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Group 9: Arctic tundra

Page history last edited by Group 9 15 years, 1 month ago

 

           

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^ Leader^

^ Writer ^ 

^ Researcher ^

^ Researcher ^

  

Names / Roles:

  •   Soon Hao  (Leader)  
  •   Hannah Ibrahim   (Writer)    
  •   Danny Wong   (Research)    
  •   Nurul Hidayah  (Research)  
*[Note: When reading the info.s, red words are main info.s that are impt. ...] 

 

 

Overview

 

Brief description of the ecosystem:

 

     In physical geography, tundra is an biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes from Kildin Sami tūndâr, which means "uplands, treeless mountain tract." There are two types of tundra: Arctic tundra (which also occurs in Antarctica) and alpine tundra. In tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.

[Extracted from WikiPedia; http://en.wikipedia.org/wiki/Tundra]

 

     Arctic tundra is found across northern Alaska, Canada, and Siberia. This biome has long cold winters and short cool summers. The Arctic tundra has low precipitation (less than 10 inches per year) and dry winds. These conditions make the Arctic tundra a desert-like climate.

 

     One unique characteristic of the Arctic tundra is permafrost--ground that is permanently frozen. Because the permafrost has no cracks or pores, nothing can penetrate it--neither plant roots nor water. The surface layer above the permafrost thaws each summer. This layer is called the active layer. Thickness of the active layer depends on its location in the tundra. The more northerly the location, the thinner the active layer is.

[Extracted from Earth Floor: Biomes; http://www.cotf.edu/ete/modules/msese/earthsysflr/tundra.html]

 

 

 

Physical Factors

 

     The Arctic tundra is a vast area of stark landscape, which is frozen for much of the year. The soil there is frozen from 25–90 cm (9.8–35.4 inches) down, and it is impossible for trees to grow. Instead, bare and sometimes rocky land can only support low growing plants such as moss, heath, and lichen. There are two main seasons, winter and summer, in the polar tundra areas. During the winter it is very cold and dark, with the average temperature around −28 °C (−18.4 °F), sometimes dipping as low as −50 °C (−58.0 °F). However, extreme cold temperatures on the tundra do not drop as low as those experienced in taiga areas further south (for example, Russia's and Canada's lowest temperatures were recorded in locations south of the treeline). During the summer, temperatures rise somewhat, and the top layer of the permafrost melts, leaving the ground very soggy. The tundra is covered in marshes, lakes, bogs and streams during the warm months. Generally daytime temperatures during the summer rise to about 12 °C (54 °F) but can often drop to 3 °C (37 °F) or even below freezing. Arctic tundras are sometimes the subject of habitat conservation programs. In Canada and Russia, many of these areas are protected through a national Biodiversity Action Plan.

 

     The tundra is a very windy area, with winds often blowing upwards of 48–97 km/h (30–60 miles an hour). However, in terms of precipitation, it is desert-like, with only about 15–25 cm (6–10 inches) falling per year (the summer is typically the season of maximum precipitation). During the summer, the permafrost thaws just enough to let plants grow and reproduce, but because the ground below this is frozen, the water cannot sink any lower, and so the water forms the lakes and marshes found during the summer months. Although precipitation is light, evaporation is also relatively minimal.

 

 

 

 

 [Text and picture extracted from WikiPedia; http://en.wikipedia.org/wiki/Tundra]

 

 

ClimoGraph for Artic Tundras... 

 

 

 [Climograph extracted from Earth Floor: Biomes; http://www.cotf.edu/ete/modules/msese/earthsysflr/tundra.html#C1]

 

 

 

Classification of Living Organisms 

 

     The biodiversity of the tundras is low: 1,700 species of vascular plants and only 48 land mammals can be found, although thousands of insects and birds migrate there each year for the marshes. There are also a few fish species such as the flat fish. There are few species with large populations. Notable animals in the Arctic tundra include caribou (reindeer), musk ox, arctic hare, arctic fox, snowy owl, lemmings, and polar bears (only the extreme north)

 [Extracted from WikiPedia; http://en.wikipedia.org/wiki/Tundra]

 

Arctic Tundra: Animals 

 

     Not many kinds of animals live year-round in the Arctic tundra. Most birds and mammals only use the tundra as a summer home. Mammals that do live year-round in the tundra include the musk ox, arctic wolf, and brown bear; and each has its own way of adapting to the extreme climatic conditions. Animals need to find ways to stay warm and to provide nourishment for themselves in order to survive the long, cold, winter months 

 

Animal adaptations

 

     Migration and hibernation are examples of behavioral adaptations used by animals in the Arctic tundra. The fact that many animals do not live year-round in the tundra means they leave or migrate for a length of time to warmer climates.

     Hibernation is a combination of behavioral and physical adaptations. For example, during the summer the brown bear's behavior is to eat just about anything it can find; then it hibernates, or sleeps, during the winter. The bear's physical adaptation allows the food eaten during the summer to be stored as a layer of fat underneath its skin. The layer of fat insulates the bear from the cold. While in hibernation the fat is slowly converted into energy that maintains life.

 

     A physical adaptation used by the Musk Ox is the growth of two layers of fur--one short and the other long. Air is trapped in the short layer of fur and is warmed by body heat. The warmed air, trapped close to the body, acts as insulation from the cold. The layer of long fur protects the Musk Ox from the wind and water. In addition to thick layers of fur, the Musk Ox relies on another physical adaptation to help it survive. The hooves of the Musk Ox are large and hard. During the winter months, this adaptation allows the Musk Ox to break the ice and drink the water underneath

[Extracted from Earth Floor: Biomes; http://www.cotf.edu/ete/modules/msese/earthsysflr/tundraA.html] 

 

Arctic Tundra: Plants 

 

     Plants need warmth and sunlight to grow and reproduce. In the Arctic tundra, warmth and sunlight are in short supply, even in the summer. The ground is frequently covered with snow until June, and the Sun is always low in the sky. 

