Wet Upland Depression Prairie

Description

The reference plant community is categorized as a wet-mesic tallgrass prairie and includes grasses, sedges, forbs, and varying components of shrubs. The two community phases within the reference state are dependent on a fire frequency of approximately every one to six years as well as periodic ponding. Shorter fire intervals maintain dominance by grasses, while less frequent intervals allow woody vegetation to increase their importance in the plant canopy. Grazing and drought disturbances have less impact in the reference phases, but do contribute to overall species composition, diversity, cover, and productivity.

Submodel

Description

The woody-invaded state occurs as a result of long-term fire suppression efforts and exclusion of haying. Frequent, periodic fires historically kept shrubs and trees from invading the prairie, as well as maintained species diversity. However, as the prairies were settled fire suppression efforts were instituted. Similarly, wet prairies proved to be a challenge to early settlers and were often excluded from haying operations so as to avoid damage to equipment. The lack of disturbances resulted in rapid woody encroachment (LANDFIRE 2009; Nelson 2010).

Submodel

Description

The cool-season grassland state occurs when the reference state has been anthropogenically-altered for livestock production. Fire suppression, seeding of non-native cool-season grasses, removal of woody vegetation, and grazing by domesticated livestock transition and maintain this simplified grassland state (Rosburg 1994). Early settlers seeded such non-native cool-season species as Kentucky bluegrass (Poa pratensis L.) in order to help extend the grazing season (Smith 1998). Over time, as lands were continually grazed by large herds of cattle, the non-native species were able to spread and expand across the prairie habitat, reducing the native species diversity.

Submodel

Description

Loess is the main contributing factor to the Midwest’s highly-productive agricultural soils, and as a result, much of the MLRA has been converted to cropland including significant portions of this ecological site (USGS 1999). The installation of agricultural drain tiles and the continuous use of tillage, row-crop planting, and chemicals (i.e., herbicides, fertilizers, etc.) have effectively eliminated the reference community and many of its natural ecological functions in favor of crop production. Corn (Zea mays L.) and soybeans (Glycine max (L.) Merr.) are the dominant crops for the site. These areas are likely to remain in crop production for the foreseeable future.

Submodel

Description

Prairie reconstructions have become an important tool for repairing natural ecological functioning and providing habitat protection for numerous grassland-dependent species. The historic plant community of wet prairies was extremely diverse and complex, and prairie replication is not considered to be possible once the native vegetation has been altered by post-European settlement land uses. 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 wet 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 post-planting management will 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 shrubs (Steinauer et al. 2003). 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. Controlled grazing that carefully regulates the location, intensity, and season of use can help promote species richness, reduce litter, and limit non-native cool-season grasses (Steinauer et al. 2003; Brudvig et al. 2007). Grazing accompanied with fire can control the encroachment of woody vegetation (Brudvig et al. 2007).

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