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.

Ethanol in ponderosa pine as an indicator of physiological injury from fire and its relationship to secondary beetles

2003 ◽  
Vol 33 (5) ◽  
pp. 870-884 ◽  
Author(s):  
Rick G Kelsey ◽  
Gladwin Joseph
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Xylem Sap ◽  
Upward Movement ◽  
Stem Base ◽  
Breast Height ◽  
Dead Trees ◽  
Crown Scorch ◽  
Second Year ◽  
The Relationship

Sixteen days after a September wildfire, ethanol and water were measured in phloem and sapwood at breast height and the base of Pinus ponderosa Dougl. ex P. & C. Laws. with zero (control), moderate, heavy, and severe crown scorch. The quantity of ethanol increased with each level of injury, resulting in trees with severe scorch containing 15 and 53 times more phloem and sapwood ethanol, respectively, than controls. Ethanol concentrations in the sapwood and adjacent phloem were related, probably as a result of diffusion. Upward movement in xylem sap was most likely responsible for the relationship between sapwood ethanol concentrations at breast height and the stem base. As trees recovered from their heat injuries, the ethanol concentrations declined. In contrast, ethanol accumulated in dead trees that lost their entire crowns in the fire. Various bark and xylophagous beetles landed in greater numbers on fire-damaged trees than on controls the following spring and summer, suggesting that ethanol was being released to the atmosphere and influencing beetle behavior. Beetle landing was more strongly related to sapwood ethanol concentrations the previous September than in May. Sapwood ethanol measured 16 days after the fire was the best predictor of second-year mortality for trees with heavy and severe crown scorch.

Predicting Pinus ponderosa Mortality From Dormant Season and Growing-Season Fire Injury

1993 ◽  
Vol 3 (2) ◽  
pp. 65 ◽  
Author(s):  
MG Harrington
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Prescribed Burning ◽  
Growing Season ◽  
Single Class ◽  
Crown Scorch ◽  
Large Trees ◽  
Different Seasons ◽  
Dormant Season

Understory prescribed burning was conducted in an immature Pinus ponderosa (ponderosa pine) stand in southwestern Colorado during three seasons, late spring, midsummer, and autumn. Tree mortality from various levels of crown scorch was compared for the different seasons of injury. A total of 526 trees of different sizes, with crown scorch ranging from 20 to 100%, were monitored annually for 10 years. Over 80% of the 10-year mortality from injury in all three seasons had occurred by year 3, with over 90% occurring by year 4. Mortality of trees scorched in the spring and summer was about 2.5 times greater than that in the autumn for similar crown damage. Most trees larger than 18 cm in diameter survived autumn injury, even with greater than 90% scorching. Following spring and summer injury, trees smaller than 10 cm in diameter died readily with greater than 50% scorching, but about 90% crown scorch was required by large trees to be lethal. A logistic regression model was developed to predict the probability of mortality given tree size, scorch class, and season of injury. Because mortality was similar within scorch classes less than 90%, they were combined into a single class. Scorch thresholds with large increases in mortality occurred at 90% and 100% crown scorch. The season variable includes two groups, dormant (autumn) and growing (spring and summer). Use of this model to predict mortality of immature P. ponderosa is appropriate where stand, fuel, and fire conditions resemble those of this study.

Reproductive output of ponderosa pine in response to thinning and prescribed burning in western Montana

2008 ◽  
Vol 38 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Gregory Peters ◽  
Anna Sala
Keyword(s):  
Pinus Ponderosa ◽  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Reproductive Output ◽  
Management Practices ◽  
Prescribed Burning ◽  
Seed Mass ◽  
Reproductive Traits ◽  
Western Montana ◽  
Cone Production

Thinning and thinning followed by prescribed fire are common management practices intended to restore historic conditions in low-elevation ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the northern Rocky Mountains. While these treatments generally ameliorate the physiology and growth of residual trees, treatment-specific effects on reproductive output are not known. We examined reproductive output of second-growth ponderosa pine in western Montana 9 years after the application of four treatments: thinning, thinning followed by spring prescribed fire, thinning followed by fall prescribed fire, and unthinned control stands. Field and greenhouse observations indicated that reproductive traits vary depending on the specific management treatment. Cone production was significantly higher in trees from all actively managed stands relative to control trees. Trees subjected to prescribed fire produced cones with higher numbers of filled seeds than trees in unburned treatments. Seed mass, percentage germination, and seedling biomass were significantly lower for seeds from trees in spring burn treatments relative to all others and were generally higher in trees from fall burn treatments. We show for the first time that thinning and prescribed-burning treatments can influence reproductive output in ponderosa pine.

