scholarly journals Chronosequence of Fuel Loading and Fuel Depth Following Forest Rehabilitation Frill Treatment of Tanoak to Release Douglas-Fir: A Case Study from Northern California

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Raven M. Krieger ◽  
Brian E. Wall ◽  
Cody W. Kidd ◽  
John-Pascal Berrill
Keyword(s):  
Woody Debris ◽  
Fire Severity ◽  
Fire Behavior ◽  
Fire Effects ◽  
Behavior Modeling ◽  
Northern California ◽  
Fuel Loading ◽  
Excessive Competition ◽  
Pre Treatment ◽  
Forest Rehabilitation

There is concern that forest management activities such as chemical thinning may increase hazardous fuel loading and therefore increase risk of stand-replacing wildfire. Chemical thinning, often accomplished by frill treatment of unwanted trees, leaves trees standing dead for a time before they fall and become surface fuels. In coastal northern California, frill treatment is used as a forest rehabilitation treatment that removes tanoak (Notholithocarpus densiflorus) to release merchantable conifers from excessive competition. We studied fuel bed depth and fuel loading after frill treatment of tanoak along a 16-year chronosequence that substituted space for time. The total depth of fuel bed was separated into woody fuels, litter, and duff. The height of each layer was variable and greatest on average in post-treatment year 5 after treated tanoak had begun to break apart and fall. Initially, the evergreen tanoak trees retained their foliage for at least a year after treatment. Five years after treatment, many tanoak had fallen and transitioned to become fine- and coarse woody debris. After 11 years, the larger pieces of down wood were mostly classified as rotten. After 16 years, the fuel loading appeared roughly equivalent to pre-treatment levels, however we did not explicitly test for differences due to potential confounding between time and multiple factors such as inter-annual climate variations and site attributes. Nevertheless, our data provide some insight into changes in surface fuel characteristics due to rehabilitation treatments. These data can be used as inputs for fire behavior modeling to generate indicative predictions of fire effects such as fire severity and how these change over time since treatment.

scholarly journals Decomposing the Interactions between Fire Severity and Canopy Fuel Structure Using Multi-Temporal, Active, and Passive Remote Sensing Approaches

Fire ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Nicholas S. Skowronski ◽  
Michael R. Gallagher ◽  
Timothy A. Warner
Keyword(s):  
Laser Scanning ◽  
Treatment Effectiveness ◽  
Fire Severity ◽  
Fire Behavior ◽  
Three Dimensional ◽  
Structural Heterogeneity ◽  
Behavior Modeling ◽  
Fuel Loading ◽  
Subtle Difference ◽  
Multi Temporal

Within the realms of both wildland and prescribed fire, an understanding of how fire severity and forest structure interact is critical for improving fuels treatment effectiveness, quantifying the ramifications of wildfires, and improving fire behavior modeling. We integrated high resolution estimates of fire severity with multi-temporal airborne laser scanning data to examine the role that various fuel loading, canopy shape, and other variables had on predicting fire severity for a complex of prescribed fires and one wildfire and how three-dimensional fuels changed as a result of these fires. Fuel loading characteristics were widely variable, and fires were ignited using a several techniques (heading, flanking, and backing), leading to a large amount of variability in fire behavior and subsequent fire effects. Through our analysis, we found that fire severity was linked explicitly to pre-fire fuel loading and structure, particularly in the three-dimensional distribution of fuels. Fire severity was also correlated with post-fire fuel loading, forest structural heterogeneity, and shifted the diversity and abundance of canopy classes within the landscape. This work demonstrates that the vertical distribution of fuel is an important factor and that subtle difference has defined effects on fire behavior and severity.

scholarly journals Prediction of Fuel Loading Following Mastication Treatments in Forest Stands in North Idaho, USA

2020 ◽  
Vol 12 (17) ◽  
pp. 7025
Author(s):  
Ryer Becker ◽  
Robert Keefe
Keyword(s):  
Fire Behavior ◽  
Stand Density ◽  
Post Treatment ◽  
Behavior Modeling ◽  
Fuel Reduction ◽  
Fuel Loading ◽  
Stem Size ◽  
Fuel Loads ◽  
Pre Treatment ◽  
Mean Square Errors

