Hobbies And Interests
Plant Adaptations: Growth
Tundra plants are clump-forming and low-growing. In part this is because nutrition is limited, but small stature is also an adaptation to climate. Deep-rooted plants cannot penetrate the permafrost -- only shallow-rooted plants can grow here. These can utilize small crevices in rocks, gaining shelter. Forming clumps conserves heat. Hugging the ground, which is warmed by the sun, prevents plants from freezing. It also protects them from wind. Mosses, grasses and lichens predominate. A prolonged life-cycle is an adjustment to the short growing season -- plants may produce buds one season, flower in the second, then seed in the third.
Plant Adaptations: Color and Structure
Tundra plants are often dark or reddish. These colors absorb the sun's heat. Flowers are dish-shaped and move to follow the sun. Pale petals reflect heat into the flower, warming the plant and attracting pollinating insects. Leaves are small and narrow, reducing water-loss in an environment with drying winds and limited precipitation. Hairy or waxy leaves conserve warmth and water. Tundra grasses have a chemical adaptation, preventing them from freezing and enabling them to photosynthesize at low temperatures.
Animal Adaptations: Physiological
Arctic insects similarly produce glycerol, a natural, internal "antifreeze." Tundra animals are able to accumulate thick body fat within the very short growing season. This insulator doubles as an energy source. Tundra animals mature slowly, postponing reproduction until conditions are favorable. Large feet work as natural snowshoes. Examples of this adaptation include caribou, hares and feather-footed ptarmigans. Caribous' splayed hooves are also adapted to scrape away snow, exposing moss. Animals of the tundra must utilize a diet of lichens and mosses, or feed upon animals that can. Caribou live on lichen, but since this is slow-growing, they must constantly move in search of more.
Animal Adaptations: Lifestyle
Migration is an adaptation by which caribou and other animals escape tundra winters and seek food. Some predators adapt to the lemming population, breeding when lemmings are plentiful, migrating if lemmings grow scarce. Hibernation is an invaluable adaptation, enabling animals to eat voraciously in the summer and winter in a semi-dormant state. Allowing their body temperature to drop and metabolism to slow enables animals to survive months without food. Tundra life utilizes snow's insulating properties: ptarmigans fly into snow banks for shelter, ground squirrels and lemmings dig burrows. Voles store buds until winter and dry grasses in the sun, using this for insulation and for food. Insects crawl rather than fly, conserving energy.
Animal Adaptations: Morphology (Color and Shape)
Tundra animals are squat with short legs and ears. This reduces surface area, cutting heat loss. Thick, heavy coats of fur or feathers provide good insulation. Commonly this includes two layers of different types: the outer coat is wind- and water-proof; the inner traps warmth. Arctic hares, Arctic foxes, ptarmigans and weasels have a camouflaging adaptation, turning white when the snows come. Caribou have this adaptation -- although never pure white, they grow substantially paler in winter.