{"id":40240,"date":"2022-06-04T02:50:24","date_gmt":"2022-06-04T08:50:24","guid":{"rendered":"https:\/\/dh.durangoherald.com\/tj\/can-we-replace-fire-with-mechanical-thinning-in-southwest-colorado\/"},"modified":"2026-03-31T02:54:21","modified_gmt":"2026-03-31T08:54:21","slug":"can-we-replace-fire-with-mechanical-thinning-in-southwest-colorado","status":"publish","type":"post","link":"https:\/\/dh.durangoherald.com\/tj\/can-we-replace-fire-with-mechanical-thinning-in-southwest-colorado\/","title":{"rendered":"Can we replace fire with mechanical thinning in Southwest Colorado?"},"content":{"rendered":"\n

\"Colton
Colton McLaughlin with Telluride Fire Protection District uses a drip torch while spreading the Pine Tree Fire north of Arboles in 2019. The U.S. Forest Service is conducting a 90-day review of its prescribed burn policies and procedures after agency burns ignited a number of wildfires this spring. However, forest ecologists say fire is crucial for Southwest Colorado\u2019s mixed conifer and ponderosa forests. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n<\/p>

On Wednesday, the U.S. Forest Service\u2019s Grand Mesa, Uncompahgre and Gunnison national forests confirmed that a prescribed burn started the Simms Fire near Montrose, a 313-acre blaze that destroyed one home.<\/p>\n

Five days earlier, the agency announced that a U.S. Forest Service burn pile ignited New Mexico\u2019s Calf Canyon Fire on April 19, which then merged with the Hermits Peak Fire to form the largest wildfire in the state\u2019s history, destroying more than 350 homes.<\/p>\n

The Hermits Peak Fire erupted from a 1,200-acre Forest Service prescribed burn that escaped control near Las Vegas in north-central New Mexico.<\/p>\n

The spate of burn-induced wildfires led Forest Service Chief Randy Moore to suspend the agency\u2019s prescribed fire operations to conduct a 90-day review of its protocols and practices.<\/p>\n

Yet, amid renewed awareness of the risks of prescribed fire, forest ecologists and biologists say fire serves an irreplaceable role in Southwest Colorado\u2019s mixed conifer and ponderosa pine forests, and that limiting the use of fire would do more harm than good.<\/p>\n

\"A
A fire mitigation crew from the Durango Fire Protection District and the Dolores Fire Protection District thin brush from the Power Line Trail on the east side of Durango in 2020. While the U.S. Forest Service and other agencies use a combination of thinning and prescribed fire in their forest health and fire mitigation efforts, scientists say the two should not be conflated with thinning aimed at wildfire mitigation and prescribed fire toward forest restoration. (Jerry McBride\/Durango Herald file)<\/span>Jerry McBride\/Durango Herald<\/span><\/figcaption><\/figure>\n<\/p>

As agencies and initiatives increasingly employ both thinning and prescribed fire in the names of forest health and fire mitigation, scientists are drawing a line between the two and their benefits, even as climate change increasingly makes the application of fire more difficult.<\/p>\n

\u201cMechanical thinning is not so much to restore the forest, it\u2019s fuels mitigation,\u201d said Julie Korb, a professor of biology at Fort Lewis College who studies fire and forest ecology. \u201cThe key thing is to label (forest) treatments accordingly. Is our end goal fuels mitigation? Is it ecological restoration? Is it increasing habitat (and) species diversity? Is it increasing the function and the health of that ecosystem? Those are kind of the big questions that we need to look at.\u201d<\/p>\n

Two treatment techniques<\/div>\n

In its January report \u201cConfronting the Wildfire Crisis,\u201d the Forest Service called for renewed efforts tackling increasingly large and destructive wildfires and restoring forest health in the West.<\/p>\n

The Forest Service\u2019s new \u201cwildfire crisis strategy\u201d presented in the report includes the treatment of an additional 20 million acres of national forest land and 30 million acres of forest across other federal, state, tribal and private lands using a combination of thinning and prescribed fire.<\/p>\n

