Deep Loess Protected Backslope Woodland

Description

The reference plant community is categorized as a mesic oak-basswood woodland. The two community phases within the reference state are dependent on catastrophic disturbance events (e.g. wind, ice, snow). A longer interval of no disturbances results in a mature overstory canopy and the presence of more disturbance-intolerant species, while recent events can reset the community to an earlier-successional status. Fire, grazing, and drought have less impact in the reference phases, but do contribute to overall species composition, diversity, cover, and productivity.

Submodel

Description

Overbrowsing by an unnaturally abundant white-tailed deer population can transition the reference state into an over-browsed forest state. Continuous browsing has been reported to prevent the regeneration of the historic dominant canopy, which is replaced by mid-level and invasive species (Gubanyi et al. 2008; VerCauteren and Hygnstrom 2011). White-tailed deer have been reported to prefer American basswood, which under high densities of deer can result in the reduction of seedling growth ultimately leading to a complete exclusion from the site (Tilghman 1987; Sullivan 1994). Common hackberry, on the other hand, has a greater tolerance to deer browsing thus allowing it to dominate the tree canopy under high deer browse conditions. Similarly, as small woody shrubs and plants are continuously browsed, the gaps are replaced by less palatable herbaceous species (Gubanyi et al. 2008).

Submodel

Description

The cool-season pasture state occurs when the reference state has been anthropogenically-altered for livestock production. Early settlers harvested the trees for timber and fuel and seeded such non-native cool-season species as smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poa pratensis L.), converting the woodland to pasture (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 site, reducing the native species diversity.

Submodel

Description

The combination of natural and anthropogenic disturbances occurring today has resulted in a number of forest health issues, and restoration back to the historic reference condition is likely not possible. Woodlands and forests are being stressed by non-native diseases and pests, habitat fragmentation, permanent changes in soil hydrology, and overabundant deer populations on top of naturally-occurring disturbances (severe weather and native pests) (Flickinger 2010). However, these habitats provide multiple ecosystem services including carbon sequestration; clean air and water; soil conservation; biodiversity support; wildlife habitat; timber, fiber, and fuel products; as well as a variety of cultural activities (e.g., hiking, camping, hunting) (Millennium Ecosystem Assessment 2005; Flickinger 2010). Therefore, conservation of forests and woodlands should still be pursued. Woodland reconstructions are an important tool for repairing natural ecological functioning and providing habitat protection for numerous species associated with Deep Loess Protected Backslope Woodlands. 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 ranges of stress and disturbance, and create and maintain positive biotic and abiotic interactions (SER 2002). The reconstructed woodland state is the result of a long-term commitment involving a multi-step, adaptive management process.

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