BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus muehlenbergii | Chinkapin Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Chinkapin oak is a spreading, medium to large, deciduous tree which
generally reaches 16 to 52 feet (5-16 m) in height [50] but occasionally
grows to 80 or 90 feet (24-27 m) [46,66].  On exceptional sites in the
lower Wabash and Ohio valleys, individuals can reach 160 feet (48 m) in
height and up to 4 feet (1.2 m) in diameter [23].  Chinkapin oak
typically has large, low branches and a rounded crown [66].  In closed
forest stands it develops a straight, columnar trunk, a dense rounded
crown, and fairly small branches [23].  In the open, plants usually
develop a short trunk and broad crown.  Grayish-brown twigs are rigid
and glabrous [66].  The thin bark is light gray to silvery, and rough or
scaly [50,66].  The alternate, simple leaves are coriaceous and variable
in shape [66].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Chinkapin oak is monoecious.  Staminate catkins form from the base of
new growth or from lateral buds on the previous year's growth.
Pistillate flowers grow from the axils of the current year's growth
[66].  Flowers are wind pollinated [52].  Acorns are borne singly or in
pairs, and are dark brown to nearly black [23].  About half of the nut
is enclosed by the cup [27].  Acorns mature in one season [23].

Most eastern oaks produce good seed crops at variable intervals [28].
Best seed crops are generally produced by large trees (> 20 inches [51
cm] d.b.h.) with vigorous crowns.  Cold or wet weather during flowering
can result in poor seed production [28,47].  Acorns are disseminated by
gravity, and rodents and birds [66].  Groups of seedlings commonly
originate from the caches of blue jays [30].  Although effective
dispersal agents, birds and mammals also consume many seeds.  In some
areas, 90 to 100 percent of the annual acorn crop may be lost to seed
predators [71].

Acorns of chinkapin oak germinate soon after falling to the ground [47].
Stratification is not required [46].  Acorns of chinkapin oak remain
viable for only short periods, even when properly stored.  Bonner and
Vozzo [9] reported that germinaton of fresh acorns was 91.3 percent, but
that germination declined to 39.0 percent after 1 year in storage and to
only 2.0 percent after 2 years.

Seedlings of chinkapin oak develop best on well-drained calcareous soil
[23].  They can tolerate moderate shrub-tree cover [23] but require
sufficient light for good early growth.  Seedlings are rare in gallery
forests of Kansas but are common at nearby prairie-forest borders [5].
Roots of developing seedlings must quickly reach mineral soil; in many
areas, establishment is limited by the presence of a thick organic layer
[3,55].

Vegetative regeneration:  Chinkapin oak sprouts readily after
disturbance [23].  Stump sprouting often occurs [48], but in many areas,
it is less common than root sprouting [65].  Hannah [28] reported that
the best sprouts often develop at or below the ground level.  Small
poles, saplings, and even seedlings can sprout when cut or burned [28].
Repeated sprouting is also common [74].  Seedlings often develop an
"s"-shaped curve at ground level, which helps protect dormant buds from
fire.  After repeated fires, these stems may develop "stools" or areas
comprised of callus tissue filled with dormant buds [55].  Epicormic
buds located beneath the bark of older oaks commonly sprout when these
trees are damaged [74].

Bud dormancy in oaks is largely controlled by auxins rather than by
levels of carbohydrate reserves [74].  Apical dominance can restrict the
development of belowground buds when buds survive on aboveground
portions of the plant.  Sprouting is reduced by low light levels [74]
and decreases as the stand ages [41].  McIntyre [41] reported that the
number of sprouts per group tends to decrease from poor to good sites.
Initial sprout growth is typically rapid [55].


SITE CHARACTERISTICS : 
Chinkapin oak grows on dry, rocky sites [11], such as calcareous bluffs,
rocky hillsides, and protected slopes and canyons [20].  It also occurs
in glades and valleys, and along rocky streambanks [26,27,66].  In parts
of the Midwest, chinkapin oak grows in rich forests and on stablized
dunes [70].  Chinkapin oak is particularly common near forest margins
[27].  It is fairly tolerant of shade and drought [5,19].

