A grassland biome is defined by its title. These are areas where grass is the predominant factor, rather than trees. Prairies and savannah are typical examples of grassland biomes. They are mostly populated by grazing animals, and many such areas are used for cultivation.
Grasslands tend to cover large areas and are termed ‘semi-arid’. This means that they do not have huge amounts of rainfall. On average, grasslands receive around 10-30 inches of rain per year. Grasslands temperatures vary. In summer, they can be as high as 100C and, in winter, as low as -40F. Temperatures relate directly to where the grassland is found.
There are a variety of types when looking at grasslands. The three typical examples in the United States are:
Tall grass prairie – Mainly in the eastern Midwest, grasses here can grow to five feet in height and average rainfall is around 30 inches.
Mixed grass prairie – Mid Midwest, grasses reaching between two and three feet and rainfall average around 20-25 inches. These are the plains once associated with buffalo herds.
Short grass prairie – Western Midwest, grasses reaching no more than two feet and with average rainfall around 10 inches.
Other types of grasslands across the world include:
Savannah – Often distinguished by open, grassy plains dotted with trees. Savannahs cover half the surface area of Africa, in varying forms, as well as parts of Australia, South America and India. Another distinguishing factor of Savannah grassland is climate. Savannah tends to be found in warm or hot areas, often with rainfall of up to 50 inches per year.
There must be a dry season for a grassland to be designated a savannah. This is because the dry period allows for fires which burn back growth. If this did not occur, these grasslands would become tropical forests.
The soil on these grasslands tends to be thin and drains easily. Different types of savannah support different grasses but, due to the tough living conditions, certain grasses usually come to dominate certain types of grassland. An example of this is found on the Serengeti plains where Rhodes grass and red oat grass are common, but in Uganda lemon grasses are the more dominant species.
Savannah fires are common and a natural part of the life cycle. Some poachers do start fires to clear their lines of vision when hunting, but natural fires are common. They act as a type of cleansing, burning off old growth. Savannah fires are often portrayed as being devastating to plants and wildlife, but that is not so. The roots of the grasses are protected, being below ground, and the majority of deaths come amongst the insect population, which do not have long life cycles.
Other types of grasslands include
Prairie, which tends to have richer soil,
Steppes, tending to the more arid climate
Tropical savannah, with a rich diversity of grasses, bird and animal life
Pampas – find largely in Argentina
More about all of these types of grassland can be found in links at the end of the article.
Most grasslands have an abundance of varied wildlife, mostly formed from grazing animals, but also including predators, birds and insects.
Savannah – Antelope, giraffe, elephants, leopard, lions, hyenas, moles, snakes, mice, termites, beetles and more.
Steppes, Pampas, Prairie – Zebras, rhinoceroses, wolves, prairie dogs, rabbits, skunks, birds of prey, grasshoppers, spiders and more.
