Fuels & Fuel Treatments
The Fuel Characteristic Classification System (FCCS) was designed to store and archive wildland fuel characteristics within fuelbeds, defined as the inherent physical characteristics of fuels that contribute to fire behavior and effects. The FCCS represents fuel characteristics in six strata including canopy, shrubs, herbaceous fuels, downed wood, litter-lichen-moss, and ground fuels. Each stratum is further divided into one or more categories and subcategories to represent the complexity of wildland and managed fuels. A variety of techniques to measure and summarize fuelbed data are detailed in this guide. This guide is organized by strata and categories to facilitate data input into FCCS fuelbeds and provides field sampling forms by stratum. The first section provides an overview of how FCCS reference fuelbeds were constructed from databases, literature sources, and expert opinion. The guide next describes how regional pathway fuelbeds can provide a systematic set of management fuelbeds that track vegetation and fuel succession over time as well as management activities such as prescribed burning and mechanical thinning. The final section details common field sampling methodologies for users who wish to use field measurements to construct FCCS fuelbeds.
In an empirical analysis of shaded fuelbreaks that burned during the 2014 Bald Fire (15,950 ha on the Lassen National Forest, California), we found that overall fire severity was reduced in the treated areas relative to untreated. A non-linear mixed effects model estimates that the reduction was detected more than 400 m into the treated area, greater than the standard width of the prescribed fuelbreak. Both pre- and post-fire species composition differed between treated and untreated forest, with few living stems remaining in the measured untreated areas. In the post-fire treated area, we documented a mixed conifer forest dominated by larger diameter Pinus, implying that the fuelbreak did result in a more resilient post-fire structure and composition. These results indicate that fuelbreak design may need to be wider than generally prescribed and that even during extreme fire conditions fuel treatments can result in resilient forest structures.
Using data collected as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP), this guide summarizes fuel loads, vegetation cover by functional group, and shrub and tree stem density 10 years after sagebrush and pinyon-juniper reduction treatments. The data was collected at 16 study sites in Washington, Oregon, California, Nevada, and Utah, and is summarized by treatment type, region, and roups or woodland development phases based on pre-treatment vegetation. These summarized data an be used by land managers and fire behavior specialists to quickly estimate fuel loads in older treatments or to predict fuel loads 10 years after a potential treatment. These fuel loading data can be used to create custom fuel beds to model fire behavior and effects.
In this issue:
- Fuels Guide for Sagebrush and Pinyon-Juniper Reduction Treatments: 10 years post-treatment
- Biological soil crusts as restoration targets in sagebrush steppe and woodland communities
View article.
Higher tree density, more fuels, and a warmer, drier climate have caused an increase in the frequency, size, and severity of wildfires in western U.S. forests. There is an urgent need to restore forests across the western United States. To address this need, the U.S. Forest Service began the Four Forest Restoration Initiative (4FRI) to restore four national forests in Arizona. The objective of this study was to evaluate how restoration of ~400,000 ha under the 4FRI program and projected climate change would influence carbon dynamics and wildfire severity from 2010 to 2099. Specifically, we estimated forest carbon fluxes, carbon pools and wildfire severity under a moderate and fast 4FRI implementation schedule and compared those to status quo and no‐harvest scenarios using the LANDIS‐II simulation model and climate change projections.
View article.
This study presents a fuel treatment optimization model to minimize risk to multiple water supplies based on constraints for treatment feasibility and cost. Risk is quantified as the expected sediment impact costs to water supplies by combining measures of fire likelihood and behavior, erosion, sediment transport and water supply vulnerability. We demonstrate the model’s utility for prioritizing fuel treatments in two large watersheds in Colorado, USA, that are critical for municipal water supply. Our results indicate that wildfire risk to water supplies can be substantially reduced by treating a small portion of the watersheds that have dense, fire-prone forests on steep slopes that drain to water supply infrastructure. Our results also show that the cost of fuel treatments outweighs the expected cost savings from reduced sediment inputs owing to the low probability of fuel treatments encountering wildfire and the high cost of thinning forests. This highlights the need to expand use of more cost-effective treatments, like prescribed fire, and to identify fuel treatment projects that benefit multiple resources.
Webinar recording and additional Q and A.
Federal and state agencies across Utah and the Great Basin have been actively treating pinyon and juniper woodlands to improve wildlife habitat, reduce fuel loads, and achieve watershed objectives. Increasingly these activities have been questioned by stakeholder groups and citizens who are concerned about the unintended consequences of such treatments. This webinar addresses some of the recent criticisms of pinyon-juniper treatment, sharing results of research on woody vegetation removal as well as identifying questions that still need to be answered through research and monitoring.
Speakers: Eric Thacker, Mark Brunson
Access report.
Spot fires caused by wind-blown burning embers are a significant mechanism of fire spread in the wildland and Wildland-Urban Interface (WUI). Fire spread and structure ignition by embers can be characterized by three major processes or mechanisms: ember production, ember transport, and ember ignition of fuel. This study investigates ember production from selected wildland and structural fuels under a range of environmental conditions through full-scale, intermediate-scale, and small-scale laboratory experiments.
View abstracts.
Abstracts of Recent Papers on Range Management in the West. Prepared by Charlie Clements, Rangeland Scientist, USDA Agricultural Research Service, Reno, NV.
View the study.
In this study we used the 79 western US national forests to examine tradeoffs between forest management scenarios targeting wildfire risk to the wildland urban interface (WUI) and those meeting agency convertible volume production targets. We quantified production frontiers to measure how the efficiency of meeting harvest volume targets is affected by prioritizing treatments to areas that transmit fire to the WUI. The results showed strong tradeoffs and scale effects on production frontiers, and more importantly substantial variation among planning areas and national forests. Prioritizing treatments to reduce fire transmission to the WUI resulted in an average harvest volume reduction of about 248m3 per ha treated. The analysis also identified opportunities where both management objectives can be achieved. This work represents the first large-scale tradeoff analysis for key management goals in forest and fuel management programs on national forests.