If it cannot tolerate the conditions, it will not survive as part of the ecosystem. Precipitation and sunlight determine the major climates of the earth. Within them, the earth can be divided generally into biomes, representations of plant and animal ecosystems which occur in a major climate. Occurring in the central part of North America, prairies are subject to extreme ranges of temperatures, with hot summers and cold winters. There are also great fluctuations of temperatures within growing seasons.
Rainfall varies from year to year and within growing seasons as well.
The prairie region is also subject to droughts. Usually there is a prolonged dry period during the summer months, and in addition there are major droughts lasting for several years that occur every 30 years or so. Before European settlement, the eastern boundary of the prairie was in a state of flux. During periods of drought, trees died and prairie plants took over previously forested regions. When rainfall was abundant, the trees and forest were able to reestablish themselves.