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.

scholarly journals The Effects of Fire on Understory Vegetation in Ponderosa Pine Forests

1980 ◽  
Vol 4 ◽  
pp. 96-97
Author(s):  
Jane Bock ◽  
Carl Bock
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Management Plan ◽  
Black Hills ◽  
Pine Forests ◽  
Natural Phenomenon ◽  
Natural Fire ◽  
Ponderosa Pine Forests

This was the second year of our study designed to evaluate the nature of vegetation occurring under Pinus ponderosa canopy in Wind Cave National Park and to define the relationship between this vegetation and fire. Fire is known to be a natural phenomenon in ponderosa pine forests (Wright 1978), and to play a major role in determining the position of the pine-grassland ecotone in the Black Hills (Gartner and Thompson 1973). Wind Cave personnel are developing a fire management plan allowing for prescribed burning, in hopes of bringing the park ecosystems back under a "natural" fire regime. Results of our study will help park management predict the effects of such prescribed burning on the ponderosa pine community.

Prediction of delayed mortality of fire-damaged ponderosa pine following prescribed fires in eastern Oregon, USA

2006 ◽  
Vol 15 (1) ◽  
pp. 19 ◽  
Author(s):  
Walter G. Thies ◽  
Douglas J. Westlind ◽  
Mark Loewen ◽  
Greg Brenner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Management Tool ◽  
Experimental Unit ◽  
Full Model ◽  
Prescribed Burns ◽  
Blue Mountains ◽  
Growing Seasons ◽  
Individual Trees

Prescribed burning is a management tool used to reduce fuel loads in western interior forests. Following a burn, managers need the ability to predict the mortality of individual trees based on easily observed characteristics. Astudy was established in six stands of mixed-age ponderosa pine (Pinus ponderosa Dougl. ex Laws.) with scattered western junipers at the south end of the Blue Mountains near Burns, Oregon, USA. Stands were thinned in either 1994 or 1995. Three treatments, a fall burn, a spring burn, and an unburned control, were randomly assigned to 12-ha experimental units within each stand. Prescribed burns occurred during mid-October of 1997 or mid-June of 1998 and were representative of operational burns, given weather and fuel conditions. Within each experimental unit, six 0.2-ha plots were established to evaluate responses to the burns. Ponderosa pine plot trees (n =3415) alive 1 month after the burns were evaluated and observed for four growing seasons. Nine fire damage and tree morphological variables were evaluated by logistic regression. A five-factor full model and a two-factor reduced model are presented for projecting probability of mortality. Significant variables in the full model included measures of crown, bole, and basal damage.

scholarly journals Effect of Prescribed Burning at Different Fuel Moisture Levels on Grasslands in Wind Cave National Park

1979 ◽  
Vol 3 ◽  
pp. 148-152
Author(s):  
F. Gartner ◽  
E. White ◽  
L. Worcester
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
National Park ◽  
Prescribed Burning ◽  
Fire Spread ◽  
Control Treatment ◽  
Grass Species ◽  
Fuel Moisture

The study was designed to determine whether different fuel and soil moisture levels at time of ignition would alter the response of key grass species to prescribed burning. Grasslands occupy approximately 75% of the area of Wind Cave National Park (WCNP); the remainder is dominated by ponderosa pine (Pinus ponderosa), according to Lovass (1973). The Soil Conservation Service (1969) classed only about 17% of the Park area as woodland. Nearly all grassland adjacent to woodland has been invaded by ponderosa pine. Almost without exception, pine invades the little bluestem - big bluestem (Schizachyrium scorparium - Andropogon gerardi) community, but not the wheatgrass - needle-grass - grama (Andropogon - Stipa- Bouteloua) community. While these two communities are frequently interspersed, the bluestem community probably occupies the largest percentage of the total grassland area. The general relationships between fuel moisture content and fire spread (or ease of control) are well known. However, relationships between fuel and surface soil moisture content and responses of plant species to burning are not well documented. Since the key grass species of the bluestem community are major dominants throughout the Park, that community was selected for the study. Examined were the effects of three fuel moisture levels (dry, medium and wet) at ignition on postburn species composition, cover, height, weight, soil moisture and soil chemistry. The design also included an unburned (control) treatment.

