Category Research Results

Jan 6 2023

Alaska Tundra Fires on the Rise

Smokes from East Fork Fire rise from tundra along the Yukon River around St. Mary’s, 6-12-2022. Credit: Jacob Welsh, AK IMT

Five years ago, Adam Young used paleofire evidence to hypothesize how climate warming would affect future tundra fires in Alaska.  Adam basically predicted a big increase in tundra fire occurrence if the average July temperature warmed above a threshold of 13.4°C (56°F:  Young, et al. 2017). This year, Arif Masrur et al. (2022) provided important evidence corroborating Adam’s theory using modern fire and climate records.  The research team use machine learning to determine the relative importance of various climate, prior burn history, and biophysical values on tundra fire occurrence and size. They also tapped the rich collection of field plot data collected by the National Park Service and other management agencies for vegetation characteristics and verification of reburn status.  Arif did, indeed, find a strong increase in recent Alaskan tundra fires concurrent with much warmer summers.  Annual tundra burned area has almost doubled and reburned area has increased by 61% since 2010!  The study also revealed a small but significant feedback effect of previous tundra fires on reburning, validating management strategies like using prescribed fire to reduce wildfire threat near villages.

Figure from Adam Young (2017) showing where he predicted shorter Fire Rotation Periods (more frequent fire) in Alaska with climate warming.

Citations:
Masrur, A., Taylor, A., Harris, L., Barnes, J., and Petrov, A. 2022. Topography, climate and fire history regulate wildfire activity in the Alaskan tundra. Journal of Geophysical Research: Biogeosciences, 127, e2021JG006608. Read the article HERE:  https://doi.org/10.1029/2021JG006608

Young, AM, Higuera PE, Duffy PA and Hu FS. 2017. Climatic thresholds shape northern high-latitude fire regimes and imply vulnerability to future climate change Ecography 40:606–17.  Slides and recording from Adam’s 2019 presentation on this study HERE:  https://www.frames.gov/catalog/60348

Figure 2, Masrur, et al. 2022. [Tundra fire] Regime shift detected in mean annual fire frequency based on AICC fire perimeter data. The detections were performed with the target significance level p = 0.05 and cut-off length l = 20.
Dec 5 2022

Western Forester Articles on Alaska!

See also p. 24 WFOctNovDec2022 for updates on fuel break projects on the Kenai by Tracy Robillard.

Please also note a great Post-Doc opportunity with one of AFSC’s collaborating scientists to study boreal climate change impacts and mitigation methods. It pays well (~$68,000 year for two years) and comes with a lot of flexibility and opportunities for global scale collaboration. The ad is here: https://www.edf.org/jobs/cooley-postdoctoral-science-fellow

Sep 1 2022

Fire Impacts on Kenai River Salmon Fishing

Fishing on the Kenai River (courtesy of John Winters)

Jordan Smith and Chase Lamborn, from Utah State University, recently completed a study of fire impacts on fishing in the Kenai River from the 2019 Swan Lake fire. Their study–funded by the Joint Fire Science Program— combined a literature review with interviews of local experts to identify impacts. The Kenai River is important: not only is it the most popular sportfishing destination in Alaska, averaging 275,000 angler days per year, it also produces 1/3 of the commercial salmon harvest in the Cook Inlet basin.  Smith interviewed a small but diverse group of stakeholders who had extensive experience with the KR watershed, including agency resource managers, fishing advocates, people from non-profits, tribal members, and business owners.  In addition to fire impacts, the study established a model of the Kenai River as a social-ecological system, which could be used to determine impacts from other kinds of disturbance. 

Interviewees pointed out that a certain amount of luck, such as the lack of heavy rains post-fire to add big sediment loads as well as the fire’s location missing key Chinook spawning watersheds—limited any direct reported impacts of fire on fish.  There were, however, impacts to resource users and businesses—primarily due visitors avoiding the area and road/river closures which restricted access during a brief, but critical, period of the summer. Nevertheless, a terrific early 2019 sockeye run (3-5x above preceding few years) helped to offset impacts on the sport fishery by encouraging anglers with high bag limits and success rates.

Photo: Kenai River fish (John Winters)

The literature review part of the study highlighted potential impacts to rearing and spawning habitats, water quality and fish passage.   Most sobering are examples where populations failed to recover after fire, but these are the exception, not the rule.  Adverse impacts are most likely from high-severity fires becasue they can lead to erosion and flooding. These events can induce loss of stream fishes, and generally require 3-10 years to recover when spawning habitat is affected.  For the Kenai River, early-run chinook salmon were identified as the most vulnerable to this type of event. Although Smith et al. did not directly measure water temperature, stream flow, sediments, or mercury levels following fire on the Kenai, they provide a useful literature review of examples from elsewhere.  They point out that with stream temperatures increasing and flows decreasing in the western continental US (a combination which can be deadly for fish), the threat of fire-related warming may become more serious in the future than it has been in the past.

