​Many of our forest types in the southwestern US burned at high frequency before land-use change (e.g. heavy grazing in the mid-1800s) and fire suppression (starting in the early 1900s) excluded fire from these ecosystems. A couple of wet periods in the early 1900s and lots of tree regeneration led to the dense forest conditions we see today that are capable of sustaining stand-replacing wildfire.

Research dating back to the 1970s has shown that excluding fire from these forests was a problem and we have known with lots of confidence since the 1990s that reducing tree density and the amount of dead vegetation in the forest is central to reducing the chance of these high-severity, stand-replacing wildfires. Forest managers used this research to design thinning and prescribed burning treatments to accomplish the goal of restoring fire and decreasing high-severity fire risk, but the pace and scale at which treatments were being implemented was not sufficient given the amount of forest requiring restoration.
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Meanwhile, forest managers on the Gila National Forest and Yosemite and Sequoia-Kings Canyon National Parks started working to manage naturally occurring fires to restore the system. They did this in the backcountry where there was less chance of the fire causing harm to humans and their objective was to do this when weather and moisture conditions would allow the fire to burn in a way that is beneficial to restoring the forest.

While this was happening, many people (myself included) were advocating for more funding to land management agencies to accomplish more forest restoration. Fast forward to 2020 and Congress appropriated a significant amount of money for forest restoration. Yet, the scale of the problem means that there still is not enough money to restore all of the forest using thinning and prescribed burning. I did a back-of-the-envelope calculation after the legislation passed and estimated that if you wanted to thin and prescribed burn every acre of forest on the Santa Fe National Forest that used to burn regularly, it would cost over $1 billion. There is no way we are going to make that level of investment.

There are all kinds of other things that make thinning and burning treatments slow to implement and costly, too. The simple economics of having to pay to thin the trees because they are small diameter and wood products are cheaper to make from trees grown in productive places can mean thinning costs of $2500 per acre. Then there is the NEPA planning process and the surveys for archaeological sites and endangered species that are required before work can begin. Both take time and cost money. Meanwhile, if a lightening strike or camp fire starts a wildfire, land management agencies can mobilize tons of resources (billions of dollars per year) and suppress the fire. Big fires means bulldozers and dropping retardant from airplanes and all sorts of other things without any sort of environmental assessment. The punchline here is that the best thing we can do for the ecology of our fire-prone forests is to restore fire that helps maintain the system so we don’t need to mobilize suppression forces and fight against this process at all costs.

Escape prescribed fire
Restoring fire to forests is not without risk and we have to acknowledge the impacts of the Calf Canyon-Hermits Peak wildfire on the communities and ecosystems of northern New Mexico during spring 2022. My colleagues and I wrote a number of op-eds during the 2022 fire season and you can read those here:
Use all the tools - including fire
Use all the tools to improve forest health
Prescribed burning can work

Increasing the pace and scale
The other tool that forest managers have is choosing a different management approach when a lightning-caused fire starts. When a so-called natural ignition happens and weather and vegetation moisture conditions are right and the risks to things of value are low, managers can do what the Gila National Forest and Yosemite and Sequoia-Kings Canyon National Parks have been doing for decades – they can manage that fire to benefit the ecosystem. Federal policy has called it many things over the years. The most recent incarnation is called managing fire for resource benefit. Much to the chagrin of the higher-ups in land management agencies, everyone else calls it managed wildfire. No one has ever accused a big bureaucracy for choosing clear terminology to describe their actions.

Managed wildfire can accomplish the objectives of thinning and burning, but at a much larger scale and, typically, a much lower per acre cost. There is a huge misunderstanding in the public about managed fire and I will use the Comanche Fire, which I toured on 6 July, as a case study to explain managed fire in this post.

We here in the southwest have chosen to live in and depend upon flammable landscapes. Even if you live in the city, the water that flows out of your tap is coming from a watershed that is covered in fire-prone forest. It is our responsibility to learn about fire in our landscapes and contribute to helping reduce the risks posed by our past societal choices. We need to prepare our homes and ourselves for what this means and use the resources available to prepare.

A couple of resources for living in flammable landscapes:
How to prepare your home
How to construct an inexpensive air filter

The Earth Systems Ecology Lab (www.hurteaulab.org) at the University of New Mexico is recruiting a postdoctoral researcher with a strong background in ecosystem modeling or spatial data analysis to contribute to a project aimed at understanding the interaction of climate change and disturbance impacts on western US forest ecosystems. 

The initial appointment is for one year (beginning summer/fall 2023), with the possibility of extension.  Salary is $60,000-63,000 per year, plus benefits.  Required qualifications include a PhD in ecology, ecosystem science, earth/environmental sciences, or statistics and programming experience with R.  Also, given the current backlog for obtaining a visa, applicants are required to be eligible to work in the US. Preferred qualifications include programming in C+ or C# and willingness to occasionally participate in field sampling.

