Chestnut Oak and Hickory Forest

This dry acidic Appalachian oak forest group includes mostly closed-canopy deciduous (oak) forests and mixed (oak-pine) forests with a variable mixture of dry-site oak and pine species. It is characterized by the occurrence of Quercus montana and/or other oaks, typically Quercus alba, Quercus coccinea, or Quercus velutina, often with sprouts of Castanea dentata. Pinus strobus or Pinus virginiana may be an important associate in some areas. Widespread hardwood associates include Quercus rubra, Betula lenta, Carya glabra, Nyssa sylvatica, and Sassafras albidum. Additional associated trees in parts of the group's range include Halesia tetraptera var. monticola, Liriodendron tulipifera, Magnolia acuminata, and Oxydendrum arboreum. Subcanopy, shrub, and herb layers vary, but in many cases a moderately well- to well-developed heath layer is present. Ericaceous shrubs are often common and include Kalmia latifolia, Gaylussacia baccata, Gaylussacia frondosa, Gaylussacia ursina, Vaccinium pallidum, Vaccinium angustifolium, Vaccinium stamineum, Vaccinium arboreum, Vaccinium simulatum, Menziesia pilosa, Rhododendron calendulaceum, and Rhododendron prinophyllum. This group is centered on the ranges of Castanea dentata and Quercus montana, ranging from central New England south through the Central Appalachian and Western Allegheny regions to the Cumberland Plateau and Southern Appalachians. The substrate is typically dry, acidic, and infertile. Elevation ranges from sea level (in the northern part of the range) to about 1500 m (in the Southern Appalachians).

Canopy dominants include Quercus montana (= Quercus prinus), Quercus rubra, Quercus velutina, and/or Quercus alba. At higher elevations or northern range limits, Quercus rubra may be the sole dominant. Castanea dentata is often present, though not common, as sprouts and is diagnostic when it occurs with Quercus montana. Other oaks, including Quercus coccinea or Quercus falcata, are often present at relatively lower elevations. Many forests in this group have a pine component of Pinus strobus, Pinus rigida, Pinus pungens, or Pinus virginiana, or less often Pinus echinata. Ericaceous shrubs are often common and include Kalmia latifolia, Gaylussacia spp., Vaccinium pallidum, Vaccinium angustifolium, Vaccinium stamineum, Vaccinium arboreum, Vaccinium simulatum, Menziesia pilosa, Rhododendron calendulaceum, and Rhododendron prinophyllum.

This group occurs in temperate eastern North America, occurring on predominantly acidic substrates at a range of elevations from sea level (in the northern part of the range) to about 1500 m (in the Southern Appalachians). Topography and landscape position vary from rolling hills to steep slopes. The soils are coarse and infertile; they are typically shallow, on rocky slopes of acidic rock (shale, sandstone, other acidic igneous or metamorphic rock), but north of the glacial boundary may be on deep coarse glacial deposits as well as on shallow-to-bedrock soils.

At moderate to low elevations, stands are naturally stable, uneven-aged forests, with canopy dynamics generally dominated by gap-phase regeneration. Wind or ice storms may create larger canopy openings. Fire occurred fairly frequently in pre-European-settlement times, though there is some dispute whether most of the fires were natural or anthropogenic in origin (Abrams 1992, Delcourt and Delcourt 1997). Fires were usually low-intensity surface fires. Fire occurred even more frequently in post-European-settlement times, declining again in the 1900s. The dominant species are fairly fire-tolerant, making most fires non-catastrophic. Fire also can be expected to have a moderate effect on vegetation structure, producing a somewhat more open canopy and increased density of low-shrub layers than currently seen in most examples.

In the southern part of the group's range, higher-elevation examples may occur on exposed high ridges where they are subject to frequent ice storms in the winter, wind storms in the summer, and high winds throughout the year. This helps explain these forests' stunted appearance. In presettlement times, these forests are likely to have experienced lightning-caused fires every 40-60 years (Fleming et al. 2005). In some locations, fire exclusion and competing understory vegetation are a factor in poor oak regeneration, with replacement by more mesophytic species such as Acer saccharum (Fleming et al. 2005). Oak regeneration is also threatened by high levels of deer herbivory.