The climates of the world’s grasslands vary a great deal. In Africa there are huge areas of grassland called savannah. These are warm all year round with summer rains. They support large populations of seed-eating birds and grazing animals, which in turn provide food for large meat-eating animals, such as lions, leopards, cheetahs, hyenas and jackals. The North American prairies and Russian steppes are similar in having hot summers but very cold winters. Great herds of bison once roamed the North American “sea of grass”, but early settlers killed enormous numbers of them for food and sport. Now the bison is a protected species. South American grasslands, called pampas, and the South African veld have sparser tussocks of grass.
Found in the middle of large land masses or continents. The two major areas are the prairies in North America and the steppe which straddles Europe and Asia. The majority of this biome is found between 40° and 60° north or south of the Equator.
There is a large temperature range between this region’s cold winters and hot summers, as this region is far from the moderating effect of sea breezes (warming in winter, cooling in summer) because they are found inland. A great variety of temperatures may also occur in the same place within a single day. Temperatures may change by as much as 30 °C from day to night, a diurnal (geographer’s word for daily) difference only beaten by hot deserts. However with total rainfall of between 250-500mm per year, this is a much wetter biome than a desert.
Temperate grasslands are known as the Prairies in North America, Pampas in Argentina and in Europe and Asia this kind of ecosystem is called Steppe. In New Zealand this zone includes the Canterbury Plains, and in South Africa it’s part of the Veld.
This biome is of real importance to humans for food production. Their dark, deep soils are amongst the richest in the world. This feature of temperate grasslands means that a lot of this biome is in fact now farm land. For example less than one per cent of the Prairies remain untouched, surrounded by gigantic flat fields of maize and wheat or cattle ranches.
Plants that flourish here are primarily grasses like grama and buffalo grass. It is too dry for trees here. Some grasses grow up to two metres in height in patchy tufts, whereas other feather-like plants carpet a vast area but only grow to a maximum of 50cm. The deep roots of these grasses seek out underground stores of water up to two metres below the ground. In temperate grasslands rainfall is limited apart from in late spring and early summer when seeds wake up and grow quickly, using nutrients released as last year’s plant growth rots down. The new grass provides food for grazing animals like bison, deer, and if you’re in Australia, Kangaroos. The rhea is a big flightless bird that makes its home in South America. They too eat leaves and seeds but also love lizards and beetles. Animals that like meat and veg like Rhea are called omnivores.
Wild animals remain in abundance where temperate grassland has been conserved. In the Prairies grasshoppers feed on grass but themselves make a tasty meal for prairie dogs. Prairie dogs in turn need to keep a look out for predators like rattlesnakes, coyotes and golden eagles. These ground-living squirrels live in colonies or groups and make their homes deep underground. The heaps of soil left by their burrowing form handy look out humps. Underground living can have its advantages in a place where the temperature can vary greatly, from 40 °C in summer (phew) to -40 °C in winter. The temperature also changes a lot within a twenty-four hour period in this kind of ecosystem. In Mongolia temperatures might rise and fall by as much as thirty degrees centigrade!
Picture Credit : Google