KUCHLER TYPE FIRE ECOLOGY AND MANAGEMENT
KUCHLER TYPE: Great Lakes pine forest



FUELS, FLAMMABILITY, AND FIRE OCCURRENCE : 
Historically red and white pine stands experienced moderately frequent
to infrequent surface fires and infrequent crown fires.  Short intervals
between crown fires were characteristic of jack pine forests.

Fire history studies in the Boundary Waters Canoe Area (BWCA),
Minnesota, showed an average presettlement fire interval of 36 years
between light surface fires in red and white pine stands.  Severe
surface fires and crown fires, where portions of stands were killed and
new age classes developed, occurred about every 160 years [9].  In red
and white pine stands near Lake Itasca, Minnesota, the fire regime was
similar, with slightly more frequent, moderate-severity surface fires.
The average interval between surface fires was 23 years.  Other fire
history studies for a region of lakes surrounding the BWCA showed
average fire intervals of 13 to 38 years for surface fires in red and
white pine stands [25].  Estimates of fire intervals in jack pine
forests are usually less than 50 years [8].  Jack pine forests that burn
more frequently than every 5 to 10 years become pine barrens [30].

The quantity and density of forest floor fuels in red pine stands in
Michigan and Minnesota are quite variable, but less so in jack pine
plantations.  In one study, the average total forest floor fuel weights
in red pine plantations in Michigan and Minnesota was 32,800 pounds per
acre (37,200 kg/ha) dry weight [3].  Fuel loading in red pine
plantations is given for the Great Lake States in relation to spacing,
age, and site quality.  Good sites with close spacing promote rapid fuel
buildup, but the time when fire is likely to crown is reduced [13].
Total forest floor weights in jack pine plantations in Michigan and
Minnesota averaged 23,420 pounds per acre (26,600 kg/ha) [3].  Ranges
for possible rates of slash consumption, preburn duff depths, depth of
burns, and rate of spread for prescribed fires have been given in jack
pine slash [14].  A comparison of the National Fire Danger Rating System
with the Canadian Forest Fire Weather Index is available for predicting
fuel moisture in jack pine slash in Michigan [21].

A study in red pine plantations in Michigan showed that the total weight
of forest floor fuels correlates with basal area [5].  Red pine carries
crown fires very well, and needle litter is well-aerated so that
flammability in pure stands is very high.  Red pine maintains this
maximum flammability until its height exceeds 60 feet (20 m) [26].  Dead
branches within the first 7 feet (1.3 m) of the bole persist on the tree
beginning at 11 to 15 years of age on good sites with densities greater
than 1,000 trees per acre.  On sites with stocking densities greater
than 1,200 trees per acre, branches begin to die and persist at 16 to 20
years of age.  These dead branches contribute to ladder fuels.  In red
and pine stands in the northern boreal forest, typical fuel types include
a moderately dense understory with forbs and shrubs, a continuous needle
layer, and an organic layer 2 to 4 inches (5-10 cm) deep.  In order for
fires to crown, dry, windy conditions are necessary [31].


FIRE EFFECTS ON SITE : 
On a wildfire in jack pine stands in Minnesota, A and B soil horizons
were studied for fire's effects on water availability, exchangeable
bases, pH, nitrogen, potassium, and carbon.  These results are given for
seven burned plots and compared to unburned plots [15].  Early spring
fires in the northern parts of the Great Lakes States may only reduce a
few centimeters of the duff layer because of cool, moist soil conditions
and the presence of snow.  Summer fires can remove duff and expose
mineral soil [16].


FIRE EFFECTS ON VEGETATION : 
Jack pine reproduces as early as 15 to 20 years of age [8] and has
serotinous cones that allow it to regenerate following crown fires [20].
When mature, jack pine survives low-severity fires [7].  Red and white
pines survive low-severity fires at 50 to 60 years of age.  Large trees
survive moderate-severity fires [7,26,28].  In the absence of fire red
and white pine stands may be converted to balsam fir and sugar maple [9].
If fire intervals are less than 50 years, jack pine can replace white
pine [28].

