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Wildlife, Animals, and Plants
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FIRE EFFECTS
SPECIES: Picea rubens | Red Spruce
IMMEDIATE FIRE EFFECT ON PLANT :
Red spruce is easily killed by fire [49]. Surface or ground fires that
consume the litter and organic layers covering the superficial roots of
red spruce are almost certain to severely injure the roots [39]. Fire
kills mature trees by exposing roots, subjecting the tree to water
stress and/or windthrow, which may result in the eventual death of the
tree [39,87].
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
Red spruce does not sprout. Seed germination is greater on burned areas
with exposed mineral soil than in duff; mortality, however, is also
greater due to increased surface temperature and drought [63].
Burned red spruce or spruce-fir stands are initially restocked by aspen
(Populus spp.) or birch (Betula spp.) via wind-disseminated seed; paper
birch (Betula papyrifera)-aspen stands are particularly diagnostic of
fire in upland red spruce forests [52]. Red spruce seedlings appear a
few years after fire, developing as an understory in the aspen-birch
complex, and eventually penetrate the overstory after 50 or 60 years.
Birch and aspen become decadent after 75 to 80 years and red spruce or
red spruce and balsam fir regain dominance if left undisturbed
[49,52,65]. On better sites, northern hardwoods, chiefly sugar maple
and American beech, may replace red spruce, and in some areas, balsam
fir will dominate the late postfire succession. Postharvest/postfire
restocking by red spruce is extremely slow where the organic layers are
destroyed by severe fire (particularly where harvest has been heavy)
[49].
In Nova Scotia, mature spruce forests have few herbs and shrubs in the
understory. After a fire, herbs increase in the first 6 years and
dominate for 40 or more years while conifers slowly establish [54].
After fire in the southern Appalachians, blackberry (Rubus ursinus) and
red raspberry colonize the site. Pin cherry and yellow birch follow.
Blackberry and raspberry are too competitive for red spruce and must be
shaded out by the hardwoods before red spruce can establish [39].
In West Virginia, postlogging and postfire succession in red spruce
forests follows a similar pattern: ferns and raspberry are followed by
other shrubs, then hardwoods (particularly hawthorn [Crataegus spp.]),
and eventually spruce. In many areas, this successional pattern has
been extremely slow; heaths or barrens form that do not appear as if
they will ever return to forest [13]. Martin [54] studied
postlogging/postfire succession in Nova Scotia and found that red spruce
was present on most sites after the second postfire year, becoming more
numerous and dominant in the later seres. He concluded that repeated
heavy cuttings and light fires on the poorer soils of the southern
upland of Nova Scotia encourages the invasion of heath plants, which
limits the rate and amount of tree regeneration.
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS :
Some managers believe that prescribed fire may be a useful silvicultural
tool for managing red spruce on some sites. On such sites, the exposed
mineral soil must have plentiful moisture, soil temperatures must be
moderate, and competition must be minimal [65]. In general, however,
fires in red spruce habitat are of little silvicultural value [87].
Slash burning following logging kills advance reproduction and creates
rank postfire vegetation that delays any new seedling establishment
[39].
The fire management plan for Acadia National Park, Maine, dictates the
suppression of natural fires. Prescribed fires may be used on occasion
to reduce fuels [61]. Patterson and others [60] estimated fuel loadings
for a number of stands in Acadia National Park that contained red
spruce. They concluded that fire exclusion was probably resulting in
increased fuel loads.
Alexander [4] compiled slash fuel indices for red spruce and compared
actual fire spread, intensity, and slash and organic layer depletions
with those predicted by the Canadian Forest Fire Danger Rating System.
Freeman and others [24] developed equations to determine average crown
weight per tree as a function of tree height and diameter for use in a
method to predict slash weight after logging red spruce.
Related categories for Species: Picea rubens
| Red Spruce
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