Fuel treatment effects on tree mortality following wildfire in dry mixed conifer forests, Washington State, USA

2012 ◽  
Vol 21 (8) ◽  
pp. 1004 ◽  
Author(s):  
Susan J. Prichard ◽  
Maureen C. Kennedy
Keyword(s):  
Pinus Ponderosa ◽  
Tree Mortality ◽  
Prescribed Burning ◽  
Strong Predictor ◽  
Large Diameter ◽  
Lower Probability ◽  
First Year ◽  
Prescribed Burn ◽  
Fuel Treatment ◽  
Crown Scorch

Fuel reduction treatments are increasingly used to mitigate future wildfire severity in dry forests, but few opportunities exist to assess their effectiveness. We evaluated the influence of fuel treatment, tree size and species on tree mortality following a large wildfire event in recent thin-only, thin and prescribed burn (thin-Rx) units. Of the trees that died within the first 3 years, most died in the first year regardless of treatment. First-year mortality was much higher in control and thin-only units (65 and 52%) than in thin-Rx units (37%). Cumulative third-year mortality followed a similar trend (78 and 64% in control and thin-only units) v. 43% in thin-Rx units. Percentage crown scorch is a strong predictor of mortality and is highly dependent on fuel treatment. Across all treatments, Pinus ponderosa had a lower probability of post-fire mortality than did Pseudotsuga menziesii. Finally, the probability of beetle attack on surviving trees was highest in large-diameter trees within thin-only treatments and lowest within thin-Rx treatments. This study contributes further evidence supporting the effectiveness of thinning and prescribed burning on mitigating post-fire tree mortality. We also present evidence that a combination of thinning and prescribed burning is associated with lower incidence of post-fire bark beetle attack.

Effects of fire rotation interval and overstory type on ambient soil temperatures in ponderosa pine forests in Arizona

2019 ◽  
Vol 49 (10) ◽  
pp. 1320-1328
Author(s):  
David R. Weise ◽  
Stephen S. Sackett ◽  
Sally M. Haase ◽  
Nels Johnson
Keyword(s):  
Soil Temperature ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Temperature Variability ◽  
Organic Layer ◽  
Prescribed Burns ◽  
Ponderosa Pine Forests ◽  
Low Intensity ◽  
Soil Temperatures

Ambient soil temperatures were measured every four weeks from May 1986 to November 1986 at three depths under the organic forest floor in ponderosa pine (Pinus ponderosa Lawson & C. Lawson) forests in three stand types subjected to periodic prescribed burning. Temperatures at the organic layer – soil surface interface in sawtimber stands were higher and more variable than in pole and saplings stands. Temperature variability reached a maximum in the summer and decreased into the fall and early winter. Soil temperature variability decreased as depth below the surface increased. Three years after the low-intensity prescribed burns, soil temperatures in the burned stands were not significantly different from the those in the unburned controls, suggesting that any effect, though none was detected, of the low-intensity prescribed burns on soil temperature and belowground processes affected by temperature is short-lived in these stands.

Influences of moisture content, mineral content and bulk density on smouldering combustion of ponderosa pine duff mounds

2011 ◽  
Vol 20 (4) ◽  
pp. 589 ◽  
Author(s):  
Emily C. Garlough ◽  
Christopher R. Keyes
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Mineral Content ◽  
Prescribed Burning ◽  
Klamath Mountains ◽  
Root Mortality ◽  
Decision Support Models ◽  
Smouldering Combustion

When applying prescribed fire to long-unburned but fire-adapted ecosystems, fuels managers require better decision-support models to determine appropriate conditions for achieving desired effects. Prolonged combustion in duff accumulations at the base of large conifers may lead to fine root mortality, cambial injury, enhanced susceptibility to bark beetle attack, and possibly tree death. A laboratory experiment was conducted to investigate how moisture content, mineral content, and bulk density affect smouldering combustion in ponderosa pine (Pinus ponderosa C. Lawson) duff mound fuels of the south-eastern Klamath Mountains, California, USA. Samples were divided between upper and lower duff for a total of 100 burn tests. Moisture content was adjusted to observe the transition through the ignition and spread limit. Bulk density, mineral content and percentage consumption were recorded for each burn. The moisture content threshold for smouldering combustion was 57 and 102% respectively for upper and lower duff. Percentage consumption was inversely related to moisture content for both layers of duff, and partially dependent on mineral content for lower duff. Bulk density was a non-significant factor in either ignition or percentage combustion for the conditions examined here. Results from this study identify important attributes of duff that control the burning process in order to inform prescribed burning decisions.

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