In the NY Times on January 5 (I’m a subscriber). Excerpt:
When the Bootleg fire tore through a nature reserve in Oregon this summer, the destruction varied in different areas. Researchers say forest management methods, including controlled burns, were a big factor.
SILVER LAKE, Ore. — When a monster of a wildfire whipped into the Sycan Marsh Preserve here in south-central Oregon in July, Katie Sauerbrey feared the worst.
Ms. Sauerbrey, a fire manager for The Nature Conservancy, the conservation group that owns the 30,000-acre preserve, was in charge of a crew helping to fight the blaze — the Bootleg fire, one of the largest in a summer of extreme heat and dryness in the West — and protect a research station on the property.
Watching the fire, which had already rapidly burned through thousands of acres of adjacent national forest, she saw a shocking sight: Flames 200 feet high were coming over a nearby ridge. “I said, OK, there’s nothing we can do,” she recalled.
But as the fire got closer, it changed dramatically, Ms. Sauerbrey said. “It had gone from the most extreme fire behavior I had ever seen in my career to seeing four-foot flame lengths moving through the stand.” While the fire kept burning through the forest, its lower intensity spared many trees, and the station survived.
Firefighters describe this kind of change in behavior as a fire “dropping down,” shifting from one with intense flames that spread quickly from tree crown to tree crown to a lower-level burn that is less dangerous. There are various reasons this can happen, including localized changes in winds, moisture, tree types and topography.
But for Ms. Sauerbrey and her colleagues with The Nature Conservancy, what she witnessed was most likely a real-life example of what they and others have been studying for years: how thinning of trees in overgrown forests, combined with prescribed, or controlled, burns of accumulated dead vegetation on the forest floor, can help achieve the goal of reducing the intensity of wildfires by removing much of the fuel that feeds them.
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One might also say that an unmanaged stand that was high-graded 30 years ago would probably burn very well. I think we need a more specific category than “unmanaged”. Both sides seem to have vague categories that will support their agendas, while masking the real results and baseline conditions.
Larry, I think that that’s probably a case of being too complicated for news stories. Certainly pick and pluck stands would look different 30 years later than clearcut or shelterwood or seed tree. The most important thing would probably be sizes, density and laddering profile or other things that only fuel folks really understand.
“Abandoned” might be a good term (but I’m not sure for who) *smirk*
When you high-grade some stands, what is left is shade-tolerant and highly-flammable understory trees. When you thin-from-below, the remaining trees are much more fire resistant and drought-tolerant. They both can be labeled as “managed”.
I worked in the area 40 some years ago, and I don’t remember “high-grading” as a prescription we used…
“Overstory Removal” is a more accurate term, but the meaning is the same.
Some still think that is a useful prescriptive ‘treatment’.
FWIW, here’s the end of the story.. I’m also a subsciber.
What interested me was the claim that the land burned in the Bootleg fire had been “heavily” managed. I remember in the 80’s that Weyco had done clearcutting and planting but the FS not so much. It would be interesting to see a map of past treatments.. I wonder whether one exists (and how accurate it might be)?
Here’s an open-access paper coauthored by DellaSala:
Does increased forest protection correspond to higher fire severity in frequent- fire forests of the western United States?
by Curtis M. Bradley, Chad T. Hanson, and Dominick A. DellaSala
https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.1492
Abstract. There is a widespread view among land managers and others that the protected status of many forestlands in the western United States corresponds with higher fire severity levels due to historical restrictions on logging that contribute to greater amounts of biomass and fuel loading in less intensively managed areas, particularly after decades of fire suppression. This view has led to recent proposals—both administrative and legislative—to reduce or eliminate forest protections and increase some forms of log-ging based on the belief that restrictions on active management have increased fire severity. We investigat-ed the relationship between protected status and fire severity using the Random Forests algorithm applied to 1500 fires affecting 9.5 million hectares between 1984 and 2014 in pine (Pinus ponderosa, Pinus jeffreyi) and mixed- conifer forests of western United States, accounting for key topographic and climate variables. We found forests with higher levels of protection had lower severity values even though they are generally identified as having the highest overall levels of biomass and fuel loading. Our results suggest a need to reconsider current overly simplistic assumptions about the relationship between forest protection and fire severity in fire management and policy.
Perhaps we discussed this before.. it doesn’t seem to me that you can generalize over all the western US; for example many areas were protected because they were roadless, they were roadless because they didn’t have commercial trees, or too steep to get to them, or high elevation and trees grew slowly.
