Indiana Biological Survey

Division of Fishes Projects

Eastern Corn Belt Plain Ecoregion

Eastern Corn Belt Plain sites

Pipe Creek, Indiana

The Eastern Corn Belt Plain (ECBP) consists of extensive cropland agriculture. It is distinguished from the Western Corn Belt Plain by its natural forest cover and associated soils. The gently rolling glacial till plain is dissected by moraines, kames, and outwash plains. Elevations range from 119.5 m to greater than 395.2 m. The ECBP typically has low relief, usually less than 19.8 m; however, some morainal hills occur in the northern portion of the region near Lake Erie. Stream valleys are long and sinuous and generally narrow and shallow throughout the 31,800 sq miles of the ecoregion. Small streams have narrow valley floors; larger streams have broad valley floors. Precipitation occurs mainly during the growing season and averages from 35-40 inches annually. The ecoregion has few reservoirs or natural lakes (Omernik and Gallant 1988).Both perennial and intermittent streams are common in the ecoregion. Constructed drainage ditches and channelized streams further assist in soil drainage in flat, poorly drained areas. Stream density is approximately one half mile per square mile in the most typical portions of the ecoregion.

The ECBP is almost entirely farmland. The major crops produced in the ECBP are corn and soybeans. A total of 75% of the land use is cropland, while remaining 25% is permanent pasture, small woodlots, or urban. Emphasis on livestock includes the growing of feed grains and hay. Swine, beef, and dairy cattle, chickens, and turkey are raised.

Most of the soils of the ECBP ecoregion developed under the influence of deciduous forest vegetation. The soils are loamy calcareous glacial till, overlain by loess deposits. The soils are lighter in color and more acid than the adjacent Central Corn Belt Plain. Hapludolls and Ochraqualf’s are the dominant soil groups on dry and wet upland sites, respectively. Argiaquolls, Haplaquolls, and Medisaprists have developed in flats and depressions. Hapludalf’s and Fragiudalf’s are common in well drained slopes on some valley sides where erosion has removed the glacial material and exposed the underlying shale limestone. Udifluvents and Fluvaquents have derived drom silty alluvium in narrow floodplains.

The natural vegetation of the area consisted of diverse hardwood forests, predominantly American beech and sugar maple. A significant amount of white oak, black oak, northern red oak, yellow popular, hickory, white ash, and black walnut exists. Many of the trees are common in adjacent ecoregions, but most are comprised of oak and hickory. Wet sites include white oak, pin oak, northern red oak, yellow popular, ash, and sweetgum primarily, and shingle oak, black oak, and hickory also occur. Silver maple, cottonwood, sycamore, pin oak, elm, and sweetgum grow along rivers and stream corridors.

Rock bass Ambloplites rupestris	Greenside darter Etheostoma blennioides

Fish Assemblage and Watershed Condition

We sampled 130 sites from 1990-1995. A total of 86 species were collected and were numerically dominated by cyprinid, centrarchid, and percid species.

The overall water quality of the ECBP ranges between very poor ( IBI score 14; numerous sites) to excellent (IBI score: 58, Tippecanoe River). An increasing trend was evident from headwater to higher order tributaries in the overall water quality of the ECBP. The number of sites approximated a normal distribution based on the integrity of sites sampled between 1990-1995. The following was the range of conditions (N=130 sites) within each condition class: excellent 2.6% (4 sites), good 18.4% (N=24), fair 49.2% (N= 64), poor 26.2% (N=34), very poor 14.1% (N=4).