The vast grasslands

   Tropical grasslands, called savanna, campos or llanos, occur north and south of the equator in Africa, South America, southern Asia and northern Australia. They are in warm regions with high rainfall. But, because they have a marked dry season, forests do not develop except in such areas as river valleys. Tropical grasslands are used for cattle rearing and some crop farming. But there is a danger that the winds will blow away the exposed soil in the dry season. Such soil erosion can make a region infertile in a few years. In Africa, the savanna supports many animals.
   Temperate or mid-latitude grasslands have less rain and much colder winters than tropical grasslands. Trees are also rare on the dry, windswept plains. Huge areas of temperate grasslands, which are also called prairies, steppes or pampas, have become cattle ranches or vast wheat farms. The wildlife has been much reduced. In Australia, sheep have replaced most of the kangaroos and wallabies of the grasslands.