FIRE EFFECTS
SPECIES: Bromus japonicus | Japanese Brome 



IMMEDIATE FIRE EFFECT ON PLANT : 
Fire kills Japanese brome.  Some of the seeds retained in panicles are
also killed [28,29,69,73,78].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Whisenant [71] suggested that Japanese brome postfire response is best
explained as a function of level of litter reduction by fire and the
amount of fall precipitation following fire.  Since litter accumulations
are more critical for seed germination and seedling establishment in dry
than wet years, populations are reduced when burning is followed by
below-average precipitation.  During wet years, fire has little impact
on subsequent generations.

A 1973 to 1975 South Dakota study showed that spring, summer, or fall
burning reduced Japanese brome for two postfire growing seasons.  During
the study, prescribed burning was followed by 2 years of drought [28].
In another South Dakota study where prescribed fire was followed by 2
years of above average precipitation, Japanese brome densities at
postfire years 1 and 2 were similar to prefire densities [72].
Whisenant and others [73] reported that Japanese brome frequency was not
significantly changed in postfire year 1 by fires in September 1979,
January 1980, or March 1980.  In eastern Montana, spring burning
reduced Japanese brome for one postfire growing season.  Subsequent
years were not evaluated [76].

Prescribed fire was used on a western wheatgrass-green needlegrass
(Pascopyrum smithii-Stipa viridula) prairie in Wind Cave National Park,
South Dakota, to test Japanese brome response to fire.  Treatments were
fall (Sept. 18, 1973), winter (Feb. 13, 1974), and spring (April 10,
1974) burning.  Japanese brome density (stems/sq ft) on May 24, 1974,
was as follows [27]:

                                Treatment
| fall burn  control | winter burn  control | spring burn  control | unburned |
|    0.8      80.0   |     33.8       57.3  |     15.7       56.1  |    56.9  |

Only one study was found describing Japanese brome postfire response in
palouse prairie.  A July 1961 wildfire in a bluebunch
wheatgrass-Sandberg bluegrass stand in southeastern Washington reduced
Japanese brome and cheatgrass populations for at least 2 years.
Japanese brome percentage frequency was as follows [16]:

                      unburned        burned

postfire yr  2           42             10
postfire yr  4           30             50
postfire yr 12           32             18      

Two accounts of Japanese brome postfire response in the Southwest were
found.  In Mesa Verde, Colorado, Japanese brome was a component of an
initial (postfire yrs 1 & 2) annual sunflower-pigweed community
following a July 15 to August 7, 1959, wildfire in a true pinyon-Utah
juniper (Pinus edulis-Juniperus osteosperma) woodland [19].  

The spring following prescribed winter fire in a honey mesquite/Texas
wintergrass woodland in Coleman County, Texas, cool-season annuals
including Japanese brome were reduced by 74 percent.  At postfire year 2
there was a trend toward more annual grasses on burned than unburned
sites [62,6].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Whisenant [72] stated that fire exclusion in northern mixed-grass
prairie has improved conditions for Japanese brome establishment at the
expense of native grasses.  In the absence of intensive grazing, litter
accumulations in northern mixed-grass prairie stabilize after 5 to 6
postfire years [1,18].  Whisenent [74] has recommended burning every 5
years or less to reduce litter accumulations.  This reduces Japanese
brome populations, particularly when fall precipitation is low.
However, he cautions managers to balance the benefits of litter against
need to reduce Japanese brome when preparing fire management plans.
Benefits of litter include soil stabilization and insulation, moisture
retention, and promotion of perennials [80].

Gartner and others [28] recommended burning Japanese brome in the ripe
seed stage in order to maximize kill of seeds in panicles.

Whisenant [70] has developed regression equations modelling Japanese
brome density and seed production as affected by fire.

Related categories for Species: Bromus japonicus | Japanese Brome