Removal of duff usually enhances jack pine regeneration, but moisture
stress following fire can cause seedling mortality.  Seeds in jack pine
slash may be consumed by fire except when the fire moves quickly through
an area.  Fast moving fires, however, are usually not hot enough to burn
the duff and do not provide the bare mineral soil jack pine requires for
establishment [14].

Jack pine regeneration may be sensitive to the season of burning.  Jack
pine reproduction was less on a northern Minnesota site following a
cool, spring fire than on a similar site that burned in late July.  The
spring fire burned only a few centimeters of the duff, while the July
fire burned the duff down to bare mineral soil.  Tall shrubs sprouted
more on the May burned site than on the July burned site.  Low shrubs
had a similar response [16].  Jack pine was the dominant tree on the
drier sites of the May burn, while hardwoods dominated the wetter sites.
During the first postfire year jack pine seedling density ranged from
0.86 to 1.58 per square foot (9.3-17.0 sq m) on the May burned site.
Densities on two July burned sites were 6.29 per square foot (67.6 sq m)
and 3.04 per square foot (32.7 sq m).  For more detailed information on
vegetative effects of the Little Sioux wildfire in northern Minnesota
refer to Ohmann and Grigal [15].

Fire can kill red pine by reducing its vigor through needle kill or
damaging trees so that beetles infest the stand [24].  Surface fires
greater than 1,000 Btu per second-foot can kill a red pine stand.
Excessive crown scorch kills quickly, but cambial damage takes longer.
Seeds and cones can survive light surface fires, but are usually
consumed in crown fires that burn in spring or summer.  Red pine
perpetuates well in areas where topography is broken by lakes and hills
so that these natural fire breaks create varying fire intensities in
different areas [26].  If mosses (Polytrichum spp.) establish following
fire, they create moist soil conditions and reduce competition.  Under
these conditions, red pine can establish up to 6 more postfire years
[28].

FEIS species monographs for jack, red, and white pine discuss fire's
effects beyond the Great Lakes pine forest in greater detail.


FIRE EFFECTS ON RESOURCE MANAGEMENT : 
NO-ENTRY


FIRE USE CONSIDERATIONS : 
Jack pine stands regenerate well in frequently burned areas, but red and
white pine must have 150 to 350 years between crown fires in order for
stands to perpetuate [28].  Young jack pines are susceptible to early
spring fires [20].  Fire can be used to prepare a bare mineral seedbed
for red pine and to kill competing vegetation [26].  However, fire in
red pine stands can kill trees up to 69 feet (21 m) high [19].


FIRE MANAGEMENT CONSIDERATIONS : 
Fire behavior in mature and immature jack pine stands is detailed for
experimental fires in the Great Lakes region of Ontario [22,23].
Procedures for prescribed burning of jack pine stands for regeneration
have been published [2].

Prescribed fires are used to rid jack pine stands of disease and
competition.  The number of seed trees per hectare can vary dramatically
on sites burned for natural regeneration.  Methods for direct seeding
and planting of jack pine following prescribed fire have been discussed
[14].

Prescribed fires are used in seedcone-production stands of red pine to
control red pine cone beetle (Conophthorus resinosae).  Backfires and
strip-headfires are used in seedcone plantations in Minnesota,
Wisconsin, and Michigan.  Small plots (0.2 ha) burned in spring can have
as high as 100 percent insect mortality.  Mortality in fall-burned plots
can reach 95 percent.  Larger burned plots (0.7-21 ha) also show
significant reductions of insects.  However, two other species of cone
destroyers may show increases following prescribed fires set for
controlling red pine cone beetle.  Burning during heavy cone production
years would maximize the benefits of fire [29].


REHABILITATION OF SITES FOLLOWING WILDFIRE : 
NO-ENTRY

Related categories for Kuchler Type: Great Lakes pine forest