TUNDRA FOOD CHAIN

The Tundra

2011-09-27T15:51:00.000-07:00

The Tundra
Did you know that the Arctic Tundra is the world's youngest biome? It was formed 10,000 years ago. Located at latitudes 55° to 70° North, the tundra is a vast and treeless land which covers about 20% of the Earth's surface, circumnavigating the North pole. It is usually very cold, and the land is pretty stark. Almost all tundras are located in the Northern Hemisphere. Small tundra-like areas do exist in Antarctica in the Southern Hemisphere, but because it is much colder than the Arctic, the ground is always covered with snow and ice. Conditions are not right for a true tundra to form. Average annual temperatures are -70°F (-56°C).

Tundra comes from the Finnish word "tunturia", which means a barren land. The ground is permanently frozen 10 inches to 3 feet (25 to 100 cm) down so that trees can't grow there. The bare and sometimes rocky ground can only support low growing plants like mosses, heaths, and lichen. In the winter it is cold and dark and in the summer, when the snow and the top layer of permafrost melt, it is very soggy and the tundra is covered with marshes, lakes, bogs and streams that breed thousands of insects and attract many migrating birds.

The main seasons are winter and summer. Spring and fall are only short periods between winter and summer. The tundra is the world's coldest and driest biomes. The average annual temperature is -18° F (-28° C). Nights can last for weeks when the sun barely rises during some months in the winter, and the temperature can drop to -94° F (-70° C). During the summer the sun shines almost 24 hours a day, which is why the Arctic is also called the Land of the Midnight Sun. Summer are usually warm. Temperatures can get up to 54° F (12° C), but it can get as cold as 37° F (3° C). Average summer temperatures range from 37° to 60°F (3° to 16°C).

The Arctic tundra is also a windy place and winds can blow between 30 to 60 miles (48 to 97 kilometers) per hour. Of the North American, Scandinavian and Russian tundras, the Scandinavian tundra is the warmest, with winter temperatures averaging 18°F (-8°C)

The tundra is basically like a desert when it comes to precipitation. Only about 6 - 10 inches of precipitation (mostly snow) fall each year. Below the soil is the tundra's permafrost, a permanently frozen layer of earth. During the short summers the top layer of soil may thaw just long enough to let plants grow and reproduce. Since it can't sink into the ground, water from melting permafrost and snow forms lakes and marshes each summer.

There is barely any vegetation in the tundra, only about 1,700 different species, which isn't very much. These are mostly shrubs, sedges, mosses, lichens and grasses. There are about 400 varieties of flowers. The growing season is only about 50 to 60 days long. There are no trees, except for some birches in the lower latitudes. The ground is always frozen beneath the top layer of soil, so trees can't send their roots down. Willows do grow on some parts of the tundra but only as low carpets about 3 inches (8 cm) high. Most plants grow in a dense mat of roots which has developed over thousands of years. The soil is very low in nutrients and minerals, except where animal droppings fertilize the soil. Tundra Food Chain.

Surprisingly there are animals in the tundra. Although there isn't a lot of biodiversity, only 48 species of land mammals are found on the tundra, there are a lot of each species. These consist of slightly modified shrews, hares, rodents, wolves, foxes, bears and deer. There are huge herds of caribou in North America (known as reindeer in Eurasia) which feed on lichens and plants. There are also smaller herds of musk-oxen. Wolves, wolverines, arctic foxes, and polar bears are the predators of the tundra. Smaller mammals are snowshoe rabbits and lemmings. There aren't many different species of insects in the tundra, but black flies, deer flies, mosquitoes and "no-see-ums" (tiny biting midges) can make the tundra a miserable place to be in the summer. Mosquitoes can keep themselves from freezing by replacing the water in their bodies with a chemical called glycerol. It works like an antifreeze and allows them to survive under the snow during the winter. The marshy tundra is a great place for migratory birds like the harlequin duck, sandpipers and plovers.Tundra Food Chain.

