Tundras main characteristics are that they are cold, dry, and treeless. Tundras get very little rainfall, making them technically deserts. The landscape is frozen for most of the year, followed by a short growing season. Tundras mostly lack trees but instead have low growing shrubs, grass, lichen, and moss. Tundras can also be quite windy.
Plants in the tundra have roots that are shallow and grow horizontally to avoid the permafrost. Their leaves are small and have a waxy surface prevent water loss in the dry environment. The stems are hairy which traps in heat and helps protect against the wind. The plants are usually no taller than a foot, which helps them absorb heat from the soil, and protects them from the cold and wind. Tundra plants also flower at a lower temperature than any other plant on earth, and they develop quickly to take advantage of the short summer.
There are two types of tundras, Arctic and Alpine.
Arctic tundras are found on the far Northern or Southern latitudes. In the Northern hemisphere, the Arctic tundras are above the Arctic Circle in Alaska, Canada, Russia, Greenland, Iceland, and Scandinavia. In the Southern hemisphere, Antarctica. The soil here is not very fertile. Since tundras are cold and frozen for most of the year, the ground beneath the topsoil is permanently frozen, called permafrost. The permafrost does not allow deep roots, which means any trees that could take root would have very shallow roots, and the wind can easily blow them over. There is also very little rain to support trees. This is why the arctic tundra landscape is characterized by a lack of trees.
Alpine tundras are located on top of tall mountains where overnight temperatures fall below freezing. These include the Scottish highlands, the Himalayas, the Alps, the Rift Mountains of Africa, Tibetan Plateau, the Caucasus Mountains, the Carpathian and Pyrenees in Europe, and the American Cordillera (including the Andes, Rockies, Sierra Nevadas, and Sierra Madre Occidental). While no trees grow at this high altitude, the soil is still rich. Alpine tundras get a little more rainfall and warmer temperatures than Arctic tundras. Only patchy areas of ground are covered in permafrost.
Arctic tundra locations
Alpine tundra locations
Animals in the tundra have a variety of adaptations to help them survive the harsh climate.
During the spring when snow is beginning to melt, birds start to arrive in the tundra and begin nesting. For the brief period of summer growth and abundance they fuel up and double their weight. Before the cold returns, the birds migrate south to spend the winter in warmer areas.
Caribou also arrive at the tundra to give birth during the summer when the plants are most nutritious, and migrate to warmer forests or taiga during the winter.
When food is scarce during the freezing winter, animals like grizzly bears and Arctic ground squirrels sleep through the cold season. They go into a den or burrow, slow their breathing and heart rate, and live off their fat until the warmer temperatures bring a return of food.
Some animals like arctic foxes and hares change color during the winter, and the white color provides an excellent camouflage in the snow. The white fur is also hallow which traps air inside each shaft and keeps the cold air away, which keeps the animal warmer. Layers of blubber help keep marine mammals like seals and walruses warm. Musk oxen have two layers of fur for extra warmth. Some birds like the snowy owl stay in the tundra year round, and stay warm with double layers of feathers.
Animals that live in the tundra
Caribou participate in one of the longest annual migrations of land animals. They travel north in large groups of up to 500,000 individuals to spend their summers in the tundra eating the grasses and plants that are in bloom. Caribou give birth on the tundra as well. Once the first snows come, caribou migrate south to warmer areas. Both males and females grow antlers which fall off and regrow each year. Caribou have a spongy pad under their hooves that provides traction during the summer months when the ground is wet. During the winter, the pads harden and pull upwards, exposing a sharp rim of the hoof that can be used to dig in ice and snow to look for lichen to eat. The pad of the hoof also grows fur during the winter to protect the caribou from the cold.
The snow bunting is a small ground dwelling bird. They migrate to the arctic tundra to reproduce, and spend their winters further south in areas like Canada, Northern U.S., Germany, Poland, and Central Asia. Males migrate to the arctic tundra several weeks before the females because they must select a good nesting site before other males have staked claim on the best spots. They look for rock cavities where they can hide the nest to ensure the safety of their offspring. Once males reach the breeding grounds in the tundra, they start to sing to attract a mate. Females select their mate based on the quality of the song.
Arctic wolves are smaller than their relatives, the grey wolf, with smaller ears and shorter muzzles to help conserve heat. They have two layers of fur: the undercoat which keeps the wolf waterproof, and the upper coat which gets thicker as the temperature drops. Since arctic wolves can't dig dens in the permafrost, they choose caves or rock outcroppings when raising litters of puppies. Arctic wolves eat arctic hares, and hunt in packs to take down muskoxen and caribou.
Lemmings are a small rodent that live in the tundra. They live in burrows during the winter, and dig into the snow to look for food. They move to higher ground during the summer where they breed, before they return to the tundra. Every few years there is a huge increase in the population of lemmings, while in other years the population may dwindle to very few individuals.
Polar bears have hallow clear fur which traps air and keeps them warm. Their skin is also black which attracts the warmth of the sun. Polar bears eat mainly seals which they hunt through ice cracks or breathing holes. They also eat berries, crabs, birds, caribou, beluga whales, and eggs. Polar bears are excellent swimmers and as global warming melts ice flows, they have to swim hundreds of miles between ice caps. Unfortunately, this means global warming is causing bears to starve and drown.
The arctic fox has small ears, a short muzzle, and furry soles to keep it warm in temperatures as low as -58°F. It also digs a burrow where it takes shelter, and wraps its bushy tail around its body for added warmth. The arctic fox has beautiful white camouflaged fur in the winter that changes to a grey brown color in the summer. The white fur is hallow like a polar bears, and the air inside each hair keeps the fox warm. The color camouflage also helps the fox hunt rodents and birds. It will also eat fish, vegetables, and will follow polar bears to enjoy leftover scraps.
Threats to the Tundra
Climate change is threatening the existence of tundras as temperatures increase. This is melting the permafrost, which changes the vegetation of the landscape, and effects the animals that can live there. Animals that rely on camouflage are at risk when snow melts early, throwing off the timing of the color change of their fur. Permafrost holds a large amount of carbon, and when it melts, it releases the carbon into the atmosphere, which makes climate change accelerate. Permafrost also holds the soil in place, and when it melts, erosion and landslides happen. More frequent fires have also been impacting tundras.
The tundra is also home to large reserves of oil, natural gas, and minerals which many companies want to extract. Bringing machines and vehicles in crushes the vegetation and chokes them with dust. Drilling and mining destroys the land, and opens up the possibility of oil spills which are disastrous for the environment.
How you can help
Support the creation of national parks to protect the preservation of tundra.
Write your local senator or congressperson and tell them how important it is to protect the land from extraction activities (like drilling for oil).
You can adopt a polar bear through the World Wildlife Foundation, and the money goes toward protecting the tundra.
Since climate change is such a huge threat to tundras, supporting climate change initiatives is one of the biggest things you can do to help.
Reduce your use of fossil fuels by walking more and driving less.
Turn off lights and and unplug electronics when you aren't using them.
Install energy efficient light bulbs, and hang dry cloths.
Eat meat-free and local food, and minimize the food you waste.
Consume less material goods, and instead share, fix, upcycle, or make items.
Talk to your family about the importance of voting for political candidates that support actionable plans to reduce global warming.