Applicants should submit a cover letter detailing research interests and goals, a complete CV, and names and contact information for three references to Matthew Hurteau ([email protected]).  Review of applications will begin on 7 JULY 2023.

The University of New Mexico is committed to hiring and retaining a diverse workforce.  We are an Equal Opportunity Employer, making decisions without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, veteran status, disability, or any other protected class.

There has been much consternation over a statement from the Carson National Forest about wind on its own not being a concern in the context of a prescribed fire. It was a poorly worded statement given the Calf Canyon/Hermits Peak fire from last year and the impacts it had on many communities in northern New Mexico. However, it was correct. In this post I’m going to explain why the statement is correct and then I’m going to provide some information about how there is no future where our state is not flammable. I hope this helps people understand the decision-making in prescribed burning a bit more and that managing fuels is the only tool we have for managing wildfire risk at the local level. There are a number of good sources of non-technical information available if you want to learn more. You can check the outreach page on this website, the Southwest Fire Science Consortium, and the New Mexico Forest and Watershed Restoration Institute websites. When you live in a flammable landscape, you have to be part of the solution when it comes to managing the risk to your home, your community, and your watershed.

Dr. Michael Gollner, a fire researcher at UC Berkeley, responded with the fire triangle which really encapsulates why the statement about wind was correct:

The relationship between weather, topography, and fuels determine if and how a fire burns when an ignition occurs. When it is hot, dry and windy, fire spreads faster than when it is only hot, only dry, or only windy. Fire spreads uphill faster than it spreads downhill or on flat ground in the absence of wind. Fuel and fuel moisture are a key ingredient of the fire triangle and determining the flammability of a given patch of ground. If there is no fuel or the fuel is discontinuous, there is no fire spread. When fire managers conduct a prescribed fire or backburn on a wildfire they are reducing or eliminating the amount of fuel available for combustion, which will slow or stop any subsequent fire spread. Fuel is the only part of the fire triangle that we can manage to reduce risks to communities and watersheds.

The amount of water stored in live and dead plants and the soil is a regulating factor on the flammability of the vegetation. If you have ever tried to start a campfire with wet wood, you know that no matter how much you blow on it the fire will not start. That is why “Wind on its own is not a concern.” is a factually correct statement. When planning a prescribed fire, the prescription that the fire manager writes lays out ranges of acceptable values for things like wind speed, fuel moisture, temperature, etc. That does not mean that if all of these factors are within the ranges specified in the prescription that it is safe to burn or even possible to burn. For example, if wind is at the upper end of the prescription range, fuel moisture is at the lower end, and temperature is at the upper end, these factors are working together to make the system more flammable. But, if the opposite is true for each of those factors, it will may be hard to get the system to burn. The point is that these factors all have to be considered in the context of each other. Throw in topography (is it flat or hilly) and the weather forecast (is it forecast to be wet, dry, etc) and there are many things can influence if and how fire burns. While I can certainly see why people living in northern New Mexico would be concerned by this poorly contextualized statement about wind, I hope this explanation helps them understand why it is an accurate statement and why all of these factors need to be considered simultaneously.

It is important that all of us that live in flammable landscapes educate ourselves about the role of fire in these systems and understand the risks associated with living in a flammable environment. I’ve seen people calling for putting a stop to prescribed burning. There was legislation introduced in New Mexico during this past session to ban spring burning. These are not solutions to the problems we face because our forests are already flammable and they are becoming more flammable with increasing climate change. We spend billions of dollars every year on fire suppression and we still have wildfires that burn over communities. No matter how much money we spend, we cannot prevent or stop all fires.

If we go back to the fire triangle:

The only leg that we have local control over is the fuels leg. Live vegetation stores tons of water and is only available to burn under the most extreme conditions and, even then, very little of the total amount of live fuel will be combusted. On the other hand, dead vegetation is available to burn every year during fire season in New Mexico. Because we have excluded fires from our forests for as much as 100 years, there is a large amount of dead vegetation in our forests. These dead fuels dry out fast, a process that is occurring earlier in the spring because of higher temperatures and winter snow drought. The only economically viable and ecologically appropriate way to deal with these dead fuels is with prescribed fire or managing wildfires when weather conditions allow. At the same time, high temperatures and persistent drought is killing more trees and adding to this fuel, which means that fire managers are having to manage a transition to landscapes that can support fewer trees because of changing climate. Again, the only viable tool to manage this transition at the landscape scale is fire.

I completely understand that people are concerned about prescribed fire and the USFS doesn’t help the situation when they communicate ineffectively. But, that doesn’t change the fact that our landscapes are primed to burn because of a warming and drying climate and, because we have excluded fire for so long, they are primed to burn hot. Prescribed burning and managing lightening strikes when the weather is benign are certainly not without risk. We’ve learned that twice in northern New Mexico in the past 21 years. However, it is important not to overstate the risks of escaped prescribed fires and understate the risk that wildfires pose to our communities and ecosystems.