\"Andje
Andje Knopick, a seasonal wildland firefighter with Durango Fire Protection District, piles up Gambel oak that was thinned out on La Plata County land near Edgemont Highlands northeast of Durango in September. According to the Forest Service, thinning can benefit forests by recreating their natural structures through the regulation of density, age and species distribution. (Jerry McBride\/Durango Herald file)<\/span>cca<\/span><\/figcaption><\/figure>\n<\/p>

But according to forest ecologists and biologists, the two techniques of prescribed fire and thinning should not be conflated.<\/p>\n

Thinning is often separated into two categories \u2013 hand thinning and mechanical thinning. In hand thinning, crews use chain saws to cut down trees, selecting them based on things like tree size and density.<\/p>\n

Mechanical thinning attempts to do the same thing but relies on machines such as feller bunchers, which look like excavators with a large sawing attachment to quickly cut trees. In mechanical thinning, scale and economics are often more of an imperative.<\/p>\n

According to the Forest Service, thinning can benefit forests by recreating their natural structures through the regulation of density, age and species distribution. Doing so reduces stress on trees and makes them less susceptible to disease and insects like bark beetles.<\/p>\n

But thinning, particularly mechanical thinning, can also affect forests by encouraging the growth of nonnative species and compacting soil if not done with care.<\/p>\n

\u201cPrescribed burning has very minimal soil disturbance, whereas some of the mechanical treatments can actually have pretty widespread soil disturbance,\u201d said Michael Remke, a lecturer of biology at FLC, who specializes in forest and soil ecology.<\/p>\n

\"New
New growth in the Brockover Prescribed Fire in the Turkey Springs area west of Pagosa Springs after about a month in June 2021. Fire returns nutrients to the soil, creates habitat and spurs regrowth keeping forests \u201chealthy.\u201d (Jerry McBride\/Durango Herald file)<\/span>Jerry McBride<\/span><\/figcaption><\/figure>\n<\/p>

Prescribed fire can also be broken down into two types. As the name suggests, pile burning involves the ignition of collected and previously cut vegetation, while broadcast burning is what one thinks of when they see wildland firefighters igniting a controlled blaze with a drip torch.<\/p>\n

In Southwest Colorado\u2019s fire-adapted mixed conifer and ponderosa forests, prescribed fire and naturally occurring wildfires have a number of benefits that thinning cannot replicate.<\/p>\n

Fires recycle nutrients like nitrogen by expediting the decomposition of plants and trees.<\/p>\n

\u201cAll fire is rapid decomposition, so all those nutrients that are bound in plants and trees and needles then breakdown from the fire and you get these big nitrogen pulses,\u201d Korb said. \u201cYou take nitrogen that\u2019s unavailable to plants and you make it available as forms of ammonium and nitrate. It\u2019s just like people do with their garden that they have to work the soil (and) add nutrients to it and that\u2019s what fire does.\u201d<\/p>\n

Fire creates habitat and spurs regrowth. Trees that are left dead or fallen serve as habitat for birds and small mammals while also providing shade for tree seedlings to grow, Remke said.<\/p>\n

Fire also allows forest managers to treat forests more quickly and at larger scales.<\/p>\n

But perhaps the most important advantage of fire is its ability to naturally restore the diversity of forest ecosystems, what scientists call \u201cheterogeneity.\u201d<\/p>\n

\"The
The Brockover Prescribed Fire in the Turkey Springs area west of Pagosa Springs that was conducted in May 2021 killed some trees while others survived to drop their brown needles and regrow new needles later. Though forest managers attempt to replicate that process with thinning, the complexities of mixed conifer and ponderosa pine ecosystems, which have evolved with fire over eons, make it difficult if not impossible to replace fire. (Jerry McBride\/Durango Herald file)<\/span>cca<\/span><\/figcaption><\/figure>\n<\/p>

