Natural Grasslands primarily occur in regions that receive between 500 and 900 mm of rain per year.
Climate plays an important role in the formation of grasslands, Grasslands are dominated by grasses and Grasslike plants.
There are two different kinds of grasslands: Tropical and Temperate.
Grasslands are known by different names in different parts of the world: –
‘Steppes’ in Asia;
‘Prairies’ in North America;
‘Pampas’, ‘LIanos’ and ‘Cerrados’ in South America;
‘Savannahs’ and ‘Velds’ in Africa; and
‘Rangelands’ in Australia.
Grasslands in the southern hemisphere tend to get more precipitation than those in the northern hemisphere.Some grasses grow more than 7 feet (2 meters) and have roots extending several feet into the soil.
Tropical grasslands are warm year round, but usually, have a dry and a rainy season.One such tropical grassland, the African savanna.
Temperate grasslands which receive average between 10 and 30 inches (25 and 75 centimetres) of rain per year, have shorter grasses, sometimes just a few millimetres.
- The temperate grasslands of North America are known as the Prairies.
- The prairies cover parts of United States of America and parts of Canada.
- Prairies are treeless but, near the low-lying plains, flanking river valleys, woodlands can be found.
- Tall grass, up to two metres high, dominates the landscape.
- It is actually a “sea of grass.”
- The prairies are bound by the Rocky Mountains in the West and the Great Lakes in the East.
- The summers are warm with temperatures of around 20°C, while in winter -20°C.
- The annual rainfall is moderate and is ideal for the growth of grass.
- Due to the absence of the north-south barrier, a local wind “Chinook” blows here which helps in the melting of snow, making pasture land available for grazing of animals.
Flora and Fauna
- The Rainfall is very little or unreliable, grasses are short and sparse.
- These areas are suitable for cattle rearing. Large cattle farms called ranches. Bison or the American Buffalo is the most important animal of this region.
- The Prairies are also known as the “Granaries of the world,” due to the surplus of wheat production.
- In the USA, the area is drained by the tributaries of Mississippi.
- The Canadian prairies are drained by the tributaries of Saskatchewan Rivers.
The temperate grasslands of South Africa are called the velds.
- Velds are rolling plateaus with varying heights ranging from 600 m to 1100 m.
- It is bound by the Drakensburg Mountains on the east and to its west lies the Kalahari desert.
- On the northeastern part, “high velds” are located that attain a height of more than 1600 m, in some places.
- The tributaries of rivers Orange and Limpopo drain the region.
- The velds have a mild climate due to the influence of the Indian Ocean.
- Winters are cold and dry.
- Temperatures vary between 5°C and 10°C and July is the coldest month.
- Summers are short and warm.
Flora and Fauna
- Grasses dominate the landscape. Red grass grows in velds.
- In the high velds acacia and maroola are seen to be growing.
- The animals of the velds are primarily lions, leopards, cheetah and kudu.
- Sheep rearing is the most important occupation of the people.Merino sheep is a popular species and their wool is very warm.
- Gold and diamond mining are major occupations of people of this region.
- Johannesburg is known for being the gold capital of the world.
- Kimberley is famous for its diamond mines.