Why do the interiors of continents at temperate latitudes have vast grasslands?
The interior of the continents are usually grassland because the amount of precipitation reaching the area is restricted, In both N and S America the entire west coast has a series of mountain chains. The moisture laden winds are forced over the mountains so as they rise, they cool down, condense into clouds and then it rains. The now drier wind are what blowing over the grassland area. There is an average of 20 – 35 inches of rainfall a year. “The amount of rainfall however determines the height of grasses in the grassland. For north America, this rainfall gradient helps to divide the temperate grasslands into tall grass prairies (in wetter areas) and short grass steppes (in dryer habitats). Drought plays a large role in keeping trees from taking over the grasslands. Some years receive less rain than others, just as certain seasons receive significantly less rain than others. Trees generally can not stand the lack of water as easily as grasses and thus grasses remain dominant. ” Tempe