Anyway it looks like they compared GAP classes
I tried to look at the maps but sadly am GIS-impaired. I did see this interesting note:
I can only imagine..poor USGS!
Baker’s findings that the area had “been treated, mostly through thinning or clear-cutting but occasionally prescribed burning, as far back as the 1970s” is not necessarily evidence that fuels reduction doesn’t work. This is because there is a high probability that most of the management actions they cite did not have fuels reduction as a goal. They should instead focus on projects that had fuels reduction as a stated purpose in the project plan. Fuels reduction did not become common until more recent decades.
I sincerely doubt the author is ignorant of this. If this is true, they are simply trying to incite further division on the subject in pursuit of their own political agenda.
It’s not too hard to find burned places that support your personal agenda, no matter what it is. The only way to ‘win’ is to use the site-specific conditions honestly. Most people don’t get to see all the trees that die AFTER the fire, during the next summer. I never see people talking about THOSE trees. It is always a significant amount.
I posted these Bootleg management history maps last year on the blog.
Matthew, thank you, I do remember. Here are the disconnects for me…
1. The second map says “logged or grazed” I don’t think anyone here is saying summer grazing has an influence on fire? Or exactly what is the connection that you or Oregon Wild sees?
2. Given that, map #1 might be helpful… except…I’m not sure how a satellite image can tell those things accurately.. FS records before 2013 might be useful. But it might not be FS, because it’s yellow and there might or might not be green underneath (?) formerly Weyco, now Diamond?.
Which circles back to what Tom Wenk worked on (maybe retirees could lead?) to get FS records digitized.
But, not to put too fine a point on it, the authors of the study are not exactly unbiased. So perhaps a larger mixed group could study it. But when I think on this, I wonder what would be the point? I don’t think people are going back to the old practices… we have what we have, what we need to decide is how to go forward. It seems more useful to characterize the pre-burn vegetation and see how it burned regardless of how it got that way.
“It seems more useful to characterize the pre-burn vegetation and see how it burned regardless of how it got that way.” Agree. And also how important pre-burn vegetation is as a factor determining how it burned.
Here is the latest on the topic from Chad Hanson and John Fielder:
“Moreover, the fundamental “overgrown forests” premise of the logging provisions in Build Back Better is being increasingly questioned by the scientific community. Most scientific studies that have specifically investigated the question of forest density and fire intensity, including the
largest and most comprehensive studies, have found that denser forests tend to burn less intensely when wildfires occur.”
https://www.denverpost.com/2022/01/11/marshall-fire-logging-forest-thinning-wildfire-opinion/
It surprises me that the science on this is not yet as clear as it could be, which promotes talking past each other. It would be nice if the new money available for fuels management isn’t spent on a particular location until this question is answered for that location.
“It would be nice if the new money available for fuels management isn’t spent on a particular location until this question is answered for that location.”
Complete agreement here. Site-specific conditions and a desired basal area should drive project design. Hopefully, economics might be of lesser importance, with more money available to do needed non-commercial work. Bundling non-commercial work into a commercial project is a way of leveraging that initial funding.
But the science that refute Hansen et al’s claims is very clear. For example, “Adapting western North American forests to climate change and wildfires: 10 common questions,” a paper we’ve discussed previously. It’s a review of the literature by 21 authors of “science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes.”
https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2433
“Science-based adaptation options include the use of managed wildfire, prescribed burning, and coupled mechanical thinning and prescribed burning as is consistent with land management allocations and forest conditions. Although some current models of fire management in wNA are averse to short-term risks and uncertainties, the long-term environmental, social, and cultural consequences of wildfire management primarily grounded in fire suppression are well documented, highlighting an urgency to invest in intentional forest management and restoration of active fire regimes.”
In his Denver Post op-ed, written with photographer John Fielder, Hanson writes that “the fundamental “overgrown forests” premise of the logging provisions in Build Back Better is being increasingly questioned by the scientific community. Most scientific studies that have specifically investigated the question of forest density and fire intensity, including the
largest and most comprehensive studies, have found that denser forests tend to burn less intensely when wildfires occur. This is true for forests that have not burned in nearly a century or more, and forests with the highest levels of environmental protection against tree removal. As
one recent study reported, denser, mature forests with high canopy cover “maintain cooler, more temperate microclimates and provide an insulating effect on temperatures”, which reduces fire intensity.”
“The scientific community”? “Most scientific studies”?
