Fire deficit increases the wildfire risk around communities in the Canadian boreal forest

The 8th International Fire Ecology and Management Congress, hosted by the Association for Fire Ecology had a remarkable special session “Fire in the Last Frontier: 21st Century Fire Patterns, Behavior, and Pyroecology of North American Boreal Forests and Tundra”. The Alaska Fire Science Consortium would like to highlight a few of these presentations.

Marc-André Parisien, of the Canadian Forest Service gave a presentation that addressed the effects of fire suppression on communities in boreal Canada.

Decades of fire suppression have resulted in a fire deficit around many communities in boreal Canada. Although human ignitions are 50 times more frequent within 5 km of a village, the percent of area burned within 30 years was 5-15% less around the village than in the surrounding Fire Management Zone.

“Suppression activities can offset the increased fire likelihood… until they don’t”

Since recently burned areas provide some moderation to new fire entry (especially under normal weather conditions), Parisien concludes fire suppression is increasing the risk around communities.

As an example, the 2016 Fort McMurray (top-right panel of figure) fire had only 2% recently burned-forests (pre-fire RBF) within 25 km. This is a much lower area of recently burned forests compared to an average of 42% in areas of the same fire regime zone (FRZ). After the explosive 2016 fire event, the forested area around town was 70% burned (post-fire RBF).


What’s the solution? Letting wildfire enter the WUI is risky business for managers, and prescribed fires create a lot of smoke and may be complicated by overlapping land ownership. One possibility is biomass utilization projects, which are being tapped by some communities in Canada and Alaska (Erni et al., 2017).

Want to learn more? The full presentation can be viewed here:


Parisien, M-A., Q. Barber, K. Hirsch, C. Stockdale, S. Erni, X. Wang, D. Arseneault, and S. Parks. 2019. Fire deficit increases the wildfire risk around communities in the Canadian boreal forest. Lecture at the 8th International Fire Ecology and Management Congress.  (This research is being prepared for publication).

Erni, S., D. Arseneault, and M.-A. Parisien. 2018. Stand age influence on potential wildfire ignition and spread in the boreal forest of northeastern CanadaEcosystems 21, 1471–1486.

Erni, S., D. Arseneault, M.-A. Parisien, and Y. Begin. 2017. Spatial and temporal dimensions of fire activity in the fire‐prone eastern Canadian taiga. Global Change Biology 23:1152–1166. (Firescar study of reconstructed 300 years of fire activity in Quebec to examine relative effects of climate/ weather vs. forest age controls on fire activity. In younger stands, burn rate was lower for up to 50 years, depending on landscape).

Will Forest Change Counteract Climate-Driven Increase in Fire?

At the 2019 Fall Fire Science Workshop, we had a great presentation by Jill Johnstone on the concept of fire self-regulation in the boreal forest*.  This theory holds that as fire becomes more frequent and/or severe, spruce forests will increasingly convert to mixed and deciduous forests and provide negative feedback to burn extent even as the climate warms.

Hotspotting in Hardwoods

Fire A121, 2008, Midnight Sun Hotshots fight a fire in Alaska paper birch. (D. Jandt)

As you heard there, Jill is spearheading an effort to do a synthesis of findings of many studies in AK/Canada. At last week’s Association of Fire Ecology (AFE) Congress meeting, team member Xanthe Walker shared preliminary findings of the search for evidence of the effects of stand age and alternative vegetation types on probability of burning.  Do fires seem to “prefer” or “avoid” areas which burned in recent history?  In short, several studies across Canada, and a couple from Alaska, provide evidence for some level of self-regulation.  That begs the question:  how important are fuels vs. weather?  Will the self-regulation effect be enough to moderate the influence of higher fire indices in the future on acres burned?

