BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus shumardii | Shumard Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Shumard oak is a large, deciduous, native tree.  It ranges up to 120
feet (40 m) in height, with trunk diameters of up to 80 inches (200 cm)
[9,33,38,45].  The crown is open and wide spreading, with massive,
ascending branches.  The trunk of older trees is heavily buttressed.
The bark is furrowed, with broken ridges [38].  The leaves are
five-lobed to nine-lobed.  Shumard oak acorns are egg-shaped,
approximately 1 inch (2.5 cm) long, and enclosed in a thick, flat,
saucer-shaped cup with pubescent scales [11].

Shumard oak is long-lived; the oldest Shumard oak found on a blue
ash (Fraxinus quadrangulata) savanna was 480 years of age [10].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Minimum seed-bearing age for Shumard oak is 25 years.  Optimum seed
production occurs at about 50 years of age.  Good seed crops are
produced every 2 to 3 years [11].  The acorns are frequently multiseeded
(an unusual trait).  Seeds are dispersed by seedhoarding mammals (mainly
squirrels) [11].  Acorns exhibit internal dormancy, which is broken by
cold, moist conditions.  Moist stratification at 36 degrees Fahrenheit
(2 deg C) for 8 to 12 weeks breaks dormancy.  The acorns typically
contain about 40 percent moisture at maturity [8].  Factors affecting
seed germination and seedling establishment include microclimate
conditions, soil moisture, and stand variables.  The limiting factor
appears to be seed supply, which may be affected by seed predation
[11,26].  Full light is required for good seedling establishment and
growth [11].

Shumard oak sprouts from the roots when top-killed [3].  This ability is
more pronounced in younger individuals.  Shumard oak is not a prolific
sprouter on moist sites; more sprouts are found on dry sites.  It is
difficult to propagate by cuttings [26].


SITE CHARACTERISTICS : 
Shumard oak grows best on moist, well-drained loamy soils on terraces,
colluvial sites, and adjacent bluffs associated with large and small
streams.  Shumard oak also occurs in Coastal Plains hammocks [26].
Shumard oak is intolerant or only weakly tolerant of flooding [2,19],
and does not usually occur on the lowest river bottoms [18].  It is
fairly drought tolerant, and is tolerant of alkaline soils and their
associated nutrient deficiency [11].  It can be planted in soils with pH
greater than 7.5 [2,21].  In central Texas, it occurs on dry, low
limestone hills.  In the south-central United States, it occurs on dry
uplands and ridges [26].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Shumard oak is intolerant of shade but is rare in early successional
stands.  It often occurs in climax forests.  Since Shumard oak is shade
intolerant and requires openings in which to establish, it is not
considered a true climax species [11].  Monk [27] classifies Shumard oak
as a climax exclusive:  a species which occupies specific environmental
situations in the climax community and is rarely encountered in
successional stands.  It is likely that Shumard oak colonizes gaps in
mature forests.  In Florida, Shumard oak occurs in climax magnolia-beech
forests [15].  In Missouri, it occurs as an overstory associate on river
bottom ridges occupied by sugar maple (Acer saccharum), pawpaw (Asimina
triloba), sweetgum (Liquidambar styraciflua), and swamp chestnut oak
(Quercus michauxii).  There were no Shumard oak seedlings or saplings in
these stands [31].  In Texas, Shumard oak was found in 47-year-old
bottomland hardwood stands and undisturbed adjacent forest, but not in
early successional stands [29].

It is likely that mature Shumard oak produces allelopathic substances [11].


SEASONAL DEVELOPMENT : 
Shumard oak flowers from March to April, and as late as June in some
parts of its range [9,11].  Acorns ripen from September to October of
their second year [11].

Related categories for Species: Quercus shumardii | Shumard Oak