Prescribed Burning of Thinning Slash in Regrowth Stands of Karri (Eucalyptus diversicolor) .1. Fire Characteristics, Fuel Consumption and Tree Damage

1997 ◽  
Vol 7 (1) ◽  
pp. 29 ◽  
Author(s):  
WL McCaw ◽  
RH Smith ◽  
JE Neal
Keyword(s):  
Fuel Consumption ◽  
Tree Mortality ◽  
Prescribed Burning ◽  
Flame Length ◽  
Moderate Intensity ◽  
Litter Layer ◽  
Tree Damage ◽  
Stem Damage ◽  
Fire Characteristics ◽  
Eucalyptus Diversicolor

'Fire characteristics, fuel consumption and fire-caused tree damage were investigated for ten low to moderate intensity fires in thinning slash fuel in 22-year-old karri (Eucalyptus diversicolor F. Muell) regrowth in Western Australia. Eight fires were burnt in spring and two in autumn. Most fires consumed greater than 80 per cent of dead fuel < 25 mm in diameter and between 40 per cent and 80 per cent of the litter layer. The total amount of litter and dead fuel < 100 mm in diameter consumed during burning ranged from 24 to 79 t ha-1 (31-89 per cent). Actual and percentage consumption of fuel < 100 mm diameter were inversely related to the moisture content of the litter profile. Fireline intensities determined from flame length estimates ranged from 90 kW m-1 to 2820 kW m-1. Damage to retained trees included stem wounding, crown death and complete death of the stem. Burning in spring when the litter profile was moist resulted in damage to the lower stems of up to 80 trees ha-1, with damage affecting an average of 3 m2 ha-1 of the retained basal area of 19.5 m2 ha-1. The incidence of stem damage following spring burning was considerably greater when the litter layer was dry. Autumn burning resulted in extensive stem damage and tree mortality and is not therefore recommended. Log debris within 1 m of trees significantly increased the probability of fire-caused damage, and wounds tended to be larger on trees that had debris nearby. The incidence of damage from burning was directly related to the quantity of fuel consumed and heat release per unit area, but was not significantly correlated with fireline intensity. A prescription for burning thinning slash during spring conditions is presented.

Prescribed Burning of Thinning Slash in Regrowth Stands of Karri (Eucalyptus diversicolor) .2. Nitrogen Budgets in Pre- and Post-Burn Fuel

1997 ◽  
Vol 7 (1) ◽  
pp. 41 ◽  
Author(s):  
AM O'Connell ◽  
WL McCaw
Keyword(s):  
Prescribed Burning ◽  
Fire Hazard ◽  
Weather Conditions ◽  
Moderate Intensity ◽  
Litter Layer ◽  
Nitrogen Budgets ◽  
Dryness Index ◽  
Soil Dryness ◽  
Fuel Components ◽  
Eucalyptus Diversicolor

Changes in nitrogen content of fuel were investigated following eight low to moderate intensity experimental fires conducted under a range of fire weather conditions in a recently thinned 22-year-old regrowth stand of karri (Eucalyptus diversicolor F. Muell) in Western Australia. The average amount of dead fuel < 100 mm in diameter present before burning was 76 t/ha (range 50 to 107 t/ha). The amount of live fuel was small, with a mean of 4 t/ha. Forest floor litter, consisting of fresh and partly decomposed dead leaves and fine twigs (< 6 mm diameter) contributed about 30% of total fuel weight, and wood fractions > 6 mm in diameter contributed about 60%. Remaining fuel was made up of small twigs, bark and leaves added from the thinning operation. Distribution of nitrogen in fuel fractions differed markedly from distribution of fuel weights with more than 60% of fuel-nitrogen in the litter and only about 25% of fuel-nitrogen in wood greater than 6 mm diameter. Following fire, the average amounts of nitrogen in all fuel fractions was reduced. The majority of nitrogen in wood fractions and in bark and leaves was volatilized during the fires (range 55% to 99%), while on average only about 38% of the nitrogen in litter was volatilized. The amount of nitrogen lost from dead fuel differed between the experimental fires (range 50 to 180 kg/ha) and was significantly related to the total amount of fuel consumed (r2 = 0.92). Fuel consumption and nitrogen volatilization increased as the Soil Dryness Index increased and as litter moisture decreased. Nitrogen losses due to burning were small relative to total stores of nitrogen in soil (about 6000 kg/ha) but for the most intense fires were significant in relation to amounts in growing vegetation and surface soil. Burning when moisture content of the litter profile exceeds 90% will reduce combustion of the litter layer. Burning under these conditions allows effective reduction in the flash fuel components located in the upper parts of the fuel bed while retaining much of the nutrient-rich lower strata of fuel. Burns of this type provide effective fire hazard reduction while favouring conservation of nitrogen stored in the litter layer.