Photo: Kenai River (John Winters)

Read the Report: JW Smith and CC Lamborn, 2022. Mapping the immediate and prolonged impacts of, and adaptation to, fire in the Kenai River fishery. Final Report: JFSP PROJECT: 20-1-01-30 (July 2022), 31 pp.

Mar 6 2022

The Face of a Scientist

The face of a scientist: does that conjure an image of a certain gender, race, and age?  Albert Einstein perhaps?  Those stereotypes are changing:  meet Dr. Yaping Chen–a rising star of science with a spectacular track record.  The last 3 years she has come up with one mind-boggling revelation after another about how fire works in the Alaska tundra.  After a MS degree in environmental engineering in China, Dr. Chen completed her PhD in the lab of the venerable Dr. Feng Sheng Hu at the University of Illinois.  I first met her presenting a poster on the Nimrod Hill fire (Imuruk Lake, on the Seward Peninsula) at an American Geophysical Union meeting in 2019.  The work was novel, ingenious, and suggestive of new ways to study fires with new computational and remote sensing tools. That was just the tip of the iceberg–or the thermokarst, if you will! Since then Dr. Chen has published numerous diverse research studies improving our understanding of dueling post-fire successional trajectories in tundra, improved burn severity mapping of legacy tundra fires, and fire regime effects on carbon balance.  Her most recent paper outlines the role of tundra fire vs. climate warming in thawing permafrost in Alaska tundra statewide!  If you’ve missed any of these important papers for your collection, links are included below.  Now Dr. Chen is a post-doctoral researcher at the Virginia Institute of Marine Science, continuing her work on unraveling impacts of climate change.  Thank you, Dr. Chen for all you’ve revealed to us in Alaska!

Fire hastens permafrost collapse in Arctic tundra: Short AAAS summary of Chen’s most recent paper>>>

Below: Graphical Abstract from Chen, et al. 2021 One Earth publication, illustrating the increase in thermokarst rates across arctic Alaska, and highlighting impact of fire in hastening thaw.

Jun 1 2020

Using Citizen Science to Help Monitor Air Quality–A Poster

The Environmental Protection Agency (EPA) has just ~15 official air quality monitoring sites around the immense area of Alaska to monitor air pollutants that can affect human health.   Wildfire smoke, for example, produced about 60,000 tons of PM2.5 in 2018 (400,000 acres were burned –just a moderate fire season for Alaska!)  If data from lower quality private and academic air sensors (called “Purple Air”) could also be used, we could add an additional 100 monitoring sites to better understand and forecast air quality.  NASA ABoVE scientists Allison Baer and Tatiana Loboda from the University of Maryland compared EPA and Purple Air sensor data and came up with calibrations that correlate extremely well (coded T&RH—see example graphic below).  You can view their Interactive Poster at the 6th ABoVE Science Team meeting—this week (Jun 1-4): https://astm6-agu.ipostersessions.com/default.aspx?s=09-98-87-A0-E6-1A-FA-E4-79-58-CF-F8-B6-54-4B-79

SiteCorrPurpleair-Baer

Example correlation from one private air quality monitoring station in Fairbanks.

Feb 21 2020

Upgrading Satellite Mapping of Burn Severity

As discussed in the Feb. 7 Fire Science Highlight, burn severity in Alaska is best related to the amount of consumption of the forest floor—not the degree of tree canopy mortality as is in temperate pine and fir forest.  Yet the most commonly applied metric to map burn severity using satellite remote sensing does not correlate well with substrate burn severity.  The change in Normalized Burn Ratio (dNBR; Key and Benson 2003) is based on comparing a pre- and a post-fire image. However, NBR thresholds for severity differ from one fire to another and among different years: similar numbers don’t indicate the same severity levels (D. Chen et al. 2020).  And with tundra fires, sometimes it works, other times not.  This problem has dogged fire effects and ecology studies in Alaska for some time (see list of papers in Sean Parks November 2019 presentation) leading French et al. (2008) to conclude: “Satellite remote sensing of post-fire effects alone without proper field calibration should be avoided.”

