What is the Tundra?
The tundra is a cold, treeless biome where the ground is frozen for most of the year. It gets very little precipitation (less than 10 inches per year — making it technically a cold desert), and the growing season is extremely short — just 6 to 10 weeks in summer. Despite these harsh conditions, hundreds of plant and animal species have adapted to thrive here.
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Arctic Tundra
Northern Hemisphere
- Circles the Arctic Ocean across northern Canada, Alaska, Russia, and Scandinavia
- In summer, the sun never fully sets — providing 24 hours of daylight
- In winter, temperatures drop to -50°F and the sun barely rises above the horizon
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Alpine Tundra
High Altitude
- Found on high mountains above the treeline — where it's too cold and windy for trees to grow
- Exists on every continent including the tropics — the Andes, Himalayas, Rockies, and Alps
- Has similar conditions to Arctic tundra but without the permafrost layer
Permafrost: The Frozen Underground
Permafrost is a layer of permanently frozen soil beneath the tundra surface. It can extend hundreds of feet deep and has been frozen for thousands of years. In summer, only the top few inches (called the "active layer") thaw — allowing plants to grow. Permafrost acts like a giant freezer, locking away carbon and ancient organic matter.
Tundra Animals
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Polar Bear
Apex Predator
- Roam the sea ice hunting seals — their primary food source
- Thick fur and 4 inches of blubber protect them from Arctic cold
- Mothers den in snowdrifts to give birth during the coldest winter months
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Musk Ox
Cold Survivor
- Have two layers of fur — a coarse outer layer and a soft inner layer called qiviut
- Form a defensive circle with horns outward when threatened by wolves
- Use their hooves to dig through snow to reach the frozen plants beneath
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Arctic Hare
Speed & Camouflage
- Coat turns brilliant white in winter and gray-brown in summer for camouflage
- Can run up to 40 mph — one of the fastest animals in the Arctic
- Thick fur and compact body shape minimize heat loss in bitter cold
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Lemming
Keystone Species
- Stay active all winter under the snow in tunnels — they don't hibernate
- Population boom-and-bust cycles affect the entire tundra food web
- A critical food source for foxes, owls, and other Arctic predators
Tundra Plants
Tundra plants grow low to the ground to avoid the wind, have shallow roots (permafrost blocks deep growth), and complete their entire life cycle during the brief summer.
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Arctic Moss
Most Common Plant
- Grows underwater in Arctic lakes and bogs — stores nutrients for the short summer
- Grows extremely slowly — just a fraction of an inch per year
- Provides insulation and nesting material for many Arctic birds
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Lichen
Fungi + Algae
- Not a single plant — a partnership between fungi and algae living together
- Can survive being completely frozen and revive when thawed
- A critical food source for reindeer and caribou in winter
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Dwarf Willow
World's Smallest Tree
- The world's smallest tree — grows just 1–2 inches tall to stay below the wind
- Roots spread wide and shallow across the active layer above permafrost
- Provides food for Arctic hares, musk oxen, and ptarmigans
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Cotton Grass
Summer Bloomer
- Distinctive white fluffy seed heads sway in the wind across the tundra in summer
- Can bloom and set seed in just a few weeks during the short growing season
- Grows in wet, boggy areas above permafrost across the Arctic
🌡️ Tundra and Climate Change
The tundra is one of the biomes most affected by climate change. As temperatures rise, permafrost thaws — releasing massive amounts of carbon dioxide and methane that have been locked away for thousands of years. This creates a feedback loop: more greenhouse gases cause more warming, which thaws more permafrost. Scientists consider this one of the most serious climate change risks on Earth.
Tundra Facts
-50°F
Minimum winter temperature in the Arctic tundra — cold enough to freeze exposed skin instantly
1,500 ft
Maximum depth of permafrost in Siberia — frozen ground that has been frozen for over 10,000 years
6–10 wks
Length of the tundra growing season — the brief window when the sun warms the surface enough for plants
20%
of Earth's land surface is tundra — covering the far north and high mountain peaks worldwide
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