Tundra
Description/ Characteristics
The tundra biiome usually has very little vegetation and is covered by snow. There are no or few trees. Average annual temperatures are -70°F (-56°C), but they can get much colder (-28 degrees C). The ground is permanently frozen 10 inches to 3 feet deep 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. 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. It is the coldest and driest biome. The soil is very low in nutrients and minerals, except where animal droppings fertilize the soil.
Climatograph
This climatograph compares rainfall to temperature in Alaska. This area very cold in winter and a bit warmer (but still cool) in summer months. This biome gets very little rainfall also.
Animal Adaptations
Animals in the tundra must be adapted to cold and dry conditions. Many animals can also blend in with the snow, making them more imperceptable to prey or predators. Claws or talons are also a must for predators. These animals need thick fur or feathers to keep warm.
1. Arctic Fox (pictured below)
1. Arctic Fox (pictured below)
2. Snowy Owl
3. Caribou
4. Musk Ox
5. Ermine
4. Musk Ox
5. Ermine
Plant Adaptations
Because of the hard permafrost, most plants in the tundra need to be short-rooted and be able to endure cold temperatures.
1. Arctic Moss (pictured below)
1. Arctic Moss (pictured below)
2. Arctic Willow (pictured below)
3.Labrador tea
4. Pasque Flower
5. Tufted Saxifrage
4. Pasque Flower
5. Tufted Saxifrage
Keystone Species- Arctic Fox
This species controls other populations below it by feeding on them. It is a top predatator keystone species. Without it, prey would eat too much vegetation for the ecosystem to support.
Indicator Species -Cotton Grass
This sedge grass indicates the health of the tundra. It lives in the bogs and marshes during the warmer months. It is especially affected by glabal warming, since it sometimes germinates at a different time than usual. Although this is a native plant, it is very sensitive to environmental factors such as nutrient content and temperature. Its health mirrors that of the biome, and that is how it's an indicator.
K- Strategist -Polar Bear
Polar Bears are large animals and can live for 20 years or more. Their shoulder height can be five feet or more and when they are standing up, their height can be 8-11 feet. Females weigh 660-770 lbs and males weighs 880-990 lbs. Polar bears spend most of their time on drifting packs of ice, eating, and resting. The bears reach sexual maturity 3 to 5 years after birth. They usually mate in March and have their cubs 7 to 8 months later. Each year pregnant polar bears dig a den in the snow of southern facing slopes, where they give birth. The females gives birth to one or two cubs. Cubs are usually born in December or January. They are cared for by their mother.
R-Strategist -Harlequin Duck
These ducks serve as prey for the arctic fox and others. They can have usually have 7 babies a year. They live together in flocks, but don't really care for their young long.
Environmental Problems/ Threats
The tundra is a very fragile environment. Due to extreme temperatures, plants and animals have a hard time coping with any extra stresses and disturbances. Constructing towns or oil rigs places stress on the animals by destroying natural habitats and interfering with natural feeding grounds. When animals come to towns, the can be shot at or scared away from feeding grounds. This can cause starvation. Using pesticides to control bug populations hurts the bird population and others when 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 pollution has killed many plants, and has consequentially affected animals. Even walking on the tundra can cause damage. When the sunlight hits these compressed areas, the permafrost melts. This can cause erosion and create bodies of water from the melting ice, which can destroy animal habitats and permanently change the landscape.