FIRE EFFECTS
SPECIES: Quercus kelloggii | California Black Oak 



IMMEDIATE FIRE EFFECT ON PLANT : 
California black oak is fire sensitive.  The outer bark chars readily,
and the cambium suffers heat damage even where bark is thick (over 0.5
inch [1.3 cm]).  All trees in a stand are usually top-killed following
crown fire regardless of size [33], and complete kill is common after
such fire in pole-sized or smaller trees [22].  Complete kill is also
common when individual trees or clumps of trees are surrounded by or
adjoining brush [33].

The amount of damage sustained by surface fire depends upon fire
severity.  A large percentage of California black oak are completely
killed following severe surface fire, especially when trees are shrubby
[22].  Moderate-severity fire typically produces localized charring and
cambium death in an older trunk, while other trunk portions remain
undamaged [34].  Approximately half of all young trees in a stand will
be killed by moderate-severity fire [22]; most of the others will be
top-killed.  Low-severity fire causes some cambium damage to trees
pole-sized and under [2,22].  Spring fire corresponding to the active
growing season results in greater tissue damage than fire in other
seasons [21].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Within a few weeks following fire, most surviving trees sprout from the
root crown and undamaged portions of the trunk.  This response is
independent of the rainy season; new shoots draw upon water reserves in
the root system and appear following spring, summer, or fall fire.
Sprouting is vigorous in saplings and young trees. Very old trees may
fail to sprout or produce only coppice sprouts [30].  Fire prepares an
ideal seedbed, and seedlings establish in the first postfire growing
season.  California black oak seedling populations were significantly
increased (p>0.05) following a light-intensity prescribed burn of a
Jeffrey pine (Pinus jeffreyi)-California black oak forest in Cuyamaca
Rancho State Park, California [27].  Long-term recovery of this species
is favorable; fire creates the open canopy required for optimum seedling
and sprout growth [22].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
The decline in Califonia black oak populations is due to many factors,
and past policies of fire suppression is one of them.  This species has
evolved under a fire regime of low- to moderate-severity surface fires
[22,23] at average intervals of 3.5 years [47].  Fire suppression has
resulted in major structural changes in coniferous forests and woodlands
of California and southern Oregon.  Populations of shade-tolerant white
fir (Abies concolor) and Douglas-fir have greatly increased.  There has
been a greater than 300 percent increase in aggregations of pole-sized
conifers.  The understory, once an open mixture of shrubs, saplings,
grasses and forbs, is now often dominated by dense stands of coniferous
saplings or dense, mixed stands of coniferous saplings and brush.  Fuel
loading in these forests represents an unnatural buildup of downed woody
materials.  When these forests burn, the dense understory produces a
ladder effect, resulting in crown fire [23].  This results in a
high-consumption, severe fire that is frequently fatal to California
black oak [22].  When the management objective is to increase California
black oak recruitment in these dense forests, understories are usually
cleared prior to prescribed burning.  Kauffman and Martin [22] have
recommended low- to moderate-consumption prescribed fire.  Forest floor
reductions to less than 8 to 16 tons per acre (18-36 t/ha) have been
suggested.  This may require several fires.  Burning favors seedling
establishment in several ways.  It prepares a favorable seedbed not only
by removing litter, but also by killing damaging molds and insects
present in the litter layer.  Sapling mortality due to root rot
decreases following fire [2].

Following a prescribed March burn on the Shasta-Trinity National Forest
of California, surviving California black oaks produced a bumper crop of
sound acorns, while acorns on nearby unburned ground were mostly
unviable.  Researchers attributed the difference to insect predation of
acorns on the unburned forest floor [7].  

Related categories for Species: Quercus kelloggii | California Black Oak