Forests vary according to local terrain and climates with differences in moisture, sunlight and soil, among others, determining the tree and plant species that could thrive there. That diversity made forests more resilient to wildfires, insects and pests.<\/p>\n

Fires historically regulated that diversity by disturbing the forest and resetting the distribution of trees and plants.<\/p>\n

Though forest managers attempt to replicate that process with thinning, the complexities of mixed conifer and ponderosa pine ecosystems, which have evolved with fire over eons, make it difficult if not impossible to replace fire.<\/p>\n

\u201cThe reason why ecologists want fire back in those systems is because when we talk about ecological restoration we talk about restoring ecosystems structure and function,\u201d Korb said. \u201cIn order to return the function of that ecosystem, you need to have fire as part of that management plan.\u201d<\/p>\n

Forest restoration versus wildfire mitigation<\/div>\n

At its core, the debate between thinning and prescribed fire is one of purpose.<\/p>\n

Thinning can achieve what it is intended to do, which is reduce wildfire risk, but it cannot be a replacement for fire and does not address forest restoration, said Bill Baker, an emeritus professor of ecology at the University of Wyoming who wrote the book \u201cFire Ecology in Rocky Mountain Landscapes.\u201d<\/p>\n

\u201cIf the goal is restoration, the problem mechanical thinning has is that we don\u2019t have a very good understanding of what those forests really looked like, historically,\u201d he said.<\/p>\n

Ecologists believe that mixed conifer and ponderosa pine forests evolved a particular organization called the \u201cICO structure.\u201d ICO stands for individual, clumps and openings, meaning that forests evolved to have areas with gaps between individual trees, areas where trees of different sizes were clumped closely together and openings where there were no trees.<\/p>\n

That structure represented a \u201chealthy\u201d forest.<\/p>\n

But after European colonization and the drastic reshaping of the West\u2019s forests, in part for timber production, ecologists and forest managers have little sense of what that looked like locally in Southwest Colorado\u2019s forests.<\/p>\n

\"Fred
Fred Ellis, assistant fire management officer with the Pagosa Ranger District in the San Juan National Forest, examines new growth from the Brockover Prescribed Fire near Pagosa Springs in June 2021. Historically, fire has helped to determine the organization of Southwest Colorado\u2019s forests, creating the \u201cICO structure,\u201d which stands for individual, clumps and openings. (Jerry McBride\/Durango Herald file)<\/span>Jerry McBride<\/span><\/figcaption><\/figure>\n<\/p>

\u201cThere\u2019s no question that mechanical thinning has a lot of problems in terms of just recreating that (ICO structure), because first of all we don\u2019t know much about the details of it,\u201d Baker said.<\/p>\n

Conversely, fire underpinned those forest ecosystems, so reintroducing fire will help them to revert to their historic structure and \u201crestore\u201d them, Baker said.<\/p>\n

With cautious hand thinning and mechanical treatments, forest managers can replicate some of the effects of fire, however, it\u2019s more difficult to do so.<\/p>\n

\u201cIt just takes more intentionality and effort to create that variability that a fire naturally does on itself,\u201d Remke said.<\/p>\n

Remke argues that limited intervention in wildfires when possible can often do the most good for restoring forests. He pointed to the 416 Fire, which achieved many of the outcomes that ecologists and forest managers would want, including creating openings and restructuring tree density.<\/p>\n

\u201cWe don\u2019t always need interventions for forest health,\u201d he said. \u201cEven though it sometimes seems like the most appropriate conservation tool is to intervene, I would say stepping back and recognizing that forest processes have operated in these ways for a long time can also be a really effective conservation tool.\u201d<\/p>\n

For Remke, Baker and Korb, there is simply no replacement for using fire.<\/p>\n

\u201cAll we have to do is reintroduce it (and) put it back in these forests and over time they will revert back to this (ICO) structure,\u201d Baker said. \u201cIt may take decades, but it is essentially the force that structured them originally and it will do it again.<\/p>\n