Recall that fairly rigid self-regulatory feedbacks were programmed into the Boreal ALFRESCO model that has been used by Rupp, Duffy, Shultz, and others to build scenarios for Alaska’s land managers on how much burning will occur in the future and how much that will cost in suppression effort.  (See Implications of Climate and Management Options on Wildland Fire in Alaska: Exploring Future Fire Scenarios, a presentation by Courtney Schultz and Tait Rutherford at the 2017 Alaska Fall Fire Science Workshop, October 10, 2017.)  But, can we count on this?  Xanthe’s presentation (which AFSC recorded at the meeting and will soon be posting for you on our Vimeo site) concluded there will be SOME moderation of increased burning but also that these fuel effects can be overwhelmed by weather.  The latter is no surprise to fire practitioners in Alaska, i.e. young stands burn in extreme fire years and deciduous stand burn more during drought years. Quantifying this effect is what we need, and some good studies are starting to emerge.  Across the North American boreal forest, it appears that the strongest self-regulation occurs when weather is not extreme and where deciduous forests dominate to begin with.  It’s great to have a start on the answer to our burning questions about re-burn—there is clearly more to discover and we’re tickled to have this power-house team of researchers working on the problem.  You better believe we’ll be keeping in touch and watching for their publications.  We’re also happy they have welcomed the participation of agency fire ecologists and other local practitioners into the studies, because folks in the field have a lot to bring to the observational table.

*See Fire Self-Regulation, Evaluating the Current State of Understanding from Published Studies Presented by: Jill Johnstone, University of Alaska Fairbanks and University of Saskatchewan at the October 2019 AWFCG Fall Fire Review

List of selected citations used in Walker presentation: 

Beverly, J. L. 2017. Time since prior wildfire affects subsequent fire containment in black spruce. International Journal of Wildland Fire 26:919–929.  (Assesses whether stand age of black spruce forests has a detectable effect on the success of initial attack on fires <2 ha size in Alberta.)

Boulanger, Y. et al. 2017.  Changes in mean forest age in Canada’s forests could limit future increases in area burned but compromise potential harvestable conifer volumes. Canadian Journal of Forest Research 47(6): 755-764. (Modeled fire occurrence in the face of climate change with inclusion of self-regulation due to vegetation change across fire regimes of Canada.  Self-regulation substantially moderated the climate-driven fire increases but did not fully compensate for it – so fire activity will still increase even with the inclusion of these feedbacks).

Dash, C. B., J. M. Fraterrigo, and F. S. Hu. 2016. Land cover influences boreal-forest fire responses to climate change: geospatial analysis of historical records from Alaska. Landscape Ecology 31:1781–1793. (Large fires had a greater proportion of conifer forests than small fires, suggesting preferential rapid fire spread in conifer forests, but the effect of land cover on burning is less in years with extreme fire weather, when vegetation types burn at a rate close to that expected in the random model.)

Erni, S., D. Arseneault, M.-A. Parisien, and Y. Begin. 2017. Spatial and temporal dimensions of fire activity in the fire‐prone eastern Canadian taiga. Global Change Biology 23:1152–1166. (Firescar study of reconstructed 300 years of fire activity in Quebec to examine relative effects of climate/ weather vs. forest age controls on fire activity. In younger stands, burn rate was lower for up to 50 years, depending on landscape).

Hely, C., M. D. Flannigan, Y. Bergeron, and D. J. McRae. 2001. Role of vegetation and weather on fire behavior in the Canadian mixedwood boreal forest using two fire behavior prediction systems. Canadian Journal of Forest Research, v. 31, no. 3, p. 430-441.  (Compared FBP and Behave performance in boreal mixedwood in Quebec.  Although weather was overall more influential than fuel type, expected ROS was lower in deciduous that coniferous stands, and FBP performed better than Behave in this fueltype).

Parks, S. A., M.-A. Parisien, C. Miller, L. M. Holsinger, and L. S. Baggett. 2018. Fine-scale spatial climate variation and drought mediate the likelihood of reburning. Ecological Applications 28:573–586. (Fire spread was retarded by presence of previous fires for about 33 years in Wood Buffalo Park, Alberta, but the drought reduced the self-limiting effect of previous fire).


