The distribution and characteristics of biomes

Explaining the distribution and characteristics of biomes

Climate is a key factor influencing the distribution of biomes, with rainfall and temperature determining what grows within a particular location. Temperature ranges (annual and diurnal), as well as seasonal variations in rainfall and winds, are also key climate factors that need to be considered and can affect the characteristics and distribution of biomes.

Tropical rainforests: The equator experiences direct sunlight overhead 12 hours a day, all year round, causing warm air to rise. As the air cools, it condenses, leading to an increase in water vapour. The creation of clouds leads to high rainfall. Where the atmospheric systems of the northern hemisphere meet those of the southern hemisphere, this is known as the Intertropical Convergence Zone. As a result, the tropical rainforest biome occurs.

Tropical grasslands: located further away from the equator, the tropical grassland biome still experiences high temperatures. However, the dry season only allows for tall grasses and small shrubs to thrive. Elephant grass grows rapidly in the summer, but dies back in winter when it is dry.

Hot Desert: Sinking warm air holds moisture, so limited clouds form. High air pressure leads to high daytime temperatures, but deserts have cooler nighttime temperatures due to limited cloud coverage to keep the heat in. Less cloud cover leads to limited rainfall; therefore, plants and animals must adapt to survive in the harsh conditions.

Temperate forests: Occurring at higher latitudes such as the UK, temperate forests consist of many low-pressure systems. This creates year-round rainfall. Sunlight hours are reduced in the winter, which reduces photosynthesis. Deciduous trees shed their leaves in autumn to protect themselves from the colder temperatures.

Temperate grasslands: Located generally in the interior of continents, such as the steppes of southern Russia and the prairies of central USA, temperate grasslands have more pronounced seasons. Warm, wet summers allow grasses to thrive, and they can survive the cold, dry winters. There are few trees as they cannot survive the dry winters.

Boreal forests: Located in the northern hemisphere, around 60° north of the equator and on mountains. Temperatures are colder, with sinking air leading to low precipitation. Trees such as conifers are adapted to protect themselves from the cold, with waxy needle-like leaves that allow for quick photosynthesis when spring arrives. Trees also have flexible branches, so when snow falls, the flexible branches allow the snow to slide off, reducing the damage to the tree.

Tundra Biome: Located further north of the boreal forests, the tundra biome is the closest to the North Pole. Plant growth is minimal due to the cold temperatures and the reduced sunlight hours in winter. For many months in the Arctic Circle, the sun does not rise. Limited precipitation and slow evaporation allow bog plants such as mosses and sedges to grow in these harsh conditions.