\u201cWe\u2019re much more likely to be able to restore these forests in a way that will allow them to persist if we use the natural force, which is fire, to reset them and restore them.\u201d<\/p>\n

\"The
The area on the left side of the road shows the effects of the Brockover Prescribed Fire in the Turkey Springs area west of Pagosa Springs conducted last year. Fire naturally restores forests in a way that thinning struggles to replicate, said Bill Baker, an emeritus professor of ecology at the University of Wyoming, who wrote the book \u201cFire Ecology in Rocky Mountain Landscapes.\u201d (Jerry McBride\/Durango Herald file)<\/span>cca<\/span><\/figcaption><\/figure>\n<\/p>
The challenges of fire<\/div>\n

When Moore announced the Forest Service\u2019s burn pause, Colorado\u2019s 3rd Congressional District Rep. Lauren Boebert immediately criticized the decision, saying the suspension of prescribed fire would harm Colorado\u2019s rural communities.<\/p>\n

According to Moore\u2019s news release, 99.84% of the agency\u2019s prescribed burns are successful and safe, but more than 90% are conducted between September and May.<\/p>\n

That\u2019s in part because of safety concerns.<\/p>\n

Forest managers do not perform prescribed burns when the weather is too hot, conditions are too dry or firefighting resources are insufficient. The Bureau of Land Management postponed the prescribed burn on Animas City Mountain north of Durango this spring because of dry and windy conditions that made burning risky.<\/p>\n

\u201cWe only use fire when it\u2019s safe for the public and for the resource,\u201d said Scott Owen, spokesman for San Juan National Forest. \u201cAnd we honestly haven\u2019t had many days where it is safe for us to do prescribed burning over the last couple years.<\/p>\n

\u201cWe want to make sure that we\u2019re able to contain that fire no matter what, and we don\u2019t ever want to put the public in a situation where it escapes,\u201d he said.<\/p>\n

Yet, according to Remke, Baker and Korb, forest managers and the communities they serve need to discuss how thinning and prescribed burns and the issue of forest health fit into safety, especially as climate change makes it increasingly difficult to carry out prescribed burns and exacerbates wildfires.<\/p>\n

A study published last month in the journal Science of the Total Environment<\/em> found that the window for prescribed burns in the winter and spring was decreasing by one day per year in parts of California.<\/p>\n

\"A
A prescribed burn in the Yellow Jacket area in 2018 slowly moves through Gambel oak and mixed conifer forest several miles east of Bayfield and south of U.S. Highway 160. While forest ecologists tout the benefits of fire, it can be difficult for forest managers to use fire in forest management because of safety concerns. Climate change is increasingly limiting opportunities for public land agencies to conduct prescribed burns. (Jerry McBride\/Durango Herald file)<\/span>Jerry McBride\/Durango Herald<\/span><\/figcaption><\/figure>\n<\/p>

A significant body of research also suggests that climate change is already making wildfires larger, more frequent and more severe, and will continue to do so.<\/p>\n

\u201cIf there\u2019s anything that we can expect right now, it\u2019s more fire and that means that fire preparedness and (our) readiness to accept fire on the landscape needs to be higher than it\u2019s ever been before,\u201d Remke said.<\/p>\n

Thinning can be an important tool in the wildand urban interface, or WUI, where fires are started most frequently and can be most destructive for communities, Korb said. The hope is that the thinning changes fire behavior and in doing so mitigates some of the risk to communities.<\/p>\n

However, Baker is less sure that thinning will have its intended effect as climate change continues to dry out Southwest Colorado\u2019s forests.<\/p>\n

\u201cPart of the problem is that as the fuels dry out, they become more available to participate in the burn,\u201d he said. \u201cEven though you maybe reduced the amount of fuel (through thinning), you still have fuel there. If all of it becomes available to burn because it\u2019s dried out, you still can have quite a blaze.\u201d<\/p>\n

