brief summer to survive the long winter. Arctic foxes change from brown or grey in summer to white in winter, and they scavenge, hunt birds and raid nests along the bird cliffs.

In summer the tundra fills with migrating birds: geese, waders, Arctic terns, little auks and several kinds of gulls, including glaucous gulls. The Svalbard rock ptarmigan is the only bird that stays all year.

Polar bears near people

Polar bears are dangerous and protected. Anyone leaving Longyearbyen's settled area is expected to carry suitable protection and know how to avoid encounters. In this app the bear keeps its distance, as you should in real life.

A rapidly warming Arctic

The Arctic is warming much faster than the planet as a whole, and Svalbard is one of the fastest-warming places measured. Sea ice around the islands has shrunk, glaciers are retreating, and warmer winters bring more rain on snow. When that rain freezes into an ice crust, reindeer can struggle to reach the lichens and plants beneath.

Thawing permafrost can release carbon that has been locked in frozen soil for thousands of years, and it destabilises slopes and buildings. Svalbard's research stations, in Longyearbyen and Ny-Ålesund, are important places for tracking these changes.

Surprising facts about Arctic tundra

Much of the High Arctic gets less precipitation than many deserts, yet the ground is often soggy because permafrost stops water draining away.
Polar willow is a real tree relative, but on Svalbard it grows flat along the ground and may be only a few centimetres tall.
Svalbard reindeer are a distinct subspecies with shorter legs and smaller bodies than mainland reindeer, which helps them save heat.
Seabird colonies fertilise the slopes below them so much that those slopes are among the greenest places on Svalbard.
Freezing and thawing can sort stones into neat circles and polygons, called patterned ground.
In Longyearbyen the Sun stays above the horizon for about four months in summer and below it for about three and a half months in winter.

Frequently asked questions

What is tundra?: Tundra is cold, treeless land where the growing season is too short and cool for trees. In the Arctic it usually lies over permafrost and is covered with low shrubs, grasses, sedges, mosses and lichens.
Why don't trees grow on the tundra?: Summers are too short and cold for trees to grow and reproduce, strong winds dry and damage anything that sticks up, and the frozen ground below limits roots and drainage.
What is permafrost?: Permafrost is ground that stays frozen for at least two years in a row. Only the top layer thaws in summer, and the frozen ground below can be hundreds of metres thick.
Which animals live on the Svalbard tundra?: The native land mammals are Svalbard reindeer, Arctic foxes and polar bears. Many birds, including geese, waders, terns and gulls, come to breed in summer, and the rock ptarmigan stays all year.
Is the tundra changing?: Yes. The Arctic is warming several times faster than the global average, which is thawing permafrost, shrinking sea ice and glaciers, and changing which plants and animals can thrive.

Keep exploring

The landscapes in Ember’s Universe are procedural 3D scenes modelled on real places. The landforms, plants and light follow the real thing, but the details are generated, not mapped.

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