Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees. In the Miocene and Pliocene Epochs, which spanned a period of about 25 million years, mountains rose in western North America and created a continental climate favorable to grasslands. Ancient forests declined and grasslands became widespread. Following the Ice Ages, grasslands expanded in range as hotter and drier climates prevailed worldwide. There are two main divisions of grasslands: (1) tropical grasslands, called savannas,
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showed last 75 words of 597 total
range is very large over the course of the year. Summer temperatures can be well over 38° C (100 degrees Fahrenheit), while winter temperatures can be as low as -40° C (-40 degrees Fahrenheit).
The Human impacts on grasslands are as follows...
·Destroyed vegetation, re-growth is very slow
·Burning, plowing savannah for cropland
·Overgrazing as water becomes available
·Plowing temperate grasslands; poor farming practices
·Destruction of tundra by oil exploration, drilling & transport, air pollution, vehicle damage