This summer, I was able to attend a bioblitz at the Whiterock Conservancy near Coon Rapids, Iowa.
On one of the field trips we saw three types of habitat typical to Iowa. We traveled through the first two to find my favorite. On a hill, surrounded by farmland, we found a prairie remnant.
This was the focus of our visit. The tallgrass prairie originally covered large areas of Iowa, and it was beautiful. A patch this size would typically have had a few hundred species of plants, with a very rich fauna. The tallgrass prairie was a habitat that probably resulted from management by man–the original people of the area would set wild fires that wiped out the forests that might otherwise grow there, given the amount of rain. There may have also been vast wildfires from natural causes.
We passed through a corn field–this is an extensively managed monoculture. There is corn (maize) and not much else. After spending five (almost six) decades in Iowa, I can say that I remember a time when the corn in the fields was planted in wider rows, and that there were more weeds in the rows. You are not likely to find a plant that is not maize in a cornfield now.
Around the edges of the fields were the grasses–areas that have been mowed, probably cultivated at one time or another, and in general have been heavily managed. There might be a dozen or two species, mostly grasses but some flowering plants.
Iowa is probably 65% monoculture, either corn or soybeans. Other agricultural uses would take another 20%. Two percent is public land. Prairies are maybe one tenth of one percent.