Evaluation of the CONSUME and FOFEM fuel consumption models in pine and mixed hardwood forests of the eastern United States

2014 ◽  
Vol 44 (7) ◽  
pp. 784-795 ◽  
Author(s):  
Susan J. Prichard ◽  
Eva C. Karau ◽  
Roger D. Ottmar ◽  
Maureen C. Kennedy ◽  
James B. Cronan ◽  
...  
Keyword(s):  
United States ◽  
Fuel Consumption ◽  
Prescribed Burning ◽  
Forest Type ◽  
Fire Effects ◽  
Eastern United States ◽  
Validation Data ◽  
Data Set ◽  
Predicted Values ◽  
Fine Fuels

Reliable predictions of fuel consumption are critical in the eastern United States (US), where prescribed burning is frequently applied to forests and air quality is of increasing concern. CONSUME and the First Order Fire Effects Model (FOFEM), predictive models developed to estimate fuel consumption and emissions from wildland fires, have not been systematically evaluated for application in the eastern US using the same validation data set. In this study, we compiled a fuel consumption data set from 54 operational prescribed fires (43 pine and 11 mixed hardwood sites) to assess each model’s uncertainties and application limits. Regions of indifference between measured and predicted values by fuel category and forest type represent the potential error that modelers could incur in estimating fuel consumption by category. Overall, FOFEM predictions have narrower regions of indifference than CONSUME and suggest better correspondence between measured and predicted consumption. However, both models offer reliable predictions of live fuel (shrubs and herbaceous vegetation) and 1 h fine fuels. Results suggest that CONSUME and FOFEM can be improved in their predictive capability for woody fuel, litter, and duff consumption for eastern US forests. Because of their high biomass and potential smoke management problems, refining estimates of litter and duff consumption is of particular importance.

Prescribed Burning for Stand Conversion in Budworm-killed Balsam Fir: An Ontario Case History

1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae
Keyword(s):  
Fuel Consumption ◽  
Prescribed Burning ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Fire Spread ◽  
Fire Effects ◽  
Balsam Fir ◽  
Prescribed Burn ◽  
Stand Conversion

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.

scholarly journals Estimating Fuel Consumption for the Upper Coastal Plain of South Carolina

2010 ◽  
Vol 34 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Scott L. Goodrick ◽  
Dan Shea ◽  
John Blake
Keyword(s):  
South Carolina ◽  
Air Quality ◽  
Fuel Consumption ◽  
Prescribed Fire ◽  
Coastal Plain ◽  
Prescribed Burning ◽  
Management Tool ◽  
Fuel Load ◽  
Trade Offs ◽  
Continued Use

Abstract Recent changes in air quality regulations present a potential obstacle to continued use of prescribed fire as a land management tool. Lowering of the acceptable daily concentration of particulate matter from 65 to 35 μg/m3 will bring much closer scrutiny of prescribed burning practices from the air quality community. To work within this narrow window, land managers need simple tools to allow them to estimate their potential emissions and examine trade-offs between continued use of prescribed fire and other means of fuels management. A critical part of the emissions estimation process is determining the amount of fuel consumed during the burn. This study combines results from a number of studies along the Upper Coastal Plain of South Carolina to arrive at a simple means of estimating total fuel consumption on prescribed fires. The result is a simple linear relationship that determines the total fuel consumed as a function of the product of the preburn fuel load and the burning index of the National Fire Danger Rating System.

Calibration and Field Testing of Passive Flame Height Sensors

1992 ◽  
Vol 2 (3) ◽  
pp. 115 ◽  
Author(s):  
MA Finney ◽  
RE Martin
Keyword(s):  
Experimental Test ◽  
Prescribed Burning ◽  
Fire Retardant ◽  
Field Testing ◽  
Flame Length ◽  
Flame Height ◽  
Video Tape ◽  
Fire Damage ◽  
String Type

The concept of a passive flame height sensor involves thin strings permeated with fire retardant or solder which record heights of flame contact. Both types of sensors were calibrated during 12 experimental test fires with respect to flame heights measured on video tape. Three thresholds of fire damage to string-type sensors were identified: singeing of fine string fibers, complete blackening of the string, and thorough charring or consumption. These damage thresholds were found to exceed95%, 71% and48% of all flame heights measured from video tape, respectively. 18-gauge solder melted to a height exceeding 86% of measured flame heights. Field testing of 512 sensors during prescribed burning affirmed the potential practicality of this technique for estimating flame length.

scholarly journals Antelope Bitterbrush and Scouler's Willow Response to a Shelterwood Harvest and Prescribed Burn in Western Montana

1999 ◽  
Vol 14 (3) ◽  
pp. 137-143 ◽  
Author(s):  
Dayna M. Ayers ◽  
Donald J. Bedunah ◽  
Michael G. Harrington
Keyword(s):  
Fuel Consumption ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Selective Logging ◽  
Western Montana ◽  
Fire Damage ◽  
Prescribed Burn ◽  
Large Trees ◽  
Shelterwood Cut

