• 1st CASE STUDY:
Range/wildlife prescribed burning on the Fort Rock Ranger District, Central Oregon

• 2nd CASE STUDY:
Prescribed burn in an Idaho sagebrush/bunchgrass site

Range/wildlife prescribed burning on the Fort Rock Ranger District, Central Oregon

• REFERENCE
• SEASON/SEVERITY CLASSIFICATION
• STUDY LOCATION
• PREFIRE VEGETATIVE COMMUNITY
• TARGET SPECIES PHENOLOGICAL STATE
• SITE DESCRIPTION
• FIRE DESCRIPTION
• FIRE EFFECTS ON TARGET SPECIES

REFERENCE:

Adams, G. R. 1980 [2]

SEASON/SEVERITY CLASSIFICATION:

Spring and fall/low to severe

STUDY LOCATION:

The south-southwest slope of Pine Mountain, Fort Rock Ranger District, Oregon

PREFIRE VEGETATIVE COMMUNITY:

Big sagebrush (Artemisia tridentata)-antelope bitterbrush (Purshia tridentata)/bunchgrass community with bluebunch wheatgrass (Pseudoroegneria spicata), Idaho fescue (Festuca idahoensis), sedges (Carex spp.), junegrass (Koeleria macrantha), needle-and-thread grass (Hesperostipa comata), and decadent shrub canopy, and a ponderosa pine (Pinus ponderosa)/antelope bitterbrush-big sagebrush/Idaho fescue community in similar condition.

TARGET SPECIES PHENOLOGICAL STATE:

Not given

SITE DESCRIPTION:

The site ranged from 15 to 60% slope, at an elevation of 5,500 feet to 6,850 feet (1678-2089 m), with well-drained, shallow to moderately deep volcanic ash residuum and colluvium soils, with some pumice.

FIRE DESCRIPTION:

Burning prescriptions, techniques, and conditions were as follows:

                   Spring 1979   Fall 1979     Spring 1980
Temperature        62°F (17°C)   60°F (16°C)   64°F (18°C)
Relative humidity  32%           29%           31%
10 hour F.M.       12%           9%            14%
Slope              5-35%         5-35%         15-40%
Aspect             S/SE          S/SE          S
Wind speed         6-8 m.p.h.    5-10 mph      5 mph
Wind direction     SE            S/SE          SE
Month              April         September     April
Live FMC           150%+         50%+          150%+

FIRE EFFECTS ON TARGET SPECIES:

Both burning seasons resulted in increased stand density and patchiness of vegetation. Following the spring burns, bluebunch wheatgrass and all of the grasses and sedges sprouted, and stand vigor improved following the first growing season. After the second growing season, the areas burned in the spring of 1979 produced 1,735 pounds of grass and "green weight" per acre, compared to 133 lbs/acre on a similar unburned area.

The authors did not publish forage production effects for the fall burn.

2nd CASE STUDY:

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

CASE NAME:

Prescribed burn in an Idaho sagebrush/bunchgrass site

REFERENCE:

Blaisdell, J. P. 1953 [38]

SEASON/SEVERITY CLASSIFICATION:

August, 1936/severity not given

STUDY LOCATION:

U.S. Sheep Experiment Station, 11 miles northeast of Dubois, Clark County, Idaho

PREFIRE VEGETATIVE COMMUNITY:

This was a big sagebrush (Artemisia tridentata)/bunchgrass site with 35% perennial grasses including thickspike wheatgrass (Elymus lanceolatus), plains reedgrass (Calamagrostis montanesis), sedges (Carex spp.), prairie junegrass (Koeleria macrantha), Sandberg's bluegrass (Poa secunda), and needle-and-thread grass (Hesperostipa comata); 5% perennial forbs and 5% annual forbs; 40% big sagebrush; and 15% downy rabbitbrush (Chrysothamnus puberulus), spineless gray horsebrush (Tetradymia canescens var. inermis), and other shrubs.

TARGET SPECIES PHENOLOGICAL STATE:

Seeds had been disseminated and plants were dry or nearly dry. The site had not been grazed the previous growing season in order to have sufficient fuels to carry the fire.

SITE DESCRIPTION:

The study site was at approximately 6,000 feet (1830 m) elevation, with 11 inches (279 mm) annual precipitation, with sandy soils of basaltic origin. Dry southwestern winds during the summer months make this an arid site, with 100° Fahrenheit (38 °C) temperatures possible in the summer and -35° Fahrenheit (-37 °C) in the winter.

FIRE DESCRIPTION:

The fire burned in a mosaic pattern, with scattered unburned islands. Immediately following the burn, the study plots were classified according to the following definitions: 1) heavy burn-trunk or main stem of big sagebrush consumed, 2) moderate burn-larger branches of big sagebrush remaining but smaller ones consumed, 3) light burn-only leaves consumed, and 4) unburned-no evidence of fire in brush or understory.

FIRE EFFECTS ON TARGET SPECIES:

Within 3 years of the burn, bluebunch wheatgrass was producing as much as or more than under prefire conditions. After 12 years, the burned plots were producing (lbs./acre) considerably more bluebunch wheatgrass, but the values were not statistically significant:

unburned     light burn     moderate burn     heavy burn
16.5         32.3           29.5              23.1

FIRE MANAGEMENT IMPLICATIONS:

The authors conclude that burns of heavy intensity are most damaging to bluebunch wheatgrass, and the best management for the plant would include light intensity burning.

Related categories for SPECIES: Pseudoroegneria spicata | Bluebunch Wheatgrass