Synthesis of 127 Studies on Fuels Treatment Effectiveness

Summary of a new “Science You Can Use” bulletin from the Rocky Mountain Research Station: “Can Fuel Treatments Change How a Wildfire Burns Across a Landscape?” Summary below. One interesting observation:

Theresa “Terrie” Jain, an RMRS research forester (now scientist emeritus) with the Forest and Woodland Ecosystems Program and the project lead, says the lack of a clear understanding and agreement of what is meant by the term “landscape” underscores the need for the synthesis.

“We found that in the science papers, researchers used the term landscape, but they never defined their landscape. We found that the term was used in the title or as a keyword, but often the paper did not really address the landscape,” Jain says. “Even though fire is a landscape process, few researchers are really doing landscape-level analysis.”


By all measures, wildfires in the western United States are becoming more extreme. Fires are growing larger and burning more intensely, and suppression costs are spiraling upward. Maximizing the effectiveness of fuel treatments at the landscape scale is key given limited resources and the inability to treat all areas likely to burn in a wildfire.

Research forester Theresa Jain with the Rocky Mountain Research Station collaborated with fellow Station scientists along with colleagues from research institutions across the country to synthesize existing scientific literature on landscape-scale fuel treatment effectiveness in North American ecosystems through a systematic literature review.

The team identified 127 studies that addressed the fuels treatment effectiveness using simulation modeling, empirical analysis, and case studies. The studies show that fuel treatments reduced negative outcomes of wildfire and often promoted beneficial wildfire outcomes. Weather conditions influenced the effectiveness of treatments, and effectiveness lessened over time following treatment, pointing to the need for maintenance treatments. The studies also emphasized the importance of treating multiple fuel layers (canopy, ladder, and surface) to reduce fire spread and severity. Fuel treatments also contributed to fire suppression efforts by reducing costs and facilitating suppression activities, such as fireline construction.

The science team has developed a fuel treatment effectiveness framework with measurable criteria to better understand how stand-level fuel treatments collectively contribute to broader landscape-level fuels management goals.

8 thoughts on “Synthesis of 127 Studies on Fuels Treatment Effectiveness”

  1. One of the specific studies they are summarizing here has some nuances that REALLY get lost in the summary. A review of simulation studies of fuel treatment effectiveness brings into question the effectiveness of fuel reduction, especially when it is accomplished with commercial timber sales. The public and the decision-maker might like to know the extent to which commercial log extraction undermines fuel reduction objectives.

    Ex et al. (2019) addressed a question that is applicable to many montane landscapes in western North America that contain a patchwork of cover types associated with different topographic settings. They asked whether it would be more effective to treat more mesic north-facing slopes dominated by Douglas fir versus more xeric south-facing slopes dominated by ponderosa pine, given a one-time treatment opportunity at the start of a 50-year simulation. The south-facing slope strategy was initially more effective, but after the first decade, effects of the two strategies became more similar, and both strategies were ultimately less effective than the untreated control at reducing the ratio of crown fire to surface fire (Ex et al. 2019).

    Studies that compared fuel treatment scenarios with scenarios where the main objective was commercial timber harvest (or a combination of harvest and fuel reduction) showed that harvest-oriented scenarios tended to be less effective at reducing fire impacts (Fig. 11; Merzenich et al. 2003; Ganz et al. 2007; Kim et al. 2009; Cassell 2018; Krofcheck et al. 2019b) and sometimes even resulted in increased fire impacts compared to untreated scenarios (Merzenich et al. 2003) … Prescriptions aimed at restoring historical forest structure also tended to be less effective …

    Sturtevant et al. (2009) found that eliminating ignitions caused by debris burning had a greater effect than fuel treatments on reducing area burned by wildfire on a forested landscape in northern Wisconsin.

    Tradeoffs between wildfire protection and other management objectives such as commercial harvest, forest restoration, habitat protection, and carbon sequestration may need to be addressed on many managed landscapes (Stockmann et al. 2010; Ager et al. 2016, 2019; Stevens et al. 2016; James et al. 2018). Potential strategies for dealing with these tradeoffs include adjustments to harvesting procedures or restoration prescriptions to make them better aligned with fuel reduction goals (Acuna et al. 2010; Stephens et al. 2021) or the use of optimization algorithms to identify management solutions that could maximize a set of competing benefits (Hummel and Calkin 2005; Bagdon et al. 2016; Kreitler et al. 2020).
    … [S]ingle-year studies did not capture feedbacks between fuel treatments, wildfire, and vegetation succession, such as the possibility that short-term reductions in wildfire due to treatments allow greater fuel buildup leading to more damaging subsequent wildfires (Calkin et al. 2015; Parks et al. 2016; McKenzie and Littell 2017).

