Missouri's Northern Plains
Glaciers shaped northern Missouri. Like giant earthmovers, they pushed sand, rocks, gravel and boulders as far south as the Missouri River. Even areas the glaciers didn’t touch were covered with glacial sediment and shaped by erosion from glacial runoff.
Driving through northern Missouri, it’s difficult to imagine anything but crops and pastures, interspersed with forests. Underlying the region’s rolling hills and gentle slopes, however, are deep, fertile soils that once supported a vast range of prairies, savannas and woodlands.
The northern part of Missouri, above the Missouri River, constitutes the ecological region called the Central Dissected Till Plains. The name is a mouthful, but the words define the region’s characteristics.
Plains refers to an area that is generally flat, level and open. Till refers to the type of soil, in this case, a mix of clay, sand, gravel and even boulders deposited by past glaciers. Soil was also deposited by winds blowing across the Great Plains. In some places this wind blown soil, or loess, is 25 to 100 feet thick.
Central means that it’s part of a larger area of dissected till plains. The Central Dissected Till Plains extend into parts of Iowa, Kansas, Nebraska and Illinois.
Dissected means cut by erosion into valleys and hills. Much of this erosion resulted from glacial runoff.
High prairie landscapes containing savanna and woodland characterize the Central Dissected Till Plains. Tallgrass prairie and savannas once occupied the drier, more fire-prone ridges and upper slopes, while woodlands occurred on side slopes and draws.
Many species are restricted to this region of productive glacial soils. These include plants like western prairie fringed orchids, ostrich ferns and rose turtlehead; also animals like Franklin’s ground squirrels, northern prairie skinks and Topeka shiners.
On the till plains, wide, windblown floodplains of the Missouri River and the Mississippi River became a complex of sandbars, marshes and wet prairies. Annual flooding probably kept these natural communities from becoming well established in any one place. Both the Grand River and the Chariton River, major tributaries to the big rivers, functioned similarly, producing floodplains that were mostly open prairies and wetlands. triangle
Before the 1800s, there were more than six million acres of savanna habitat in Missouri. Common species such as northern bobwhite quail, red-headed woodpeckers, field sparrows and brown thrashers thrived in these savanna communities. Today, much of the till plains has been converted to productive pastures and cropland.
There are many conservation opportunities in the Central Dissected Till Plains. Union Ridge Conservation Opportunity Area represents one of our best examples of the prairie-savanna edge that was once typical of northern Missouri.
Natural or human-caused fires, as well as grazing bison and elk, historically maintained savanna and associated prairie and woodland natural communities. The Department has been using carefully controlled prescribed fires to recreate habitat at Union Ridge.
There is also great potential to improve populations of northern bobwhite quail as a result of natural community management at Union Ridge.
Star School Hill Prairie NA
Garlic mustard (Alliaria petiolata) is an invasive exotic plant that can proliferate on the ground in woodlands and forests and choke out native plants. Native to Europe and eastern Asia, it was planted for use as a kitchen herb. It persists at old home sites.
Garlic mustard primarily spreads by flooding. Techniques for control include prescribed fire in the spring and hand-pulling or herbicide application before seeds are produced.
Streams in the Central Dissected Till Plains often meander across broad, flat valleys. They are fed mostly by runoff , or by slow percolation through deep soils and plant roots. Topeka shiners, plains killifish and trout-perch are all characteristic species of the prairie region.
Star School Hill Prairie Natural Area
Prairie plant communities on loess hills include rare species, such as blue and hairy grama grass, yucca, silvery psoralea and skeleton plant. These grow among the more common prairies species, such as big and little bluestem, purple prairie clover and lead plant. Rare animals found here include the plains pocket mouse and the Great Plains skink.
This summer, a nearly 2,700-acre addition to B.K. Leach Conservation Area opened and became fully operational as a new wetland wildlife area in Lincoln County.
This project required nearly $6 million for acquisition and restoration of critical wetland habitat, with only $1 million coming from the Missouri Department of Conservation. A group of seven other conservation organizations and agencies contributed the remainder.
This new wetland wildlife area was developed to provide habitat for least bitterns, rails and other marsh-nesting wildlife. It will be a popular, nearby birding destination for St. Louis residents.