FIRE EFFECTS
SPECIES: Populus balsamifera ssp. balsamifera | Balsam Poplar 



IMMEDIATE FIRE EFFECT ON PLANT : 
Severe fires kill balsam poplars [53]; however, underground parts
survive in moist soils [111].  Moderate fires may top-kill some trees;
light fires usually do not harm mature balsam poplars [53].  Young trees
may be top-killed because of their thin bark [16].  Repeated burning may
permanently exclude balsam poplars [16].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Balsam poplar is stimulated to produce root suckers within several weeks
following fire [36,38].  Active recovery is likely to begin 1 year after
fire; balsam poplar increased in cover and frequency after 1 year on a
severely burned site in Alberta [53]:

                 cover   frequency
     prefire      .4 %       5 %
     postfire    3.2 %      33 %


Most balsam poplar suckering occurred in the second season after a
spring burn in a 15-year-old stand in Alberta, and after 5 years poplar
density was greater on burned areas than before the fire [4].

Two years after logging and broadcast slash burning in a floodplain
white spruce area, white spruce seedlings were outnumbered and
overtopped by hardwood seedlings, including balsam poplar [28].  Soil
temperatures on these sites were doubled, which encourages vegetative
expansion by balsam poplar [36,86].

See "Plant Response to Fire" in the "Fire Effects" section of the FEIS 
summary of black cottonwood for further information on sprouting 
response of balsam and other cottonwoods.

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 



FIRE MANAGEMENT CONSIDERATIONS : 
Prescribed burning for wildlife:  Fire-induced poplar and willow
sprouting can increase forage for moose [67].  Beaver also benefit from
an increased supply of poplar sprouts following fire [83].  Repeatedly
burning white spruce forests and balsam poplar stands can convert large
areas into grasslands used by elk and Stone's sheep [90].  Cyclic burns
(every 10 years) are needed to maintain sedge (Carex spp.) grasslands
which would otherwise be taken over by shrubs and deciduous trees,
including balsam poplar; sedges are the main food item for bison in
northern latitudes [15].  Wood Buffalo National Park, a large bison
preserve in Canada, is characterized by extensive areas of white spruce
and mixed hardwoods, and extensive sedge meadows.  Natural fire cycles
here have been estimated to be 50 years [40].

Fire control has had little or no impact in most of the far northern
boreal forest and natural lightning-caused fire regimes prevail [40].
Estimated fire intervals of white spruce stands vary from 80 years on
morainic uplands to 300 years in floodplain stands [40].  Closed white
spruce forests of interior Alaska tend to have either high intensity
crown fires or severe surface fires which kill and regenerate entire
stands [40].  Balsam poplar present in white spruce stands will recover
rapidly after fire [78].  White spruce replacement may be retarded with
cyclic fires [63].

Balsam poplar easily colonizes large burn areas due to seed dispersal
distances and its ability to regenerate vegetatively.  White spruce may
be more successful at reestablishing small burns [96].

Related categories for Species: Populus balsamifera ssp. balsamifera | Balsam Poplar