FIRE EFFECTS
SPECIES: Quercus incana | Bluejack Oak 



IMMEDIATE FIRE EFFECT ON PLANT : 
In southwestern Alabama, a 1976 prescribed, late summer fire in a
longleaf pine stand resulted in only 9 percent complete kill of all oaks
(bluejack oak stems numbered 23 out of a total of 75 oak stems), even
though the fire caused 89 percent defoliation of oaks.  A second summer
fire in 1978 resulted in a total of 20 percent complete kill of oaks,
mostly among those stems that had been top-killed in the first fire.
Crown reduction and mortality were strongly associated with diameter;
for all hardwoods, mortality was highest for the 1-inch diameter class.
On a rating scale where 5 indicates no effect and 1 is complete kill,
the average degree of damage sustained by bluejack oak stems (average
1.7 inches [4.3 cm] dbh) from summer fire was rated as 3.9, with an
average crown reduction of 29 percent [3].

In the same study, 1980 spring prescribed fires (3 fires, which were set
at specific phenological stages) resulted in a 47 percent crown
reduction the first year after burning, and a 39 percent crown reduction
(i.e., 8% recovery of crown canopy) after the second growing season.
Only 5 out of 537 hardwood trees were completely killed by these fires.
A second set of spring fires (in 1981) was more effective at causing
hardwood damage, but still completely killed only 12 of 526 trees.  The
species most resistant to fire injury were bluejack oak and turkey oak
[3].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Bluejack oaks sprout following top-kill by fire; fires usually result in
an increase in the number of bluejack oak stems even when they have
been repeatedly killed back [13,43].  Stems larger than 8 inches dbh
have a greatly reduced ability to sprout after top-kill [43].  In
Florida, prescribed summer fires in oak domes (within longleaf pine
communities) caused stem mortality of bluejack oak.  The degree of
mortality was not reported.  Bluejack oak sprouted in less than 1 year
following the fire (most of the other species in the dome sprouted in
less than 6 months) [47].  In northern Florida, a 50-year-old slash
pine-longleaf pine stand was subjected to two prescribed winter fires 2
years apart.  The overstory pines were unaffected by the fire; canopy
coverage of bluejack oak decreased from 0.9 percent after the first fire
to 0.2 percent after the second fire [26].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Prescribed fire could be used to maintain longleaf pine/wiregrass
communities (in which bluejack oak occurs).  There is a need to consider
the following factors when planning prescribed fires for these
communities:  1) fire regimes need to be variable within and among
sites, 2) the sites themselves are variable, 3) ecotones and
transitional communities need to be maintained, and 4) there are species
and communities which were historically dependent on fires originating
within pinelands and flatwoods [27].

Where longleaf pine has been removed, and if there are few or no
longleaf pine seed trees, frequent fire results in a nearly pure scrub
oak type.  Heavy logging followed by infrequent fire results in
succession to oak-hickory with or without an intervening scrub oak stage
[13].  Fire may be effective in reducing canopy cover and stature of
bluejack oak but it is not effective in eradicating bluejack oak from a
site [44].  Single prescribed fires have very little effect on bluejack
oak; fires repeated annually are more effective in reducing bluejack oak
cover and density [3].  In South Carolina, a patchy, lightning-caused,
mid-summer fire resulted in significantly reduced growth (the first
growing season following the fire) in all species except bluejack oak
[5].  It has been suggested that timing prescribed fires for periods
when reserves are lowest may decrease oak sprouting potential [44].
Seasonal trends in carbohydrate reserves for bluejack oak have been
reported for western Florida [44].  Other factors being equal, burning
later in the season may increase crown reduction and top-kill.  Timing
fires to maximize intensity may be just as important or more important
than phenological stage for maximizing oak reduction.  Growing season
fires carry a greater risk of damaging pines, however [3].

Related categories for Species: Quercus incana | Bluejack Oak