The tundra is one of Earth's three major carbon dioxide sinks. A carbon dioxide sink is a biomass which takes in more carbon dioxide than it releases. Carbon dioxide is a greenhouse gas that contributes to global warming. During the short summer tundra's plants take in carbon dioxide, sunlight and water in the process of photosynthesis. Plants normally give off carbon dioxide after they die and decompose. But because of the short, cool summer and freezing winter temperatures, plants can't decompose. Remains of plants thousands of years old have been found in the tundra permafrost. In this way the tundra traps the carbon dioxide and removes it from the atmosphere. Today global warming is melting the permafrost of the tundra and every year several feet of tundra are lost. As the tundra melts, the plant mass decomposes and returns carbon dioxide to the atmosphere.Tundra Food Chain.

The tundra is a very fragile environment. The extremely cold temperatures makes it a difficult environment to survive in during the winter, and plants and animals have a hard time coping with any extra stresses and disturbances. More people moving to the tundra to work in the mines and oil rigs have created towns and more roads. Some animal's movements to traditional feeding and denning grounds have been disrupted by these obstacles. When they try to pass through a town they are often scared away or shot. With their feeding patterns disrupted, many polar bears have starved. The Alaskan oil pipeline was built across a caribou migration route. In some places the pipeline has been raised above the ground so the caribou can pass under it. Pesticides have been used to control the hordes of insects. Thousands of migrating birds come to the tundra because of the abundant insects. Through the food chain the pesticides reach many of the animals that live on the tundra.

Pollution from mining and drilling for oil has polluted the air, lakes and rivers. The land around some nickel mines in Russia has become so polluted that the plants in the surrounding area have died. Footprints and tire tracks can be visible for many years after they were made. When the sun hits the ruts it causes the permafrost to melt. This causes erosion and the ruts get bigger, and eventually the ruts turn into gullies. Tracks made during WW II have grown so large that some of them are now lakes.

The tundra is not a cold and useless wasteland. It is a very fragile environment and the plants and animals that have made their home on the tundra biome have made some incredible adaptations to the long, cold winters and the short but abundant summers. They live on a precarious edge and the smallest stresses can bring about their destruction.Tundra Food Chain.

Tundra Food Chain / Web

2011-09-07T15:49:00.000-07:00

Tundra Food Chain

The Tundra food chain starts with the producers. The producers of this Tundra food chain are the Purpule Saxifrage, the Arctic Willow, and some grasses and sedge. The next stage consisits of the herbivore. The only herbivore in the web demostrated above is the arctic hare. The hare eats the plants, but the herbivore only receives ten percent of the plants' energy.
While the Hare is alive, fleas feed off of it. The hare's predators are the Ermine, the Rough-necked Hawk, the gyrfalcon, the snow owl, humans, and the arctic wolf and fox. The hare has many predators while it is alive, and it also has predators when it dies. The species, Blow flies, and the arctic fox are scavengers who will eat at dead and decaying animals. The "pellets" of the arctic hare also acts as a source of nutrition for plants.
The main predators of the hare, the fox and wolf, also have a predator, the human being, making us the top of the Tundra food chain.

Alaskan Tundra Animals

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Tundra Food Chain
Alaskan Tundra Animals

	Arctic fox Also known as polar fox Lives in arctic regoins Genus:Lagopus Species:alopex
	Arctic Wolf Length: Head and body, 100-150cm. Height: To shoulder, 65-80cm. Lifespan:7 years average. Diet: Arctic hares, caribou, musk ox Genus:Canis *Species:* lupus arctos
	Arctic Hare Long hair for the cold Is longer than the normal Hare Genus:Lepus Species: acrticus
	Blow fly Length: 6 to 14 mm, average Life Span: 2 to 8 weeks Diet: Adult blow flies are attracted to nectar, carrion, garbage and other refuse, soggy, bloody or soiled hair, fur, or wool Genus: Phormia Species:regina
	Gyrfalcon Largest true falcon in the world eat mainly ptarmigan and grouse Genus:Falco Species:rusticolus Tundra Food Chain

Alaskan Tundra Plants

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Tundra Food Chain
Alaskan Tundra Plants

Saxifrage

Genus:Saxifraga
Species:caespitosa

Saxifrage is a small perennial that grow in thick mats on the tundra.

