Biomes are large natural terrestrial ecosystems. We identify a biomes by its vegetation. This is because plants from bulk of the community in any ecosystem. For example, a forest biome has densely packed tall trees, while grasses and a few scattered shrubs are found in a savanna biome.
The type of vegetation in a biome is largely determined by climate factors, especially rainfall and temperature. Regions throughout the world which have similar climate have similar biomes. This causes zones of different biomes to occur from the equator to the Arctic, and to the Antarctic. For example,
• in equatorial and tropical areas where temperature is high all the year round tropical forests occur;
• in Temperature regions coniferous and deciduous forest occur;
• while treeless plains (tundra) are found in the cold arctic regions.
Forest give way to tropical and temperate grasslands and the annual rainfall is low (about 300 to 1000mm) and to deserts when rainfall is extremely low (below 300 mm).
Climate also changes with height above sea levels. As a result , zones of different biomes occur on s mountain side.