Fuel reduction in forests is a high management priority in the western United States and mechanical mastication treatments are implemented common to achieve that goal. However, quantifying post-treatment fuel loading for use in fire behavior modeling to forecast treatment effectiveness is difficult due to the high cost and labor requirements of field sampling methods and high variability in resultant fuel loading within stands after treatment. We evaluated whether pre-treatment LiDAR-derived stand forest characteristics at 20 m × 20 m resolution could be used to predict post-treatment surface fuel loading following mastication. Plot-based destructive sampling was performed immediately following mastication at three stands in the Nez Perce Clearwater National Forest, Idaho, USA, to correlate post-treatment surface fuel loads and characteristics with pre-treatment LiDAR-derived forest metrics, specifically trees per hectare (TPH) and stand density index (SDI). Surface fuel loads measured in the stand post-treatment were consistent with those reported in previous studies. A significant relationship was found between the pre-treatment SDI and total resultant fuel loading (p = 0.0477), though not between TPH and fuel loading (p = 0.0527). SDI may more accurately predict post-treatment fuel loads by accounting for both tree number per unit area and stem size, while trees per hectare alone does not account for variations of tree size and subsequent volume within a stand. Relatively large root-mean-square errors associated with the random forest models for SDI (36%) and TPH (46%) suggest that increased sampling intensity and modified methods that better account for fine spatial variability in fuels resulting from within-stand conditions, treatment prescriptions and machine operators may be needed. Use of LiDAR to predict fuel loading after mastication is a useful approach for managers to understand the efficacy of fuel reduction treatments by providing information that may be helpful for determining areas where treatments can be most beneficial.

scholarly journals Remote sensing techniques to assess active fire characteristics and post-fire effects

2006 ◽  
Vol 15 (3) ◽  
pp. 319 ◽  
Author(s):  
Leigh B. Lentile ◽  
Zachary A. Holden ◽  
Alistair M. S. Smith ◽  
Michael J. Falkowski ◽  
Andrew T. Hudak ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Fire Severity ◽  
Fire Behavior ◽  
Fire Effects ◽  
Ecological Effects ◽  
Fire Intensity ◽  
Active Fire ◽  
Post Fire Effects ◽  
Remote Sensing Techniques ◽  
Fire Characteristics

Space and airborne sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Confusion about fire intensity, fire severity, burn severity, and related terms can result in the potential misuse of the inferred information by land managers and remote sensing practitioners who require unambiguous remote sensing products for fire management. The objective of the present paper is to provide a comprehensive review of current and potential remote sensing methods used to assess fire behavior and effects and ecological responses to fire. We clarify the terminology to facilitate development and interpretation of comprehensible and defensible remote sensing products, present the potential and limitations of a variety of approaches for remotely measuring active fires and their post-fire ecological effects, and discuss challenges and future directions of fire-related remote sensing research.

Fuel treatments alter the effects of wildfire in a mixed-evergreen forest, Oregon, USA

2005 ◽  
Vol 35 (12) ◽  
pp. 2981-2995 ◽  
Author(s):  
Crystal L Raymond ◽  
David L Peterson
Keyword(s):  
Tree Mortality ◽  
Fire Regime ◽  
Fire Severity ◽  
Fire Behavior ◽  
Evergreen Forest ◽  
Fire Intensity ◽  
Crown Fire ◽  
Fuel Loading ◽  
Fuel Treatments ◽  
Surface Fire

We had the rare opportunity to quantify the relationship between fuels and fire severity using prefire surface and canopy fuel data and fire severity data after a wildfire. The study area is a mixed-evergreen forest of southwestern Oregon with a mixed-severity fire regime. Modeled fire behavior showed that thinning reduced canopy fuels, thereby decreasing the potential for crown fire spread. The potential for crown fire initiation remained fairly constant despite reductions in ladder fuels, because thinning increased surface fuels, which contributed to greater surface fire intensity. Thinning followed by underburning reduced canopy, ladder, and surface fuels, thereby decreasing surface fire intensity and crown fire potential. However, crown fire is not a prerequisite for high fire severity; damage to and mortality of overstory trees in the wildfire were extensive despite the absence of crown fire. Mortality was most severe in thinned treatments (80%–100%), moderate in untreated stands (53%–54%), and least severe in the thinned and underburned treatment (5%). Thinned treatments had higher fine-fuel loading and more extensive crown scorch, suggesting that greater consumption of fine fuels contributed to higher tree mortality. Fuel treatments intended to minimize tree mortality will be most effective if both ladder and surface fuels are treated.

scholarly journals Long-Term Effects of Fuel Reduction Treatments on Surface Fuel Loading in the Blue Mountains of Oregon

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1306
Author(s):  
Kat E. Morici ◽  
John D. Bailey
Keyword(s):  
Fire Behavior ◽  
Fuel Load ◽  
Fire Season ◽  
Fuel Reduction ◽  
Prescribed Burn ◽  
Long Term Effects ◽  
Fuel Loading ◽  
Fuel Treatments ◽  
Blue Mountains ◽  
Pre Treatment