Tundra Rose

Genus:Dasiphora
Species:floribunda

Shrubby cinquefoil is a much-branched, deciduous shrub with a spreading to erect habit. It may attain a height of 10 to 160 cm.

Pasque Flower

Genus: Anemone
Species: patens

Pasque flower is a pretty tundra plant. It is a member of the Ranunculaceae family, which is Latin for little frog. The name was given to the family because a group of plants in this family grow where frogs live.

Tundra Moss

Genus: Calliergon
Species:giganteum

The Calliergon giganteum grows in the arctic tundra which is a harsh cold environment in the Northern Hemisphere within the arctic circle.

Diamond-leaf Willow

Genus: Salix
Species: pulcha

The twigs on a willow are soft, slender, and they bend easily. A willow has thin branches. The leaves are narrow and grow alternately on the branch. Some leaves have serrated edges.
Tundra Food Chain

TYPES OF FOOD CHAIN

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TYPES OF FOOD CHAIN
There are mainly two types of food chains operating in nature.

a) Grazing food chain
b) Detritus food chain.

Grazing food chain is generally seen in ecosystems such as grassland, pond or lake where a substantial part of the net primary production is grazed on by herbivores (cattle and rodents). Usually upto 50% of the NPP is grazed on by these animals in their respective ecosystems and the remaining 50% goes to the decomposer organisms as dead organic matter. Thus, in these ecosystems, the food chain is herbivore based.
Tundra Food Chain

FOOD CHAIN

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FOOD CHAIN
All living organisms of the biosphere are related to each other by a common factor, i.e., food, which contains not only energy but also materials in usable forms that are needed by the organisms.
We know that green plants manufacture their own food with the help of sun's energy and from common elements derived from air, water and soil. These green plants are, therefore, called the autotrophs. The autotrophs are the chief source of potential energy for the living world. Hence they are called the producers. When the producers are eaten by some animal, the energy of the producers is passed on to the animal which is called consumer. The primary consumer is eaten by another animal which is called the secondary consumer which may be eaten by a tertiary consumer and so on. This pathway of energy transfer from one organism to another constitutes a food chain. For example, in a forest community, grass is eaten by a deer which, in turn, is eaten by a lion. This flow of energy from grass (producer) to deer (primary consumer) and then to lion (secondary consumer) is called a food chain.

tundra-biome.

Characteristic features of tundra biome

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Characteristic features of tundra biome
Characteristic features of tundra biome are:

a) Ground surface is spongy, uneven as a result of freezing and thawing. This is because the plains of tundra are covered with snow, ice and frozen soil most of the year (permafrost).
b) Extreme cold climate with temperature ranging from -30oC to -40oC in winter.
c) Highest summer temperature is only about 10o C , only for a very brief period. During this time upper 10 - 20 cm deep surface region melt forming ponds, marshes and bogs in the depressions on terrain plain
d) Annual precipitation (mostly as snow) is below 25 cm.

Flora
Vegetation in tundra is very sparse. Hence, it is also called 'arctic desert'. It exhibits very low species diversity.

a) Biome is virtually treeless and is comprised of only Lichens (Cladonia - Reindeer moss) and Mosses (Sphagnum - Peat moss) forming the main vegetation.
b) Other plants growing are sedges, heaths, grasses, dwarf birches (Betula) and dwarf willow trees (Salix).
c) Plants are mostly shallow rooted and they often possess xerophytic adaptations.
d) Bilberries, dwarf huckleberries, low flowering herbs also grow in tundra.

Fauna
a) No amphibians and reptiles are found.
b) Insects like biting flies, dipteran flies (black flies), mosquitoes etc are found here.
c) Migratory birds like water fowls are seen in summer. Other birds found here are snow - owl, snow - grouse (ptarmigan) etc.
d) The caribou, musk ox, arctic hare, arctic fox, lemming, polar bear and weasels are the mammalian residents of tundra. Some of them hibernate in winter in caves and others migrate to coniferous forests.

Productivity of tundra is estimated to be 200 k cal/m2/year. Recovery from any disturbance is very slow in tundra as it is a very delicate and fragile biome.
Tundra Food Chain

What is the food chain of the tundra and also the food web?