Fire management adaptability in Alaska: as seen by the managers

Tait Rutherford and Courtney Shultz just published the results from the social science part of their Joint Fire Science Program (JFSP) funded study: Impacts of Climate and Management Options on Wildland Fire Fighting in Alaska—see full citation below. The paper seeks to understand strengths and weaknesses of the Alaska fire management process and how cooperating agencies are adapting to changes in the fire environment with warming climate. The data for the analysis came from 41 hour-long interviews with fire management decision-makers across Alaska, which were categorized and analyzed for common themes.

The authors note that “bridging” institutions can be “repurposed to meet new challenges” and can provide key assistance to more hierarchical federal and state agencies in adapting to new issues (including climate change). Examples of this in action at the national level were on display at the recent meeting of JFSP regional Fire Science Exchange Networks in Washington, DC. It was interesting how diverse the main business lines were in different regions. For example, Hawaii’s Pacific Fire Exchange focuses mainly on community protection and invasive species, several exchanges are deeply engaged in supporting training and workforce development to implement prescribed burns, and California Fire Science Consortium is gearing up efforts to help those already stricken by wildfire and looking into new closer working relationships with FEMA. Another example of “bridging” mentioned by several interviewees in Alaska was the Kenai Peninsula All-Lands All-Hands working group, which has been very instrumental in coordinating inter-agency fuelbreaks.

Rutherford, in summarizing manager’s views, notes that some challenges are enduring (like WUI protection) but a few emerging issues are also highlighted. For example, regarding subsistence use opportunities, participants indicated that the maintenance of wildlife habitat will require both using fire and fire suppression to support a diversity of age classes and forest cover types on the landscape. There is a growing recognition of the need for enhanced policy and management tools to support “point protection” of values like private lands and cabins, including improved data and interagency communication and efficient protection techniques. In short, the collection of viewpoints is very instructive about the “state of the art” of fire management as seen by the experts and executors of that art. A highlight of the paper is the Appendix, which includes 64 quotes from the interviews, allowing one to hear “from the horse’s mouth” about current priorities and challenges in Alaska fire management as well as potential future directions and requirements to meet new challenges.

Citation:  Rutherford, T. K., and C. A. Schultz. 2019. Adapting wildland fire governance to climate change in Alaska. Ecology and Society 24(1):27.

Download is Open Access at:


Building a Better Mousetrap to Estimate Dead Grass Fuel Moisture

Who says you can’t build a better mousetrap?  Local BLM Alaska Fire Service ecologist Eric Miller recently published a study using his extensive data on dead grass fuel moisture in Alaska to compare the performance of several models to predict moisture content from environmental variables.  Currently, Van Wagner’s (1969) model, with tweaks and add-on’s, is used in the Canadian Forest Fire Danger Rating System fire weather indices.  Eric notes that statistically Van Wagner’s model is overly complex, and at least 3 models used in industry or other processes that account for ambient temperature and relative humidity (or alternatively, dewpoint depression) can model standing dead grass fuel moisture in Alaska pretty well.  Fuel moisture content is integral to fire behavior prediction and fire danger ratings, and the reason standing dead grass moisture content can be predicted so reliably is that its thin structure and aeration keeps it very close to equilibrium with atmospheric moisture.  The drying lag time may be even less than 1 hour, although it is often referred to as a “1-hour lag time” fire fuel.  Eric’s working on some applications of his findings for the spring prescribed fire season in Alaska’s military land holdings.  Check out the paper:  Miller, Eric A. 2019. Moisture Sorption Models for Fuel Beds of Standing Dead Grass in Alaska. MDPI Fire 2(2):1-18.

Eric has several tools available for practitioners in Alaska on his website:,  including simple rules-of-thumb and CFFDRS calculators for fuel moisture content.  These are partially described in a 2015 AFSC Research Brief What is the moisture content of standing dead grass?


