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Unlock This CourseA biome is a large-scale ecosystem characterised by distinctive plant and animal communities that have adapted to specific climate conditions. Understanding biomes is crucial for geography students as they help us see how climate, vegetation and wildlife are connected across our planet. World maps showing biome distribution reveal fascinating patterns that tell the story of Earth's diverse environments.
Key Definitions:
World biome maps use different colours to show where each biome is found. The key or legend tells you which colour represents which biome. Look for patterns - notice how similar biomes appear at similar latitudes (distances from the equator).
There are several major biomes found across the world, each with unique characteristics shaped by temperature, rainfall and seasonal patterns. Let's explore the main biomes you'll encounter on world maps.
Found near the equator, tropical rainforests are the most biodiverse biomes on Earth. They appear as dark green bands on biome maps, stretching across the Amazon Basin, Central Africa and Southeast Asia.
Hot and wet year-round, with temperatures around 25-30°C and over 2000mm of rainfall annually.
Incredibly diverse, including jaguars, toucans, poison dart frogs and millions of insect species.
Dense, multi-layered forests with emergent trees, canopy, understory and forest floor layers.
The Amazon covers 5.5 million km² across nine countries, with 60% in Brazil. It's often called the "lungs of the Earth" because it produces 20% of the world's oxygen. However, deforestation for cattle ranching and soy farming threatens this vital biome, with an area the size of a football pitch cleared every minute.
These biomes appear in mid-latitude regions on world maps, typically shown in medium green. They're found in eastern North America, western Europe and parts of East Asia.
Trees lose their leaves in autumn and regrow them in spring. This adaptation helps them survive cold winters when photosynthesis is difficult.
Grasslands appear as yellow or light green areas on biome maps. There are two main types: temperate grasslands (prairies, steppes) and tropical grasslands (savannas).
Found in North American prairies, Argentine pampas and Eurasian steppes. Perfect for agriculture due to fertile soils.
Found in Africa, northern Australia and parts of South America. Home to large herbivores like zebras and elephants.
Dominated by grasses with few trees. Rainfall is moderate and often seasonal.
Deserts are shown in tan, yellow, or orange colours on biome maps. They're found in two main belts around 30° north and south of the equator, plus some inland areas.
Not all deserts are hot and sandy. There are four main types, each adapted to different climate conditions.
Like the Sahara and Arabian deserts. Extremely hot days, cool nights and very little rainfall (less than 250mm per year).
Like the Gobi Desert in Asia. Cold winters, warm summers and low precipitation that often falls as snow.
The Sahara is the world's largest hot desert, covering 9 million km² across North Africa. It's roughly the size of the entire United States! Despite extreme conditions, it supports 2.5 million people who have adapted to desert life through nomadic herding and oasis agriculture. Climate change is causing the Sahara to expand southward, affecting the Sahel region.
These cold biomes appear at the top of world maps, shown in light colours. They're found in the far north of Canada, Alaska, Siberia and Scandinavia.
The northernmost biome, characterised by permanently frozen subsoil called permafrost. Summers are brief and cool, winters are long and harsh.
Polar bears, Arctic foxes, caribou and migratory birds that arrive in summer.
Low-growing plants like mosses, lichens and small shrubs that can survive extreme cold.
Average temperatures below -10°C, with the warmest month rarely exceeding 10°C.
Just south of the tundra, the taiga is the world's largest biome, forming a belt across northern Canada, Alaska and Siberia.
Dominated by evergreen conifers like spruce, fir and pine. Their needle-shaped leaves and waxy coating help them survive cold winters.
When studying biome maps, geographers use specific skills to understand patterns and relationships. Here's how to analyse biome distribution effectively.
Look for these key patterns when examining world biome maps:
Similar biomes appear at similar distances from the equator due to climate similarities.
Interior areas of continents often have different biomes than coastal regions.
Mountain ranges create barriers that affect precipitation and temperature patterns.
Humans have significantly altered many biomes through agriculture, urbanisation and resource extraction. Understanding these impacts is crucial for sustainable development.
Different biomes face different types of human pressure, leading to various environmental challenges.
Most temperate grasslands have been converted to farmland because of their fertile soils, making them one of the most altered biomes.
Deforestation affects both tropical and temperate forests, reducing biodiversity and contributing to climate change.
The North American Great Plains were once vast temperate grasslands supporting millions of bison. Today, over 90% has been converted to agriculture, producing wheat, corn and cattle. This transformation has created one of the world's most productive farming regions but has also led to soil erosion, water depletion and loss of native species. The Dust Bowl of the 1930s showed the consequences of unsustainable farming practices.
Global warming is causing biome boundaries to shift, with significant implications for ecosystems and human societies. Understanding these changes helps us predict future environmental conditions.
Scientists have documented several biome shifts occurring due to climate change:
Forest boundaries are moving northward and upward in mountains as temperatures warm.
Some deserts are expanding into neighbouring grasslands due to changing rainfall patterns.
Tundra permafrost is melting, potentially converting tundra to taiga forest.