ARF63_0-50m_2008

2008 Transect photo from Anaktuvuk River tundra fire (R. Jandt)

Recently, we’ve seen some promising new methods used to improve satellite remote sensing of burn severity in boreal forest.  Whitman et al. compared several indices including a relativized index that facilitated comparisons between different fires in Canada.  She told us about it at the Opportunities to Apply Remote Sensing in Boreal/Arctic Wildfire Management and Science Workshop in 2017—here’s her presentation if you missed it: Improving Remotely Sensed Multispectral Estimations of Burn Severity in Western Boreal Forests.  Loboda et al. ( 2020) found single images using just NIR (near-infrared) bands of Landsat did better than NBR in discriminating tundra fire severity.  Sean Parks is attempting to harness the power of Google Earth Engines and cloud-based computing to use multiple images to further define the ecological burn severity (Parks et al. 2019)—this work is kicking off at the University of Montana.  He also found that unusual aspects of some fires in Alaska (pre-existing beetle kill, short fire return interval) contribute to poor performance of the standard index (see his recorded November, 2019, Association of Fire Ecology meeting presentation HERE).  And Yaping Chen, from the University of Illinois, explored using indices based on Visible and NIR bands (which have a large archive of available imagery going back to the early 1970’s) to evaluate tundra fire severity.  Her paper (Y. Chen et al. 2020) points to a VNIR index called GEMI as a “robust surrogate to NBR in Arctic tundra ecosystems, capable of accurately estimating fire severity across fire seasons, tundra fires, ecoregions, and vegetation types.”  The fact that GEMI is not as influenced by different vegetation types as dNBR gives it a distinct advantage mapping tundra burn severity.

Being able to more accurately map burn severity levels from space would give ecologists a boost for understanding why fires sometimes induce radical changes in ecosystems while other times the system self-replaces in a very short span.  For example, Yaping Chen used GEMI to reconstruct burn severity on older tundra fires like the 1977 example below and tie it to thermokarst effects (like catastrophic lake drainage or ponding) resulting from the fires (poster presented at AGU meeting December 2019).  We look forward to more exciting products and tools coming from these research teams!

Y. Chen et al. 2020, Fig. 7

Reconstructed fire severity map of the 1977 OTZNNW 38 tundra fire computed with dGEMI using Landsat MSS imagery.

Citations:

Chen, Yaping; Lara, Mark J.; Hu, Feng Sheng. 2020. A robust visible near-infrared index for fire severity mapping in Arctic tundra ecosystems. ISPRS Journal of Photogrammetry and Remote Sensing 159:101-113.

Chen, Dong; Loboda, TV.; Hall, JV. 2020. A systematic evaluation of influence of image selection process on remote sensing-based burn severity indices in North American boreal forest and tundra ecosystems. ISPRS Journal of Photogrammetry and Remote Sensing 159:63-77.

French, NHF.; Kasischke, ES.; Hall, RJ.; Murphy, KA.; Verbyla, DL.; Hoy, EE.; Allen, JL. 2008. Using Landsat data to assess fire and burn severity in the North American boreal forest region: an overview and summary of results. International Journal of Wildland Fire 17(4): 443-462.

Key, Carl H.; Benson, NC. 2003. The normalized burn ratio (NBR): A Landsat TM radiometric measure of burn severity. US Geological Survey Northern Rocky Mountain Science Center.

Loboda, Tatiana V.; Hoy, EE.; Giglio, L; Kasischke, ES. 2011. Mapping burned area in Alaska using MODIS data: a data limitations-driven modification to the regional burned area algorithm. International Journal of Wildland Fire 20(4):487-496.

Parks, SA.; Holsinger, LM.; Koontz, MJ.; Collins, L; Whitman, E; Parisien, MA; Loehman, RA.; Barnes, JL.; Bourdon, JF; Boucher, J; Boucher, Y; Caprio, AC.; Collingwood, A; Hall, RJ.; Park, J; Saperstein, LB.; Smetanka, C; Smith, RJ.; Soverel, NO. 2019. Giving ecological meaning to satellite-derived fire severity metrics across North American forests. Remote Sensing 11(14):1735.

Whitman, E, MA Parisien, DK Thompson, RJ Hall, RS Skakun, and MD Flannigan. 2018. Variability and drivers of burn severity in the northwestern Canadian boreal forest. Ecosphere 9(2):e02128. 10.1002/ecs2.2128

Mar 21 2019

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: https://www.ecologyandsociety.org/vol24/iss1/art27/

 

Nov 24 2018

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:

https://www.frames.gov/catalog/56894

Oct 8 2018

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

Feb 28 2018

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.