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Tundra
CHAPTER 7.3
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OBJECTIVE
Describe why the characteristics of thetundra make it a fragile ecosystem.
Compare the characteristics of tundraorganisms with those of their relativesin warmer climates.
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Tundra Climate
The tundra is a cold, windy, dryregion located in the NorthernHemisphere just south of the polarice caps in Alaska, Canada,Greenland, Iceland, Scandinavia,and Russia.
The tundra is one of the largestbiomes, making up almost 10% ofEarth's surface.
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Tundra Climate
Few types of organisms live in thetundra.
The lack of biodiversity makes tundraecosystems very fragile andunstable if disturbed.
Like a desert, the tundra receives littleprecipitation, usually less than 25 cma year.
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Tundra Climate
The main difference between dessertsand tundra is temperature.
Temperatures in the tundra are belowfreezing almost all year, mostprecipitation falls as ice and snow,and because of this temperature is thelimiting factor in the tundra.
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Tundra Climate
During the summer only the top layerof soil will thaw, this is called theActive Zone.
Beneath the active zone, usually only8 cm deep, is the Permafrost.
Permafrost is a frozen soil below theactive zone.
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Tundra Climate
A dense mat of mosses, grasses,and other plant life covers the activezone during the summer.
Because of the short growing seasonand low temperatures, tundravegetation does not recover fromdisruption as quickly as doesvegetation in other biomes.
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Tundra Climate
Tracks from wagons that crossed thetundra 100 years ago are stillvisible in some areas.
The rain that falls in the summer isunable to drain past the permafrostand forms bogs and ponds that serveas breeding grounds formosquitoes and black flies.
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Tundra Climate
Insects are an important link in thefood web of the tundra and thereforean important factor in the stability ofa tundra ecosystem.
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Bogs and Ponds
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Tundra Organisms
Even though the tundra is a coldclimate and there is little rain, someplants do grow there.
The growing season in the tundra isabout 60 days.
The most common plants are mosses,shrubs, grasses, lichens and small,colorful wildflowers.
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Tundra Organisms
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Tundra Plants
Tundra plants are very small due to– Roots are unable to grow thru the
permafrost– Dwarfed by the short growing season– Limited space for roots and strong polar
winds
Tundra trees usually grow to lessthan 1 meter
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Tundra Animals
Many of the tundra animals areseasonal visitors.
Seasonal travel is called Migration. Birds migrate to the tundra for the
breeding season because there arefew predators.
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Tundra Animals
The migratory birds mostly feed on themosquitoes and black flies from thebogs.
The birds are then food for the Articfox.
There are no reptiles oramphibians.
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Tundra Animals
The caribou, a close relative of thereindeer, is a large migratorymammal of the tundra.
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Tundra Animals
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Tundra Animals
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Tundra AnimalsReindeer
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Tundra Animals
It has adaptations that help it to live inthe tundra,– Thick coat of hair– Hairs that are hollow and filled with air
for insulation– Wide hooves to help them walk through
snow and mud
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Tundra Animals
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Tundra Animals
Thousands of caribou migrate to thetundra each year to feed on lichensthat grow on rocky surfaces.
Lichens are plant like organisms thatare made up of a fungus and analga.
Lichens grow very slowly and are verysensitive to air pollution.
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Tundra Animals
Mammals that are year-roundresidents of the tundra,
– Artic fox– Musk oxen– Coastal polar bears– Wolverines
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals
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Tundra Animals