FIRE CASE STUDIES
SPECIES: Amorpha canescens | Leadplant 



CASE NAME : 
Prescribed fire effects/southern Black Hills Cone Fire


REFERENCES : 
Bock, J. H.; Bock, C. E. [n.d.] [6]
Bock, J. H.; Bock, C. E. 1984 [7]


SEASON/SEVERITY CLASSIFICATION : 
Spring/moderate
Fall/moderate


STUDY LOCATION : 
Wind Cave National Park, South Dakota.
    


PREFIRE VEGETATIVE COMMUNITY : 
This fire took place in a ponderosa pine (Pinus ponderosa) forest and
pine-grassland ecotone.  The vegetative community consisted of ponderosa
pine, sedges (Carex spp.), big bluestem (Andropogon gerardii var.
gerardii), little bluestem (Schizachyrium scoparium), needlegrasses
(Stipa spp.), Sandburg bluegrass (Poa secunda), sideoats grama
(Bouteloua curtipendula), blue grama (B. gracilis), hairy grama (B.
hirsutum), western snowberry (Symphoricarpos occidentalis), Saskatoon
serviceberry (Amelanchier alnifolia), currant (Ribes spp.), chokecherry
(Prunus virginiana), strawberry (Fragaria spp.), and skunkbush (Rhus
trilobata).  The stand was about 100 years old.


TARGET SPECIES PHENOLOGICAL STATE : 
Dormant 


SITE DESCRIPTION : 
 Elevation:  4,100 to 4,675 feet (1,250-1,425 m)
          


FIRE DESCRIPTION : 
Two areas were burned for this study.  The first was ignited on 17
October 1979.  Conditions at the time of the fire were as follows:

        Air temperature:  58 degrees F (14.4 deg C)
        Relative humidity:  45%
        Wind speed:  9.6 mph (16 km/hr)
        Soil moisture:  3.7%
        Class I (litter):  28.5% moisture content
        Class II (0.5-inch to 2-inch twigs):  16.9% moisture content
        Class III (> 2-inch diameter twigs):  7.4% moisture content
        Cool ground fire
        Combustion of surface fuels nearly complete
 
The second ares was ignited at 10:30 a.m. on April 14, 1980.  Conditions
at the time of the fire were as follows:

        Air temperature:  57 degrees F (13.9 deg C)
        Relative humidity:  32%
        Wind speed:  4.8 mph (8 km/hr)
        Soil moisture:  27.8%
        Class I   (litter):  30.0% moisture content
        Class II  (0.5-inch to 2-inch twigs):  20.9% moisture content
        Class III (twigs> 2 inch diameter):  36.0% moisture content
        Cool ground fire
        Combustion of surface fuels nearly complete


FIRE EFFECTS ON TARGET SPECIES : 
Leadplant increased significantly in density as measured in May-June
following the burns.  Increased height and increased crown diameter were
also measured.

Percent cover for combined experimental (burned) plots and control plots
was as follows:

Treatment                    Percent Cover
                    Prefire   1 year    2 years 
                             postfire   postfire
-------------------------------------------------
Combined exp.         0.6      1.0        2.1   
Cont.                 0.1      0.4        0.6

Total numbers of shrubs counted on eight burned and six unburned plots:

Treatment                  Number of Individuals
                        Prefire    1 year     2 years
                                  postfire    postfire
-----------------------------------------------------
Combined exp.            1005      2781         1976
Cont.                     462       662          609

Mean maximum heights (cm) of leadplant on eight burned versus six
control plots:

Treatment       Prefire      1 year    2 years
                            postfire   postfire
-----------------------------------------------
Combined exp.    15.7         6.9        192
Cont.            15.9         7.9         76

Mean maximum crown width (cm) of leadplant on eight burned versus six
control plots:

Treatment        Prefire     1 year    2 years
                            postfire   postfire
-----------------------------------------------
Combined exp.     10.7        6.1        192
Cont.             13.4        7.3         76


FIRE MANAGEMENT IMPLICATIONS : 
Results indicate that cool prescribed fires can be used in the Black
Hills as a management tool for reducing fuels in ponderosa pine forests
and temporarily improving them as wildlife habitat.  However, with the
exeception of Saskatoon serviceberry and leadplant, such fires will not
encourage shrub growth.

Related categories for Species: Amorpha canescens | Leadplant