State 1
Reference State Oak-Heath

The reference state for this ecological site is characterized by a closed-canopy hardwood forest dominated by oaks. Maintenance of this state requires that oak species occur in multiple age classes. In many situations red maple, sugar maple and American beech are colonizing the midstory and understory. A species composition shift toward these more mesophytic species is widely recognized throughout the eastern United States (McEwan et al. 2011). The reference state described represents a condition dependent on complex, multiple disturbances. In order to get oak to succeed and recruit into the next stand, advanced oak regeneration must be present before a major canopy disturbance. Oaks must be able to reach a size that is competitive via canopy disturbance (through smaller-scale clear cuts or fire or herbicide of midstory, and/or tree planting with vigorous seedlings/saplings). There may need to be multiple disturbances to eliminate competition.

Community 1.1
Chestnut oak-red oak /blueberry-laurel/ teaberry-poverty grass

Figure 9. Oak/Heath Forest

Without management, stands may succeed to a more mesophytic forest type dominated by shade tolerant species (i.e. maples and American beech) (Nowacki and Abrams, 2008). Dendroecology studies in old-growth forest stands indicate that oak species have dominated stands for the past 300 years. Researchers speculate that the recent proliferation of maples in the understory will inhibit regeneration of oak under the current disturbance regime (Hart et al. 2012). Oak can regenerate in canopy gaps formed by uprooted trees, but only on very dry sites, indicating that gap-phase dynamics will favor maple overall (Hart and Kupfer 2011). The American chestnut was an important part of this ecological site prior to decimation by the chestnut blight but it is unclear how abundant it would have been. Colloquial estimates based on local names like "Chestnut Ridge" indicate that it may have been prolific.

Forest overstory. Tree species commonly include Quercus prinus and Quercus coccinea, along with Quercus alba, Quercus rubra, and Quercus velutina. Other associates can include Acer rubrum , Carya alba, Nyssa sylvatica. Tall shrubs and small trees can include Cornus florida, Sassafras albidum, and Viburnum acerifolium.

Forest understory. Characteristic dwarf-shrubs and vines include Gaylussacia baccata, Gaultheria procumbens, Smilax glauca, Smilax rotundifolia, Vaccinium pallidum, Vaccinium stamineum, and, more locally, Kalmia latifolia. The herbaceous layer includes Antennaria plantaginifolia, Symphyotrichum cordifolium (= Aster cordifolius), Carex pensylvanica, Cypripedium acaule, Danthonia spicata, Epigaea repens, Helianthus divaricatus, Helianthus hirsutus, Dichanthelium dichotomum (= Panicum dichotomum), Polystichum acrostichoides, and others. Lichens (Cladina spp. and Cladonia spp.) and mosses can form a prominent layer.

State 2
Mesophication State

This site is resultant of micro environmental conditions (cool, damp, and shaded conditions; less flammable fuel beds) continually improving for shade-tolerant mesophytic species (i.e. maples) and deteriorate for shade-intolerant, fire-adapted species (i.e. oaks). As a result of abandonment of extensive woodland grazing, and the industrialization of timber harvest in the 1880's, the use of fire to maintain woodland pasture was largely abandoned. Fire-suppression policies in the 1920s resulted in additional compositional and structural changes and these sites are on a trajectory towards the eventual replacement of fire-dependent plants by shade-tolerant, fire-sensitive vegetation. This trend continues today with ongoing fire suppression. Historic oak forests in MLRA 127 have had “multiple interacting ecosystem drivers” (McEwan and others 2011) including decades of fire suppression and increasing deer herbivory that have facilitated the proliferation of shade-tolerant, fire-intolerant species into historically oak-dominated stands (Abrams 1992). In many stands red maple dominates the seedling and sapling pool beneath the oak overstory (Abrams 1998). Oak seedlings, which have relatively high light requirements and a conservative growth strategy, require periodic disturbances to open the canopy and promote height growth (Abrams 1992). In an undisturbed understory, shade-tolerant, fast-growing species like red maple outcompete oaks (Lorimer 1984). Although overstory oaks still dominate stands in eastern forests, many researchers predict a compositional shift following mortality of the current canopy dominants in the absence of successful restoration attempts (Goins et al. 2013). Numerous attempts have been made to restore fire to these forests and halt compositional changes, but results are highly site-specific and largely inconclusive (Arthur et al. 2012). Brose et al. (2014) provides and synthesis of the fire oak literature and guidelines for using fire in oak ecosystems.