    Ott, J.E., Kilkenny, F.F. & Jain, T.B. Fuel treatment effectiveness at the landscape scale: a systematic review of simulation studies comparing treatment scenarios in North America. fire ecol 19, 10 (2023). citing Ex, S.A., J.P. Ziegler, W.T. Tinkham, and C.M. Hoffman. 2019. Long-term impacts of fuel treatment placement with respect to forest cover type on potential fire behavior across a mountainous landscape. Forests 10 (5): 438.

    • I’d appreciate a little more context for, “Prescriptions aimed at restoring historical forest structure also tended to be less effective …” Is it because historical structure is not relevant to future conditions, or something more complicated? Thanks.

  2. Steve: “pretty much the same as the proven science that some of us learned in the 1960’s”

    2nd Law: Your input is well received and only goes to show that that there is no “one size fits all” approach to minimizing annual acreage loss to fire considering the complexity of fire intensity variable interactions. Which is why the local USFS staff forestry professionals should be allowed to use their scientific training and accumulated local experience (including fire professionals and predicted fire weather conditions) to provide site specific fire risk reduction solutions with a higher probability of success than doing nothing until nature (15%) or a human (85%) lights a torch.

    In terms of recovery, we also have to remember that currently overstocked areas are going to have more failures than back in my day when stocking was much more appropriate and there were loggers working in the woods who, when the faintest wisp of smoke was spotted from a fire tower, would drop everything that they were doing to help the USFS make a timely initial attack while the fire was more easily stopped. Then there were those clearcuts and thinnings that helped to drop crown fires to the ground or keep a fire on the ground. It’s going to take a great many decades to get conditions back to where forest management will have any great chance of consistent success but it is the only way to get total USFS costs down and provide beautiful, healthy forests. Silviculturally appropriate, raw material providing clearcuts and thinnings are much more preferable to ashtrays (as opposed to clearcuts) and cost intensive brush piles that are just gas cans waiting to be set off (as opposed to thinnings).

    Emotions sans science got us into this mess. Ignorance and fearmongering about northern spotted owls and anything else, no matter how speculative, were a large part of creating this mess. Not so funny that after all of the hundreds of millions spent trying to save the northern spotted owls, we discover that evolution is the culprit. What is worse is that the species that is naturally replacing the NSO is much more suited to survive in the present or any future climate/environment/ecosystem. So what happened? Those proclaiming “nature knows best” seem to flip flop when it suits their interests. Now they want to kill the natural successor to the NSO. Seems they like it their way without considering consequences. Combine that with their combined political power and we see that they have certainly overruled: Integrity, Logic, Science and consistency which seem to be the missing components in all of this. Oh, I forgot, the NSO had a FWS biologist who had a pet NSO (all legal) and made a national crusade to save the species before congress, a president, the press and anywhere else. Opportunists jumped on the band wagon and stirred up a national panic attack. Far reaching decisions were made based on guesswork when there was clear evidence that the NSO was surviving in plantations better than anywhere else – (‘heaven forbid, those foresters can’t be right’).

  3. Since, “Maximizing the effectiveness of fuel treatments at the landscape scale is key given limited resources and the inability to treat all areas likely to burn in a wildfire,” do studies also emphasized the RELATIVE importance of treating canopy, ladder, or surface fuels? If (commercial) “harvest-oriented scenarios tended to be less effective” (per 2nd Law cite), that would suggest that removing canopy trees should not be a priority for fuel production.

    In general, the “landscape” question should be addressed through forest planning by providing desired fuel conditions, fire frequency and severity that vary across the forest based on vegetation and values at risk.

    • Jon, this is very interesting.. wouldn’t desired fuel conditions be m/l the same as desired veg conditions? After all, veg is fuel among other things.

      • That’s what I think – once you figure out the desired vegetation, the fuel/fire conditions should follow. Or if you decide that an area should have a low fire risk, that could dictate the fuel conditions, and therefore vegetation conditions, that would be acceptable/desirable. I think the circumstances are potentially variable enough, and the possibility of confusion high enough, that a forest plan would be better if it went beyond desired vegetation to also include desired fuels-related conditions, at least in those areas where fire is an important consideration.

    • Removing dominant canopy trees is usually not be a priority for fuel reduction, but removing co-dominant trees is sometimes warranted in forest health/resilience treatments. See your recent discussion of the “eastside screens.”

      • If you think I’m being inconsistent on something, you’ll need to spell it out (I’ve said a lot about the Eastside Screens). I usually argue that “health” includes at-risk species, and site-inappropriate large trees should not be removed if they are now important habitat for such species. And there is the large tree carbon consideration.


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