FIRE EFFECTS
SPECIES: Buchloe dactyloides | Buffalo Grass 



IMMEDIATE FIRE EFFECT ON PLANT : 
Buffalo grass is not completely consumed in most grassland fires.
Typically the upper part of the plant burns, and damage to basal
portions of the plant is uncommon [45,99].  With grassland fires, flames
fanned by even light winds seldom stay in one spot long enough to
produce high temperatures at the soil surface.  Fire intensities lethal
to native perennial grasses such as buffalo grass rarely, if ever, occur
during prescribed grassland fire [45].  Even with wildfires,
temperatures near perennating tissues at the soil surface are usually
not lethal.  Unburned stubble often remains after fire has passed, and
shallowly placed buds and seeds are unharmed [32 and references
therein].  Wildfire occurring during drought, however, may generate
temperatures high enough to kill buffalo grass perennating buds [32,45].
Lethal temperatures may also occur at the soil surface if woody plant
invasion into grassland has occurred.  Soil surface temperatures tend to
rise when woody plants burn, and elevated temperatures last for longer
periods of time [32].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Burning generally either favors buffalo grass or has no long-term effect
upon it [108,110].  In some studies, buffalo grass productivity is
unchanged or increases in the first postfire year [14,15].  Wright [110]
concluded from several studies that in western Texas, buffalo grass was
neither harmed nor favored by fire.  In southern Nebraska, April burning
of loess hill mixed-grass prairie had no significant (p=.1) effect on
buffalo grass cover the following June or Septemeber.  However, buffalo
grass cover on burn plots had increased significantly compared to
control plots by the second September after fire [84].

Fire had no long-term effect on buffalo grass at the Kansas Agricultural
Experimental Station.  Launchbaugh [63] reported that after a March
wildfire in shortgrass prairie there, buffalo grass cover at postfire
year 1 was reduced by 48 percent on burned areas as compared to adjacent
unburned areas; height at the end of the first growing season was 6.7
inches (17.0 cm) on burned sites and 11.9 inches (30.2 cm) on unburned
sites.  By postfire year 2, buffalo grass cover on burned sites was 39
percent less than on unburned sites, and by postfire year 3 there was no
significant difference in buffalo grass cover between burned and
unburned sites.

Buffalo grass recovery time may vary depending upon phenological stage,
season of burning, fire severity, and/or postfire weather conditions.
In a bluestem (Andropogon gerardi and Schizacharium scoparium) pasture
in Kansas, buffalo grass declined under 10 years of early (20 March) and
late spring (1 May) annual burning compared to annual mid-spring (10
April) and no burning.  Buffalo grass basal cover (%) after 10 years was
[5]:
                             Spring Burning                    
                   ---------------------------------      
                   unburned  early    mid-     late      
                   2.21a     1.08b    2.65a    1.37a       
                   --------------------------------- 
                   Percentages followed by the same letter
                   do not differ significantly (p<0.05).

Spring (April) prescribed burning in mixed-grass praiaire in Badlands
National Park, South Dakota, favored buffalo grass.  Buffalo grass began
vegetative expansion and produced seed during the first growing season
after fire [107].  Compared to the control (no burn), buffalo grass
standing crop increased for 2 to 3 postfire years, then returned to
approximate prefire levels with onset of a drought [108].

Buffalo grass increased significantly (p=0.05) after various treatments
involving prescribed burning on the South Texas Plains-Texas Gulf
Prairie interface.  Burning was effected to reduce woody plant invasion.
Treatments were shredding, chopping, or scalping followed by prescribed
burning 2 years later, and a control (prescribed burning only).  All
prescribed burning was done in September 1965.  Percentage composition
of buffalo grass in July 1966 was [14]:

-------------------------------------------------------------------------
    Control       Shredded       Chopped       Scalped       Average
    -------       --------       -------       -------       -------
     U   B         U   B          U   B         U   B         U   B
     13  15        11  12         6   17        6   17        9   15
-------------------------------------------------------------------------
U=unburned; B=burned

Brush cover was significantly (p=0.05) reduced from prefire levels at
postfire year 1, although less than 15 percent of woody plants were
actually killed by the fire [14].

In another southern Texas study on the Rob and Bessie Welder Wildlife
Refuge, plots were subjected to a fall (September) fire, a winter
(December) fire, or a fall fire with a winter reburn the following year.
Burning was conducted in 1965 and 1966.  Buffalo grass production
(lb/acre) in August 1967 was [15]:

        Control          Fall          Winter          Fall & Winter
          355             330            315               401

April prescribed burning in cultivated buffalo grass in Kansas reduced
subsequent summer seed yield.  Unburned portions of the field produced
303 pounds of buffalo grass seed per acre compared to 79 pounds per acre
on the burned portion [27].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Fall burning in a shortgrass-mixed-grass transition zone of the Flint
Hills of Kansas reduced prairie threeawn (Aristida oligantha), an annual
grass with little to no forage value for livestock, and increased
relative abundance of the dominant perennial grasses, buffalo grass and
blue grama.  Percentages of total herbage production in fall, 1972, with
no burning, fall burning, and spring burning, were [72]:

            prairie threeawn     Perennial grasses     Western ragweed
            ----------------     ------------------     ---------------
unburned          73.7                  21.2                  5.0
spring (1)        84.0                  14.0                  2.0
fall (2)          13.7                  75.8                  7.0
-----------------------------------------------------------------------
1=burned 4 April 1972; 2=burned 8 November 1971   

April prescribed fire in mixed-grass prairie of southern Nebraska also
reduced nonnative, cool-season annuals and increased the native,
warm-season dominants, buffalo grass and blue grama [84].

There was no significant relationship between fireline intensity and
postfire response of buffalo grass after spring burning in western Texas
grassland.  High-intensity (approximately 5,570 kW/m) headfire did no
more damage to buffalo grass than low-intensity (approximately 70 kW/m)
headfire [83].

Buffalo grass mortality may be higher with backfires than headfires.
Being more slow-moving, backfires tend to generate more heat at ground
level [45].

Wright has provided prescriptions for burning buffalo grass in the
central and southern Great Plains [111], the Edwards Plateau [115] and
Rio Grande Plains [113,114] regions of Texas, and in chained
mesquite-tobosa communities [112]. 

Related categories for Species: Buchloe dactyloides | Buffalo Grass