FIRE EFFECTS
SPECIES: Quercus falcata | Southern Red Oak 



IMMEDIATE FIRE EFFECT ON PLANT : 
In general, southern red oak up to 3 inches (7.6 cm) in d.b.h. is
top-killed by low-severity fire [7].  High-severity fire can top-kill
larger trees and may kill rootstocks as well.
  
Fires during the growing season tend to be more detrimental to southern
red oak than winter fires.  In Texas, a winter headfire top-killed 20
percent of a southern red oak and post oak understory; a late winter
fire top-killed just over 40 percent; a spring fire top-killed just
under 40 percent; and a late summer fire top-killed 55 percent.  Winter
fires killed on average less than 2 percent of rootstocks; summer fires
killed on average less than 10 percent.  The top-kill was substantially
greater for oaks between 0.6 and 2.5 inches (1.5-6.4 cm) in diameter
than those between 2.6 and 4.5 inches (6.5-11.4 cm) in diameter.
Diameter was measured 6 inches (15.2 cm) above the groundline [13].

A spring fire in Alabama resulted in 51 percent crown reduction of
southern red oak understory which averaged 1.8 inches (4.6 cm) in
diameter 6 inches (15.2 cm) above the groundline [6].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
If top-killed by fire, southern red oak sprouts from the root crown.  In
Tennessee, sprouts of the typical variety averaged 1.3 feet (0.4 m) one
growing season after a series of eight annual winter fires [51].  In
another study, at the end of two postfire growing seasons, dominant
sprouts averaged 2.2 feet (0.7 m) in height and 0.26 inch (0.66 cm) in
diameter 6 inches (15 cm) above the ground [13].

Because of sprouting, fire tends to increase the number of southern red
oak stems.  The eight annual winter fires in Tennessee resulted in 3,420
stems per acre (8,444/ha) compared to 1,510 stems per acre (3,728/ha) in
the unburned control [51].  If high fire frequency continues, however,
the stem density will decrease as root systems are killed.  Southern red
oak stem density increased, then decreased, in abundance after 27 annual
late winter fires on an upland site in Tennessee [10].  In a study on
the Santee Experimental Forest in South Carolina, 43 years of
periodic winter and summer low-severity fires and annual winter and
summer low-severity fires reduced the number of hardwood stems
(including southern red oak) between 1 and 5 inches (2.6-12.5 cm) in
d.b.h.  However, the number of stems less than 1 inch (2.5 cm) in d.b.h.
increased slightly under all treatments except annual summer fires.
Root systems were weakened and eventually killed by annual burning
during the growing season [57].

Fire wounds on surviving trees allow entry of fungi which can cause
heartrot decay.  Within 1 to 2 years postfire, wounded areas are invaded
by fungi.  The rot takes an average of 4 years to reach the heartwood
[52].  Average rate of spread of established rot in cherrybark oak is
1.25 feet (0.4 m) per decade [53].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Hardwoods growing within a pine forest are often controlled with
prescribed fire.  Southern red oak up to 3 inches (7.6 cm) in d.b.h. is
usually top-killed and sprouts kept small and controllable with winter
fires.  Summer fires are also effective but are more detrimental to the
wildlife food supply and pine species [7].  If southern red oak is being
grown commercially, protection from fire is highly desirable once the
stand is established.  One fire per decade makes it impossible to manage
hardwoods profitably because fire wounded trees are so susceptible to
rot [52].

Prescribed fire may promote advance regeneration of southern red oak.
Because oak seedlings are less susceptible to root kill by fire than
competitors and because sprouts grow faster than seedlings, low-severity
fire can be used to promote advance oak regeneration.  In fact, the
decrease in natural oak regeneration may be a direct result of fire
exclusion.  The exact combination of season and frequency of prescribed
burning for the purpose of advance regeneration has not been determined.
Repeat low-severity fires seem to have more effect on advance
regeneration than single fires [55].  In a study in Alabama, upland oaks
did not increase in relative dominance after a single spring fire in a
4- to 6-year-old mixed hardwood stand [19].

An equation has been developed to predict the total aboveground fuel
dry-weight of southern red oak.  A manager would need to know the
average stem basal diameter and the number of stems per hectare to
predict dry material per hectare [47].

Related categories for Species: Quercus falcata | Southern Red Oak