2009-10-16T03:14:00.000-07:00

What is the food chain of the tundra and also the food web?
Producers: Grasses and Caribou Mosses
Carnivores: Polar Bears and Arctic Wolves
Herbivores: Caribou and Lemmings
Omnivores: Arctic Fox and Brown Bears
Decomposer: Bacteria and Fungi
Tundra Food Chain....

THE TUNDRA FOOD WEB

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THE TUNDRA FOOD WEB

Tundra Food Chain :

- small predators such as the snowy owl and artic fox. Most small predators feed off the lemmings which are the KEYSTONE ANIMAL to the food web as they are very populoous and widely consumed. Above the small predators, are larger predators such as the polar bear, which are not shown on this chart.

- the primary consumers such as lemmings, musk oxen and insects who feed on the limited plant life avaliable.

- the primary producers, or the plants. These are very limited resources, which are thrown off by the slightest lack of sunlight and water avaliable to them. The permafrost in the ground also throws off the drainage of the water leaving the plants there hard to digest.

This ecosystem is extremely fragile because of the lack of plant life so if tthe primary consumers can't find enough food, the predators can't eat. Therefore, the population continually oscillates and the extinction of just one species has the threshold to destroy this ecosystem.
Tundra food chain..
what-is-food-chain-of-tundra

What is the food chain of the tundra ?

2009-07-06T22:51:00.000-07:00

What is the food chain of the tundra ?

The Tundra food chain are as follow :

Producers: Grasses and Caribou Mosses
Carnivores: Polar Bears and Arctic Wolves
Herbivores: Caribou and Lemmings
Omnivores: Arctic Fox and Brown Bears
Decomposer: Bacteria and Fungi

Tundra Food Chain....
tundra-food-web.

Tundra (Artic) Habitat

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Tundra (Artic) Habitat

Where is the Tundra Habitat?

The tundra habitat is at the top of the world, near the North Pole.

How much of the earth is Tundra?

About one fifth of the earth's land is Tundra

What is the ground like?

The ground is permanently frozen 10 inches to 3 feet (25 to 100 cm) down so that trees can't grow there

How do plants grow on the solid ground?

The bare and sometimes rocky ground can only support low growing plants like mosses, heaths, and lichen. During the brief summers, the top section of the soil may thaw out allowing plants and microorganisms to grow and reproduce. However, these plants and microorganisms become dormant during the cold winter months.

Is there another type of Tundra other than artic tundra?

Yes, it is called alpine tundra and is found on the tops of tall, cold mountains.

How do animals survive in this habitat?

Animals are adapted to handle cold winters and to breed and raise young quickly in the very short and cool summers.

What living things are found in the Tundra?

Herbivorous mammals: lemmings, voles, caribou, arctic hares and squirrels
Carnivorous mammals: arctic foxes, wolves, and polar bears
Migratory birds: ravens, snow buntings, falcons, loons, ravens, sandpipers, terns, snow birds, and various species of gulls
Insects: mosquitoes, flies, moths, grasshoppers, blackflies and arctic bumble bees
Fish: cod, flatfish, salmon, and trout
Tundra Food Chain..
what-is-food-chain-of-tundra.

The Tundra Biome

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The Tundra Biome (Rus:Tundra - Arctic hill)

The word 'tundra' means 'North of the timber line'. Tundra biomes lie north of timberline or 60o N latitude between the Arctic ocean and the Coniferous forests. It covers about 8 x 106 sq.km area (8 million km2) extending across North America, Europe and Asia.

There is no tundra biome in the Southern hemisphere.
Characteristic features of tundra biome are:

a) Ground surface is spongy, uneven as a result of freezing and thawing. This is because the plains of tundra are covered with snow, ice and frozen soil most of the year (permafrost).
b) Extreme cold climate with temperature ranging from -30oC to -40oC in winter.
c) Highest summer temperature is only about 10o C , only for a very brief period. During this time upper 10 - 20 cm deep surface region melt forming ponds, marshes and bogs in the depressions on terrain plain
d) Annual precipitation (mostly as snow) is below 25 cm.