Research Brief on What NASA is Contributing to Alaska Fire Science

Capture-thumbRB2018-4It’s hard to keep up with the myriad investigations NASA ABoVE campaign is working on in Alaska.  This short research brief is a round-up of recently published fire effects field studies and remote sensing products research and has some LINKS to show you where to access some intriguing new datasets and project results.  The “Big Data” coming from ABoVE is going to be a big boost to conducting regional or state-wide fire trends and assessments–you’ll want to know where that data lives. Access the Research Brief at:

Why Alaska Fire Potential Assessments are Different

There are at least 5 important factors that lead Alaska fire managers to continue their use of the Canadian CFFDRS system of fire danger and fire behavior tools for fire potential assessments in Alaska.  Fire behavior expert Robert “Zeke” Ziel gives a succinct review of them in this illustrated 3-page report.  Essential reading for anyone involved in fire management here in the 49th state! Download it <<HERE>>

AFSC Fact Sheet

Why Alaska Fire Potential Assessments are Different, Robert Ziel, 2018

Wildland fire in boreal and arctic North America

The editors of the State of the Climate in 2017 invited AFSC and our collaborators Uma Bhatt and Rick Thoman to contribute a sidebar on wildland fire in boreal and arctic North America to the chapter on the Arctic. We were excited at the chance to share information about the region with an international audience. Check out a PDF of our contribution here: York et al_wildlandfire_Ch05_Arctic.

How much sprinkling is enough?

Reading today’s update from AKFireInfo about the Livingston Fire, it mentions smokejumpers setting up sprinklers around 5 cabins about a mile from the head of the fire. This is a common tactic for protecting isolated values at risk, but we did not have good information on how much sprinkling was needed and how long wetting down an area would last. Until now.

Devon Barnes, a graduate student at the University of Alberta, worked with BLM-Alaska Fire Service Fire Ecologist Eric Miller to measure the effect of sprinkling on interior Alaska feathermoss fuel beds. Their work found that it takes 0.8 inches (20 mm) of sprinkled water to bring the top 5 inches of duff to saturation. This takes about 7 hours of sprinkling with a Mark 3 pump at a low throttle, and uses about 2 gallons of gas. Devon and Eric estimate that the sprinkled area can resist ignition by firebrands and surface spread for about 3 days in typical summer weather. The area may of course dry more quickly in very hot and windy conditions.

You can find more details on the project and its results in this new AFSC research summary.

Fire, Lichens & Caribou: What Do We Know?

Caribou herds in North America seem to be declining.  Is warming climate or it’s effects on habitat to blame? The relationship of caribou to lichen-rich winter ranges and fire is oftenThumbnailRB2018-1 oversimplified.  Many factors besides habitat affect caribou numbers, which undergo large fluctuations naturally.  In this new Research Brief, we highlight recent publications on caribou-fire relationships and explore some of the factors that make it complicated to predict exactly what will happen and when if old-growth caribou habitats diminish with warming climate and more frequent burning.






Findings from Alberta’s Ft.McMurray Fire

Fires on both sides of Ft. McMurray May 1, 2016

Alberta’s Cordy Tymstra discusses decisions facing fire managers during the 2016 Ft. McMurray fire.

Alaskans were paying close attention in 2016 when a spring firestorm called Horse River burned over a Fairbanks-sized Alberta town resulting in unprecedented evacuation of 90,000 people with insurable losses over $3.77 billion so far.  The disaster even had a negative impact on Canada’s National GDP–at 1.5 million acres it was the 3rd largest fire in Canada’s history. What have we learned from this catastrophic fire and can we co-exist with fire? Fire researcher Mike Flannigan, and Alberta’s fire science and prevention officer Cordy Tymstra teamed up on an important webinar for the AFSC last fall (watch it on our AFSC Vimeo Channel).   Mike gave us a lot of additional insights into fire ecology:  like the number of fires in Canada has doubled since the 1970’s, and spring fires are becoming increasingly important.  Cordy provided intimate “behind-the-scenes” looks into decision-making and the challenges faced by fire managers.  On May 5th, for example, the fire’s rate of spread was estimated at 2.86 km/hr (0.8 m/sec).  The pyrocumulus clouds that developed deposited firebrands up to 35 km ahead of the main fire.  Half of the discussion focused on recommendations from the after-action review:  for example, Alberta moved their official fire season start up to March 1.  They are going to review Incident Commander qualifications for WUI incidents and work on more ICS training for municipal cooperators.  And they are going to ramp up their provincial FireSmart program.  These are just a few.  Watch the presentation:  it will be an hour well-spent.