FIRE EFFECTS
SPECIES: Quercus virginiana | Live Oak 



IMMEDIATE FIRE EFFECT ON PLANT : 
Fire top-kills live oak.  Dominant live oaks can survive low-severity
fire that does not crown.  Dominant live oaks larger than 3 inches (8
cm) in d.b.h. survived a fire on Cumberland Island, Georgia.  Smaller
trees were top-killed [10].

The root crown and roots of young top-killed live oaks survive most
fires.  A dry season hot fire in Florida killed and top-killed many live
oak that had invaded a prairie from a nearby hammock. Live oaks greater
than 12 inches (30 cm) in d.b.h. did not recover by sprouting, but
smaller oaks did.  Dominant live oaks in the established hammock areas
were not killed [24].

The average surface fire is hot enough to destroy all acorns on the
ground [16].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
If top-killed, young live oaks sprout from the root collar and from
roots.  Most sprout growth occurs in the first postfire year.  Seven
months after a prescribed fire in Florida, the mean height for sand live
oak sprouts was 9.5 inches (24 cm).  The mean height remained near 12
inches (30 cm) for the next 5 years [2].  After this fire, sand live oak
returned to preburn levels of dominance with respect to cover in 2 to 3
years.  The number of sprouts declined with time [1].

Live oak stem densities increased after a prescribed fire of scrubby
live oak plots in the Aransas National Wildlife Refuge on the Texas
Coastal Plain.  Acorn production was reduced in the first postfire year,
but increased to preburn levels in the second year.  Top-killed live oak
is capable of flowering and producing acorns on sprouts in the first
postfire year.  Mottes containing large live oaks did not burn [42].

The same plots in the Aransas National Wildlife refuge were burned every
2 years for 10 years.  After 10 years, acorn production was reduced
compared to unburned plots, but the density of live oak stems remained
higher than preburn levels.  Height growth was kept at a minimum by the
biennial fires.  Large mottes were more susceptible to burning with each
subsequent fire [42].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Prescribed surface fires are used to maintain live oak savanna by
killing juniper and improving grass and forage quality.  If fires are
frequent, however, large live oak mottes will eventually be eliminated
[28,42,51].

Lack of fire in oak savannas in Texas results in increased, dense,
thickets of live oak.  Fire cannot be used to restore savannas because
fire results in increased stem densities.  Frequent fires keep oak under
control, but do not eradicate it [43].  The prevalent sand live oak
groves in Florida may be an artifact of former burning practices of the
United States Forest Service [33].

In Florida, fires during a dry, growing season may reduce live oak-saw
palmetto hammock fringe habitat and restore prairie [24].

Related categories for Species: Quercus virginiana | Live Oak