Flora
Vegetation in tundra is very sparse. Hence, it is also called 'arctic desert'. It exhibits very low species diversity.
a) Biome is virtually treeless and is comprised of only Lichens (Cladonia - Reindeer moss) and Mosses (Sphagnum - Peat moss) forming the main vegetation.
b) Other plants growing are sedges, heaths, grasses, dwarf birches (Betula) and dwarf willow trees (Salix).
c) Plants are mostly shallow rooted and they often possess xerophytic adaptations.
d) Bilberries, dwarf huckleberries, low flowering herbs also grow in tundra.

Fauna
a) No amphibians and reptiles are found.
b) Insects like biting flies, dipteran flies (black flies), mosquitoes etc are found here.
c) Migratory birds like water fowls are seen in summer. Other birds found here are snow - owl, snow - grouse (ptarmigan) etc.
d) The caribou, musk ox, arctic hare, arctic fox, lemming, polar bear and weasels are the mammalian residents of tundra. Some of them hibernate in winter in caves and others migrate to coniferous forests.

Productivity of tundra is estimated to be 200 k cal/m2/year. Recovery from any disturbance is very slow in tundra as it is a very delicate and fragile biome.
Tundra food chain...
tundra-artic-habitat.

TUNDRA FOOD CHAINS

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TUNDRA FOOD CHAINS

There are two different types of animals in this biome: migratory and permanent . Some of the most common permanent tundra animals found are some bird species as well as mammals such as the Arctic fox, the Arctic hare, and caribou. Most tundra animals are large. The weather conditions of the tundra biome require these species to have a large amount of feathers or fur to provide thick body insulation. In addition, as winter covers the land, their insulated coats turn from summer brown to entirely white. The short growing season enables these animals to feed enough to form the thick layer of fat. It will provide them both energy and a protection against the cold.

In the tundra food chain biomes, the animal population varies in size, sometimes in response to the change in population in other species. For example, the lemming consumes some of the plain vegetation. During the summer when there is food, they breed with astounding speed. One female produces five or six babies in a litter and does so, four or five times in a single season. In a few months, she may have produced thirty young. The babies grow so quickly that the first to be born in the spring can themselves reproduce before the winter returns. If vegetation is insufficient, some of the newborn will die and the population will decrease.

Fluctuations in the number of predators can also greatly affect species existence. The snowy owl is a predator of the lemming. It will emigrate from the tundra if the lemming is scarce, and might travel south, sometimes beyond South-Virginia. Many of these snowy owls die when they attempt to return to the plains.

The migratory species such as the caribou will only remain in the tundra plains during the summer season. The herd moves as much as 50 miles a day (over 80 km) following the same route each year. In places, paths have been worn 18 inches deep (45 cm) where the animals have passed century after century. They have to keep traveling in order to find enough food to sustain them all. Caribous will migrate south to avoid winter but will return to the plains to breed when the winter ends. The Arctic tern, a white seabird, migrates from the Arctic where it breeds, to the Antarctic.
Producer: Algae, Primary Consumer: Plankton, Secondary Consumer: Cod, Ringed Seal, Polar Bear.

Tundra Food Chain....
tundra-food-web.

Plant and Animal Adaptations in the Arctic Tundra

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Plant and Animal Adaptations in the Arctic Tundra
Animal Adaptations
Fur and Feather Coat Adaptations

http://www.itsnature.org/ice/above-the-ice/musk-ox/

In order to cope with the extreme cold of the arctic tundra biome, animals have adapted to be able to use their fur as insulation. These animals have specialized layers of fur to use a protection and to trap heat. For instance, The musk ox has two layers to their fur coats. First, the outside layer is made up of long hairs that act as a windbreaker and rain coat combined. This layer is designed to one, protect the musk ox from the cold wind and two, to keep out the rain. The inside layer of the musk ox's fur is more like the wool liner in one of our coats. This layer is close to the animal's body in order to trap warm air and keep it close to the body. This double fur coat is able to keep the musk ox warm even at the cold temperatures of -40 degrees C in the arctic. This adaptation is not limited to the musk ox; can be seen in other animals such as brown bears, caribou, wolves, squirrels, foxes and hares. This adaptation can even be seen in some birds. For instance, the willow ptarmigan has two layers of feathers; the outer layer is water repellent , and the inner layer keeps the bird warm. Animals in the arctic tundra have developed a double layer fur, or feather, coat in order to stay warm; this is much like us putting on a raincoat with a wool liner on the inside (Brune).

