Factors affecting the distribution and characteristics of biomes

Edexcel B GCSE Geography > People and the Biosphere > Factors affecting the distribution and characteristics of biomes

Factors affecting the distribution and characteristics of biomes

Biomes are very large ecosystems such as tropical rainforests, deserts and taiga. The following diagram shows the distribution of major global biomes. Climate has a key role to play in influencing the global distribution of ecosystems, while on the smaller scale, altitude and soil type are more important.

A map to show the main biomes of the world

Biome	Climate Characteristics	Distinctive Vegetation
Tropical rainforest	Hot and wet all year, temperatures range from 25-30°C and precipitation between 200-3000mm.	Dense vegetation, forests have several layers competing for light and nutrients. Home to many species of flora and fauna.
Tropical grasslands (savanna)	Temperatures are highest (around 35°C) just before the wet season and lowest (around 15°C) just after it. Rainfall is relatively low (around 500-1000mm per year)	Mainly grass, scrub, small plants and a few specially adapted trees e.g. baobab. These plants are adapted to recover quickly after a fire.
Deserts	Very hot days (+30°C), and cold nights (-0°C) Rainfall is low, less than 250mm per year.	Plant growth is scare due to limited rainfall. Plants that can survive include cacti and thorn bushes which are adapted to the harsh environment.
Temperate grasslands	Hot summers (up to 40°C) and very cold winters (down to -40°). Rainfall is quite low, around 500-900mm per year.	Mainly grassland vegetation, few trees and bushes. Limited species of animals.
Temperate forest	Summers are warm, and winters are cool, temperatures range from 18°C to 5°C. Precipitation falls throughout the year, around 1000mm.	Rich deciduous woodlands, such as oak trees. These trees lose their leaves in autumn creating nutrient rich soils.
Boreal forest	Summers are short & mild (10-20°C) but winters are long and very cold (below 0°C). Precipitation is limited, less than 500mm and usually falls in summer.	Vegetation and trees are evergreen, growing wherever there is enough sunlight. Coniferous trees such as pine and fir are common.
Tundra	Temperature stays below freezing for most of the year, with summer temperatures reaching 10°C. Less than 250mm of rainfall falls each year. There is near-continuous sunlight during the summer, and little or no sunlight during the winter.	Due to the harsh environment, very few plants can survive. There are few trees due to lack of light in the winter. Vegetation includes mosses, grasses and low shrubs.