Igneous Upland Woodland

Description

The historical reference state for this ecological site was old growth oak woodland with an open understory and a dense ground flora of native grasses and forbs. This state was dominated by white oak, northern red oak, with occasional black oak, post oak, and shortleaf pine. Periodic disturbances from fire, wind or ice maintained the woodland structure and diverse ground flora species. Long disturbance-free periods allowed an increase in both the density of trees and the abundance of shade tolerant species. Two community phases are recognized in the reference state, with shifts between phases based on disturbance frequency. Reference sites are uncommon today.

Most of these sites have been subject to repeated, high-graded timber harvest (State 3). Fire suppression has resulted in increased canopy density, which has affected the abundance and diversity of ground flora (State 4). Relatively few Igneous Upland Woodlands have been managed effectively for timber harvest (State 2), resulting in either even-age or uneven-age forests. Some areas have been cleared and planted to cool-season grassland species (State 5) and are being used for grazing and haying.

Submodel

Description

This state develops from mixed oak woodlands, which over time, increase in canopy cover, eventually transitioning into forest-like communities. These early woodlands tend to be rather dense with a depauperate understory and ground flora. Periodic timber management, along with the absence of fire, will maintain this phase. Continued exclusion of prescribed fire without a regular 15 to 20 year harvest re-entry into these stands, will slowly create an increase in more shade tolerant species. White oak will become less dominant and understory species such as flowering dogwood and hickory will become more dominate and cause a transition to community phase 2.2. With periodic unmanaged logging that result in high-grading the stand, this state will transition to the High Graded Mixed Oak Woodland state (State 3). Restoration back to the reference state is possible with selective thinning to favor white oak and northern red oak species and a prescribed fire interval of 3 to 5 years are typically used.

Submodel

Description

This state is subjected to repeated, high-grading timber harvests resulting in a significant reduction in white oak and northern red oak densities. Fire cessation has also occurred. This state exhibits an over-abundance of black oak and hickory and other less desirable tree species, and weedy understory species such as coralberry, gooseberry, poison ivy and Virginia creeper. Proper forest management techniques can create a transition to State 2. This state is often experiences clearing/clear-cutting and conversion to grassland, State 5.

Submodel

Description

This state is dominated by white oak and northern red oak. They can form relatively even-aged stands, dating to when fire suppression became the dominant management characteristic on the site. This stage can occur relatively quickly (10 to 20 years). Canopy closures can approach 70 to 90 percent with decreasing ground flora. Without active management or long term presence of fire, woody species will continue to encroach into these woodlands. Once established, these woody species can quickly fill the woodland system.

Most occurrences of this state today are dense and shady with a greatly diminished ground flora. Removal of the younger understory, opening the upper canopy, and the application of prescribed fire has proven to be effective management tools in restoring the stage back to the reference state. Some logging typically occurs. These states are good wildlife sites.

Submodel

Description

Conversion of wooded sites to planted, non-native grassland species such as tall fescue is a stage that is primarily associated with summit and shoulder positions of this ecological site. If active grassland management is discontinued, the site will eventually transition to phase 5.2 with an increase in broomsedge and oak sprouts. Return to the reference state from this state may be impossible requiring a very long term series of costly management options and stages. Many species may need to be eventually planted or reseeded to restore the system.

Conversion to grassland may result in soil loss from the clearing process and from erosion before the grassland is well established. Long-term grassland management results in higher soil pH levels and higher levels of calcium and magnesium from pasture liming. These effects may extend a foot or more into the soil profile. The effects of liming are more evident in phase 5.1.

Submodel