Calcareous Loess Exposed Backslope Prairie

Description

The reference plant community is categorized as a dry tall/midgrass prairie and includes an assemblage of xeric grasses, forbs, and limited components of shrubs. The two community phases within the reference state are dependent on a fire frequency of every one to six years. Shorter fire intervals maintain dominance by grasses and forbs, while less frequent intervals allow grass litter to accumulate and crowd out the native forbs. Grazing and drought disturbances have less impact in the reference phases, but do contribute to overall species composition, diversity, cover, and productivity.

Submodel

Description

Fire suppression by livestock can transition the reference prairie community into a semi-natural woodland state dominated by eastern redcedar (Juniperus virginiana) (Briggs et al. 2002; Anderson 2003; Steinauer and Rolfsmeier 2010). Eastern redcedar is a species native to the eastern half of North America with a range spanning from Ontario east to Nova Scotia, south across the Great Plains into eastern Texas, and east to the Atlantic coast (Lawson 1990; Lee 1996). It is a long-lived (450+ years), slow-growing, fire-intolerant dioecious conifer and historically was found in areas that were protected from fire (e.g., bluffs, rocky hillsides, sandstone cliffs, granite outcrops, etc.) (Ferguson et al. 1968; Anderson 2003). Today, however, decades of fire suppression have allowed this species to spread and it can now be found occupying sites with highly variable aspects, topography, soils, and formerly stable plant communities (Anderson 2003).

Submodel

Description

The cool-season grassland state occurs when the reference state has been anthropogenically-altered for livestock and/or hay 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 smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis) 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.

Submodel

Description

Prairie reconstructions have become an important tool for repairing natural ecological functioning and providing habitat protection for numerous grassland-dependent species. Because the historic plant community of the tallgrass prairie was extremely diverse and complex, prairie replication is not considered to be possible once the native vegetation has been altered by past 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 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 will help the site progress from an early successional community dominated by annuals and some weeds to a later seral stage composed of native grasses, forbs, and 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).

Submodel