geography year 9 - great plains
TRANSCRIPT
GREAT PLAINS
WHAT IS A PLAIN?
In geography, a plain is a flat area. Plains occur as lowlands and at the bottoms of valleys but also on plateaus or uplands at high elevations. Plains may have been formed from flowing lava, deposited by water, ice, wind, or formed by erosion by these agents from hills and mountains.
IMPORTANCE
Plains in many areas are important for agriculture because where the soils were deposited as sediments they may be deep and fertile, and the flatness facilitates mechanization of crop production; or because they support grasslands which provide good grazing for livestock.
OPEN SPACES
The great plains are the vast open spaces of our planet. These immense wilderness areas are seemingly empty. The plains of our planet support the greatest gatherings of wildlife on earth: two million gazelles on the Mongolian steppes, three million caribou in North America and one and a half million wildebeest in East Africa. Close on their heels come an array of plains predators including eagles, wolves and lions.
GRASS
At the heart of all that happens here is a single living thing - grass. Flooded, burnt, baked and frozen - grass is almost indestructible, able to survive from the baking savannahs of Africa to the frozen tundra of the Arctic, from the floodplains of India to the high altitude steppes of the Tibetan plateau. Together, these hugely productive grassland plains encompass a quarter of the land on earth.
THE GREAT PLAINS IN NORTH AMERICAThe Great Plains in North America is the flat land covered in prairie, steppe and grassland, that lies west of the Mississippi River tallgrass prairie states and east of the Rocky Mountains in the United States and Canada.
CLIMATEIn general, the Great Plains have a wide variety of weather through the year, with very cold and harsh winters and very hot and humid summers. Wind speeds are often very high, especially in winter. Grasslands are among the least protected biomes. Humans have converted much of the prairies for agricultural purposes or to create pastures. The Great Plains have dust storms mostly every year or so.