KUCHLER TYPE FIRE ECOLOGY AND MANAGEMENT
KUCHLER TYPE: Bluestem Prairie



FUELS, FLAMMABILITY, AND FIRE OCCURRENCE : 
Historically, fires were large and frequent on the bluestem prairie, but
exact fire intervals are unknown [15,27].  Native Americans regularly
burned the prairie to drive game animals.  In addition lightning fires
were frequent, perhaps several per decade [10].  Grasslands can burn
whenever soils are dry, even in mid-summer when foliage is green [1].
Fires that occurred here sometimes burned tens of thousands of acres at
a time [27].  Fire frequency was affected by topographic relief [1] and
by the amount of fuel, which may have been dramatically affected by
bison [15].

Controlled fires on the Konza Prairie, Kansas, are conducted in April at
intervals of 1, 2, 4, and 10 years [27].


FIRE EFFECTS ON SITE : 
Burning can increase surface soil temperatures by as much as 62 degrees
Fahrenheit (17 deg C) [21].  Annual burning may reduce soil nitrogen
[15].  On the Konza Prairie (and presumably other prairie sites) where
fires eliminate standing vegetation down to bare soil, the rapid drying
of the soils on burned sites can change plant community composition from
its prefire composition.  If fires occur more often than every other
year, biomass production can be lowered.  Conversely, if fire intervals
are more than 5 years, litter buildup can stagnate nutrient flow [27].

For the effects of fire on soil nutrients and water availability refer
to Seastedt and Ramundo [19].


FIRE EFFECTS ON VEGETATION : 
Some general effects of fire on prairie grasses include increased
production, earlier greenup of warm-season grasses like bluestems (on
sites burned in late autumn), improved seed germination, and increased
flowering [7,10,21].  Results of individual burns differ greatly,
however, because of variations in prefire species composition, season of
fire, geographical location, climatic cycles, and the influence of
grazing livestock and wildlife [1,21].  For more information on
prescribed fire's effects on the Konza Prairie refer to Reichman [27].

Prescribed burns were conducted in early April on a prairie reserve in
Iowa on both upland and lowland sites.  Fire effects did not differ
between upland and lowland sites.  Big bluestem was the most abundant
grass on burned sites, and dry weight biomass for this species was
significantly greater on burned than unburned sites (p<0.001).  Average
wet and dry weight biomasses were significantly lower (p<0.001) on
burned sites immediately following the fires, but after May were greater
on burned than unburned sites.  Burning did not affect the number of
species present per unit area (species richness), but species diversity
was significantly higher on burned sites during June [8].

Prescribed burns were conducted in spring for 3 consecutive years on a
prairie in Minnesota to control the advancement of quaking aspen
(Populus tremuloides) onto bluestem prairie.  Both big and little
bluestem showed an increase in flowering on burned sites.  On unburned
control plots big bluestem relative frequency was 5.5 percent.  It
increased gradually with annual burning.  After the third annual burn,
big bluestem relative frequency was 29.2 percent.  Little bluestem
frequency changed little with burning, although clumps on burned plots
appeared more vigorous than those on unburned plots [20].

Prescribed burns were conducted in mid- to late April annually for 5
years on Minnesota prairie land.  By the end of the fifth year big
bluestem stands increased 11 percent in linear extent on a 907-foot
(275-m) transect.  Prairie dropseed increased to nearly double its
original percent cover by the end of year 5.  Switchgrass appeared by
the end of the study where no plants were previously observed [2].

A germination study used seeds from three tallgrass prairies in
Nebraska, portions of which were burned in late April.  Germination
rates for big bluestem were higher in samples from burned plots.
Sideoats grama and leadplant showed slightly higher germination rates
in samples from burned plots.  Indiangrass showed higher germination
rates in samples from burned plots on two sites and much lower rates in
samples from burned plots on a third site [18].

For more information on prairie fire ecology or fire's effect on
individual species refer to the following studies:

Fire and drought effects on big bluestem and switchgrass on Konza
  Prairie, Kansas [12].
Response of big bluestem to sun/shade differences on Konza
  Prairie, Kansas [11,13].
Production, density, and height of flower stalks of big and
  little bluestem and Indiangrass on Konza Prairie, Kansas [14].
Fire frequency and community heterogeneity on Konza Prairie, Kansas [4].
Fire's effects when combined with grazing on Konza Prairie,
   Kansas [22,23]; elsewhere in Kansas [9]; in Oklahoma [3].
Response of grasses to fire, fertilizer, and atrazine in Nebraska [17].

For specific effects of fire on species diversity refer to Collins and
Gibson [6].

For specific effects of fire on individual species refer to species
monographs in the FEIS database.


FIRE EFFECTS ON RESOURCE MANAGEMENT : 
Burning every 3 to 5 years has been rcommended for maintaining prairie
chicken habitat [20].


FIRE USE CONSIDERATIONS : 
Spring burning appears to benefit warm-season grasses such as the
bluestems by reducing the litter layer and promoting new growth.  This
can increase the food value for wildlife and livestock.  Fire can also
prevent the encroachment of brushy vegetation which may eventually
dominate over grasses [20].  Fire is used for prairie restoration as
well as to improve forage for livestock [6].


FIRE MANAGEMENT CONSIDERATIONS : 
NO-ENTRY


REHABILITATION OF SITES FOLLOWING WILDFIRE : 
NO-ENTRY

Related categories for Kuchler Type: Bluestem Prairie