What controls vegetation?
Natural vegetation is plant life that grows without being planted by humans. Its distribution across the world is largely controlled by climate, especially temperature and rainfall. As a result, vegetation changes with latitude from the Equator towards the poles.
Key idea
Climate determines the type of natural vegetation — hot, wet areas are lush, while cold or dry areas have sparse vegetation.
Hot and dry belts
The tropical rainforest is found near the Equator. It is evergreen, dense, tall and has many species because rain falls heavily all year round. The savanna is a wide grassland with scattered trees, found in areas with a dry and a wet season. The savanna grasses can grow tall and provide food for grazing animals.
In the hot, dry desert, rainfall is very low. Plants such as the cactus have waxy, spiny or thick leaves and long roots to reduce water loss and reach water deep in the soil. Desert plants also grow far apart from one another.
Temperate and cold belts
Temperate deciduous forests shed their leaves in the cold season. The taiga or coniferous forest grows in cold high-latitude regions; its trees have needle-shaped leaves to reduce water loss. In the coldest areas, the tundra has only mosses and lichens with no tall trees.
Example
The Amazon in Brazil is tropical rainforest; the Sahara is desert; the taiga stretches across Siberia and Canada.
Remember
Needle-shaped and waxy leaves are how plants adapt to cold or dry conditions.