BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus virginiana | Live Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Live oak is a shrubby to large and spreading, long-lived, nearly
evergreen tree.  It drops its leaves and grows new leaves within several
weeks in the spring.  Open-grown trees average 50 feet (15 m) in height
and 36 to 48 inches (91-122 cm) in d.b.h., but can have trunks up to 79
inches (200 cm) in d.b.h.  The rounded crowns may span 150 feet (46 m)
or more [20,21].  Lower limbs sweep to the ground and then curve upward.
Live oak growing at an angle of up to 45 degrees can still support a
great mass of limbs.  The bark is furrowed longitudinally, and the small
acorns are long and tapered.  Trees usually have rounded clumps of ball
moss or thick drapings of spanish moss [19,21].

The sand live oak and Texas live oak varieties frequently have a shrubby
stature which is thought to be soil and moisture dependent.  Both
varieties become trees in good site conditions [48].  Sand live oak can
grow to 33 feet (10 m) in height and 24 inches (60 cm) in d.b.h.  Its
oblong leaves curl under at the margin and the lower surface is densely
whitish-pubescent [11].


RAUNKIAER LIFE FORM : 
   Phanerophyte (mesophanerophyte)
   Phanerophyte (microphanerophyte)
   Phanerophyte (nanophanerophyte)


REGENERATION PROCESSES : 
Live oak is monecious.  Acorns are produced annually and often in great
abundance [21].  Acorns can be produced on root sprouts only 1 foot (0.3
m) high [45].  Dissemination is by gravity and, to a lesser extent,
animals [21].

Germination is hypogeal and occurs shortly after seedfall if the site is
moist and warm.  Few acorns overwinter since they are eaten by weevils
and animals [21].  Live oak is fast growing if well-watered and soil
conditions are good.  Seedlings can grow 4 feet (1.2 m) in the first
year, but this rate tapers off as size increases [19,45].  Under ideal
conditions, a live oak can attain a d.b.h. of 54 inches (137 cm) in less
than 70 years [20].

Live oak sprouts from the root collar and roots, and forms dense clones
up to 66 feet (20 m) in diameter [8].  The sand live oak clones are
called groves, and clusters of live oak in the Texas prairie are called
mottes.



SITE CHARACTERISTICS : 
Live oak grows in moist to dry sites.  It withstands occasional floods,
but not constant saturation [47].  It is resistant to salt spray and
high soil salinity.  Live oak grows best in well-drained sandy soils and
loams but also grows in clay and alluvial soils [21].  It grows up to
328 feet (100 m) in elevation [11].  The native range of live oak
coincides approximately with the southeastern maritime sand strands
[35], as well as with the 41.9 degrees Fahrenheit (5.5 deg C) isotherm
for the average minimum daily temperature of the coldest month [26].

Although generally considered a mesophytic species, live oak is common
on xeric, mesic, and hydric hammocks in the southeastern United States.
(A hammock is a dense, hardwood forest that occurs in pinelands and in
limited, elevated areas amidst wet prairies and marshes.)  Although live
oak is absent from the wetter areas in hydric hammocks [47], it occurs
in some hammocks where its roots are covered by salt water during high
tide [45].  Live oak also occurs in flatwood sites and on the outer
terraces of floodplains [53].  In the coastal sand plain of southern
Texas, live oak forms mottes within grasslands [14].

The sand live oak variety, considered xerophytic, grows on drier and
more acid sites than does the typical variety.  Sand live oak occurs in
greater quantity in the subtropical climates [2,35].  This variety
occurs in sandhills with other nearly evergreen scrub oaks including
Chapman oak (Quercus chapmanii) and myrtle oak (Q.myrtifolia) [33].

In addition to overstory associates mentioned in SAF cover types, common
associates of live oak include southern magnolia (Magnolia grandiflora),
water oak (Quercus nigra), pignut hickory (Carya glabra), red bay
(Persia bobonia), sweetgum (Liquidambar styraciflua), and saw palmetto
(Serenoa repens).  On less well-drained sites, live oak is associated
with sugarberry (Celtis laevigata), green ash (Fraxinus pennsylvanica),
and American elm (Ulmus americana) [21].  Woody species found with live
oak in mottes include American beautyberry (Callicarpa americana),
yaupon (Ilex vomitoria), and greenbrier (Smilax spp.) [42].  Netleaf
hackberry (Celtis reticulata) and cedar elm (Ulmus crassifolia) grow
with live oak in riparian areas in Texas [53].

The Texas live oak variety grows in grasslands and in riparian areas.
It grows as large trees in deep soils along streams and as large shrubs
in canyon headers.  Texas live oak is often associated with Texas
persimmon (Diospyros texana), Texas red oak (Q. texana), post oak (Q.
stellata), and honey mesquite (Prosopis glandulosa) [41,42].


SUCCESSIONAL STATUS : 
Live oak is intermediate in shade tolerance.  Once established, it
withstands competition.  Live oak is extremely salt tolerant, and this
resistance may account for its dominance in many climax coastal forests
in the northern part of its range [22].  Live oak may also be a climatic
climax on Carolina coasts [26].  In the succession from coastal shrub
thicket to maritime forest, the typical live oak variety is often
preceded by the sand live oak variety.  Live oak will usually become the
chief dominant, but southern magnolia has the potential of partial or
complete dominance [35].

The exclusion of fire has increased the presence of live oak in the
Atlantic and Gulf coastal plains.  In the absence of fire, live oak
expands from hammocks into dry, coastal prairies in Florida and
Louisiana.  The expanding vegetation is dominated by live oak and saw
palmetto, which are characteristic of hammock fringe vegetation [16,24]

In the absence of fire, southern magnolia and live oak form a climatic
climax on former longleaf pine (Pinus palustris) savannas [8].  Slash
pine (P. elliottii)-oak vegetation is also replaced by live oak [16].
In Texas, fire suppression and overgrazing have created a live
oak-juniper disclimax in place of mixed prairie [39].

Twenty-five years after abandonment, live oak seedlings appear in fallow
agricultural fields on floodplains that once supported live oak.  A live
oak forest matures 50 years after seedling establishment [12].

In the absence of fire, xeric hammocks dominated by live oak, may
develop into mesic hammocks, but changes are slow [46].  


SEASONAL DEVELOPMENT : 
Small flowers are produced in the spring when new leaves are grown.
Pollen is wind dispersed during the first 2 weeks in April.  Acorns
mature the following September and fall before December [19,21].  Sand
live oak produces flowers 2 to 3 weeks later than the typical variety
when in the same locality [11].

Related categories for Species: Quercus virginiana | Live Oak