Tundra is the coldest biome with an average annual temperature of less than 5°C, and precipitation (mostly in the form of snow) less than 100 mm per year.
The tundra is such a harsh environment that few species of plants or animals can survive there. The word tundra is derived from the Finnish word ‘tunturia’ meaning treeless plain.
The tundra is one of the least known and most interesting biomes on earth. It is nearly impossible for life to thrive in this extreme climate.
The environment itself possesses a strange and varied assortment of animals that have figured out how to survive when green plant life, sun, or water is a limited resource.
Because of extreme cold temperatures, the layer thawing just below the surface (called permafrost) is permanently frozen.
Many people associate tundra biome with the “frozen tundra,” but this biome includes a variation in temperature, climate, and amounts of precipitation depending on the exact location.
Tundra is largely known for it’s frost-molded landforms, extremely low temperatures, little precipitation, nutrient-poor soils, and a short growing season. Broadly tundra can be separated into two types: arctic tundra and alpine tundra.
As many climate scientists have said, their “greatest fear” would be the melting of the Arctic permafrost which stretches for thousands of miles across Alaska, Canada, and Siberia.
Climate of the Tundra
The climate of the tundra is defined by extreme cold conditions.
The arctic tundra is northern hemisphere area surrounding the North Pole that is characterized by extremely cold, dry conditions which are the similar conditions as a frozen desert. In the winter, there can be weeks of no daylight, and extremely cold temperatures.
In the summer, however, the sun can shine almost all day which is why most plants and animals depend on this to survive.
The alpine tundra can be found at the top of the highest mountains in the world. Like the arctic tundra, these climatic regions exhibit freezing temperatures and dry air, but they are phenomenon of high elevations.
Because of the higher elevations, the alpine tundra can sustain more concentrations of sunlight for a few hours at a time, because the air and atmosphere is thinner, the rays penetrate stronger.
The tundra climate produces short growing seasons which produces low species diversity because the animals, and plants have adapted under these sorts of harsh climatic conditions.
Location of the Tundra
There are two types of tundra biomes on Earth: one is an area of cold weather in the North, near the Arctic Circle, the other is located at the high elevations of Earth’s tallest mountain ranges.
- The Arctic Tundra: The Arctic tundra is located in the northern hemisphere, where the North Pole is located. It covers almost one third of the globe, running north from around latitudes 55° to 70° N. The temperatures are extremely cold, and it is one of the world’s least populated regions.
- Alpine tundra: The alpine tundra is found at the tops of mountain ranges that are too cold for tree growth.
- While the Antarctic region is much colder than the Arctic, it is not technically considered a tundra because average yearly temperature can drop as low as -70°F (-56°C), and therefore has entirely different ecosystems.
Temperature of the Tundra
The tundra is the coldest of the biomes, and it is also one of the least populated by man.
Tundra areas are also classified as windy, with normal sustained wind gusts of approximately 30 – 60 mph, on the flatter arctic tundra and at high altitudes on mountain tops.
- The arctic tundra has average winter temperatures of -34° C (-30° F) and average summer temperatures of 3° to 12° C (37° to 54° F).
- The higher parts of the arctic tundra may even have winter temperature averages of −28 °C (−18 °F) with the possibility of sometimes dropping to near −50 °C (−58 °F). It is obvious that most lifeforms in the arctic tundra have a two month, 50-60 day growing season to grow and find nutrients to sustain living throughout the year when conditions are unlivable.
- The alpine tundra generally has a longer growing season every year of around 180 days. In this case, the temperatures still drop below freezing during the night and the strong wind patterns are continuing to challenge the ecosystem and it’s ability to sustain life. During a warmer month, the expected average temperatures will be anywhere from about -12 to 10°C (10 to 50°F).
Precipitation of the Tundra
The tundra’s very cold temperature prevents precipitation from occurring, as it is simply too cold for it to precipitate. It has desert-like yearly amounts of precipitation when compared to an area like a desert; thus, it is often referred to as a frozen desert.
Although relatively low amounts of precipitation occur, the frozen ground and cold air allow plant and animal life to exist in the alpine tundra with limited amounts of precipitation because evaporation is not the same as warmer locations.
During winter months, precipitation is in the form of snow, while in summer, the water exists as either rain or fog. Water is retained in the tundra and alpine tundra through permafrost and bogs.
- The arctic tundra has precipitation (rainfall/snowfall and melting snow and ice) between 15 and 25 cm (6-10 inches) each year.
- Alpine tundra precipitation is slightly higher on average around 30 cm (almost 12 inches).
Plants of the Tundra
Tundra is derived from the words tundar of Russian and tunturia of Finnish respectively meaning “treeless mountain tract” and “treeless plain.” Because of the unforgiving climate and relatively constant frozen ground cover, it is difficult for plants to survive in areas of extreme cold with prolonged periods of little light.
Research has shown that there are almost 1,700 different types of plants that exist in the tundra. Nitrogen and phosphorous instead of plant life make up a typical food source because they are nutrients released by the decomposition of dead organic matter.
The soil characteristics in arctic tundra are different from that in other areas of the world. The subsoil in the tundra is made up of permafrost, which is a horizon of frozen rocks and smaller material and is typically about 25 to 100 cm (10 inches to 3 feet) in depth.
During warmer periods of the year the melting snow will result in moisture accumulating in the soil above the level of the permafrost, which enables plant life to proliferate.
While the alpine tundra may be better drained, the plant life in this zone is similar to that of the arctic tundra.
One of the most interesting adaptations of plant life in the tundra biome is that none of the plants in this area have deep root structures. This keeps the roots in the wet topsoil.
