By Suzanne Zwaanswijk Tundra

What? Tundra : A treeless area between the icecap and the tree line of Arctic regions, having a permanently frozen subsoil and supporting low-growing vegetation such as lichens, mosses, and stunted shrubs.

Climatic Factors? Precipitation- Less that 250mm annually, making it drier than the average tropical desert! A major controlling factor for the climate! The season during which the precipitation falls is different for several areas. It can be in winter as in Norway or in summer as in Alaskan tundra.

Climatic Factors? Precipitation- Less that 250mm annually, making it drier than the average tropical desert! A major controlling factor for the climate! The dry climate does not mean there is no water. The frozen soil thaws during summer and the water released forms lakes and provides moisture for animals and plants . The humidity is not low in summer due to the melting snow, allowing plants to grow during this season!

Climatic Factors Temperature – the winter temperatures might be as low as -34°C and the average summer temperature not higher than +10°C. A major controlling factor for the climate! The temperature is ca 9 months below 0, making the growing season short. The low temperatures mean that many organisms have to adapt. Animals such as the arctic fox and plants such as reindeer mosses can live in the cold.

Climatic Factors Wind – very often present due to the lack of physical barriers to stop it. Because strong winds are often present, organisms adapt to it. The plants are small and dwarfed shrubs which are deformed due to the wind.

Climatic Factors Light – due the position of most tundra, they get sun for 24/7 during the short summer and no sun at all during winter. This greatly limits the growing season. Also, the high altitude of the alpine tundra limits the amount of oxygen available organisms.

Climatic Factors Seasonality – extremely short growing season of 6 to 10 weeks Long, cold, dark winters with snowfall. Snowfall allows plants to survive by providing an insulating layer

Soil Factors No true soil is developed in this biome due to the constant thawing and melting of the top layer of the permafrost. Only a thin active layer which allows life. Because there are low temperatures, dead organisms take a long time to decompose and form humus.

Landscape Factors Aspect Slope No sun, no advantage in winter. Constant sun, no advantage in summer Slope The constant, strong winds make growth difficult for plant, a sheltered corner would be an advantage.

Landscape Factors Altitude Alpine Tundra is tundra created because of its high altitude. It is very similar to Arctic Tundra and has many things in common. Here, the high altitude prevent tree growth. In the alpine tundra, aspect is an important factor since south facing slopes get more sun and have higher temperatures and thus more organisms. Also, alpine tundra has (unlike the arctic tundra) well drained soils.

Biotic Factors Species– low biodiversity 1,700 species of vascular plants and only 48 land mammals and even fewer fish. There are many insects and some migrating birds. Examples of species: Herbivorous mammals: lemmings, voles, caribou, arctic hares and squirrels Carnivorous mammals: arctic foxes, wolves, and polar bears Migratory birds: ravens, snow buntings, falcons, loons, sandpipers, terns, snow birds, and various species of gulls Insects: mosquitoes, flies, moths, grasshoppers, black flies and arctic bumble bees Fish: cod, flatfish, salmon, and trout

Biotic Factors Species– low biodiversity 1,700 species of vascular plants and only 48 land mammals and even fewer fish. There are many insects and some migrating birds. Few species with large populations. Little competition between animals due to the small numbers of animals present . Also, chances that two animals who eat the same food ever get close together are very small.

Adaptation of Animals Since the environment in the tundra is not very welcoming to organisms, special adaptations in animals have evolved to allow life in this region. These include:

-Adaptations to prevent their bodily fluids from freezing. - animals use solar heating to stay warm and save energy. They stay out in the sun to warm up and during the summer when the weather is warm, seek shade to cool off. -short and stocky arms and legs. - thick, insulating cover of feathers or fur. colour changing feathers or fur: brown in summer, and white in winter. - thick fat layer gained quickly during spring in order to have continual energy and warmth during winter months.

Human Impact The tundra biome is very fragile. Because of the cold, dead organisms take a long time to break down and a small change may result in nutrients not being restored.

Human Impact Natural resources have been found in great numbers in tundra across the world. Especially oil and valuables minerals are being extracted in tundra regions. This has many effects on the area surrounding the site.

Human Impact Oil spills – these kill many organisms and are often not cleaned up properly. The cold preserves the oil and sometimes even holds it in place for hundreds of years, preventing plant growth and thus destroying the ecosystem. Mining – by digging large holes in the ground, an ecosystem can be destroyed forever.

Human Impact Nuclear Testing – America and Russia have used the deserted Tundra landscape to test nuclear weapons. The toxins have collected in the snow and are now slowly being released. They also build up in animals and plants, leading to their deaths.

Human Impact Hunting – in the past, many animals have been hunted in the tundra. Animals like musk oxen and caribou have been hunted in the past and are now endangered. The reduction in their numbers has affected the energy flows in the ecosystem.

Human Impact Tourism and improper development – by walking on a plant, the population can be damaged for decades since growth is so slow. Also, the buildings made to accommodate tourists and researches are often no good and damage the soil. The soil may then wash or blow away leaving the ecosystem damaged.

Human Impact Air pollution- The thinning of the ozone layer is an effect of pollution. The actual effect of this on the ozone layer is yet unknown. Also, pollution from dirty factories in Russia and the USA is blown over to the Tundra and settles here, polluting the area.

Human Impact Global warming – When the earth warms up, the tundra warms up too! This allows the spread of *alien * species into the ecosystem and the demise of the original species. The area in which tundra is found may get smaller and it could eventually be damaged so much that tundra will disappear!