State 1
Naturalized State-Upland Mixed Hardwood

The Naturalized State for this ecological site is characterized by a closed-canopy hardwood forest dominated by oaks. Tupliptree may be more common on these sites than on similar drier sites, indicating that fragment content is related to soil moisture. Tuliptree would be more competitive on sites with more available moisture while white oak, for example, would likely do better on drier sites. To maintain this state, the mixed hardwood species, especially oaks, must be present in multiple age classes. In most cases 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).

Community 1.1
White oak-Black oak

This phase is dominated by oaks and hickories in the overstory, but mid-story composition is shifting toward more shade and moisture-loving species. The understory is relatively rich in herbaceous diversity (including vines) but tree regeneration overwhelmingly favors the shade-tolerant species. Oak regeneration is difficult and often requires management. Decisions should be made on-site, based on existing conditions. These conditions include acorn production, seedling establishment, and the amount of advanced regeneration from seedlings (Brose et al., 2013). Several types of management can be employed, including prescribed fire, mechanical and chemical competition control, site preparation, and planting. However, depending on the stand and its history, management for oak/hickory is typically intensive and often requires multiple treatments over time ( approximately 10-25 years), (Loftis, 2004). Without intensive management, in most cases, stands will naturally succeed to a more mesophytic forest type dominated by shade tolerant species (the maples and American beech). Dendroecology studies in nearby, very similar old-growth forest stands indicate that oak species have dominated stands for the past 300 years. They speculate that the recent proliferation of maples in the understory will inhibit the regeneration of oak and pine under the current disturbance regime (Hart et al., 2012a). Oak and hickory 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).

Community 1.2
Maple species-American beech

This community phase has not yet been attained in most cases because forests currently dominated by oaks and hickories are in transition. Without management or large-scale disturbance, stands will naturally succeed to more mesophytic species composition in the overstory and the oaks and hickories will lose their dominance over time. Small-scale gap dynamics caused by tree throws would likely be a natural part of this state and would favor the maple component in forest stands (Hart et al., 2012a). A recent study of red maple on the nearby Cumberland Plateau found that canopy accession strategy and climate-growth relationships are critical factors in the shift from state 1.1 to state 1.2 (Hart et al., 2012b). Red maples are gap-opportunists and can take advantage of smaller-scale disturbances such as tree-throws. Oaks in contrast, seem to have needed high frequency, intense disturbances to establish their current dominance in the forest. Red maples do best in times of cool, wet springs preceded by wet autumns and warm winters (Hart et al., 2012a). Depending on climate conditions in the coming years, the weather may or may not favor their continued establishment. Red maple might also cause local environmental changes that facilitate perpetuation of favorable conditions for regeneration such as modification of understory light levels and soil characteristics (Nowacki and Abrams, 2008). The denser canopies might reduce understory temperature and increase relative humidity, which would also favor the more shade-tolerant, moisture loving state (Alexander and Arthur, 2010). Prescribed burning is a management tool that may be used to reverse the trend. While it may be a useful tool in some cases and most likely in combination with other management approaches, using fire alone is unlikely to produce the desired results in most stands (Clark and Schweitzer, 2013).

Forest overstory. The forest overstory is dominated by mature maples and American beech. Tree throws create small-scale gap dynamics in the forest, which favor recruitment of the maples and in some cases, tuliptree. Oaks and hickories will always be a part of the species composition in this state, but will not be dominant.

Forest understory. Forest understory composition will be similar to community phase 1.1, dominated by native herbs, forbs, and vines. Shade tolerant trees will be present in the regeneration. Spring ephemeral wildflowers will be prolific in places.

Pathway 1.1A
Community 1.1 to 1.2

Time (typically greater than 100 years) with little or no large-scale disturbance will favor shade-tolerant, late-successional species including sugar maple, red maple and American beech.

Pathway 1.2A
Community 1.2 to 1.1

Establish advanced oak regeneration (natural or planted) is critical to recruiting oak back into the overstory, but a combination of natural and managed steps will likely be required to favor oak. Depending on the residual stand, management recommendations might include timber stand improvement, mechanical or chemical treatment of unwanted species, and prescribed fire. Consult with a professional forester before implementing any management practice, especially the use of prescribed burning. Arthur et al. (2012) discusses conditions when fire should and should not be used in oak management.

State 2
High-graded Forest State

Forests in the high-graded state have been logged using diameter-limit cutting methods, multiple times in most cases. As a result, most forest stands have undesirable species 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.

Community 2.1
American beech - Sugar maple/Sourwood - Sassafras

Canopies in the high graded state are generally thick enough to prevent adequate oak regeneration; more shade tolerant species such as red maple, sugar maple and American beech will predominate. Oak and hickory species that remain typically have low genetic timber quality, so white and northern red oak are noticeably absent in stands that have been high-graded multiple times.

