FIRE CASE STUDIES
SPECIES: Buchloe dactyloides | Buffalo Grass 



CASE NAME : 
Postfire forage production in Custer State Park, SD


REFERENCE : 
Easterly, T. G.; Jenkins, K. J. 1991 [40]


SEASON/SEVERITY CLASSIFICATION : 
spring/variable


STUDY LOCATION : 
The study area was on the north edge of French Creek Natural Area in
Custer State Park, South Dakota.


PREFIRE VEGETATIVE COMMUNITY : 
The study area was a mosaic of mixed-grass prairie and ponderosa pine
(Pinus ponderosa) forest.  Prairie was dominated by buffalo grass
(Buchloe dactyloides), bluegrasses (Poa spp.), gramas (Bouteloua spp.),
and western wheatgrass (Pascopyrum smithii).  The forest understory was
dominated by sedges (Carex spp.) and bluegrasses.


TARGET SPECIES PHENOLOGICAL STATE : 
NO-ENTRY


SITE DESCRIPTION : 
General:  Site description was not given in detail.  Aspect and slope
were variable.  Mean annual temperature at Custer, South Dakota (20 km
northwest), was 42 degrees Fahrenheit (6 deg C).  Mean annual
precipitation was 18.4 inches (460 mm).  Annual precipitation at Custer
State Park was 14.9 inches (372 mm) in 1987 and 13.5 inches (337 mm) in
1988.

Burn days:  Peak temperature was 75 deg Fahrenheit (23 deg C) on 27
April 1987 and 82 degrees Fahrenheit (28 deg C) on 28 April 1987.
Relative humidity ranged from 17 to 34 percent.  Winds were from the
south to southeast at 13 to 42 miles per hour (8-25 km/hr).  Fine fuel
moisture was approximately 5 percent.


FIRE DESCRIPTION : 
Primary goals of the study were to reduce encroachment of ponderosa pine
onto the prairie and increase forage available to bighorn sheep.  The
235-acre (94-ha) burn was conducted on 27 and 28 April 1987.
Strip-firing techniques were used to meet different burn objectives in
different areas.  In meadows and sites dominated by cool-season species,
fire intensity was low and flame length was less than 12 inches (30 cm).
Green-up of cool-season herbaceous species in the fall before the fire
resulted in an incomplete burn pattern with large unburned patches.
Sites dominated by warm-season species including buffalo grass burned
hotter than cool-season sites, with flame lengths of 18 to 30 inches
(45-75 cm).  Fire intensities in forested areas varied widely depending
upon fuels, aspect, time of day, and width of firing strip.  Some direct
mortality of pines occurred due to fire in tree crowns.


FIRE EFFECTS ON TARGET SPECIES : 
Percent cover of buffalo grass in July was:

                 1987                             1988
           __________________               __________________
           Burned    Unburned               Burned    Unburned
              4         2                      5         3


FIRE MANAGEMENT IMPLICATIONS : 
Spring prescribed burning increased buffalo grass cover within the
2-year study period, and reduced ponderosa pine cover.

Burning in mixed-grass prairie increased production of forbs and
warm-season grasses including buffalo grass.  Utilization of herbaceous
species by elk, deer, and bison was higher in burned than unburned
areas.  Of all the Park ungulates, bison used the burns most intensively,
with their use peaking in summer.  Prescribed burning did not, however,
increase the amount of forage available to bighorn sheep in late summer
and presumably, winter.

Mortality of ponderosa pine over the study area was approximately 50
percent.  Pine expansion into mixed-grass prairie was curtailed.

Related categories for Species: Buchloe dactyloides | Buffalo Grass