Community 2.1
Chestnut oak- red maple /service berry-dogwood/blueberry-poverty grass

This phase is characterized by canopy dominance of chestnut oak, but has a major canopy component of red maple. The shrub layer shows a mix of xerotropic and mesotrophic species. This phase is maintained in the absence of fire by being located on shallower soil on steep convex south aspects. Extended periods of drought may favor this phase. Red maple can influence its surrounding environment via a suite of mechanisms: Decreased fuel loads and higher fuel moisture associated with increased red maple cover could decrease forest flammability, whereas decreased N availability could hinder growth of plants with higher N requirements than red maples. All these changes could feed back to exacerbate red maple proliferation and the mesophication of this phase. (Alexander and Arthur 2014)

Community 2.2
Red maple-chestnut oak /stripped maple/ blueberry-poverty grass

This phase is characterized by canopy domminance of red maple, but has a major canopy component of chestnut oak. The shrub layer shows mesotrophic species. This phase is maintained in the absence of fire by being located on moderately deep soil on steep linear south aspects and north aspect slopes. Red maple can influence its surrounding environment via a suite of mechanisms: Decreased fuel loads and higher fuel moisture associated with increased red maple cover could decrease forest flammability, whereas decreased N availability could hinder growth of plants with higher N requirements than red maples. All these changes could feed back to exacerbate red maple proliferation and the mesophication of this phase. (Alexander and Arthur 2014) As red maple grows to maturity and dominates the canopy, this phase may reach a tipping point, where restoration via prescribed fire or other stand management techniques is impossible (Abrams 2005; Nowacki and Abrams 2008).

Pathway 2.1A
Community 2.1 to 2.2

When average precipitation is greater than normal during several growing seasons red maple can gain canopy dominance. Under reduced light conditions, fire-adapted species perform poorly in the understory and increasingly give way to shade-tolerant species.

Pathway 2.2A
Community 2.2 to 2.1

Harvest of red maple and a fire could set this community on a differennt trajectory.

State 3
Recent Logged State (<75yrs)

Forests in this state have often been logged using diameter-limit cut methods multiple times in most cases. This results in a stand with mesophytic species (i.e. maple and tulip poplar)composition, low vigor and poor health. The genetic quality of the forest has been depleted due to the best trees being taken out over time. While oak species may be present in this state, microenvironmental conditions (cool, damp, and shaded conditions; less flammable fuel beds) continually improve for shade-tolerant mesophytic species and deteriorate for shade-intolerant, fire-adapted species. As a result of fire-suppression policies in the 1920s compositional and structural changes took place and sites succeeded to closed-canopy forests, followed by the eventual replacement of fire-dependent plants by shade-tolerant, fire-sensitive vegetation. This trend continues today with ongoing fire suppression.

Community 3.1
Red maple-tulip poplar /greenbrier-blackberry/hay scented fern-poverty grass

Canopies in the logged state are generally thick enough to prevent adequate oak regeneration; more shade tolerant species such as red maple and tulip poplar will predominate. Oak species that remain are typically of low genetic quality in terms of timber. Stands that have had multiple entries have a conspicuous lack of oak.

State 4
Grazed Woodland State

Scattered, open-grown oaks with large, spreading branches are characteristic. Woodlands have a closed overstory of trees but maintain an open understory. This allows enough sunlight to reach the ground to favor a group of sedges, grasses, low shrubs and wildflowers that do best in a woodland environment. Fire was widespread and frequent throughout much of the eastern United States before European settlement (Pyne 1982, Abrams 1992). Widespread burning created a mismatch between the physiological limits set by climate and the actual expression of vegetation—a common phenomenon throughout the world (Bond et al. 2005). In the eastern United States, presettlement vegetation types were principally pyrogenic; that is, they formed systems assembling under and maintained by recurrent fire (Frost 1998, Wade et al. 2000). Fire frequency remained the same or even increased where settlers adopted Native burning practices. Here, frequent understory burning helped maintain the dominance of oak and of fire-adapted associates, especially grasses for pasturage.