Plant communities:  Chinkapin oak is common in only one cover type, the
post oak (Quercus stellata)-black oak (Q. velutinus) type [23].
Elsewhere, it grows as scattered individuals or in relatively isolated
groves.  It occurs in a variety of communities, including gallery
forests along stream channels and ravines in the southern and central
Great Plains at the edge of eastern deciduous forests [1].  It is also
present in the Cross Timbers, blackland prairies, post oak savannas, and
pine-oak forests of Texas [48,61].

In the eastern United States, chinkapin oak grows in a number of mixed
mesophytic or submesic woodlands, including beech (Fagus spp.)-maple
(Acer spp.), maple-basswood (Tilia spp.), oak-hickory (Carya spp.),
oak-chestnut (Castanea dentata), chestnut oak (Quercus prinus), and
northern red oak (Q. rubra)-basswood [6,23,26,39,49,60].  In parts of
southern Indiana, it occasionally codominates the crown canopy with
northern red oak.  In Ohio, chinkapin oak commonly grows in areas
transitional from swamp forest to mesophytic forests [23].  Chinkapin
oak was a prominent species in several presettlement, open woodland
communities of the Midwest and middle South, including portions of Inner
Bluegrass region of Kentucky [15].

Plant associates:  Common plant associates in different geographic
locations include:

Midwest - Common associates in gallery forests of the prairies include
hackberry, American elm (Ulmus americana), bur oak, and sycamore
(Platanus occidentalis) [3,63].  Bur oak, white oak, black oak, northern
red oak, and shagbark hickory (Carya ovata) grow with chinkapin oak in
parts of the upper Midwest [12].

Texas - In pine-oak forests of Texas, chinkapin grows in association
with ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga
menziesii) [16,48].  Other common associates in Texas include American
elm, hackberry (Celtis spp.), blackjack oak (Quercus marilandica),
Shumard oak (Q. shumardii), western soapberry (Sapindus saponaria ssp.
drummundii), and black cherry (Prunus serotina) [61].

South - Chinkapin oak occurs with white oak, black oak (Quercus
velutinus), sugar maple (Acer saccharum), hickory, black cherry, ash
(Fraxinus spp.), Arizona walnut (Juglans major), yellow-poplar
(Lirodendron tulipifera), and cucumbertree (Magnolia acuminata) in the
Southeast [23].  In remnants of open woodlands common in portions of the
Inner Bluegrass region of Kentucky during presettlement times, chinkapin
oak occurs with bur oak, blue ash (Fraxinus quadrangulata), Shumard oak,
shellbark hickory (Carya laciniosa), shagbark hickory, sugar maple,
black cherry, yellow-poplar, and red mulberry (Morus rubra) [15].  In
the deep South, it grows with holly (Ilex spp.) and other oaks in stands
dominated by beech and magnolia (Magnolia spp.) [23].  In Arkansas,
butternut (Juglans cinera), Arizona walnut, and other oaks are
particularly common associates [23].

Soils:  Chinkapin oak commonly occurs on calcareous soils which are
derived from limestone [23].  It also grows on deep, well-drained soils
of river and creekbottoms [61] and on limestone outcrops [23].  Soils
are often of low fertility and deficient in nutrients such as phosphorus
[33].  Chinkapin oak grows on medium acidic to highly alkaline soils
[23] but reaches greatest abundance on basic soils [50].  In parts of
the Midwest, it is absent in relatively level areas where soil leaching
has resulted in an acidicification of a glacial till mantle [23].
Edaphic factors can greatly influence growth rate of chinkapin oak [1].

Climate:  Chinkapin oak grows in moist subhumid to humid zones
throughout most of its range but grows in dry subhumid conditions at the
southwestern edge of its range [23].  Growing-season precipitation
ranges from 10 inches (25 cm) in Texas to 80 inches (203 cm) in the
southern Appalachians.  The length of the growing season ranges from 120
to 240 days [23].

Elevation:  Chinkapin oak grows from 400 to 3,000 feet (122-914 m) [79].
It is absent or rare at higher elevations in the Appalachian Mountains
[23].


