The limit for arboreal vegetation, the trees are bare on the side that the wind blows. The flowering plants remain short, grass and moss and lichens survive better near the ground. This is the landscape of the Arctic zone in America, in Europe and Asia, where the climate is dry and cold. In the Arctic tundra the ground is frozen all year round and can extend deeply for hundreds of metres. Reindeer, hares, Arctic foxes, ermines and numerous migrating species can be seen in the Arctic tundra.
The word “tundra” comes from a Lapp word, meaning “barren land”. The area is flat, with scarce vegetation and virtually no rises: a cold desert. The climate of the tundra depends on the region being either oceanic or mainland. For instance, in the European tundra, which is heated by the Gulf Stream, the land is unfrozen for many months, while the Canadian mainland tundra is always frozen. In Europe, the tundra begins at 7°N latitude, while in eastern Canada is begins at 55°N. During the long winter, the monthly minimum temperatures never drop below -10°C in the European tundra and can reach -30°C in Alaska. In eastern Siberia, the average winter temperature can reach -50°C. Since the sun does not rise in winter, the tundra spends several months in long, cold darkness. Conversely, during the summer the sun is always, or almost always, above the horizon with no real nights. The solar energy that reaches the ground is in any case little, since the sun stays very low on the horizon. It ensues that the water trapped in the soil freezes down to many metres, forming a layer of hard soil, the surface of which thaws in summer only. The frozen soil of the tundra is called permafrost (from the English permanent frost). Evaporation is very low, therefore, even if it rains very little; nevertheless, the melting of the upper layers of soil form large wet areas during the Arctic summer.
The Tundra in the world
The biome of the tundra covers the northernmost lands of Europe, Siberia and north America. Overall, the tundra covers 5% of lands above sea level. Some areas of tundra can also be found at the southern end of south America. In the Austral hemisphere, large expanses of perennial ice cover Antarctica; mosses and lichens grow, however, in some very small areas along the borders of the mainland.
The mountains of the temperate areas - above 2.000 metres a.s.l. - do not have trees either, because of the cold, so they look like the tundra.
Plants of the tundra
The vegetation of the tundra is almost entirely composed of perennial plants, came phytic plants (cushion-like plants) and hemicryptophytic plants (perennial herbaceous plants). Cushion-like plants include Ericaceae and saxifrages, while hemicryptophytic plants include sedges. There are no forest trees at all. Shrubs, birches and willows are few and small, to resist frost and strong winds. Mosses, rushes, graminaceous plants and peat mosses (a type of moss which has adapted very well to live in swampy areas) grow in wet areas, where the land is soaked in water.
Animals of the tundra
Despite the cold temperature, the tundra is inhabited by a lot of animal species. Many animals migrate to avoid the colder months. Others have developed, instead, different systems to defend themselves from the cold, through which they can survive in the tundra even during the long, cold winter night. In the tundra, animals cannot hibernate since the frozen soil cannot be dug up to make shelters or tunnels and because the warm season is too short to provide enough food to stock.
Birds of the tundra
The birds of the tundra are mostly migrant birds. Some of them, such as the greater willow chicken, move short distances away, while others travel for thousands of kilometres. The Arctic tern travels 36 thousand kilometres to reach the northern tundra from Antarctica! The goose is perhaps the most typical bird of the tundra. Many different species come here to breed after spending the cold months in the Mediterranean, Mexico, Africa or in the south of the United States. In summer, wet areas are the ideal place for many species of insects, that spend the winter as eggs.
The origin of tundra
The tundra as it looks today seems to have appeared on earth just two million years ago, before the succession of ice ages and following a general and lengthy cooling of the earth. The typical species of animals of plants that can be found in this biome must have come from high mountain areas. These organisms found a favourable habitat in the tundra, because it was like their native one.
The Samis, normally known as Lapps, live in a very wide territory stretching from the coasts of Norway to the peninsula of Kola, in Russia. They live in a particularly harsh environment in the heart of their lands: at Karesuando, in Sweden, the temperature may drop down to 45°C below zero. The Samis are nomadic shepherds and their economy is based on reindeer rearing. Their nomadic life is due to the reindeers’ dietary needs. These big herbivores mainly feed on slowly-growing lichens, so they need very large areas to survive. The Lapps follow their animals, as they move in search of new pastures. The origin of the Samis is not perfectly known yet: some say they are European, while others say they come from Asia. The nomadic groups of Lapps still live in reindeer skin tents that look like those of native Americans. Dinner is their main meal. Traditional Sami dishes are mainly made of reindeer meat and fish. Reindeers are the only tamed animals. They were the basis of many people’s economy, and entire Lapp families still live on what this big herbivore can offer. Food, hides, beverages, horns and bones, used to make tools, are obtained from reindeers. They are also used for transport.
Peoples of the tundra: the Ciukcis
Between the Pacific Ocean and the Arctic Sea, there is a roughly triangular peninsula, separated from Alaska by the Straits of Bering: it is the land of the Ciukcis. They seem to have come from north America across the thin strip of land which until 30 thousand years ago used to join Siberia to Alaska. Their economy is based on reindeer-rearing, hunting and fishing. Today, the Ciukcis are much fewer than in the past, and few of them continue to follow their traditional lifestyle. They used to be nomads for most of the year, following their reindeer herds towards new pastures.
Energy from glaciers
Some areas covered by the biome of the tundra contain huge oil fields. In 1997, for instance, 162 million tons of oil were extracted from the subsurface of Siberia. Western Siberia alone contains over one half of the oil reserves of all Russia. Another important product supplied by the Russian tundra is methane. 220 billion cubic metres of gas are extracted every year, large part of which is channelled to Europe through methane pipelines measuring thousands of kilometres long.
Although remote and far away, the tundra is not spared the negative impact of some of man’s activities. Its most important problems have to do with the pollution which is caused by mining. The flowrate of the main Siberian rivers, the Lena and the Yenisey, has dramatically increased lately, despite the reduced rainfall. According to researchers, the water that swells up the rivers comes from the tundra.
Natural parks of the tundra
The flora of the tundra is damaged by the passage of vehicles or even footfalls. Plants grow slowly, so they take long to recover. In addition, the destruction of bushes leaves the soil underneath more exposed to the sun, which makes it drier. A number of natural reserves, where man’s activities are controlled and restrained by law, have been established to preserve the biome of the tundra. One of the most important ones is the National Pallas Ounastunturi reserve, in the north of Finland.