Tundras are arctic plains that are dominated by sedge, heath, willow, and lichen. They are found in most of the earth's northern terrain. Another type of tundra is the alpine tundra. This type of tundra occurs above the timberline in the high mountains of the world. The Antarctic has a few areas of tundra as well. Tundra has a distribution throughout the northern hemisphere, but in the southern hemisphere it is only found on the Antarctic Peninsula and surrounding islands.
Weather Cycles: Tundra is known for its harsh winters, low average temperatures, little snow or rainfall, and a short summer. The arctic tundra, which we will be focusing on, is so intensely cold that a layer of permanently frozen subsoils in the ground. This is called permafrost. In the summer, the surface soil thaws to many different depths. Because of the frozen ground, the water is unable to drain, therefore providing moisture for plants. Rainfall is minimal in the tundra so this water is needed to keep plant life alive.
Adaption: There are many different organisms living in the Arctic Tundra that have special adaptations to assist in their survival. The polar bear is a good example of an animal that is well adapted to the tundra environment. It has a layer of fat underneath its skin that is 3 inches thick. This provides warmth for the bear in the extreme weather conditions. This layer of skin also serves another purpose, it allows the polar bear to stay buoyant when hunting in the deep water. When winter time comes and the water freezes, the polar bears are now ready to survive through the winter. Their paws are hairy, which enables them to run on ice up to 18 m.p.h., if attacked.
Plant life in the tundra is few, and the growth is low. The growing season is short so the plants can't grow tall. This is the reason why trees are so scarce, and the trees that exist are short.
Environmental Threat: The tundra has an extremely sensitive ecosystem. The tundra wildlife is very vulnerable to habitat destruction. A major threat to this habitat is over hunting. The tundra is a highly interdependent community.
Survey of Organisms: Plantae: grass, willow, and moss.
Protista: algae (found in water).
Fungi: lichen.
Monera: Generally in the tundra, Monera live on organisms symbiotically.
Symbiosis: Lichen is an example of symbiosis in the tundra. Lichen is a plant consisting of a type of fungus and a type of alga. The fungus makes up over 90% of the lichen plant body. Algae produces food through photosynthesis and the fungus gives the alga water and minerals that it collects from the ground surface.
Classification of Organisms: The black fly and the mosquito are two examples of invertebrates from the phylum Arthropoda. The polar bear and the caribou are two vertebrates from the class Mammalia. The snowy owl is a vertebrate from the class Aves.
