Prairie History
Prairie is an ecosystem of flora (grasses and flowering plants or forbs), fauna (vertebrates and invertebrates), on a substrate (soil) which has been shaped by frequent fire. Together these components create an interdependent ecosystem. The prairie is an intricate web. More of its living mass is below ground than we can see above ground. The roots of the grasses and flowering plants grow deep beneath the surface.
As the glacial ice-sheets retreated from Iowa 12,000 to 10,000 years ago, the climate gradually changed. As the spruce and pine forests retreated with the colder glacial climate, prairie became established in the warmer, drier climate. Forests have made advances into the prairie at different times in the past 8,000 years as the climate has changed. Fires kept most of the forest at bay. Certain trees could survive some of the fires and grew wide-spaced intermingling with the prairie, creating savannas.
As prairie plants grow, most of the initial growth is below ground into very deep root systems. Two-thirds of the living portion of the prairie is below ground in the roots. As fire burns across the land, it burns the dead material from the top of the plants, returning its' nutrients to the earth. Fire eliminates most plants that have shallow roots. Prairie plants then re-sprout from its deep roots. Over thousands of years, the continuous cycle of life and death on the prairie built the rich, black soils of Iowa and the Midwest.
When European-American settlers first came to Iowa and the midwest, they thought it was a desert because there were few trees over much of the land.
The prairies have inspired many accounts in diaries and journals. People soon learned that under the sea of Iowa's grasses lay some of the richest soil in the world. As agricultural expansion took off across the state, the prairie soon succumbed to the plow. These soils created by the prairies over thousands of years have led to Iowa's prominence in global agriculture today.
Today, less that 0.1% of Iowa's native prairies remain.
It's demise is the result of many factors including agriculture conversion, urban sprawl, fire suppression, and ignorance. These important remnants harbor knowledge yet untold. It gives us clues and insight into how our soils, landscape, and even the lives native peoples, pioneers, and all us Iowans have shaped this land we call home. The prairie's beauty is unrivaled, with the blooms of its' flowers and grasses changing with each passing season and feeding the senses with a calming aesthetic. The genetic and biological diversity it harbors in its flora and fauna are disappearing from the earth. The prairie is our most diverse and complex ecosystem in Iowa, and even the small remnants harbor more diversity than most of the rest of the state. We are committed to saving this natural, historic legacy.
Map of Iowa's original landcover:
Map of Iowa's current landcover:
The landcover of Iowa has changed dramatically since the time of settlement in the mid-1800's. The maps provided here document this drastic change and the need to save the remaining small pieces of natural areas, prairies in particular.
The maps of the pre-settlement vegetation of the state of Iowa have been derived using two different methods. It is important to understand how this data was derived, and the inherent limitations of the data. It is strongly encouraged that you read the metadata about these projects at their respective sites.
The GLO (Government Land Office) maps were developed by the Government Land Office Project at Iowa State University, that looks at what was recorded by surveyors when the state was surveyed. Overlaid on top of this data for spatial reference, is the current stream network, highways, and rail lines.
The Soils maps information was derived from the county soil surveys. They were developed under the Iowa Cooperative Soil Survey. It looks at the soils information, and determines what vegetation was present to derive the current soils. This data is overlaid onto an elevation model. Overlaid on top of this soils data is the current highways, rail lines, and stream network.
The 1992 Landcover Maps were derived from Satellite Imagery. Overlaid on top of this data is the current highways, rail lines, and stream network.
Remnant: A pre-settlement native plant community (i.e. prairie or forest). A plant community that has survived on a site to the present day.
Restoration: A native ecosystem that has been taken over to some degree by another plant community. Management is being used to restore pre-settlement vegetation. Restorations are often supplemented with seeds from plants that may have grown on the site. Restorations usually involve removing a plant community that has taken over the remnant.
Reconstruction: A planted prairie. Usually a planting of grasses and forbs (flowering plants) onto land that had the native vegetation removed (i.e. agricultural land). Reconstructions usually will not have the plant diversity of a Remnant or a restoration. Insect and other organisms are missing too.
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A subset of a species that has adapted to a specific geographic environment and as a result has evolved to be genetically distinct from other members of the same species found in different environments. Different ecotypes of the same species can usually form fertile hybrids but in some cases they do not.​​