 

     Only plants with shallow root systems grow in the Arctic tundra because the permafrost prevents plants from sending their roots down past the active layer of soil. The active layer of soil is free from ice for only 50 to 90 days

 

     Arctic plants have a very short growing season. However, in spite of the severe conditions and the short growing season, there are approximately 1,700 kinds of plants that live in the Arctic tundra. Some of the plants that live in the Arctic tundra include mosses, lichens, low-growing shrubs, and grasses--but no trees. In fact, "tundra" is a Finnish words which means "treeless"

 

Plant Adaptations 

 

     Growing close together and low to the ground are some of the adaptations that plants use to survive. This growing pattern helps the plant resist the effects of cold temperatures and reduce the damage caused by the impact of tiny particles of ice and snow that are driven by the dry winds.

 

     Plants also have adapted to the Arctic tundra by developing the ability to grow under a layer of snow, to carry out photosynthesis in extremely cold temperatures, and for flowering plants, to produce flowers quickly once summer begins. A small leaf structure is another physical adaptation that helps plants survive. Plants lose water through their leaf surface. By producing small leaves the plant is more able to retain the moisture it has stored

[Extracted from Earth Floor: Biomes; http://www.cotf.edu/ete/modules/msese/earthsysflr/tundraP.html] 

 

Producers:

 

Artic willows...                                         Bearberries...                               Labrador tea...

 

  

Salix Pulchas...                          Tufted Saxifrages...

 

  

 

 

Consumers:

 

Artic Foxes...                           Caribous...                                       Grizzly Bears...

 

    

 

Harlequin ducks...                       Mustela Ermineas...                    Snowy owls...

 

      

 

Musk oxs...                                  Lemming...

 

   

 

Decomposers:

 

Artic mushrooms...

 

  

 

Moss...

 

 

 

Another kind of moss...

 

   

 

Lichens...

 

 

Close up...( Lichens )

 

 

[Text extracted from WikiPedia; http://en.wikipedia.org/wiki/Tundra]

 

 

Food Web 

 

*[I really did this! I did not copy 'n' paste! - Hannah]

 

Interrelationship in Ecosystem

 

Predator-prey relationship

 

     New findings suggest that a special combination of predators can drive lemming populations through a four-year boom and bust cycle, which has been one of ecology's big mysteries for over half a century.

 

    The collared lemming, which lives in the high-arctic tundra, is the single prey in one of the world's simplest vertebrate predator-prey relationships. The stoat, arctic fox, snowy owl, and a seabird called the long-tailed skua all dine on this hamster-like animal.

     Scientists now suggest that these four predators may be solely responsible for the four-year population cycle in eastern Greenland and possibly in many other collared lemming populations.

 

     For the Science study, Gilg, Hanski and Sittler compiled the 15 year's-worth of data for each of the five species

     The results showed the stoats' population cycles lagging behind those of the lemmings. This was expected, according to the authors, because the stoat is a specialist predator that depends exclusively on lemmings for prey. The only predator that remains in the study area year-round, the stoat also reproduces more slowly than lemmings do. 

     The numbers of foxes, owls, and skuas -- all generalist predators that eat lemmings only when they are abundant -- fluctuated right in sync with the lemming numbers, the authors found.

[Extracted from Science Daily; http://www.sciencedaily.com/releases/2003/11/031104063521.htm]

 

Parasitism

 

     Lichens, which are composed of a fungus and an algae living together, are another example of mutualistic symbiosis. Lichens can be found in habitats as diverse as deserts and arctic tundra.

     In the tundra lichens serve as a major food source for caribou (reindeer). The algae in the lichen performs photosynthesis, producing food that is shared with the fungus. The fungus in the lichen provides the supporting structure for the algae and helps retain moisture. If you separate the algae from the fungus in a lichen and try to grow them individually, they both die.

[Extracted from Biology Concepts - online; http://www.mc.maricopa.edu/~johnson/online100/demo.html]

 

Mutualism

 

     Both the sea anemone and the hermit crab are benefitting from their association with one another. The sea anemone has access to an increased supply of food and the hermit crab gets protection. This is a long-term relationship between organisms of two different species so it is an example of symbiosis . Because both organisms benefit from this symbiotic relationship, it is termed mutualism.

[Extracted from Biology Concepts - online; http://www.mc.maricopa.edu/~johnson/online100/demo.html]

 

Useful Links

 

 

          - If u dun understd the meanin' of the wrds that is...

 

 

 

 

Comments (3)

Sherlyn Chew said

at 9:35 pm on Feb 19, 2009

ehhhh... nobody did anything from this group!!! DEADLINE IS TMR!!!!!!!!!

Sherlyn Chew said

at 8:13 pm on Feb 22, 2009

AWESOME job!!! I like that you guys highlighted the important words and it shows that you didn't just copy and pasted blindly but actually read through the stuff you put up on your wiki.
Also, the pictures were relevant and you cited your sources. Good work.
One thing to improve on would be the Interrelationship between organisms in the Ecosystem... Missing part in an otherwise super wiki page!

Sherlyn Chew said

at 8:46 pm on Feb 22, 2009

I believe you Hannah =) hahaha...

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