Abstract In many western Montana ponderosa pine (Pinus ponderosa) stands, fire suppression and past selective logging of large trees have resulted in conditions favoring succession to dense stands of shade-tolerant, but insect- and disease-prone Douglas-fir (Pseudotsuga menziesii). Stand thinning and understory prescribed burning have been proposed as surrogates for pre-Euro-American settlement ecological processes and as potential treatments to improve declining forest condition and reduce the probability of severe wildfire. To test the effectiveness of these silvicultural techniques on overstory and understory conditions, research is ongoing in the Lick Creek Demonstration Site in the Bitterroot National Forest, Montana. Our research examined the response (mortality and vigor) of the dominant browse species, antelope bitterbrush (Purshia tridentata) and Scouler's willow (Salix scouleriana), to a ponderosa pine stand restoration project utilizing four treatments: (1) a shelterwood cut that removed 53% of the tree basal area; (2) a shelterwood cut with a low fuel consumption burn; (3) a shelterwood cut with a high fuel consumption burn; and (4) a control. Prior to the application of treatments, 1,856 bitterbrush and 871 willow were located, and their survival and vigor subsequently monitored for 2 yr posttreatment. The cut and burn treatments resulted in the greatest reduction in antelope bitterbrush and Scouler's willow density averaging 66% and 24% of pretreatment density, respectively. The shelterwood cut reduced bitterbrush and Scouler's willow density by 35% and 14%, respectively. On treatments receiving a shelterwood cut (all treatments but the control), but where antelope bitterbrush and Scouler's willow did not have fire damage, mortality was 45% for bitterbrush and 20% for willow, respectively. For bitterbrush and Scouler's willow plants that received fire damage, mortality was 72% for bitterbrush and 19% for willow. Although the burn and shelterwood harvest treatments resulted in reduced density of antelope bitterbrush and Scouler's willow 2 yr posttreatment, these treatments increased vigor of both species and created mineral seedbeds that may be necessary for establishment of seedlings. West. J. Appl. For. 14(3):137-143.

An experimental demonstration of stem damage as a predictor of fire-caused mortality for ponderosa pine

2004 ◽  
Vol 34 (6) ◽  
pp. 1343-1347 ◽  
Author(s):  
Phillip van Mantgem ◽  
Mark Schwartz
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Control Group ◽  
Critical Determinant ◽  
Dead Trees ◽  
Crown Scorch ◽  
Increased Sensitivity ◽  
Stem Damage ◽  
Removal Group

We subjected 159 small ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) to treatments designed to test the relative importance of stem damage as a predictor of postfire mortality. The treatments consisted of a group with the basal bark artificially thinned, a second group with fuels removed from the base of the stem, and an untreated control. Following prescribed burning, crown scorch severity was equivalent among the groups. Postfire mortality was significantly less frequent in the fuels removal group than in the bark removal and control groups. No model of mortality for the fuels removal group was possible, because dead trees constituted <4% of subject trees. Mortality in the bark removal group was best predicted by crown scorch and stem scorch severity, whereas death in the control group was predicted by crown scorch severity and bark thickness. The relative lack of mortality in the fuels removal group and the increased sensitivity to stem damage in the bark removal group suggest that stem damage is a critical determinant of postfire mortality for small ponderosa pine.

Fire damage, mortality, and suckering in aspen

1987 ◽  
Vol 17 (9) ◽  
pp. 1100-1109 ◽  
Author(s):  
James K. Brown ◽  
Norbert V. DeByle
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Tree Mortality ◽  
Fire Severity ◽  
Fire Damage ◽  
Bark Thickness ◽  
Breast Height ◽  
High Severity ◽  
Tree Number ◽  
Fire Characteristics

Relationships among fire characteristics, fire damage, tree mortality, and sucker response in Populustremuloides Michx. are described. Circumference charred averaged more than 75% on trees killed and less than 50% on live trees. Average char heights ranged from 0.5 m in low severity fire to 1.5 m in high severity fire. Logistic regression analysis showed that probability of mortality was strongly related to diameter at breast height (dbh), char height, and circumference charred. Char heights of 30 cm had a 90% probability of killing aspen less than 25 cm dbh. Bark thickness at breast height and 10 cm aboveground, which relates to fire resistance, related strongly to tree dbh. Bark thickness was the same at sidehill, downhill, and uphill positions. Minimal flame heights required to kill aspen with 90% probability ranged from 10 cm for a 10-cm dbh tree to 60 cm for a 25-cm dbh tree. Number of suckers per hectare on three burns varied from 9 880 to 57 570 the 1st year following fire and from 7 060 to 21 240 4 years after the fire. Depth of sucker origin ranged from 0.2 to 18 cm and was related to fire severity. Sucker density varied greatly between plots and was not significantly related to fire severity.

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