Community 4.1
Chestnut oak-red oak/black berry-greenbrier /sweet vernal-poverty grass

This phase may be a relict of the open “park-like” conditions (Wright and Bailey 1982, Frost 1998)established by Native burning practices. This is a xerotrophic plant community in an area of abundant precipitation. The shrub layer may be resultant of absent fire return intervals and/or absence of livestock browsers.

State 5
Pasture State

This state represents a once-forested area now cleared for pasture. Most pastures are very old and have been established for a long time. Management practices focus primarily on maintaining healthy pasture conditions; examples include balancing stocking rates to forage availability, grazing rotation, weed control and nutrient inputs. In general, pasture management recommendations focus on maximizing desirable forage species to outcompete undesirable/weedy species. Production practices that result in overgrazing and low fertility levels favor emergence, propagation, and growth of weeds (Green et al. 2006).

Community 5.1
Orchardgrass-Fescue

The dominance of orchardgrass (Dactylis glomerata), and tall fescue (Schedonorus arundinaceus) in this community phase indicate that nutrient levels are adequate and grazing management is adequate to allow pasture plants to recover. Overstocking and infrequent pasture rotation will allow weedier species to invade such as multiflora rose and brambles.

Community 5.2
Multiflora rose-blackberry/sweet vernal-broomsedge

This community phase is a more degraded phase for livestock. While some utilization ofpasture plants will occur undesirable species are prolithic. Soil nutrient improvement through fertilization and liming is necessary. Control of multiflora rose (i.e. herbicide) is necessary.

Pathway 5.1A
Community 5.1 to 5.2

Lack of soil fertility management (N,P,K) and lack of lime application. Lack of herbicide treatment of invasive species and brambles.

Pathway 5.2A
Community 5.2 to 5.1

Addition of fertilizer and lime. Herbicide treatment of invasive palnts.

Transition T1A
State 1 to 2

The absence of fire and/or disturbance (i.e. clearcutting) for over 100 years. Without the rejuvenating effects of recurrent fire, environmental conditions shifted incrementally to favor fire-sensitive, shade-tolerant competitors. Under reduced light conditions, fire-adapted species performed poorly in the understory and increasingly gave way to shade-tolerant species.

Transition T1C
State 1 to 3

Selective harvesting and high grading multiple times results in degradation of forest stand quality in terms of altered species composition, forest structure, and genetic fitness. Diameter limit cuts, incorrectly implemented, remove the biggest and best trees and leave those of lowest quality in terms of both timber and ecology.

Transition T1D
State 1 to 4

Long term (100+ years) access by livestock and subsequent browsing of woody understory and establishment/maintenance of grassy understory. Over the past 50 years sheep and goats have been removed from the grazing scenario and brambles have established.

Transition T1B
State 1 to 5

Tree clearing and the establishment of pasture plants. A majority of pasture conversions occured many years ago.

Restoration pathway R2A
State 2 to 1

Harvest or elimination (i.e. herbicide)of red maple. Reintroduce fire according to recomendation made by a forester or fire ecologist.

Transition T3A
State 3 to 2

mesophitic tree (i.e. maple) regeneration Harvest of tulip poplar

Transition T3B
State 3 to 5

Eliminate woody species combined with pasture species planting/recruitment. This transition rarely occurs currently.

Restoration pathway R4A
State 4 to 1

Removal of grazing (browsing) livestock, herbicide treatment of undesirable shrubs and/or prescribed fire. Reintroduce fire according to recommendations made by a forester or fire ecologist.

Transition T4A
State 4 to 3

logging and removal of trees in the abscence of advanced regeneration oak.

Transition T5A
State 5 to 2

maple invasion of pasture livestock have been removed or stocked at a low rate.