BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus incana | Bluejack Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Bluejack oak is a native, deciduous small tree, usually growing to 35
feet (10.6 m), with a maximum height of about 50 feet (15 m) [11,40].
The crown is open and irregular, the trunk is usually short [15], and
the branches are stout and crooked [40].  On the Coastal Plain of
Florida, bluejack oak roots were concentrated in the top 5 inches (13
cm) of soil; this may have been related to the low fertility of deeper
soil horizons in this habitat.  A deep root system is normal for most
oaks [1].  The acorns are 0.4 to 0.72 inch (10-18 mm) broad; the
involucre covers one-half to one-third of the acorn [11].

The national champion bluejack oak was reported from Texas; it measured
51 feet (15.5 m) in height, 7 feet (2.1 m) in circumference, and had a
crown spread of 56 feet (17 m) [15].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Bluejack oak reproduces by seed (acorns) [15].  Acorns are first
produced when trees are about 2 inches (5 cm) dbh, with optimum yields
at 4 to 8 inches (9.6-20 cm) dbh.  Acorn yields per square foot of basal
area are relatively high.  Bluejack oak is a consistent acorn producer
[17]; one study reported that 91 percent of bluejack oaks produced
acorns over a 6-year period [32].

Bluejack oak sprouts vigorously from the root crown when aboveground
stems are damaged or removed.  It also forms thickets which are produced
by subterranean runners [15].


SITE CHARACTERISTICS : 
Bluejack oak is restricted to well-drained, sandy upland soils,
flatwoods, and river terraces [11,15].  It increases in dominance
downslope of the ridge tops; these downslope areas have finer soils and
better developed underlying clay horizons nearer the surface than do
ridgetop sites.  Thus downslope sites are slightly less xeric than the
ridgetops [6,39].  The highest elevation at which bluejack oak occurs is
about 660 feet (200 m) [11].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Bluejack oak is probably not tolerant of deep shade, although it does
grow under open pine canopies.  Monk [25] described bluejack oak as a
successional species: it is characteristically associated with
successional communities and is encountered in climax stands only as
widely scattered individuals.  The successional relationships of
bluejack oak are closely controlled by fire and are therefore further
discussed in FIRE ECOLOGY and FIRE EFFECTS.


SEASONAL DEVELOPMENT : 
Bluejack oak flowers from April to May [11].  The acorns mature in the
fall of their second season.  The leaves are sometimes retained until
late into winter, particularly when winter temperatures are mild [15].

Related categories for Species: Quercus incana | Bluejack Oak