Antifreeze Adaptations
Another special adaptation found in the arctic tundra has to do with keeping the water in an or

http://www.charr.org/maitland/issue2.htm

ganism from repeatedly freezing and thawing. Water makes up 70% of most living organisms, but the temperatures in the arctic tundra is cold enough to freeze water. The problem with this is that a repeated freezing and thawing of water could cause harm to living tissue. So animals in the arctic tundra have adapted and created a chemical in order to deal with this problem. The Alaskan blackfish produces a chemical in its body that is similar to an antifreeze we use in cars. The chemical works to lower the freezing point of its bodily fluids. This stops the creation of large ice crystals inside the blackfish's body and allows them to survive in temperatures as cold as -20 degrees C for up to a few days (Arctic Adaptations).

Camouflage

Animals in the tundra, such as the arctic fox, change their color of their fur and feathers based on the season to blend into their environment. This allows them to hide from predators and avoid becoming another organism’s prey. This camouflage technique increases their chances of survival out in the wild. Their color changing feathers and fur turn brown in summer, and white in winter. These arctic animals molt twice each year as the seasons change. Most animals begin to shed their long winter fur in early A pril. By late June, the animal’s face, legs and upper parts of the body are covered with short, brown, summer fur. The change into their winter coat of camouflage begins in September. Usually by October or November, the animals have grown a luxurious, white, winter coat just in time to blend into the upcoming winter’s snow (Arctic Adaptations).

This arctic fox's white coat is the same color as the snow,
thus making it harder for predators to see him.

As it gets warm, their fur
becomes a nice summer brown.

FOOD WEB IN THE TUNDRA

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FOOD WEB IN THE TUNDRA

Tundra Food Chain
On top are the small predators such as the snowy owl and artic fox.

Most small predators feed off the lemmings which are the KEYSTONE ANIMAL to the food web as they are very populoous and widely consumed. Above the small predators, are larger predators such as the polar bear, which are not shown on this chart.

In the middle are the primary consumers such as lemmings, musk oxen and insects who feed on the limited plant life avaliable.

On the bottom there are the primary producers, or the plants. These are very limited resources, which are thrown off by the slightest lack of sunlight and water avaliable to them. The permafrost in the ground also throws off the drainage of the water leaving the plants there hard to digest.

This Tundra food chain ecosystem is extremely fragile because of the lack of plant life so if tthe primary consumers can't find enough food, the predators can't eat. Therefore, the population continually oscillates and the extinction of just one species has the threshold to destroy this ecosystem.
tundra-food-chains.

Tundra

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The word tundra derives from the Finnish word for barren or treeless land. The tundra is the simplest biome in terms of species composition and tundra food chains.

Vegetation:
lichens, mosses, sedges, perennial forbs, and dwarfed shrubs, (often heaths, but also birches and willows).

Growthforms:
typical are ground-hugging and other warmth-preserving forms including:

* tussock-forming graminoids
* mats or cushion plants, often evergreen members of the heath family
* rosettes
* dwarf shrubs, some of which are deciduous in habit

Climate:
The high latitude conditions of Koeppen's ET climate type that impact life in this biome include

* extremely short growing season (6 to 10 weeks)
* long, cold, dark winters (6 to 10 months with mean monthly temperatures below 32° F or 0° C.)
* low precipitation (less than five inches/year) coupled with strong, drying winds. Snowfall is actually advantageous to plant and animal life as it provides an insulating layer on the ground
surface.

Edaphic controls:
Permafrost, not cold temperatures per se, is generally believed to be what prevents tree growth. Furthermore, freeze-thaw activity, a thin active layer, and solifluction during the warmer months contribute to strong controls on vegetation patterns and create a mosaic of microhabitats and plant communities.

