Crooked Run Valley
white oak (Quercus alba)
ridge white oak
SCIENTIFIC SYNONYMS: There are no scientific synonyms for
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name of white oak is
Quercus alba L. It is a member of the order Fagales and has been placed
within the white group. Three varieties of white oak are commonly
recognized: 1) Quercus alba var. alba, 2) Quercus alba var. repanda
Michx., and 3) Quercus alba var. latiloba Sarg. Some authorities recog-
nize these entities as forms rather than varieties. White oak is highly
variable genetically, and many forms and ecotypes have been described.
White oak readily hybridizes with many other species within the genus
Quercus, including swamp white oak (Quercus bicolor), bur oak (Quercus
macrocarpa), chinkapin oak (Quercus muehlenbergi), dwarf chinkapin oak
(Quercus prinoides), overcup oak (Quercus lyrata), swamp chestnut oak
(Quercus michauxii), sandpost oak (Quercus margaretta), chestnut oak
(Quercus prinus), English oak (Quercus robur), Durand oak (Quercus
durandii), and post oak (Quercus stellata).
Introgressive populations are locally common throughout much of the
range of white oak. Hybrid swarms derived from complex mixtures of
parental forms are particularly common on disturbed sites, at the margins
of white oak's range, and where several oak species occur sympatrically.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: White oak is a medium
to large, spreading, deciduous tree which commonly reaches 60 to 80 feet
(18-24 m) in height. On favorable sites, individuals may grow to more than
100 feet (30 m) in height and exceed 5 feet (1.5 m) in diameter. White oak
is slow-growing and long-lived (up to 600 years). White oak is monoecious.
Yellowish staminate catkins are borne at the base of new growth, whereas
reddish pistillate catkins grow in the axils of new growth. The short-stalked,
glabrous, ovoid acorns are tan to brown. Acorns are generally borne in pairs.
The rough, warty cup covers approximately 33 to 50 percent of the nut.
REGENERATION PROCESSES: White oak reproduces through
seed and by vegetative means. Both modes of regeneration appear to be
important. White oak produces good acorn crops at erratic intervals.
Good crops have been reported at 4- to 10-year and at 3- to 5-year
intervals. Vigorous crowned trees greater than 20 inches d.b.h. (51 cm)
generally produce the best seed crops. Pollen, which is produced in
abundance, is dispersed by wind, but generally travels less than 656 feet
(200 m). Plants generally bear fruit between 50 and 200 years of age,
but open-grown trees on good sites may produce seed as early as 20
years of age. Reproduction from seed can occur when (1) large seed
trees are present within 200 feet (61 m), (2) litter cover is moderate,
and (3) the site receives at least 35 percent of full sunlight. Seeds of white
oak do not store well. Seed longevity is less than 1 year; white oak is not
considered a seed banker. Viability in storage declines from 90 percent
for fresh seed to 7.0 percent for seed stored for 6 months. Only 14 to 18
percent of the total seed produced may be sound. Many acorns are
damaged or destroyed by insects or bird and mammal seed predators.
Several studies have reported that animals consumed 72 to 83 percent
of all white oak acorns. In years of poor acorn production, the entire seed
crop may be eliminated.
Acorn production varies annually with the individual tree or stand . Certain
trees tend to produce larger acorn crops on a consistent basis. Weather
conditions, and tree size and vigor, also influence acorn production. An
individual oak 69 feet (21 m) tall with a d.b.h. of 25 inches (63.5 cm)
produced more than 23,000 acorns in a favorable year. However, most
forest-grown trees produce less than 10,000 acorns annually. Annual
yields may range from 0 to 202,000 acorns per acre (500,000/ha). Acorn
production may be reduced by cool April temperatures and drought.
In parts of Michigan, the blue jay is the primary dispersal agent of white
oak. Blue jays commonly exhibit a preference for burying acorns in bare
open areas which are well suited for germination. Gray squirrels are also
important dispersal agents in many locations and are the only known long-
distance disperser. The now-extinct passenger pigeon may have effected
long-distance dispersal of many eastern oaks. Wind and gravity also aid in
White oak acorns do not exhibit dormancy. In storage, seeds germinate
readily at temperatures of 33 to 37 degrees F (1-3 deg C). Under natural
conditions, acorns begin germinating soon after they fall. Acorns require
a cover of litter for good germination and seedling establishment. Acorns
without such protection are often damaged or killed by frost or drought.
Germination capacity ranges from 50 to 99 percent.
Seedling establishment is generally limited to years of abundant acorn
production. Light to moderate litter cover and periods of full sunlight are
required for establishment. Establishment is best on loose soils.
White oak exhibits a number of modes of vegetative regeneration. Vigorous
sprouting from the stump or root crown is commonly observed after fire,
mechanical damage, and other types of disturbance. Sprouting generally
decreases with increasing stem diameter, although trees up to 80 years of
age occasionally retain the ability to sprout. Small poles, saplings, and even
seedlings sprout readily if cut or burned.