From the 10 Questions paper — note that Hanson is mentioned in the second paragraph:
“Evidence from a broad range of disciplines documents widespread, multi-regional 20th-century fire exclusion in interior forested landscapes of wNA (see a detailed reference list and discussion in Hagmann et al. 2021). Collectively, these studies reveal extensive changes in tree density, species and age composition, forest structure, and continuity of canopy and surface fuels. Forests that were once characterized by shifting patchworks of forest and nonforest vegetation (i.e., grasslands, woodlands, and shrublands) in the early 20th-century gradually became more continuously covered in forest and densely stocked with fuels (Fig. 4).
“However, for over two decades, a small fraction of the scientific literature has cast doubt on the inferences made from fire-scar based reconstructions and broader landscape-level assessments to suggest that estimates of low- to moderate-severity fire regimes from these studies are overstated. Hagmann et al. (in press) examine this counter-evidence in detail and identify critical flaws in reasoning and methodologies in original papers and subsequent re-application of these methods in numerous geographic areas. Subsequent research shows that studies relying on Williams and Baker (2011) methods for estimating historical tree densities and fire regimes overestimate tree densities and fire severity (see also Levine et al. 2017). Moreover, established tree-ring fire-scar methods more accurately reconstruct known fire occurrence and extent. Other studies, also based on the methods of Williams and Baker (2011), conflate reconstructed low-severity, high-frequency fire regimes with landscape homogeneity. These interpretations disregard critical ecosystem functions that were historically associated with unevenaged forests embedded in multi-level fine-, meso- and broad-scale landscapes. By extension, claims that low-severity fire regimes are overestimated then imply that large, high-severity fires were a regular occurrence prior to the era of European colonization. Such interpretations may lead to the conclusion that recent increases in high-severity fire are still within the historical range of variability, and that there is no need of restorative or adaptive treatments (Hanson and Odion 2014, Odion et al. 2014, Baker and Hanson 2017). “
Chad Hanson certainly shouldn’t be regarded as someone the science community would select to speak about what is the consensus in the science community.
I don’t think that “most” or close to “most” studies that have looked at density have found that denser forest burn less intensively. Yes, dense forests can burn less intensively than less dense forests, but the metric of density one is referring to must be defined. Basal Area is a measure of density, just as trees per acre is. Basal area is likely not a causal driver of wildfire intensity (the bole doesn’t burn in a fire and large trees have higher BA, but often lower crown base height). In contrast, TPA likely is a drive of fire intensity (small trees are better ladder fuels than big trees). Example, a stand with 250 sqft/acre of BA with 50 TPA will probably burn less intensively under the same abiotic conditions as a stand with 150 sqft/acre BA and 500 tpa, but which stand has a higher density?
I think it is much more appropriate to talk about wildfire risk in the context of surface, ladder, and canopy fuels. Simply addressing surface and ladder fuels will go a long way to reducing fire intensity. Removing trees larger than ladder fuels can be justified for other reasons, such as forest health.
I’d also like to point out that in some out of whack western forests (e.g., Sierra Nevada), BA is the one forest metric that is within the natural/historical range, the issue is the BA is all tied up in a lot of small trees and the TPA is way outside of the natural range. So, no treatment in such forests can actually achieve restoration metrics.
There seems to be plenty of consensus in Sierra Nevada thinning projects….. except for Hanson and company.
Some eco-groups seem unwilling to move the goalposts again. I highly doubt that new funds will lead to changes in project details. The 30″ diameter limit still remains, as does the clearcut ban. The science behind those policies is pretty strong, with an almost 30-year track record.
I think the idea was to take out the merchable trees and let the other trees grow up. Those times have changed. Now its clear cuts on private ground or thinning of the understory on federal lands, at least of the Westside here. I have heard of some small regen-harvesting on BLM ground.
I see the usuals are still promoting fire and opposing logging as a form of wildfire control. I just wish they might mention something we could do beside spending billions burning up our forests.
I wonder, when a wildfire becomes completely resistant to control due to extreme long-term drought and some wind, when an ember has over a 90% change of igniting a new fire, does any specific type of management, or management/non-management at all make a cost effective difference or; defining “difference” more broadly, do human efforts matter?
The photo in the article offers an answer. If fuel loading is low and ladder fuels at a minimum, an ember may start a fire, but it will likely be a low-intensity one, and will be easier to contain. Of course, high winds like the winds that drove the Bootleg and Dixie fires can render treatments moot, but that’s not justification for abandoning thinning and fuels reduction. Think of it this way: If you had a house on the coast of Florida, would you decide not to strengthen it to withstand hurricanes, since a Cat 5 hurricane would probably destroy it anyway? Maybe making the house more resilient would help it weather less powerful storms.