The awesome Arctic
Have you heard of biomes? What is it? The earth is divided into large areas of land classified by its distinct plants and animals. Each biome is characterised by its temperature and the amount of rain it receives. A biome is made up of many ecosystems–the interaction of living and non-living things in an environment.
There are eight major terrestrial biomes. They are Tropical Rainforest, Savannah, Grassland, Desert, Temperate deciduous forest, Boreal forest/Taiga and Tundra.
The characteristics of each biome are dependent on its climate, particularly temperature and the amount of precipitation the area receives.
Let’s take a look at the Arctic Tundra
This is the northernmost biome and covers the lands north of the Arctic Circle up to the polar ice cap. It reaches as far south as the Hudson Bay area of Canada and the northern part of Iceland. It covers approximately 11.5 million km2.
The Arctic Tundra is a vast, dry, rocky place that is noted for its lack of trees. One important characteristic is the permafrost, which starts within a metre of the soil surface. The permafrost prevents trees from growing. Despite the lack of trees, this biome is considered a major carbon sink as there are large amounts of organic matter found in deposits of peat and humus.
Due to its northern position, the Arctic Tundra has a very cold climate. Temperatures range from 15.5 °C in summer to -60 °C in winter and mean temperatures are below 0°C for six to 10 months of the year. Summers are also much shorter than winters.
Due to the cold climate and short growing season, most vegetation in the tundra tends to be herbaceous. This includes grasses, mosses such as reindeer moss, liverworts and lichens. The few woody plants which live in the tundra, such as dwarf willows, tend to be short and spread across the ground.
Many large mammals, such as caribou, polar bears, arctic foxes, and musk ox, are found in this biome. There are also several smaller mammals, such as lemmings and arctic hare which are prey to the larger mammals.
During the summer many migratory birds, such as loons, snow geese and terns, come to the tundra to breed. Although there is low insect biodiversity, the insects that live in the arctic tundra, such as mosquitoes, can have large populations.
Climate change has a large impact on this biome. Higher global temperatures are melting the sea ice and permafrost. This is altering and sometimes destroying the habitats of plants and animals.