Northern Red Oak Forests
Dominance by northern red oak (Quercus rubra) characterizes these forests, which reach maximal importance at elevations above 900 m (3,000 ft) throughout western Virginia. Similar forests are found throughout higher elevations of the Southern and Central Appalachians. Although composition varies with parent material and landscape position, prolonged weathering and limited accumulation of soil organic matter have generally resulted in moderately to strongly infertile soils and consequently moderate to low species richness. In addition to the prevalent red oaks, scattered associates of white oak (Quercus alba), birches (Betula alleghaniensis and Betula lenta), and black cherry (Prunus serotina var. serotina) are often present in the overstory. Typical small trees and shrubs include mountain holly (Ilex montana), witch-hazel (Hamamelis virginiana), striped maple (Acer pensylvanicum), minnie-bush (Menziesia pilosa), early azalea (Rhododendron prinophyllum), beaked hazelnut (Corylus cornuta var. cornuta), and sprouts of American chestnut (Castanea dentata). In southwestern Virginia stands with Southern Appalachian affinities,flame azalea (Rhododendron calendulaceum), southern mountain cranberry (Vaccinium erythrocarpum), and mountain highbush blueberry (Vaccinium simulatum) are characteristic shrubs. Stands typically contain ground layers of hayscented fern (Dennstaedtia punctilobula), New York fern (Thelypteris noveboracensis), low ericaceous shrubs (e.g., lowbush blueberry, [Vaccinium pallidum]), or patches of graminoids such as Pennsylvania sedge (Carex pensylvanica) and wavy hairgrass (Deschampsia flexuosa var. flexuosa). Other characteristic herbs include fly-poison (Amianthium muscitoxicum), poke milkweed (Asclepias exaltata), panicled hawkweed (Hieracium paniculatum), whorled loosestrife (Lysimachia quadrifolia), eastern lousewort (Pedicularis canadensis), rattlesnake-roots (Prenanthes spp.), whorled aster (Oclemena acuminata = Aster acuminatus), cut-leaved goldenrod (Solidago arguta var. arguta), and Curtis' goldenrod (Solidago curtisii).
Most stands in this group were formerly dominated or co-dominated by American chestnut (Castanea dentata) before overstory trees of this species were decimated by an introduced fungal blight (Cryphonectria parasitica) in the early 20th century, and all but the most inaccessible had previously been logged. Trees on more exposed sites often exhibit stunted, gnarled stature, reflecting the influences of high winds and frequent ice damage. Pre-settlement chestnut and mixed oak-chestnut forests at high elevation likely experienced low-intensity fires ignited by lightning strikes every 40-60 years. Contemporary fire exclusion and the abundance of competing vegetation in the understory contribute to poor oak regeneration and invasion by mesophytic trees such as red maple (Acer rubrum) or sugar maple (Acer saccharum var. saccharum) in many montane red oak forests. Gypsy moth infestation, which has lead to repeated defoliation and widespread tree mortality on the northern Blue Ridge, is another serious threat to this and other oak-dominated communities.
References: Abrams et al . (1997), Agrawal and Stephenson (1995), Coulling and Rawinski (1999), Fleming and Coulling (2001), Johnson and Ware (1982), Rawinski et al . (1994), Rawinski et al . (1996), Rheinhardt and Ware (1984), Stephenson (1982a), Stephenson (1982b), Stephenson and Adams (1989), Stephenson and Adams (1991).
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Northern Red Oak Forest with gnarled overstory trees and an herb layer dominated by hayscented fern (Dennstaedtia punctilobula). Stony Man Mountain, Madison County (Shenandoah National Park). Gary P. Fleming / © DCR Natural Heritage.
Orchard-like stand of Northern Red Oak Forest on Hogback Mountain, Rappahannock County. The herb layer is patch-dominated by wavy hairgrass (Deschampsia flexuosa), whorled loosestrife (Lysimachia quadrifolia), and Pennsylvania sedge (Carex pensylvanica). Gary P. Fleming / © DCR Natural Heritage.
Northern red oak (Quercus rubra) and hayscented fern (Dennstaedtia punctilobula) at 1300 m (4300 ft) elevation on Flagpole Knob, Shenandoah Mountain, Rockingham County (George Washington and Jefferson National Forests). Gary P. Fleming / © DCR Natural Heritage.
Northern Red Oak Forests have been fairly well documented by 82 plot samples from 26 counties in western Virginia (map). The Evergreen Shrub Type (see below) is a relatively rare community in Virginia and needs additional inventory and sampling. Click on any highlighted CEGL code below to view the global USNVC description provided by NatureServe Explorer.