Repeated sprouting is commonly observed. Seedlings often develop an
"s"-shaped curve at ground level, which helps protect dormant buds from
fire. Root stools develop under the ground surface after repeated fires or
herbivory. These root stools, made up of callus tissue filled with dormant
buds, typically sprout vigorously in the absence of further disturbance.
Seedling sprouts persist beneath the forest canopy even in the absence of
disturbance. Although the top dies back every few years, the root system
continues to develop and plants may persist for up to 90 years or more. As
the forest canopy is opened, the seedling sprouts grow rapidly. Buds are
stimulated to sprout by sudden shifts in light intensity, partial removal of
the crown, and a loss of plant vigor. Sprouting is reduced by low light levels
and decreases as the stand ages. The number of sprout groups decreases
from poor to good sites.
SITE CHARACTERISTICS: White oak grows in rich uplands, moist
bottomlands, along streams, on hammocks, sinks, sandy plains, and on dry,
gravelly slopes. It occurs on all upland aspects, and slope positions, but in
the southern Appalachians, it exhibits best growth on northern lower
slopes and in coves. White oak is absent on ridgetops with shallow soil, on
poorly drained flats, and on very wet bottomlands. Latitude, aspect, and
topography are important factors influencing the distribution of white oak
within its range. White oak grows in a variety of dry to mesic woodland
communities including pine-oak-hickory woods, beech-maple, and mixed
White oak grows in pure or mixed stands in the Southeast but towards
the northern portion of its range it rarely occurs in pure stands. Important
tree associates are numerous and include beech (Fagus grandifolia), sugar
maple, black cherry (Prunus serotina), white ash (Fraxinus americana),
yellow poplar, shortleaf pine (Pinus echinata), loblolly pine (Pinus taeda),
eastern white pine (Pinus strobus), jack pine (Pinus banksiana), eastern
hemlock, sweet gum, black gum (Nyssa sylvatica), American basswood
(Tilia americana), shagbark hickory (Carya ovata), and other hickories
(Carya spp.). Scarlet oak, post oak, bur oak, black oak, and northern red
oak are also important associates, Upland oaks and hickories are the most
common associates. Many herbaceous species grow in association with white
White oak is often associated with a cool, temperate, continental climate
but can grow under a variety of climatic regimes. Mean average
temperatures range from 45 degrees F (7 deg C) in the North to 70
degrees F (21 deg C) in eastern Texas and northern Florida. Annual
precipitation averages 80 inches (203 cm) in the southern Appalachians
but is less than 30 inches (77 cm) in southern Minnesota. Growing
season length ranges from 5 months in the North to 9 months in the South.
White oak grows on a wide variety of soils derived from many types of
parent materials . It grows on silty loam, clay loam, silty clay loam, fine
sand, and loamy clay but grows best on deep, well-drained loamy soils.
Low soil-nutrient levels limit growth of white oak only on sandy soils.
White oak is common on rocky soils.
White oak grows from sea level to 5,900 feet (0-1,800 m). In the North,
it generally grows under 500 feet (152 m) in elevation, but in the southern
Appalachians, it grows as a "scrub tree" at 4,500 feet (1,372 m). It is
absent from higher elevations in the northern Appalachians. In the
Smoky Mountains, two populations are separated by an elevational gap
of 1,000 feet (305 m). White oak grows below 2,000 feet (610 m) in the
SUCCESSIONAL STATUS: White oak readily regenerates after
disturbances such as fire or logging and often assumes prominence in mid
to late seral stages. In the North, white oak is commonly seral to sugar
maple and other species characteristic of mixed mesophytic stands. In
much of its range, it is succeeded by beech and other shade-tolerant species
on well-drained second bottoms and in protected coves. In much of the
eastern deciduous woodlands, forests formerly dominated by white oak,
beech, red maple, yellow poplar, and northern red oak are now being
replaced by more shade-tolerant species such as sugar maple and
American basswood. White oak cannot regenerate successfully beneath
a dense canopy and in many areas, grows in forests transitional to climax
sugar maple or mixed mesophytic forests. Because of the longevity of
white oak, climax development proceeds very slowly. White oaks may
persist on exposed sites within climax stands. White oak is considered a
climax tree in oak-hickory stands in the central and southern hardwood
forest zone. It grows as a climax dominant or codominant on certain lower
elevation sites in the Smoky Mountains and occurs in climax pine-oak
forests of New Jersey.
SEASONAL DEVELOPMENT: Leaves begin to develop and new shoots
are initiated in mid-March to late May, depending on geographic location.
The timing of bud break is largely dependent on latitude but also depends
on soil nutrient levels and weather. Most vegetative growth takes place
during the spring, with up to 50 percent of seedling height growth attained
in April (researchers have found seedling height growth 90 percent
complete by July 1). Plants may become dormant in late fall, although
leaves commonly persist into winter. Flowering generally occurs in spring
when the new leaves are elongating but varies according to latitude,
weather conditions, and with the genetic composition of individual trees.
