• CASE NAME
• REFERENCE
• SEASON/SEVERITY CLASSIFICATION
• STUDY LOCATION
• PREFIRE VEGETATIVE COMMUNITY
• PLANT SPECIES PHENOLOGICAL STATE
• SITE DESCRIPTION
• FIRE DESCRIPTION
• FIRE EFFECTS ON PLANT SPECIES
• FIRE MANAGEMENT IMPLICATIONS

CASE NAME:

Battleflat Watershed Burn, Arizona

REFERENCE:

Wienhold, J. O.; Klemmedson, B. J. 1992 [103]

SEASON/SEVERITY CLASSIFICATION:

fall/severe

STUDY LOCATION:

The study was located in the Battleflat Watershed in the Bradshaw Mountains of central Arizona.

PREFIRE VEGETATIVE COMMUNITY:

The study site was covered by dense shrubby vegetation. Crown cover averaged 75 to 80%. Dominant shrubs included pointleaf manzanita (Arctostaphylos pungens), shrub live oak (Quercus turbinella,) and mountain-mahogany (Cercocarpus betuloides). Subdominant species included Emory oak (Q. emoryi), alligator juniper (Juniperus deppeana), Apache plume (Fallugia paradoxa), and yerba-santa (Eriodictyon angustifolium). The shrub stand was approximately 85 to 90 years old.

PLANT SPECIES PHENOLOGICAL STATE:

Not reported

SITE DESCRIPTION:

Topography was rough and dissected. Slopes ranged from 8 to 80^o. Mean daily temperature was 15 ^oC.

FIRE DESCRIPTION:

The burn occurred over a 2-day period: October 30th and 31st, 1985. The burn was described as "intense" with a rate of spread of 12 m min^-1 and flame heights exceeding 4 meters. The fire was ignited with a helitorch. The burn was described as "patchy." Specific conditions during the burn were as follows:

relative humidity: 10-30%
air temperature: 16-29oC
wind speed: 2-8 m s-1
fuel moisture of shrub live oak:
     new growth - 72%
     old growth - 61%

FIRE EFFECTS ON PLANT SPECIES:

The prescribed fire consumed 65% of aboveground dry matter on shrub live oak plants. Effect of fire on aboveground dry biomass of shrub live oak was as follows:

                                           Loss
                                    -------------------         
           preburn     postburn     amount     relative
           (kg m-2)    (kg m-2)     (kg m-2)    (%)
shoots     1.2         --           --         --
litter     3.3         --           --         --
total      4.5         1.6          2.9        64.6

FIRE MANAGEMENT IMPLICATIONS:

Prescribed fire increased inorganic nitrogen in the 0- to 2-cm soil layer under shrub live oak plants, mainly through increases in ammonium concentration. Inorganic nitrogen in the 2- to 10-cm soil layer did not change significantly. After fire, available phosphorus increased, especially in the top 2 cm of soil.

Related categories for SPECIES: Quercus turbinella | Shrub Live Oak