Fire exclusion and a lengthening fire season has resulted in an era of megafires. Fuel reduction treatments in forested ecosystems are designed to guard against future extreme wildfire behavior. Treatments create a heterogenous landscape and facilitate ecosystem function and resilience in fire-adapted forests of the western United States. Despite widespread recognition that repeated fuel treatments are needed to maintain desired stand characteristics over time, few field studies have evaluated treatment longevity. The Blue Mountains Fire and Fire Surrogate site in northeastern Oregon presented an opportunity to investigate woody fuel loading 15–17 years after four treatments: mechanical thin, prescribed burn, both thin and burn, and no treatment control. The principal findings were: (1) fine fuel load 15 years post-burn remained slightly below pre-treatment values; (2) rotten coarse fuel load was reduced post-burn, but sound coarse fuel was not altered by any active treatment; and (3) total woody fuel load 15–17 years post-treatment was similar to pre-treatment values. Understanding surface fuel loading is essential for predicting fire behavior. Overall, the effects of fuel reduction treatments on woody surface fuels were transitory in dry mixed conifer forests. Frequent maintenance treatments are recommended to protect values at risk in areas with high fire hazards. Quantifying the persistence of changes in forest conditions aids in the planning and analysis of future fuel treatments, along with scheduling maintenance of existing treated areas.

A surface fuel classification for estimating fire effects

2009 ◽  
Vol 18 (7) ◽  
pp. 802 ◽  
Author(s):  
Duncan C. Lutes ◽  
Robert E. Keane ◽  
John F. Caratti
Keyword(s):  
Surface Temperature ◽  
Soil Temperature ◽  
Woody Debris ◽  
Classification Tree ◽  
Soil Surface ◽  
Fire Effects ◽  
Misclassification Rate ◽  
Fuel Loading ◽  
Fine Woody Debris ◽  
Soil Surface Temperature

We present a classification of duff, litter, fine woody debris, and logs that can be used to stratify a project area into sites with fuel loading that yield significantly different emissions and maximum soil surface temperature. Total particulate matter smaller than 2.5 μm in diameter and maximum soil surface temperature were simulated using the First Order Fire Effects Model. Simulation results were clustered into 10 Effects Groups using an agglomerative routine where each Effects Group defined a unique range of soil temperature and emissions. Classification tree analysis was used to estimate the critical duff, litter, fine woody debris, and log loadings associated with the soil temperature and emissions of each Effects Group. The resulting 21 fuel classes are called Fuel Loading Models and classified the study dataset with an ~34% misclassification rate. The classification can be used to describe fuel loadings for a plot or stand, or as map units for mapping fuel loadings across large regions. The classification process can be used to develop finer-scale fuel classifications for specific regions or ecosystems.

Fire Behavior and Fire Effects on Eastern Redcedar in Hardwood Leaf-Litter Fires

1995 ◽  
Vol 5 (3) ◽  
pp. 135 ◽  
Author(s):  
DM Engle ◽  
JF Stritzke
Keyword(s):  
Leaf Litter ◽  
Fire Behavior ◽  
Late Summer ◽  
Ambient Air ◽  
Fire Effects ◽  
Cross Timbers ◽  
Fuel Loading ◽  
Eastern Redcedar ◽  
Crown Scorch ◽  
In Fire

Treatment of stands of hardwoods in the cross timbers of the central United States with tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-dimethylurea) can significantly decrease canopy cover of hardwoods. However, at the rate used for hardwood control, tebuthiuron does not control eastern redcedar (Juniperus virginiana L.). Our objective was to determine the potential of using fires in the hardwood leaf litter, either before or after tebuthiuron, for controlling eastern redcedar. To do this, we compared fuelbed characteristics, fire behavior, and fire effects on eastern redcedar in naturally occurring hardwood leaf litter with those augmented by leaves dropped following a single application of tebuthiuron. Studies were conducted in 1988, 1989, and 1991 on a cross timbers site dominated by an overstory of post oak (Quercus stellata Wangenh.) and blackjack oak (Q. marilandica Muenchh.) and with eastern redcedar in the understory. Factors evaluated included herbicide treatment (tebuthiuron or no herbicide) and burning season (late summer or winter). Tebuthiuron at 2.2 kg a.i. Ha-1 was applied to plots (25 X 25 m) in March of the study years. In late summer, tebuthiuron-treated plots contained almost twice the 1-hr fuel loading as untreated plots. Fuel depth on untreated plots in late summer was about half that of other herbicide treatments and burning date combinations. Fuel loading on plots burned in winter was not affected by tebuthiuron treatment, and no differences in fuel consumption were detected among any treatments. Moisture content of 1-hr fuels on plots burned in winter was more than twice that of 1-hr fuels on plots burned in late summer. Fire intensity was low with all bums, and no differences in fire behavior were detected among any treatments. Crown scorch of 75% or greater on small eastern redcedar trees was considered a successful burn, and this resulted on all but the late summer-no tebuthiuron treatment. The natural log of fireline intensity explained about 47% (P<0.0006)) of the variation in fire success, and ambient air temperature explained an additional 19% (P<0.0468). Although tebuthiuron treatments effectively augmented leaf-litter fuel load by late-summer and provided a suitable fuelbed for burning, crown scorch and tree kill were not greatly improved by burning in late summer as compared to winter. We conclude that understory eastern redcedar can be controlled successfully by burning leaf-litter fuelbeds in either late fall or winter after natural leaf-fall from hardwood trees or in late summer, fall, or winter following a spring application of tebuthiuron for control of overstory hardwoods.

