Outwash Upland Prairie

Description

The reference plant community is categorized as a midgrass community, dominated by xeric vegetation. The two community phases within the reference state are dependent on periodic fire. The intensity and frequency of fire alters species composition, cover, and extent, while regular fire intervals recycle nutrients, encourage flowering and seed production, and keep woody species from dominating (MDNR 2005). Drought and native mammal herbivory have more localized impacts in the reference phases, but do contribute to overall species composition, diversity, cover, and productivity.

Community Phase 1.1 Blue Grama – Little Bluestem – Sites in this reference community phase exhibit a patchy to continuous vegetative cover (50 to 100 percent), grass heights are less than 3 feet tall, and patches of bare soil and gravel may be present (MDNR 2005; LANDFIRE 2009). Blue grama, little bluestem, and sideoats grama are the dominant grasses. Plains muhly, composite dropseed, and prairie dropseed are common grass associates. Characteristic forbs can include dotted blazing star (Liatris punctata Hook.), purple prairie clover (Dalea purpurea Vent.), hoary tansyaster (Machaeranthera canescens (Pursh) A. Gray ssp. canescens var. canescens), and blacksamson echinacea (Echinacea angustifolia DC.). Terricolous lichens are a diagnostic component of this phase (MDNR 2005; NatureServe 2015).

Submodel

Description

The forage state occurs when the site is converted to a farming system that emphasizes domestic livestock production, known as grassland agriculture. Fire suppression, periodic cultural treatments (e.g., clipping, drainage, soil amendment applications, planting new species and/or cultivars, mechanical harvesting) and grazing by domesticated livestock transition and maintain this state (USDA-NRCS 2003). Early settlers seeded non-native species, such as smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poa pratensis L.), to help extend the grazing season (Smith 1998). Over time, as lands were continuously harvested or grazed by herds of cattle, these species were able to spread and expand across the prairie ecosystem, reducing the native species diversity and ecological function. This state is more prevalent on sites with higher gravel content.

Submodel

Description

The low topographic relief across the MLRA has resulted in nearly the entire area being converted to agriculture (Eilers and Roosa 1994). The continuous use of tillage, row-crop planting, and chemicals (i.e., herbicides, fertilizers, etc.) has effectively eliminated the reference community and many of its natural ecological functions in favor of crop production. Corn and soybeans are the dominant crops for the site, and oats (Avena L.) and alfalfa (Medicago sativa L.) may be rotated periodically. These areas are likely to remain in crop production for the foreseeable future. This state is more prevalent on sites with lower gravel content.

Submodel

Description

Prairie reconstructions have become an important tool for repairing natural ecological functions and providing habitat protection for numerous grassland dependent species. Because the historic plant and soil biota communities of the tallgrass prairie were highly diverse with complex interrelationships, historic prairie replication cannot be guaranteed on landscapes that have been so extensively manipulated for extended timeframes (Kardol and Wardle 2010; Fierer et al. 2013). Therefore, ecological restoration should aim to aid the recovery of degraded, damaged, or destroyed ecosystems. A successful restoration will have the ability to structurally and functionally sustain itself, demonstrate resilience to the natural ranges of stress and disturbance, and create and maintain positive biotic and abiotic interactions (SER 2002). The reconstructed prairie state is the result of a long-term commitment involving a multi-step, adaptive management process. Diverse, species-rich seed mixes are important to utilize as they allow the site to undergo successional stages that exhibit changing composition and dominance over time (Smith et al. 2010). On-going management via prescribed fire and/or light grazing can help the site progress from an early successional community dominated by annuals and some weeds to a later seral stage composed of native, perennial grasses, forbs, and a few shrubs. Establishing a prescribed fire regimen that mimics natural disturbance patterns can increase native species cover and diversity while reducing cover of non-native forbs and grasses. Light grazing alone can help promote species richness, while grazing accompanied with fire can control the encroachment of woody vegetation (Brudvig et al. 2007).

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