FIRE EFFECTS
SPECIES: Cladonia (Cladina) spp. | Reindeer Lichen 



IMMEDIATE FIRE EFFECT ON PLANT : 
Reindeer lichens can survive cool fires but are almost always killed by
severe fire [16,26,40].  In the black spruce zone, lichens generally
burn poorly in early morning or near sunset, even on hot days, whereas
at mid-day they flare up with almost incredible heat and flame.
Humidity changes in the microclimate at ground level and dehydration of
the lichens appear to be the most likely factors involved.  Fifty
percent or more of the lichens may survive if there is not much organic
litter to retain the fire [16].  Following fire in a black spruce
community, all the Cladonia spp. survived a light burn, whereas none
survived a heavy burn [38].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 



PLANT RESPONSE TO FIRE : 
Reindeer lichens recover very slowly after fire [22].  The length of
time required for full recovery varies with species, the extent and
intensity of the fires, and site and microclimatic condition, but an
average of 40 to 50 years appears to be a conservative estimate [22,40].
Based on annual growth rates of 0.14 and 0.16 inch (4.1 and 4.9 mm) for
C. alpestris and C. rangiferina, it has been estimated that these
species would require nearly a century to reach prefire abundance [21].
After fire the first reindeer lichen to become established is Cladonia
mitis.  The second reindeer lichen phase is generally dominated by C.
alpestris, C. rangiferina, or C. arbuscula [22,40].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
One hundred forty years after a severe wildfire in Sweden, Cladonia
alpestris still showed no recovery, but did show good recovery only 20
years after a light, controlled burn.  Slow recovery rates were reported
from the Seward Peninsula of Alaska, while rapid recovery rates have
been reported from the open lichen woodlands of Newfoundland, where the
climate is warmer than in Alaska [40].
 
In a black spruce and jack pine woodland in northwestern Manitoba and
northeastern Saskatchewan, Cladonia mitis became established in less
than 40 years after fire, while C. alpestris and C. rangiferina first
appeared in stands greater than 40 years of age.  A dense growth of
reindeer lichens was found in stands that had not burned for at least
150 years.  In south-central Alaska it took 30 to 40 years for C.
rangiferina and C. arbuscula to recover after fire [25].  In a postfire
black spruce-lichen vegetation type of interior Alaska, cover values for
Cladonia species were 32 percent in 26- 50-year-old stands, and 41
percent in stands greater than 100 years [25].  In a lightly burned
75-year-old stand with a open canopy of spruce and occasional jack pine,
C.  alpestris made up 32.8 percent of the total ground cover and C.
rangiferina made up 1.7 percent [16].


FIRE MANAGEMENT CONSIDERATIONS : 
Reindeer lichens are highly flammable.  Cladonia rangiferina collected
from Ely, Minnesota, and ovendried had a heat value of 4,360 cal/g [15].
They dry rapidly during periods of low atmospheric humidity because of
the absence of roots, water storage tissues, and low resistance to water
loss.  Reindeer lichens resemble dead litter more than live tissue in
their susceptibility to fire.  Continuous mats of reindeer lichen
present an uninterrupted surface along which a fire spreads.  Lichen
mats also typically accumulate tree and shrub litter which adds to the
flammability [3].  In black spruce-Cladonia alpestris woodland, litter
suspended in the lichen mat added 20.5 percent dry weight to the total
combustible material present above the soil [3].

While the destruction of reindeer lichens may have an immediate effect
on the winter range of caribou, some studies indicate that at least
infrequent fire is necessary to maintain optimum lichen cover [40].  In
the northern boreal lichen belt, lichen supplies could be increased by
burning Sphagnum fuscum peatlands, treeless bogs, or wooded muskegs.
The result of severe fire is an almost solid reindeer lichen stand in
some 40 to 50 years.  Because black spruce and mosses regenerate more
slowly than lichen on these sites, good lichen growth persists for at
least 100 years [2].  Light burning has been suggested as a method to
improve reindeer range in Scandinavia [40].

Related categories for Species: Cladonia (Cladina) spp. | Reindeer Lichen