Novel fuelbed characteristics associated with mechanical mastication treatments in northern California and south-western Oregon, USA

2009 ◽  
Vol 18 (6) ◽  
pp. 686 ◽  
Author(s):  
Jeffrey M. Kane ◽  
J. Morgan Varner ◽  
Eric E. Knapp
Keyword(s):  
Time Lag ◽  
Fire Behavior ◽  
Fuel Load ◽  
Northern California ◽  
Fuel Loading ◽  
Quadratic Mean ◽  
Fuel Models ◽  
Quadratic Mean Diameter ◽  
Fuel Particles ◽  
Particle Shapes

Mechanically masticated fuelbeds are distinct from natural or logging slash fuelbeds, with different particle size distributions, bulk density, and particle shapes, leading to challenges in predicting fire behavior and effects. Our study quantified some physical properties of fuel particles (e.g. squared quadratic mean diameter, proportion of non-cylindrical particles) and surface fuel loading with planar intercept and plot-based methods in 10 mechanically masticated sites in northern California and south-western Oregon. Total woody fuel load differed among masticated sites, ranging from 15.3 to 63.4 Mg ha–1, with the majority of the load concentrated in the 10-h (53.7%) and 1-h (29.2%) time-lag classes. Masticated fuels were densely packed, with total depths ranging from 4.6 to 8.0 cm and fuelbed bulk densities ranging from 45.9 to 115.3 kg m–3. To accurately quantify loading in masticated fuelbeds, we recommend using a hybrid methodology, where 1-h and 10-h fuel loadings are estimated using a plot-based method and 100-h and 1000-h fuel loadings are estimated using the standard planar intercept method. Most masticated fuelbeds differed in loading by fuel class and fuelbed depth, when compared with existing natural and slash-based fuelbeds, suggesting new fire behavior fuel models specific to masticated fuelbeds may be warranted.

Effectiveness of prescribed fire as a fuel treatment in Californian coniferous forests

2009 ◽  
Vol 18 (2) ◽  
pp. 165 ◽  
Author(s):  
Nicole M. Vaillant ◽  
Jo Ann Fites-Kaufman ◽  
Scott L. Stephens
Keyword(s):  
Prescribed Fire ◽  
Forest Structure ◽  
Tree Mortality ◽  
Wildland Fire ◽  
Fire Behavior ◽  
Weather Conditions ◽  
Fire Effects ◽  
The United States ◽  
Behavior Modeling ◽  
Fuel Loads

Effective fire suppression and land use practices over the last century have altered forest structure and increased fuel loads in many forests in the United States, increasing the occurrence of catastrophic wildland fires. The most effective methods to change potential fire behavior are to reduce surface fuels, increase the canopy base height and reduce canopy bulk density. This multi-tiered approach breaks up the continuity of surface, ladder and crown fuels. Effectiveness of fuel treatments is often shown indirectly through fire behavior modeling or directly through monitoring wildland fire effects such as tree mortality. The present study investigates how prescribed fire affected fuel loads, forest structure, potential fire behavior, and modeled tree mortality at 90th and 97.5th percentile fire weather conditions on eight National Forests in California. Prescription burning did not significantly change forest structure at most sites. Total fuel loads (litter, duff, 1, 10, 100, and 1000-h) were reduced by 23 to 78% across the sites. The reduction in fuel loads altered potential fire behavior by reducing fireline intensity and increasing torching index and crowning index at most sites. Predicted tree mortality decreased after treatment as an effect of reduced potential fire behavior and fuel loads. To use limited fuel hazard reduction resources efficiently, more effort could be placed on the evaluation of existing fire hazards because several stands in the present study had little potential for adverse fire effects before prescribed fire was applied.

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