The prairies of the Great Plains of the northern part of mainland America, before being developed by Europeans, occupied about 4 thousand kilometers in length and about 800 kilometers in width. The intracontinental location and protection from the west from precipitation by the Rocky Mountains determined their climatic features and limited vegetation. So what are prairies?
Of course, this is the steppe. They got their name from the French settlers. The meaning of the word "prairie" is meadows. Geographically, they are located in the east of the Great Plains, in the midwest of Canada and the USA. In the north, prairies border coniferous forests, in the west - with mountains, in the east - with forest-steppes, and in the south they gradually turn into savannah and semi-desert. The amount of precipitation in the territory of the North American steppes decreases in the direction from east to west. The most arid zones are located in the center. Therefore, the vegetation on the prairies is heterogeneous, it is located in three wide stripes: tall grass, mixed and low grass.
Relief of the North American Prairies
What is the prairie of the Great Plains in terms of relief? This territory extends along the Cordillera. It is a fairly flat surface with areas of slight hillyness. In fact, this is a plateau of a low plateau, which is a continuation of the Western Plain from east to west. The average altitude of this zone is within 1.5 kilometers above sea level. The rivers deviate east and belong to the basin of two rivers: Missouri and Mississippi. Once this territory was the bottom of the ancient ocean, from the sediments of which it is composed. The prairies can be conditionally divided into four physiographic regions: three plateaus - Eduards, Missouri, Llano Estacado - and the central part of the Great Plains.
Climate
The basic component of the entire climate in North America is the air currents that carry moisture from the Pacific Ocean. But almost no water enters the prairie - it remains among the Rocky and Cascade Mountains and the Sierra Nevada. Dry winds rush along the steppes without encountering obstacles, except for the wet streams from the Gulf of Mexico. In summer, these meetings end in thunderstorms and storms, in winter - heavy snowfalls. In general, prairies are characterized by constant strong winds. The temperature here is continental - contrasting. In summer - an average of 20-25 degrees Celsius, in winter - up to -25. There are frosts and up to -50 degrees. In the east, the climate is more humid - up to 600 mm of precipitation can fall annually. The western part is more arid, here the norms do not exceed 300 mm. Approximately every five years, fires occur on the prairies. But fire rushes, as a rule, very quickly, without severely injuring the earth.
Flora of the prairies
What is the prairie in terms of flora? Natural vegetation is forest-steppe and steppe. The first is expressed by a grassy-grass cover and aspen and birch spikes. This zone is located along the Canadian border. Further south on the chernozem soils directly formed prairies. Here there is a low-growing shrub (acacia and mesquite) and a low-growing sparse grass cover. Yucca, cacti and agaves appear in more southern areas. Inside the prairies there are forest formations. In the north there is a birch forest. In the south - oaks, mesquite, acacia and juniper. Currently, the flora of the prairies is undergoing changes, since fertile soils are mostly developed by farmers and regularly irrigated.
Fauna fauna
The animals of the prairies are interesting, but, like the vegetation, they are not diverse. The most common relatives of squirrels are meadow dogs. They got their name because of the barking sounds that transmit danger signals to each other. Meadow dogs live in large colonies. They live in burrows of a rather complicated design. Dwellings can be located at a depth of 5 meters. These creatures are food for local predators: black-footed ferrets, Mexican falcon, coyote, badgers, rattlesnakes and rabbit owls. Previously, numerous herds of bison lived on the prairies. At one time they were on the verge of extinction, because of the ruthless hunt for them. Today, these large animals are protected by law. Coyotes are still quite numerous. Among the birds, meadow grouse, Canadian geese and geese can be noted.
Expansion of the prairies contributed to fires and bison
Who knows, perhaps today no one would have a question about what the prairies were, if not for the fires and all the same bison. Scientists believe that in these places forests could grow long ago, according to the soil and climatic conditions of the area. Natural fires, burning everything to the ground, and herds of animals, completely eating and trampling young growth, did their job. Scientists draw their conclusions based on similar processes in Africa, where elephants also contribute to the spread of steppe vegetation. And so these open spaces were formed ... Look at the photo of the prairie - how beautiful it is!