Northern Hardwoods

Northern hardwood forest occur in high mountains at approximate elevations between 4000 and 5500 ft in the Southern Appalachians. They are dominated by deciduous trees and are found on upper slopes and high ridges. Due to high elevations with increased precipitation, these landscape positions are more mesic than slopes and ridges at lower elevations. Therefore, northern hardwood forests have some species in common with cool north-facing coves at moderate elevations.

The forests of this community type are dominated by northern red oak, yellow birch, American beech, and yellow buckeye. However, the representation of these four species changes from site to site. Red oak is more prominent on less mesic, south-facing sites, while yellow birch is more prominent on mesic north-facing exposures. Sugar maple and yellow buckeye are usually present at the most mesic sites. Likewise, chestnut oak and red maple can occur on the less mesic sites. Small stands or isolated individuals of red spruce or eastern hemlock may occur in these forests.

Two of the most distinctive stand types include beech forests and boulderfield forests. Beech forests consist almost entirely of American beech and are found at elevations above 4500 ft (Whittaker 1956). They have been referred to as "beech gaps" where they occupy concave topography or "beech orchards" where they are found on broad open ridges (McLeod 1988, Pittillo and Smathers 1979, Russell 1953). Beech gaps may also occur as small pockets in spruce-fir forests. Boulderfields, which were deposited by glaciers, are found mainly on steep, north-facing slopes. The forest floor is covered by moss-covered boulders and canopy is usually dominated by stands of yellow birch. Skunk currant (Ribes glandulosum) is a characteristic shrub. Where water is present, pink turtlehead (Chelone lyonii), pale touch-me-not (Impatiens pallida), beebalm (Monarda didyma), and umbrellaleaf (Diphylleia cymosa) may be present in the herb layer (White and others1993, Shafale and Weakley 1990).

Umbrella leaf

Norhtern Hardwood forests contain both evergreen and deciduous shrubs. The evergreen component includes rosebay rhododendron (Rhododendron maximum) on mesic sites at the lowest elevations of this forest types. Higher and more exposed sites have mountain laurel (Kalmia latifolia) and Catawba rhododendron (R. catawbiense). These two species can form nearly impenetrable thickets under the canopy. Similar thickets that lack trees are called heath balds. The deciduous shrubs include mountain maple (Acer spicatum), hobblebush (Viburnum lantanoides), mountain holly (Ilex montana), elderberry (Sambucus pubens), and bearberry (Vaccinium erythrocarpum). Catawba rhododendron and mountain ash (Sorbus americana) are characteristic shrubs of high-elevation communities, including northern hardwood forests, spruce-fir forests, heath balds and grassy balds.

Northern Hardwood forests support a number of wildlife species. Representative mammals include black bear (Ursus americanus), red squirrels (Tamiasciurus hudsonicus), bobcats (Lynx rufus), and red-backed voles (Clethrionomys gapperi). These forests also support endemic races of species that are limited to the high mountains of the southern Appalachians. Examples include the Carolina northern flying squirrel (Glaucomys sabrinus coloratus), the Appalachian cottontail (Sylvilagus obscurus), the Appalachian yellow-bellied sapsucker (Sphyrapicus varius appalachiensis), and the saw-whet owl (Aegolius acadicus). Common birds that nest in these forests are dark-eyed junco (Junco hyemalis caroliniensis), blue-headed vireos (Vireo solitarius aticola), black-throated blue warblers (Dendroica caerulescens cairnsi), and ruffed grouse (Bonasa umbellus). These forests also support a number of endemic salamander species and subspecies, such as the pygmy salamander (Desmognathus wrightii) and various color morphs of Jordans salamander (Plethodon jordani). The high elevations and rugged terrain of the northern hardwood zone has historically discouraged settlement of these forests, leaving large unbroken patches of habitat for wildlife and plants. In the late 20th century, economic development for summer and vacation homes began to affect these forests.

Representative tree species of Northern Hardwood Forests:

• Northern red oak (Quercus rubra)
• Yellow birch (Betula allegheniensis)
• American beech (Fagus grandifolia)
• Yellow buckeye (Aesculus octandra)
• Sugar maple (Acer saccharum)
• Red maple (Acer rubrum)
• Red spruce (Picea rubens)
• Black cherry (Prunus serotina)
• Fire cherry (Prunus pensylvanica)