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
– 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!