Soil:
No true soil is developed in this biome due to the edaphic factors mentioned above.

Fauna:
Strategies evolved to withstand the harsh conditions of the tundra can be divided among those species that are resident and those that are migratory.

* Among the small number of bird (e.g., ptarmigan) and mammal (e.g., muskox, arctic hare, arctic fox, musk ox) species that reside year-round on the tundra one commonly finds:
Morphological adaptations
+ large, compact bodies following Bergmann's and Allen's rules
+ a thick insulating cover of feathers or fur
+ pelage and plumage that turns white in winter, brown in summer
Physiological adaptations
+ ability to accumulate thick deposits of fat during the short growing season. Fat acts as insulation and as a store of energy for use during the winter, when animal species remain active.
Population adaptations
+ cyclical fluctuations in population size, best seen perhaps in the lemming, a small rodent which is the major herbivore in the tundra's simple food chain. Predator populations
and plant populations respond in kind to the peaks and crashes of the herbivore populations.

* Migratory species such as waterfowl, shorebirds and caribou adapt to the tundra by avoiding the most severe conditions of winter. Each year at the end of the short growing season they move southward into the boreal forest or beyond, but return to the tundra to breed.

Aperiodic emigration from the tundra is exhibited by the snowy owl during those years that the lemming populations have crashed. Those winters see snowy owl irruptions as far south as Virginia. Most owls are found with empty stomachs and do not survive to return to the Arctic.

Distribution:
The tundra biome is restricted to the high latitudes of the northern hemisphere in a belt around the Arctic Ocean. Many of its species, both plant and animal, have circumpolar distribution
areas.
Within the tundra biome a latitudinal zonation of communities is realized:

* High Arctic Tundra: essentially confined to the islands of the Arctic Ocean and characterized by scattered lichens and mosses on care rock surfaces and perennial forbs growing in protected crannies among sharp, ice-fractured rock debris.
* Middle Arctic Tundra: restricted to the Arctic Coastal plain where level terrain, a thin active layer, and freeze and thaw result in patterned ground, or rock polygons. The sorting of particles by freeze-thaw activity results in a waterlogged center to the polygons, a microhabitat conducive to sphagnum moss and sedges; and an outer ring that is drier and provides a microhabitat favorable to forbs and some dwarf heaths.
* Low Arctic Tundra: the majority of the tundra lies on better drained slopes with greater depth to permafrost than is encountered on the Arctic coastal plain. Here there is a greater frequency of woody shrubs: willow, birch, and various berry-bearing members of the heath family. Along streams willows and alders may be 10 feet high. On south-facing slopes needleleaf evergreen trees (spruce and fir) are established and represent the northernmost extensions of
the great boreal forest to the south. (Such areas where two biomes interdigitate are known as ecotones.)

Alpine Tundra
Many tundra species can be found at high elevations in the mountains of the northern hemisphere. The arctic-alpine lifezone of high elevations experiences a different climate--in terms of daylength and seasons--than does the true tundra of the Arctic. However, thin soils and cold temperatures create an environment that many middle latitude trees cannot tolerate and thus allow tundra species to invade and thrive.

In the tropics, the climate of very high elevations is extremely different than that of the Arctic. Freeze-thaw, instead of following a seasonal cycle, follows a diurnal cycle. Also, the peaks
are isolated from the Arctic tundra. Often endemic species derived from a tropical flora or from Antarctic flora create the unique communities of tropical high mountain tops. See Tropical Lifezones for additional information and some photographs of the giant lobelias and groundsels of Mt. Kenya.

Tundra

2009-01-10T17:14:00.000-08:00

Tundra food chain....
The word tundra derives from the Finnish word for barren or treeless land. The tundra is the simplest biome in terms of species composition and food chains.

Vegetation:
lichens, mosses, sedges, perennial forbs, and dwarfed shrubs, (often heaths, but also birches and willows).

