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Herbert Hoover National Historic SiteA red barn on the ridge of a green prairie.
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Herbert Hoover National Historic Site
Environmental Factors
 
A shrub burns during a prairie fire.

Sheila Edwards

Grasses and forbs recover more quickly from periodic fires than do woody plants like young trees and shrubs.

Pioneers crossing Iowa found this land among the most difficult portions of their passage. Iowa’s groundwater-based hydrology resulted in a myriad of sloughs that stopped wagon wheels, as they penetrated the saturated soil to the hubs.

Development of the land resulted in the loss of these wetlands in eastern Iowa. Small creeks cut into the soils where linear wetlands once stored rainwater and refreshed the ground water. This change in hydrology has impacted water quality and quantity.

Temperatures range broadly over the year with –28º F and 108º F representing the extremes. The average growing season extends over 183 days from April through September. Average precipitation is 36 inches a year with about 60% occurring during the growing season. These extremes in temperature and moderate rainfall allow for lush growth of the prairie. Fire also maintains the prairie and savannas in Iowa by excluding shrubs and small trees.

A man with binoculars searches for birds.
Inventory & Monitoring
Natural resources inventory and monitoring at Herbert Hoover NHS
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Trees and snow-covered banks along a creek.
Hoover Creek
The creek faces serious problems with water quality, erosion, and flooding.
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Photograph of Herbert Hoover as an infant.  

Did You Know?
Herbert Hoover was the first person born west of the Mississippi River to become president. Seven other presidents were born west of the river.
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Last Updated: May 22, 2008 at 17:49 EST