\"Firefighters
Firefighters watch the Brockover Prescribed Fire which burned in May 2021. Using prescribed fire is \u201clike being a lion tamer,\u201d said Bill Baker, an emeritus professor of ecology at the University of Wyoming who wrote the book \u201cFire Ecology in Rocky Mountain Landscapes.\u201d However, it is important for the health and resiliency of Southwest Colorado\u2019s forests. (Durango Herald file)<\/span>cca<\/span><\/figcaption><\/figure>\n<\/p>

Prescribed fire, as a driver of natural selection, is the best way to increase community resiliency against wildfires, Baker said.<\/p>\n

\u201cThe argument has been made, and I think this is a very sound argument, that it\u2019s much better to use fire to restore these forests because future forests need to be adapted to more fire,\u201d he said. \u201cFire is the force that can right now go through and select the trees that are unlikely to be able to survive future fire. We can\u2019t do that mechanically.\u201d<\/p>\n

After a spring in which prescribed fires have started multiple fires, forest managers and communities in Southwest Colorado must decide what risks they are willing to take and the role they envision for fire in restoring forests and creating resilient communities.<\/p>\n

\u201cIt\u2019s like being a lion tamer,\u201d Baker said. \u201cFire is a huge, dangerous force that really can cause a lot of damage to people and infrastructure, but we\u2019re going to have more fire so we can make some choices about it.\u201d<\/p>\n

ahannon@durangoherald.com<\/a><\/em><\/p>\n

\"A
A controlled burn in 2016 in Fosset Gulch east of Bayfield shows how the fire reduced the oak brush and burned the smaller trees reducing the threat of a crowning fire. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n
\"The
The right side of the road going through Fosset Gulch east of Bayfield shows the result of a prescribed burn in 2016. The other side, which was not burned, has more brush and trees. The prescribed burn is meant to mimic the natural cycle of low-level fire in the forest. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n
\"Chris
Chris Swift of Swift Creek Brush Cutters uses a masticator to clear brush in the Elk Springs Ranch subdivision. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n
\"Without
Without adequate thinning of overstocked forests, catastrophic wildfires can occur like the Missionary Ridge Fire of 2002, which burned so intense at times it created firestorms \u2013 or in other words, generated its own weather. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n
\"With
With their thick bark, ponderosas can resist ground-crawling wildfires and prescribed burns. These types of fires clear the forest of brush and small trees that act as ladder fuels, which allow fires to climb into the forest canopy and create more intense fires. (Jerry McBride\/Durango Herald file)<\/span>du1-i-syn<\/span><\/figcaption><\/figure>\n<\/p>","protected":false},"excerpt":{"rendered":"

ecologists argue prescribed burns are necessary even as they have caused blazes this spring<\/p>\n","protected":false},"author":1,"featured_media":40241,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[2838,2570,120,350,2487,918,1712,132,28,1613,3468,476,1290,445,2582,199,145,358,498,549,84],"naviga_topic":[],"class_list":["post-40240","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","tag-416-fire","tag-biology","tag-colorado","tag-fire","tag-forestry-and-timber","tag-forests","tag-forests-and-wilderness","tag-fort-lewis-college","tag-headlines","tag-natural-disasters","tag-natural-resources","tag-natural-resources-general","tag-natural-science","tag-newsletter-lead","tag-research","tag-san-juan-national-forest","tag-science-general","tag-science-and-technology","tag-southwest-natural-resources","tag-united-states-forest-service","tag-wildfire"],"acf":[],"author_name":"dh_admin","_links":{"self":[{"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/posts\/40240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/comments?post=40240"}],"version-history":[{"count":1,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/posts\/40240\/revisions"}],"predecessor-version":[{"id":84592,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/posts\/40240\/revisions\/84592"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/media\/40241"}],"wp:attachment":[{"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/media?parent=40240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/categories?post=40240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/tags?post=40240"},{"taxonomy":"naviga_topic","embeddable":true,"href":"https:\/\/dh.durangoherald.com\/tj\/wp-json\/wp\/v2\/naviga_topic?post=40240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}