Zones of different biomes occur from the equator to the arctic and to the antarctic due to differences in climate. In the equatorial and tropical areas where temperature and rainfall are high all year round, tropical forests occur while in the cold arctic regions, treeless plains called tundra are found.
Climates change with distance from the equator and also with height above sea level, as such zones of different biomes occur from the equator to the poles and on a mountain side.
Examples of Major Biomes of the World
- Tropical rain forests:These consist of dense forests with many types of trees, epiphytes and climbers. Rainfall is abundant throughout the year and an average temperature of 27ºc is recorded throughout the year. Located around the equator e.g. around coasts of West Africa, Amazon basin of South Africa, etc.
- Temperate forests:These consist of broad-leaved deciduous trees which shed their leaves during winter. A lot of different plants grow at many levels from the ground as the trees are not densely packed as in the tropical forest. It has a moderately wet climate and a dry or cold season. Examples are found in North America, lowlands of North – West Europe (e.g. France), and Britain.
- Coniferous forest:These consist of needle leaved, evergreen conifers e.g. pines, fires and spruces. Only a few types of tree are found in these forests. Other plants such as shrubs, ferns and mosses are also present. The temperature is cool and rainfall is light. There is also light snow. Examples are found in Eurasia and North America.
- Temperate shrubland: Consist of drought-resistant shrubs, aromatic plants and dwarf trees. The temperature is very high (over 30ºc), rainfall is low, the summers are hot and dry and the winters are mild and rainy. Examples are found in North-Eastern Brazil, Australia, and close to the Sahara in West Africa.
- Savanna:These are tropical grasslands with few scattered trees. It has a moderately dry climate, a warm dry season and a hot rainy season. Examples are found in Central America, Interior of Brazil, West Africa, East Africa, and South-East Asia.
- Temperate grassland: Consist of large stretches of perennial grasses growing on very fertile soil. Examples are the steppes, prairies, plains, pampas and veld. The climate is moderately dry with a cold winter and hot summer. Examples are Found in the interior continents in Asia, North America, South America, (Argentina), South Africa and Australia.
- Desert: Consist of very sparse vegetation which are mainly succulent perennials with deep root systems and annuals which exist mainly as seeds, germinate and grow rapidly, flower and produce seeds during brief periods of rain. Rainfall is very low and temperature is very high. E.g. Sahara desert (North Africa), Arabian Desert (Arabia), e.t.c.
- Tundra:Consists of treeless marshy vegetation composed mainly of dwarf shrubs, grasses, sedges, lichen and moss. The climate is clod with long icy winters and very short summers. The average temperature is 10ºc. Examples are the coastal strip of Greenland, Northern Canada and Alaska, Arctic seaboard of Eurasia.
- Mountain vegetation:Consist of evergreen rain forest occurring on the slopes of mountains. The forests are less luxuriant than the tropical rain forest. The Afro-alpine vegetation occurs at height above 3000m on mountains. The vegetation consist mainly of heaths, grasses and sedges. In Africa it is found in Cameroon mountain, Kenya highland and Kilimanjaro mountain. Temperature decrease with altitude. Rainfall is heavy on the windward side and less on the leeward side of the mountains.