SUCCESSIONAL STATUS : 
Chinkapin oak is a climax tree on dry soils, particularly those of
limestone origin.  It is seral on more moist sites [23].  Chinkapin oak
is moderately shade tolerant when young, but becomes increasingly
intolerant of shade with age.

Upper Midwest:  Chinkapin oak and bur oak commonly dominate oak savannas
of the upper Midwest.  Evidence suggests that tree density in these oak
savannas increased after settlement [12].  Fire frequencies were
presumably much reduced at this time, enabling chinkapin oak to reach
extremely large sizes.  With continued fire suppression, these oak
savannas are being replaced by more shade-tolerant species such as elm
(Ulmus spp.), sugar maple, and buckeye (Aesculus spp.) [42].  In the
absence of disturbance, sugar maple assumes dominance in climax stands
[42].

Central Midwest:  In oak-hickory forests of southern Indiana, chinkapin
oak stands are seral to climax beech-ash-maple forests.  Chinkapin oak
grows in the final successional stages of Ozark floodplain communities
which are dominated by sugar maple and bitternut hickory (Carya
cordiformia) at climax.  On south- and west-facing slopes near these
communities, it is considered a subclimax or seral species [23].

Southeast:  Chinkapin oak and bur oak dominate certain early seral
forests in Mississippi Valley lowlands [3].  These forests are replaced
first by black oak, then northern red oak-shagbark hickory, and finally
American basswood (Tilia americana)-eastern hophornbeam (Ostrya
virginiana) forests [3].  Chinkapin oak also grows in certain climax
floodplain oak-hickory communities in the lower Mississippi Valley [60].
Hickories and the rapidly growing southern red oak (Quercus falcata)
develop first following disturbance on sites in this region.  Seedlings
of chinkapin oak generally appear 75 to 100 years after the initial
disturbance [60].  Martin and DeSelm [39] reported that in eastern
Tennessee, chinkapin oak occasionally occurs in old-growth forests in
limestone valleys.

Middle South:  In presettlement times chinkapin oak grew as an overstory
codominant in certain unique open woodland communities of the Inner
Bluegrass region of Kentucky [15].  Evidence suggests that these
communities were maintained by a combination of factors such as soil,
climate, grazing, and fire history.  With changes in fire frequency and
increased grazing brought about by settlement, these communities
declined and were ultimately replaced by cultivated fields and pastures
dominanted by cool-season grasses [15].

Eastern Great Plains:  During settlement times, reductions in fire
frequency enabled woody species, such as chinkapin oak, to expand
westward into parts of the prairie [3,10].  However, with further
reductions in fire frequency, oak woodlands dominated by chinkapin oak
and bur oak are being replaced by maple-basswood forests [3].
Historically, these narrow oak forests burned periodically as fires from
grasslands spread into adjacent woodlands.

In the Kansas prairie, chinkapin oak is a component of early seral
forests [5].  In many of these forests, this oak apparently grew and
reproduced beneath the overstory canopy until approximately 50 years ago
[3].  At this point, development of a thick organic seedbed, attributed
to fire exclusion, may have limited oak establishment.  Continued
overstory development within the past 10 to 30 years has led to the
proliferation of more shade-tolerant species [3].  Species such as
hackberry ultimately replace the oaks on moist sites, whereas redbud
(Cercis spp.) assumes dominance on more xeric sites [3,52].  A return to
more frequent fires could permit the oaks to assume dominance on these
sites [52].


SEASONAL DEVELOPMENT : 
Chinkapin oak leafs out in mid-spring [52].  Plants flower when leaves
are approximately 25 percent grown [23].  Fruit ripens at the end of the
first growing season [27].  Generalized flowering and fruiting dates by
geographic location are as follows:

Location          Flowering         Fruiting          Authority

WI                May               ----              Curtis 1959
New England       May 21-June 8     ----              Seymour 1985
n-c Great Plains  early May         September         Stephens 1973
NC-SC             April             October           Radford and
                                                        others 1968
Great Plains      April-May         ----              Great Plains Flora
                                                        Association 1986
KS                May               ----              Reichman 1987
Blue Ridge Mtns.  April-May         ----              Wofford 1989            

Related categories for Species: Quercus muehlenbergii | Chinkapin Oak