Shrubs and lower plants are more common than large trees in the tundra environment because they do not require deep roots and can addapt quickly during the cold and growing seasons.
Plants are shorter and grow in groups to adapt to the harsh cold and wind. Interestingly, similar to animals, plants grow closely together in order to retain warmth.
Additionally, the tundra’s minimal amount of trees remains stunted to adapt to the protective insulating snow cover on the ground. The plants also photosynthesize in cold temperature and in low light conditions.
Many plants in the tundra reproduce asexually rather than flowering and pollination given the lack of pollinating insects and birds.
Plants that can be commonly found in the tundra biome include:
- Reindeer moss
- Crowberry
- Heath
- Liverwort
- Tussock grass
- Willow grows as a low carpet cover in some areas
- Over 400 different types of flowers
- Lichen
- Dwarf trees, including small birches
The tundra is one of three major carbon dioxide sinks on Earth, removing more carbon dioxide than it emits. During the short summer, tundra plants absorb carbon dioxide, sunlight, and water in their effort to photosynthesize.
Furthermore, plants cannot decompose due to the short, cool summer and the freezing winter; remains of plants from a thousand years ago have been found in the permafrost tundra. This acts to trap carbon dioxide and remove it from the atmosphere.
Animals of the Tundra
The tundra biome has a limited animal population. Often, the animals in this biome have a variety of adaptations for survival in this windy environment. There are believed to be about 48 species of mammals found in the tundra.
Animals living in tundra climate have a variety of adaptations for survival. Animals in the tundra biome generally have large stocky bodies with thick insulation. They have thick layers of fat and fur or feathers that act as insulators from the cold weather.
Animals usually have a white winter coat or plumage that blends in with snow, while the summer coat or plumage may be brown.
There is a lack of burrowing animals found in the climate of the tundra biome due to the presence of permafrost.
As the climate does not provide sufficient food for the animals in winter, hibernation is not a common adaptation. Animals in the tundra are generally forced to remain active in the winter, and most types of birds migrate south for the winter.
As was stated earlier, birds tend to have larger wingspans. There are no cold-blooded vertebrates, and no insect species are cold-blooded vertebrates, but there are numerous insect species in the tundra ecosystem, and most of those species are aquatic.
While diversity tends to be limited in the tundra biome, there are still many species that are either permanent residents or migratory species.
Land Animals
Large groups of caribou (called reindeer in Eurasia) inhabit North America and consume lichens and vegetation.
The tundra lure migratory species away from Artic food chains: caribou and waterfowl particularly during breeding times which will migrate south when adverse conditions begin.
Smaller herds of musk-oxen inhabit tundra regions. Predators of the tundra include wolves, arctic foxes, polar bears, and wolverines. Smaller mammals include snowshoe rabbits and lemmings.
The principle herbivore of the tundra is the lemming while the snowy owl is a partially migratory predator that also follows lemming populations.
The general herbivores found in the tundra eat plants while carnivores include animals, fish, insects, and birds.
Plant-eating Animals (Herbivores)
- Voles
- Lemmings
- Squirrels
- Arctic hare
- Snowshoe rabbits
- Caribou/Reindeer
- Musk-oxen
- Mountain goats
- Snow geese
Meat-eating Animals (Carnivores)
- Wolves
- Wolverines
- Arctic foxes
- Polar bears
Aquatic Animals
The aquatic animals that ply the Arctic waters are:
- Seals
- Walrus
- Beluga
- Whales
Fish
Tundra fish species include:
- Salmon
- Cod
- Trout
- Flatfish
Insects
Tundra insects include black flies, deer flies, mosquitoes and “no-see-ums” (tiny biting midges) that are dreadful in summer.
The mosquitoes can use a chemical called glycerol to replace the water in their bodies to keep from freezing. The glycerol works like antifreeze and allows mosquitoes to survive under the snow during winter. Found are:
- Mosquitoes
- Flies
- Grasshoppers
- Moths
- Arctic bumble bees
- Beetles
Birds
The migratory birds like the harlequin duck, sandpipers and plovers make the marshy tundra a great place.
Birds found are:
- Falcons
- Ravens
- Loons
- Sandpipers
- Terns
- Gulls
- Snow buntings
- Harlequin duck
People in Tundra
People live in certain parts of the tundra out of necessity for work, like on oil rigs. Overall, however, those settlements are few and far between, are less numerous than other man-inhabited areas, and the individuals humans will affect, and did affect, the tenuous balance of the ecosystem.
Typically for native people of tundra, all the people will follow the patterns relating to the main source of survival; there are tribes that try and exist on entire reindeer bodies in tundra areas.
Threats to Tundra
Carbon dioxide, a greenhouse gas for global warming, is melting tundra permafrost, resulting in losing several feet each year, largely from pollution and greenhouse gases.
As the tundra melts, plant mass decomposes because of global warming and returns carbon dioxide to the atmosphere, which is an existential threat to the arctic tundra.
The movement of people to the tundra to work in oil rig jobs and for mining has led to building towns and roads becoming expanded area.
Their movement to new feeding areas and denning areas has been altered and extended. This is the cause for starving polar bears.
Thousands of birds migrate to the tundra and thrive because of abundant insects. Pesticides are used for large populations of insects, which in turn enter into many animals in the food chain.
Mining and drilling for oil has resulted in additional air and pollution in lakes and rivers because of polluted air. The land surrounding nickel mines has become so polluted that the plants have died.
The ruts develop so deep from the sun hitting them, which causes the permafrost to melt. Consequently, erosion is caused because of the melting, the rut gets deeper and wider become gullies. Some ruts from WW II have finished developing into lakes.