Why Did Ohio’s Large Prairies Persist into Modern Times?
Ohio gets ample precipitation every month of the year, enough to support the growth of typical eastern deciduous trees and the forests they compose. Why, then, did Ohio have three large landscape prairies in presettlement times?
How these prairies first came to Ohio is known. From 8000 to 4000 years ago the Midwest had a climate that was much drier and warmer. During that time, known as the Xerothermic Interval, it was too hot and dry for typical forests to thrive. Tallgrass prairie invaded. But about 4000 years ago the climate returned to the moist one we have today, and forests recaptured most of Ohio — except in the state’s large prairie areas.
How did those prairies persist for 40 centuries in the face of invading forests that would otherwise shade out sun-requiring prairie plants?