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Geography

Tropical rainforests

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The tropical rainforest is a biome [biome: A large-scale ecosystem. ] with a constant temperature and a high rainfall. The level of humidity [humidity: The amount of water vapour in the atmosphere measured as a percentage. ] and density of the vegetation give the ecosystem a unique water and nutrient cycle. Rainforests around the world are threatened by human expansion.

Characteristics and climate

See where tropical rainforests are found on this biomes map.

A tropical [tropical: The northern boundary of the Tropic of Cancer is found at a latitude of 23.5° North. The southern boundary of the Tropic of Capricorn is 23.5° South. Everything between these two lines is said to be tropical. ] rainforest biome is found in hot, humid environments in equatorial climates. They contain the most diverse range and highest volume of plant and animal life found anywhere on earth.

In general, tropical rainforests have hot and humid climates where it rains virtually everyday. The level of rainfall depends on the time of year. Temperatures vary through the year - but much less than the rainfall.

The graph shows average rainfall and temperature in Manaus, Brazil, in the Amazon rainforest. The rainy season is from December to May. Notice how much the rainfall varies over the year - the highest monthly rainfall is in March with over 300mm, while the lowest is in August with less than 50mm. Over the year, the temperature only varies by 2°C.

Monthly average of rainfall/temp in rainforest area of Manaus, Brazil

Monthly average of rainfall/temp in rainforest area of Manaus, Brazil

Compare these patterns with the one for savannah grassland and coniferous forest. Make sure you know the differences between them!

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Back to Ecosystems - the living world index

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