Wet Footslope/Drainageway Prairies

Description

The Wet Footslopes/Drainageway Prairies reference state is a native prairie that has a diversity of wet-tolerant grasses and forbs. Community phases within the Reference State are dependent upon the influences of the frequency of fire events. Fire is a natural trigger that promotes continued herbaceous vegetation dominance. Fire removes plant litter, helps cycle nutrients, and allows light to reach the seedbed. Frequent fire maintains the community in a grassland state, by keeping fire-sensitive woody species from proliferating.
A secondary trigger is grazing. Overgrazing will reduce the extent of highly palatable species thereby allowing the growth of less desirable plants to increase.

Reference plant communities are characterized as native tallgrass prairie, with a diversity of grasses, sedges, and forbs characteristic of poorly drained conditions. Variation in water table allows both wetland and non-wetland species to thrive. Prairie cordgrass (Spartina pectinata Bosc ex Link) is a common dominant species. Other grasses include big bluestem (Andropogon gerardii Vitman) and Indiangrass (Sorghastrum nutans (L.) Nash). Sedges are an important component, particularly in wetter areas. Several species are possible. The most noteworthy species are Bicknell’s sedge (Carex bicknellii Britton), woolly sedge (Carex pellita Muhl ex. Willd.), and Buxbaum’s sedge (Carex buxbaumii Whalenb.). Tussock-forming species like Hayden’s sedge (Carex haydenii Dewey) and upright sedge (Carex stricta Lam.) may be on site. Shrub cover is variable and includes leadplant (Amorpha canescens Pursh), willows (Salix L.) and dogwoods (Cornus L.), which quickly spread in the absence of frequent fire.

Today, high-quality, unplowed areas are extremely uncommon. Most remaining natural areas that are managed for tallgrass prairie were once tilled and utilized for agricultural production. It is therefore likely that many of the historic native prairie species are extirpated even from these sites.

Resilience management

Prescribed fire and managed grazing are key resilience management practices. This is a stable plant community when grazing and fire are adequately managed. Prescribed fire is the controlled application of fire to modify vegetation structure and influence ecological processes. Prescribed grazing incorporates periods of grazing rest during the growing season which benefits tallgrass maintenance. Excessive grazing can quickly impact the vegetative composition and negatively impact soil stability.

Dominant plant species

1. leadplant (Amorpha canescens), shrub

2. prairie cordgrass (Spartina pectinata), grass

3. stiff goldenrod (Oligoneuron rigidum), grass

Submodel

Description

Soil tillage is the primary mechanism affecting the transition to this state. Tillage affects dynamic soil properties such as bulk density, structure, organic carbon content, and saturated hydraulic conductivity. Hydrological modifications (tiling and ditching) are commonly installed to improve drainage, so natural hydrology is also altered. Most areas in this state will remain in use for crop production in the foreseeable future.

Certain practices can mitigate the impacts of traditional agricultural practices on soil health. Conservation tillage minimizes soil disturbance and can improve soil structure and overall soil health. Corn or soybean plantings and a cover crop rotation can build soil structure, improve infiltration rates, and protect water quality.

A small percentage of this ecological sites have been seeded to grass. Some previously tilled areas have been converted to warm-season grasslands under an NRCS conservation program. Species seeded will depend upon the hydrology of the site. Cool-season grasses are also feasible. The most common cool-season grasses are non-native species, such as reed canarygrass (Phalaris arunidinacea) and Kentucky bluegrass (Poa pratensis). Although cool-season grasslands are not biologically diverse, they still offer soil health and wildlife benefits.

Some tilled sites may revert to a woodland through abandonment; however, this is a small percentage of acres within MLRA 103 so is not currently given a community in this model.

Resilience management

Disturbance management and harvest management are resilience management practices. The maintenance of this state requires that the intensity, frequency, duration, and timing of agricultural practices (disturbances) be managed to control or modify vegetation structure.

Dominant plant species

1. corn (Zea mays), grass

2. soybean (Glycine max), grass

Submodel

Description

In the absence of a natural fire or management, this site will transition toward the Wooded State. Disturbances such as unmanaged grazing, altered hydrology, and invasive species are often present. Vegetative composition and characteristics will vary depending on the age of the community and the type and severity of disturbances. Dominant tree species will vary, but commonly include eastern cottonwood, black willow, green ash, and boxelder. Reed canarygrass may be dense in open areas. Cool-season grasses such as Kentucky bluegrass and smooth brome may be present.

A small percentage of acres within MLRA 103 are in this State. Some remaining areas are conservation easements. Areas not in a conservation programs may be jurisdictional wetlands, making it very unlikely they will be transitioned to State 2 due to various wetland programs and laws, including the Swampbuster provision of the Food Security Act of 1985 (P.L. 99-198, as amended by P.L. 115-25) and the Minnesota Wetland Conservation Act (WCA) of 1991 (M.R. 8420.0100, as amended in 2009).
 

Dominant plant species

1. eastern cottonwood (Populus deltoides), tree

2. black willow (Salix nigra), tree

3. green ash (Fraxinus pennsylvanica), tree

4. boxelder (Acer negundo), tree

5. dogwood (Cornus), shrub

Submodel