FIRE CASE STUDIES
SPECIES: Quercus kelloggii | California Black Oak 



CASE NAME : 
Fire severity & survival/Forest floor biomass & germination


REFERENCE : 
Kauffman, J. B.; Martin, R. E. 1987 [22]


SEASON/SEVERITY CLASSIFICATION : 
early spring/low-severity
late spring/moderate-severity
early fall/moderate-severity
late fall/low-severity


STUDY LOCATION : 
The study site was located in the Blodgett Forest Research Station near
Georgetown, California.


PREFIRE VEGETATIVE COMMUNITY : 
The forest was composed of second-stand growth, approximately 70 years
of age, and codominated by ponderosa pine (Pinus ponderosa), white fir
(Abies concolor), and incense-cedar (Libocedrus decurrens).  Very old
California black oak (Quercus kelloggii) and young, shrub-like
individuals were present.  Understory species were not reported.


TARGET SPECIES PHENOLOGICAL STATE : 
NO-ENTRY


SITE DESCRIPTION : 
Soil is classified as occurring in the Holland family, Moderate Deep
Basic (fine-loamy, mixed mesic Ultic Haplo eralfs).  Fuel loading ranged
from 134 to 181 tons per acre (131-177 t/ha).  Organic horizons
accounted for 60 to 80 percent of total fuel load.  Slopes were nearly
level (<10%), elevation was 4,330 feet (1,300 m), and mean annual
precipitation was 68 inches (1,700 mm).

Burn day conditions were as follows:

                        Relative     Temperature     Wind        Lower Duff
                        humidity                     speed     moisture content
                           (%)         (deg C)     (km/hr)          (%)
Date of burn                
early fall (9/20/84)      25-48         19-23         0-8        23.2 +/-  4.6 
late fall (10/8/83)       49-63         16-18         0-3        90.1 +/-  7.8
early spring (5/17/84)    31-57         16-17         0-3       135.0 +/- 16.3
late spring (6/26-29/84)  21-72         17-27         0-3        51.6 +/- 10.6


FIRE DESCRIPTION : 
Six 0.25-hectare blocks with four treatment units per block were
established.  The treatments included four different prescribed fires of
varying season and fire severity levels and a control (no burn).  

Survival of existing California black oak was established by randomly
tagging 15 to 50 individuals in each treatment unit from each block prior
to burning.  Trees were examined for mortality and survival for the next
2 years after burning.

Density of seedlings was calculated by two measurements in 15 2-meter- 
squared, permanent plots in each treatment subunit of each block.  Plots
were measured prior to burning, and at the second growing season after
fire.

Burn treatments resulted in the following fuel consumption:

     early fall/moderate-severity      74.7 %
     late fall/low-severity            67.8 %
     early spring/low-severity         16.3 %
     late spring/moderate-severity     61.1 %


FIRE EFFECTS ON TARGET SPECIES : 
Moderate-severity fall fire resulted in the lowest survival rate.
Results were as follows:

                    Early fall  Late fall  Early spring  Late spring  Control
                     mod-burn    low-burn    low-burn     mod-burn     
survival (%)          9.0          35.0         69.0         28.0       100
comsumption (%)      93.5          64.2         11.3         75.9       ---
biomass consumption
  (tons/hectare)    110.4          68.0         11.1         63.2       ---    

At two postfire growing seasons, California black oak seedlings appeared
in significantly (p>0.05) greater densities at all burn sites except the
early spring/low-severity fire.  Results were as follows:

                                   % Seedlings         Postfire biomass of
                          #/ha     in population        duff layers(t/ha)
early fall/mod-sev.    367(+/-327)      79                     7.7     
late fall/low-sev.     333(+/-152)      67                    37.8
late spring/mod-sev.   267(+/-200)      80                    20.1
early spring/low-sev.   67(+/- 67)      15                    86.4
control                133(+/-133)      17                   100.0


FIRE MANAGEMENT IMPLICATIONS : 
California black oak seedling density increased as a result of the
prescribed fire.  Optimum seedling establishment was realized when the
duff component was reduced to 15.5 tons per acre (38 t/ha) or less.  Few
California black oaks were killed by low-intensity prescribed fire.
Late fall, low-intensity burning probably represents a good compromise
between loss of existing trees and increased seedling establishment.

Related categories for Species: Quercus kelloggii | California Black Oak