FIRE ECOLOGY
SPECIES: Picea abies | Norway Spruce 



FIRE ECOLOGY OR ADAPTATIONS : 
Norway spruce is not well adapted to survive fire.  Fire in mature
stands of Norway spruce is usually of high intensity and destroys all
standing trees [15].  Fire severity usually depends on a number of
factors, primarily soil moisture [74].  In taiga forests over
permafrost, low-severity fires leaving standing live trees may
eventually result in complete stand destruction since windfall of the
remaining trees may occur when increased insolation on blackened soil
thaws the permafrost.  There is little regeneration in stagnant stands
of Norway spruce; the next generation of trees is only produced after a
fire [15].  Norway spruce is easily killed by fire and is not an early
colonizer in postfire succession; stand-destroying fires usually result
in replacement by Scot's pine.  Norway spruce develops as the understory
in Scot's pine stands on suitable sites, and will eventually replace
Scot's pine to complete the successional cycle [7,15,70].

Fire history in Norway:  Fire was used extensively for agricultural
clearing in southeastern Norway 300 to 400 years ago.  After a short
period of cultivation, depleted soils were left to natural
reforestation, forming mixtures of conifers and broadleaf trees, mostly
birch (Betula pubescens or B. verrucosa) [6].  In the pollen record,
Norway spruce pollen increased during periods of lower disturbance and
fewer fires.  In the last 200 years, since agricultural burning has
virtually ceased, Norway spruce stands have formed closed canopies with
very little groundlayer vegetation [7].

Fire history in Finland:  Fire frequencies have been estimated to range
from 31 to 81 years for different historical periods.  Human activity
has played a large role in fire history; a large amount of burning
occurred during the Iron Age and medieval periods, mostly due to slash
and burn agriculture, from about 1 AD to 1750 AD [72].  Prior to the
appearance of cereal pollens, charcoal analysis of bog soils indicates
that, an average of one fire every 84 years occurred between 3000 and
2000 BP.  There is an inverse relationship between the amount of Picea
pollen and the amount and frequency of charcoal particles; when fire
frequency is high, Norway spruce densities are low [73].

Fire history in Sweden:  In northern Sweden, the mean fire rotation (the
amount of time equivalent to the area studied divided by the area of
sample plot burned annually) was approximately 100 years for mixed
stands of Norway spruce and Scotch pine from the end of the medieval
period up to the end of the nineteenth century.  Since fire suppression,
the estimated fire rotation is on the order of 3,500 years.  The
presuppression fire rotation created a mosaic of even-aged stands at
different successional stages.  Norway spruce often forms the
undergrowth in Scotch pine stands that survive or are regenerated after
fire; Scotch pine often survives as an overstory tree and can reach very
old ages.  In Norway spruce forests on wet sites fires have been rare;
fire-free intervals of up to 500 years have been reported for such sites
[21,84,85].  The mean number of years between fires and the amount of
time since the last fire were positively correlated to basal area of
Norway spruce; Norway spruce density increases when fires occur at long
intervals and shorter intervals favor Scotch pine [21].

Fire history in northern European Russia:  Estimates from fire scar data
indicate fire frequencies on the order of 130 to 200 years in spruce
forests (including Siberian spruce and Norway spruce) [76].


POSTFIRE REGENERATION STRATEGY : 
   Tree without adventitious-bud root crown

Related categories for Species: Picea abies | Norway Spruce