Flowering can occur from late March to May or June. Three distinct waves
of flowering (early, middle, and late) have been reported. Warm weather
speeds up floral development, which begins after exposure to minimum
temperatures of 50 degrees F (10 deg C) for at least 10 days. Pollen is
generally shed within 3 days, but light winds can accelerate shedding.
Pollen shedding is often delayed by prolonged rainy weather. Acorns
typically ripen approximately 120 days after pollination. Acorns fall from
the trees by September or October.
GENERAL DISTRIBUTION: White oak grows throughout much of the
eastern United States from southwest Maine to northern Florida, Alabama,
and Georgia. It extends westward throughout southern Ontario and Quebec
into central Michigan, northern Wisconsin, and southeastern Minnesota and
south to southwestern Iowa, eastern Kansas, eastern Oklahoma, and
eastern Texas. Little reported that white oak may have been eliminated
from southeastern Nebraska. The best growing conditions for white oak
occur on the western slope of the Appalachian Mountains and in the Ohio
Valley and central Mississippi Valley. White oak is mostly absent from
conifer-dominated stands at higher elevations within the Appalachian
Mountains and from the lower Mississippi Delta and coastal areas of
Texas and Louisiana. The variety latiloba occurs at the northern edge of
the species' range. The range of var. repanda is poorly documented, but it
has been reported in parts of New England.
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
HABITAT TYPES AND PLANT COMMUNITIES: White oak grows
as a dominant in many communities and as a major species in several cover
types. Common codominants within the overstory include northern red
oak (Quercus rubra), scarlet oak (Quercus coccinea), northern pin oak
(Quercus ellipsoidalis), black oak (Quercus velutinus), beech (Fagus spp.),
sweetgum (Liquidambar styraciflua), chestnut (Castanea dentata), red
maple (Acer rubrum), sugar maple (Acer saccharum), and hickories (Carya
spp.). Understory dominants or codominants include deerberry (Vaccinium
stamineum), leadplant (Amorpha canescens), trailing arbutus (Epigaea
repens), huckleberries (Gaylussacia spp.), meadow-rue (Thalictrum spp.),
and false Solomon's-seal (Smilacina racemosa).
IMPORTANCE AND USES: Acorns of white oak are considered
choice food for many wildlife species, including the white-footed mouse,
fox squirrel, black bear, pine mouse, red squirrel, and cottontail rabbits.
The gray squirrel consumes white oak acorns but prefers the acorns of
other oak species. Many birds, including the bluejay, northern bobwhite,
mallard, ring-necked pheasant, greater prairie chicken, ruffed grouse,
and wild turkey, eat white oak acorns. In some areas, the abundance of
fall mast crops, such as acorns, can affect black bear reproductive success
during the following year. Sprouted acorns are often eaten by deer, mice,
The young shoots of many eastern oak species are readily eaten by deer.
Dried oak leaves are also occasionally eaten by white-tailed deer in the fall
or winter. Rabbits often browse twigs and can girdle stems. The porcupine
feeds on the bark, and beavers eat twigs of white oaks.
The palatability of oak browse is relatively high for domestic livestock and
for many wildlife species. Eastern oaks are preferred by white-tailed deer
in some locations. New growth is particularly palatable to deer and rabbits.
White oak provides good cover for a wide variety of birds and mammals.
Oak leaves often persist longer than many other plant associates and in
some areas, young oaks may represent the only brushy winter cover in
dense pole stands. Oaks frequently serve as perching or nesting sites for
various songbirds. The well-developed crowns provide shelter and hiding
cover for small mammals such as tree squirrels. Many birds and mammals
use twigs and leaves as nesting materials. Large oaks provide denning sites
for a variety of mammals.
White oak is potentially valuable for use in reforestation projects and
appears to have potential for use on other types of disturbed sites. It has
been planted on strip-mined lands in Ohio, Indiana, and Illinois and has
exhibited good growth and survival on cast overburden and graded topsoil
overlying mine spoils.
White oak wood is heavy, hard, strong, and durable. When properly dried
treated, oak wood glues well, machines very well and accepts a variety of
White oak is the most important timber oak and is commercially important
throughout much of the South and East. White oak is an important source
of wood for furniture, veneer, paneling, and flooring. It has been used to
make railroad ties, fenceposts, mine timbers, ships, and caskets. White oak
has long been used in cooperage and is currently the major source of wood
for whiskey barrels. White oak wood has also been used as a source of
clapboard shingles and woven baskets, although demands for these
products are decreasing. Its high fuel value makes white oak an attractive
Acorns were traditionally an important food source for many Native
American peoples. White oak acorns have been described variously as
sweet and edible and as slightly bitter. The acorns were often boiled to
remove bitter tannins. Oils obtained from pressed acorns were used to
alleviate pain in the joints.
White oak is commonly used in landscaping and is often planted as a shade
tree or ornamental. Its colorful purplish-red to violet-purple foliage
enhances its ornamental value in autumn. White oak was first cultivated