State 3
Cleared Grassland 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 rather than new pasture establishment, although that is certainly an option. Balancing stocking rates, grazing rotation, and nutrient inputs are the primary management concerns. Forage species considered excellent for this site include the legumes alfalfa, ladino clover, and red clover. Cool season grasses rated as excellent include annual ryegrass, orchardgrass, tall fescue, timothy, and winter small grains. Warm season grasses rated as excellent include bermudagrass, big bluestem, caucasian bluestem, eastern gamagrass, indiangrass, little bluestem, switchgrass, pearl millet and sorghum sudangrass. Some species listed as excellent were not included in this description because they are known to have invasive tendencies and should be avoided if possible. In general, pasture management recommendations focus on maximizing desirable forage species to outcompete undesirable or weedy species. Production practices that result in overgrazing and low fertility levels favor emergence, propagation, and growth of weeds (Green et al., 2006). Effective pasture management includes the following practices: - maintaining proper soil pH and fertility levels - using controlled grazing practices - mowing at proper timing and stage of maturity - allowing new seedlings to become well established before use, and - renovating pastures when needed (Green et al., 2006). Perilla (Perilla frutescens) mint is an exotic, invasive weed that is a major problem in many pastures. In Tennessee, It causes more cattle deaths than any other toxic plant (Steckel and Rhodes, 2007). Keeping a ready supply of quality feed for farm animals in the late summer and early fall will help to minimize the risk to livestock. Cattle will not normally feed on perilla unless there is a shortage of other feed.

Community 3.1
Orchardgrass-tall fescue

The dominance of orchardgrass (Dactylis glomerata), red clover (Trifolium pratense), and tall fescue (Schedonorus arundinaceus) in this community phase indicate that nutrient levels are adequate, and grazing rotations are long enough to allow pasture plants to recover. Overstocking and infrequent pasture rotation will allow weedier species to invade, such as nimblewill and rush species.

Forest overstory. The overstory in the grassland state is minimal and consists of a few trees growing along the parameter of pastures, and scattered shade trees within pastures.

Forest understory. Pastures in good condition can be characterized by the MDWRV (G128XY021TN) forage suitability group (FSG) in Tennessee. Forage species rated as excellent for this site include the legumes alfalfa, ladino clover, and red clover. Cool season grasses rated as excellent include annual ryegrass, orchardgrass, tall fescue, timothy, and winter small grains. Warm season grasses rated as excellent include bermudagrass, big bluestem, caucasian bluestem, eastern gamagrass, indiangrass, little bluestem, switchgrass, pearl millet and sorghum sudangrass. Some species listed as excellent were not included in this description because they are known to have invasive tendencies and should be avoided if possible.

Community 3.2
Tall fescue-nimblewill

This community phase is transitional to a more degraded phase. While some desirable pasture plants are still present [e.g. tall fescue, white clover (Trifolium repens)], [Dallisgrass (Paspalum dilatatum), Crabgrass (Digitaria spp.) and other warm season plants], undesirable species such as nimblewill (Muhlenbergia schreberi), rush (Carex spp.), cinquefoil (Potentilla spp.), thistle (Cirsium spp.) and little barley (Hordeum pusillum) will begin to proliferate. Heavy grazing pressure may favor weedy species over grass (Rhodes and Phillips, 2012). Just removing or reducing livestock will not always be enough to restore desirable conditions after a point. Some type of nutrient improvement may also be needed.

Community 3.3
Multiflora rose-blackberry spp.

Pastures with a history of overgrazing can be susceptible to invasion by weedy plants, shrubs, and small trees if grazing pressure is reduced and nothing further is done to improve the site. Indicator plants for this phase include blackberry, broomsedge, and multi-flora rose. Clipping undesirable plants and adding nutrient input can help pastures in this phase recover. Using goats for grazing, mowing and applying herbicide can be useful for clearing unwanted plants.

Pathway 3.1A
Community 3.1 to 3.2

Overstocked pasture with infrequent rotation.

Pathway 3.2B
Community 3.2 to 3.1

Rotational grazing with a longer recovery period and higher grazing height; improved fertility.

Pathway 3.2A
Community 3.2 to 3.3

Overgrazed; low fertility

Pathway 3.3A
Community 3.3 to 3.2

Clipping pasture with nutrient improvement or controlled grazing.

Transition T1A
State 1 to 2

Selective harvesting and high grading multiple times degrades 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 T1B
State 1 to 3

Forest clearing, herbicide application, and establishment of pasture plants, hay or crops will convert forested stands to a grassland state. Most pastures in this site are old and were converted many years ago.

Restoration pathway R2A
State 2 to 1

Implementing restoration practices should be determined strictly on a stand-by-stand basis as conditions may vary depending on the type and extent of past logging practices, the damage from wind, ice, or fire, and the presence or absence of invasive exotic plants. In general, a large scale disturbance such as a clear-cut would allow stand re-establishment over time. In some cases, planting desirable species (primarily oaks) could be merited. If planting is determined to be a viable option, competition control and protection from deer browse are important. Improved tree stock is recommended for the best results. Further management practices such as weed control, timber stand improvement, and thinning would likely be needed intermittently during stand re-establishment to achieve the desired result. NRCS conservation practice 666 is forest stand improvement (FSI) and could be utilized for this pathway.

Transition T2A
State 2 to 3

Forest clearing, herbicide application, and establishment of pasture plants, hay or crops will convert forested stands to a grassland state. Most pastures in this site are old and were converted many years ago.

Restoration pathway R3A
State 3 to 1

Abandoned pastures can revert to forest naturally, although the presence of invasive, exotic plants may prevent desirable species establishment. In the past, most of this ecological site has been cleared and grazed and then abandoned but invasive plants were not as prolific then. It is almost certain that some type of weed control will be needed in addition to the natural regeneration process. Additionally, planting desirable species can sometimes be merited. If this approach is attempted, improved tree planting stock, competition control and prevention of deer browse is recommended. Sites may need multiple treatments over time and monitoring is critical to successful restoration.