Common (Translated Scientific) Name: Northern Red Oak - Shagbark Hickory - White Ash / Black Baneberry - Eastern Waterleaf Forest

Colloquial Name: Central Appalachian Montane Oak - Hickory Forest (Basic Type)

Hierarchy Level:  Association

Type Concept: This community is known from the southern part of the Central Appalachians, extending into the extreme northern portions of the Southern Blue Ridge, Southern Ridge and Valley, and Cumberland Mountains. It occurs throughout western Virginia and adjacent eastern West Virginia, forming extensive patches on the Northern Blue Ridge and, somewhat more locally, on the higher ridges of the Ridge and Valley province. Favorable sites are upper slopes and ridge crests with deep, base-rich soils weathered from mafic and calcareous parent material, including metabasalt (greenstone), amphibolite, pyroxene-bearing granulite, charnockite, and actinolite schist. It also occurs on sites underlain by calcareous sandstone, siltstone, metasiltone, phyllite, and felsic granites with mafic clasts. Occurrences span a range of intermediate elevations, from 680-1265 m (2250-4150 feet), with a mean elevation of approximately 1000 m (3280 feet). Slopes are mostly gentle to moderate, averaging about 15°. Aspect varies considerably, but a majority of stands are located on sites with southwestern to northwestern or flat exposures. Soils are mostly dark, friable loams and silt loams with variable chemistry, but typically high in calcium, magnesium, and/or manganese. The characteristic expression of this community is that of an oak or oak-hickory forest with an herb layer that resembles that of a rich cove forest. Quercus rubra is the most constant member of the overstory but usually shares dominance with Carya ovalis, Carya ovata, Fraxinus americana or, less frequently, other mesophytic hardwoods such as Tilia americana (both var. americana and var. heterophylla), Quercus alba, Carya cordiformis, Prunus serotina, and Betula lenta. Both Liriodendron tulipifera and Quercus montana, which are ubiquitous in much of the Central Appalachians, are uncommon to rare in this community type. The subcanopy tends to be strongly dominated by Carya spp. and Fraxinus americana, with Acer saccharum, Acer rubrum, Acer pensylvanicum, and Ostrya virginiana also important in some stands. The shrub layer is typically sparse. Most stands have a lush and generally diverse herb layer, with total cover often exceeding 80% and strong patch-dominance by leafy, colonial forbs such as Actaea racemosa, Ageratina altissima var. altissima, Hydrophyllum virginianum, Collinsonia canadensis, Caulophyllum thalictroides, Laportea canadensis, Impatiens pallida, Thalictrum coriaceum, and Asclepias exaltata. At higher elevations, where the type is transitional to northern red oak forests, Dennstaedtia punctilobula often dominates the herb layer in large clones.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: As currently circumscribed, this association encompasses three community types classified by Fleming and Coulling (2001) based on limited plot data from discrete portions of western Virginia. Subsequently, much more extensive plot data were collected across the area, and the compositional and geographic distinction of these "types" became less clear. Recent analysis of a Virginia statewide dataset of 255 montane oak-hickory plots (Fleming and Patterson 2009b) supported the merger of these types as a single association appropriate at the scale of the U.S. National Vegetation Classification. This unit was represented by 77 plots. It is somewhat variable in composition, but consistent in its environmental affiliations and easily recognizable in the field. To an extent, the original classified units can be recognized as "variants" of this association, varying in the relative abundances of some species, in affiliations with geologic substrates, and in soil type or chemistry. A common characteristic of all variants is relatively high concentrations of soil manganese. Several recent studies of montane forest vegetation (Newell and Peet 1996b, Newell 1997, Coulling and Rawinski 1999) have identified a strong positive relationship between manganese levels and species richness. In this community type, however, abundant manganese may explain the total cover and, in part, the composition of the herb layer, but total herb diversity may be more a function of total base saturation and the abundance of other soil cations. In addition, the abundance of both Carya spp. and Fraxinus americana in these stands is no doubt a reflection of the higher base status of soils supporting this association. An intensive study of forest vegetation in the Southern Appalachians comprising nine landscapes and >1100 plots identified no vegetation type in which either Carya ovalis (included in Carya glabra) or Carya ovata constitutes an important component (Newell 1997). The tendency of Carya spp. to occupy more fertile soils was long ago noted (Guthrie 1820), and the relative paucity of Carya in Central and Southern Blue Ridge forests may reflect the exceptionally high base status of many Central Appalachian soils.

Several stands of this type, particularly those in northern Shenandoah National Park, experienced severe oak mortality following sustained defoliation by gypsy moth and coincident drought in the late 1980s and early 1990s.

Similar NVC Types: No Data Available

note: No Data Available