Upland Hardwood Forest Management

The southern upland hardwoods occur extensively in the Southern Appalachians, on the Cumberland Plateau, and in the Ozark region. A diverse array of hardwood species is represented by genera such as Acer, Carya, Fraxinus, Liquidambar, Liriodendron, Prunus, and Quercus. The southern upland hardwoods include pine-hardwood mixtures in the Piedmont and southern Coastal Plains, but by far the most commercially significant upland hardwoods in the South occur in the Southern Appalachian region. For purposes of this discussion, the Southern Appalachian region includes the hilly or mountainous area west and north of the Piedmont and south of the glaciated portion of Pennsylvania. Using Fennemans (1938) classification, this region is termed the "Appalachian Highlands," and contains parts of the Blue Ridge, Ridge and Valley, and Appalachian Plateau physiographic provinces. The Appalachian Highlands are classified as being in the Eastern Broadleaf Forest Province (Bailey 1996). The climate is continental and part of the Humid Temperate Domain (Bailey 1996). Rainfall is favorable for plant growth and is well distributed throughout the year. Highest precipitation rates occur in the southern Blue Ridge of the Carolinas and north Georgia, where annual precipitation averages 60 to 80 inches per year (Hicks 1998). Across most of the region, annual precipitation averages 40 to 50 inches. The geology of the Appalachian Highlands region is predominantly sedimentary. Sandstones of the Pennsylvanian period cap the highest mountains throughout the Appalachian Plateau Province, and limestones and shales predominate in the sharply folded Ridge and Valley Province. The Blue Ridge is composed primarily of metamorphic rock substrates with some igneous intrusions and small areas with sedimentary rock. At higher elevations of the southern Blue Ridge, Precambrian rock outcrops can be found. Faulting, folding, and geologic weathering have interacted with the geologic materials to produce the complex, steep, and rocky terrain found in the Appalachian Highlands.

Deciduous hardwood species predominate in the Appalachian Highlands. These include several oaks (Quercus spp.), hickories (Carya spp.), maples (Acer spp.), yellow-poplar (Liriodendron tulipifera L.), black cherry (Prunus serotina Ehrh.), and American beech (Fagus grandifolia Ehrh.). The area was also a prime range for American chestnut [Castanea dentata (Marsh.) Borkh.], a species that was all but eliminated by the chestnut blight {Cryphonectria parasitica (Murrill) Barr [formerly Endothia parasitica (Murrill) Anderson & Anderson]} during the early part of the 20^th century. Braun (1950) classified a substantial portion of the Appalachian Highlands as being in the oak-chestnut forest region. Most of the forests of the Appalachian Highlands are second growth, resulting from previous logging and fires or from revegetation of abandoned fields.

Oaks, as a group, constitute the most significant hardwood forest resource in the southern uplands. Oaks, however, are losing their position in many upland forests, being replaced by aggressive species such as red maple and yellow-poplar (Abrams 1998, Brose and others 2001).  Exclusion of periodic, low-intensity surface fires from the hardwood forests of the Appalachian Highlands in the early decades of the 20^th century has changed the character of these forests. Oaks thrive under a regime of periodic disturbance by surface fires (Brose and others 1999, Van Lear and Brose 2001). Because young oaks invest heavily in root development at the expense of height, they are at a competitive disadvantage with aggressive species like yellow-poplar and red maple, especially on above-average sites. However, when surface fires kill the aboveground portion of trees, the resulting seedling sprouts of oaks have a distinct advantage over their competitors. In the absence of periodic surface fires, oaks do not maintain a position of dominance in the advance regeneration pool. Thus as wind, ice, or partial harvesting disturbs the upper canopy, other species in the advance regeneration pool are poised to dominate.

This chapter uses concepts from Hicks (1998) book "Ecology and Management of Central Hardwood Forests" to describe the silvicultural methods that are appropriate to most upland hardwood stands. It is our goal to demonstrate that properly designed commercial harvests can utilize silviculturally sound concepts, and to provide descriptions of relevant silvicultural methods and their application to NIPF stands. We also hope to discourage the use of loose terms such as "selective cutting," and to encourage foresters to develop a vocabulary that is appropriate and descriptive of the practices being recommended. Finally we want to stress that in hardwood stands, it is often necessary to apply several silvicultural methods simultaneously, and that management of hardwood stands must remain adaptable to changing market conditions, natural occurrences such as insect and disease outbreaks, and changing social pressures.

Most silviculture and forest management texts emphasize "traditional" approaches based on German methods that were developed for use in relatively simple coniferous ecosystems. Although a great deal of research on hardwood management has been conducted in North America, the information that has been produced must be presented in a form that is useful to managers.

• Intermediate Silvicultural Operations
• Regeneration Methods