Physiognomy and Structure: No Data Available

Floristics: Stands of this forest are closed to somewhat open, and are dominated by mixtures of oaks and hickories, with Quercus alba being most prevalent, along with Quercus rubra, Quercus coccinea, Quercus velutina, Carya tomentosa (= Carya alba), Carya ovalis, and Carya glabra. Carya spp. are common in this type but often most abundant in the understory. In Virginia examples, Quercus montana (= Quercus prinus) and Quercus falcata are inconstant but sometimes important. In addition, Pinus spp., Liriodendron tulipifera, Liquidambar styraciflua, and Acer rubrum may be common, especially in disturbed stands. Understory species include Acer rubrum, Cornus florida, Oxydendrum arboreum, Ilex opaca, and Nyssa sylvatica. Shrubs include Vaccinium stamineum, Vaccinium pallidum, Viburnum acerifolium, Viburnum rafinesqueanum, and Euonymus americanus. In Virginia, Vaccinium pallidum and Vaccinium stamineum are the principal ericads of patchy low-shrub layers (G. Fleming pers. comm. 2004). The woody vines Vitis rotundifolia and Toxicodendron radicans often are present. Herbs vary from sparse to moderately dense, with dry-mesophytic species such as Hexastylis spp., Goodyera pubescens, Chimaphila maculata, Desmodium nudiflorum, Maianthemum racemosum, Polygonatum biflorum, Viola hastata, Tipularia discolor, Carex albicans, and Hieracium venosum prevalent (Schafale and Weakley 1990). Although not lush, these forests can be impressively species-rich, with high woody diversity and many low-cover herbaceous species occurring. Species richness of 116 Virginia plots averages 53 taxa per 400 m2, varying from a low of 17 to a high of 114. Low species richness in this type is most often the result of long-term overgrazing by large deer populations. At least some of the stands with high species richness are located on sites where deer populations are effectively controlled.

Dynamics:  Disturbed areas have increased amounts of pines and weedy hardwoods such as Acer rubrum, Liriodendron tulipifera, and Liquidambar styraciflua, with the amounts depending on the degree of canopy opening. Areas that were cultivated are generally dominated by even-aged pine stands which are replaced by the climax oaks and hickories only as the pines die. Logged areas may have a mixture of hardwoods and pines (Schafale and Weakley 1990). Under natural conditions, these forests are uneven-aged, with old trees present. Reproduction occurs primarily in canopy gaps. Rare, severe natural disturbances such as wind storms may allow pulses of increased regeneration and allow the less shade-tolerant species to remain in the community. However, Skeen et al. (1980) argued that even the shade-intolerant Liriodendron could reproduce enough in gaps to persist in the climax Piedmont forests. The natural fire regime of the Piedmont is not known, but fires certainly occurred periodically. Most of the component trees are able to tolerate light surface fires with little effect. In addition, the recruitment of oaks and hickories generally benefits from periodic fires. However, Acer rubrum is fairly intolerant of fire (especially when young) and often appears to be out-competing the regeneration of oaks in long-unburned stands. In Virginia, Fagus grandifolia and Ilex opaca var. opaca are additional thin-barked, fire-intolerant species that have invaded many fire-suppressed oak-hickory forests. Regular fire may have created a more open forest, with gaps persisting longer than at present and perhaps forming more frequently (Schafale and Weakley 1990).