Growthforms:
typical are ground-hugging and other warmth-preserving forms including:

* tussock-forming graminoids
* mats or cushion plants, often evergreen members of the heath family
* rosettes
* dwarf shrubs, some of which are deciduous in habit

Climate:
The high latitude conditions of Koeppen's ET climate type that impact life in this biome include

* extremely short growing season (6 to 10 weeks)
* long, cold, dark winters (6 to 10 months with mean monthly temperatures below 32° F or 0° C.)
* low precipitation (less than five inches/year) coupled with strong, drying winds. Snowfall is actually advantageous to plant and animal life as it provides an insulating layer on the ground
surface.

Edaphic controls:
Permafrost, not cold temperatures per se, is generally believed to be what prevents tree growth. Furthermore, freeze-thaw activity, a thin active layer, and solifluction during the warmer months contribute to strong controls on vegetation patterns and create a mosaic of microhabitats and plant communities.

Soil:
No true soil is developed in this biome due to the edaphic factors mentioned above.

Fauna:
Strategies evolved to withstand the harsh conditions of the tundra can be divided among those species that are resident and those that are migratory.

* Among the small number of bird (e.g., ptarmigan) and mammal (e.g., muskox, arctic hare, arctic fox, musk ox) species that reside year-round on the tundra one commonly finds:
Morphological adaptations
+ large, compact bodies following Bergmann's and Allen's rules
+ a thick insulating cover of feathers or fur
+ pelage and plumage that turns white in winter, brown in summer
Physiological adaptations
+ ability to accumulate thick deposits of fat during the short growing season. Fat acts as insulation and as a store of energy for use during the winter, when animal species remain active.
Population adaptations
+ cyclical fluctuations in population size, best seen perhaps in the lemming, a small rodent which is the major herbivore in the tundra's simple food chain. Predator populations
and plant populations respond in kind to the peaks and crashes of the herbivore populations.

* Migratory species such as waterfowl, shorebirds and caribou adapt to the tundra by avoiding the most severe conditions of winter. Each year at the end of the short growing season they move southward into the boreal forest or beyond, but return to the tundra to breed.

Aperiodic emigration from the tundra is exhibited by the snowy owl during those years that the lemming populations have crashed. Those winters see snowy owl irruptions as far south as Virginia. Most owls are found with empty stomachs and do not survive to return to the Arctic.

Distribution:
The tundra biome is restricted to the high latitudes of the northern hemisphere in a belt around the Arctic Ocean. Many of its species, both plant and animal, have circumpolar distribution
areas.
Within the tundra biome a latitudinal zonation of communities is realized:

* High Arctic Tundra: essentially confined to the islands of the Arctic Ocean and characterized by scattered lichens and mosses on care rock surfaces and perennial forbs growing in protected crannies among sharp, ice-fractured rock debris.
* Middle Arctic Tundra: restricted to the Arctic Coastal plain where level terrain, a thin active layer, and freeze and thaw result in patterned ground, or rock polygons. The sorting of particles by freeze-thaw activity results in a waterlogged center to the polygons, a microhabitat conducive to sphagnum moss and sedges; and an outer ring that is drier and provides a microhabitat favorable to forbs and some dwarf heaths.
* Low Arctic Tundra: the majority of the tundra lies on better drained slopes with greater depth to permafrost than is encountered on the Arctic coastal plain. Here there is a greater frequency of woody shrubs: willow, birch, and various berry-bearing members of the heath family. Along streams willows and alders may be 10 feet high. On south-facing slopes needleleaf evergreen trees (spruce and fir) are established and represent the northernmost extensions of
the great boreal forest to the south. (Such areas where two biomes interdigitate are known as ecotones.)

Alpine Tundra
Many tundra species can be found at high elevations in the mountains of the northern hemisphere. The arctic-alpine lifezone of high elevations experiences a different climate--in terms of daylength and seasons--than does the true tundra of the Arctic.
However, thin soils and cold temperatures create an environment that many middle latitude trees cannot tolerate and thus allow tundra species to invade and thrive.

In the tropics, the climate of very high elevations is extremely different than that of the Arctic. Freeze-thaw, instead of following a seasonal cycle, follows a diurnal cycle. Also, the peaks are isolated from the Arctic tundra. Often endemic species derived from a tropical flora or from Antarctic flora create the unique communities of tropical high mountain tops.
Tundra food chains....