Estimates of carbon released from combustion of vegetation and organic soil during wildfires have improved dramatically over the past decade. Biomass inventory, fire effects and fire severity studies have contributed more accurate data to improve these models. (See Ottmar 2007, Brendan Rogers webinar 2015) However, figuring out the net effect of all the various effects of fire, the recovery phase and warming climate on the carbon stored in Alaska’s forests and tundra is a lot more challenging! You’d have to consider changes in burn extent and/or severity, increases in plant productivity in recovering burns, changes in species composition and what that means for productivity, changes in permafrost distribution and soil C decomposition, methane emissions and carbon fluxes in lake systems and wetlands–etc.! A team lead by Dr. Dave McGuire at UAF has taken on this modeling challenge by applying their Integrated Ecosystem Model (IEM) which includes modules for fire, permafrost, and carbon cycling. Dave recently presented an overview of their findings at an IARPC-WCT/AFSC joint webinar (presentation slides available HERE). In a nutshell, they found: 1) tundra holds 2x the carbon that boreal forest does in the same area 2) there has been a net C loss from boreal land area of about 8 Tg/yr over the last 60 years, primarily driven by large fires during the 2000’s 3) arctic tundra and SE Alaska still act as C sinks, compensating for these losses so that overall, Alaska sequesters about 3.7 Tg/yr, 4) increases in fire extent predicted with with warming climate will release even more C, but longer growing seasons and increased plant growth (as much as 8-19% increased productivity throughout the remainder of this century) with warmer climate and higher CO2 concentration in the atmosphere are estimated to offset these losses under most of the climate projection scenarios. Since this nutshell summary glosses over a lot, you should take a look at the slides and the SNAP projects page with information on scenarios and the individual models used.
A new report by USFWS Kenai Refuge fire staff (Nate Perrine) examines
areas where the 2015 Card Street fire intersected completed fuels treatments. He utilized IFTDSS (Interagency Fuels Treatment Decision Support System) modeling to analyze the treatment effect on fire behavior, and also documented post fire effects within the treated areas. This well-illustrated discussion includes recommendations for future treatments and analyses–a must-read for fire fuels specialists in Alaska! Click below to download a pdf.
The first 2016 issue of Western Forester contains a pair of short articles on the Nenana Ridge crown fire experiment and fuel break effectiveness at Funny River and the studies in progress on fuel break effectiveness in Alaska. Eric Miller (BLM-Alaska Fire Service) and Nathan Lowjewski (Chugachmiut Forester) did a nice job on these write-ups! Eric’s article gives the first published account of what happened in 2016 when wildfire challenged a 10-year old thinned fuel break in black spruce, as well as insight to the “hows” and “whys” of fire behavior in fuel breaks. Here’s a link to the issue: http://www.forestry.org/media/docs/westernforester/2016/WFJanFeb2016-2_LT3qttf.pdf
You might be surprised by the amount of collaboration between Alaska and Michigan-based scientists over the last 2 decades! This has been a long-standing research relationship which has spawned many useful products–including Alaska’s fire perimeter map database! Other endeavors include satellite fire detection and mapping, fuel moisture detection, improvements in fuels mapping, tundra fire research and more. Read about the history of this research relationship and its important findings and products, still ongoing with some exciting current research endeavors in a new Research Brief (LINK).
NASA’s Arctic Boreal Vulnerability Study (ABoVE) has focused a research spotlight on Alaska & Canada this year. In August, 2015, they announced 21 new projects funded for a multi-year field campaign designed to investigate the ecological and social impacts of changing permafrost, wildfires, and wildlife habitats in Alaska and northwestern Canada. Many of these involve new approaches to use remote sensing information from satellites. At least 5 funded projects involve field work in Alaska and direct involvement with the wildfire science and/or management in Alaska. Read about the new ABoVE projects at:
A multi-decadal analysis of fire in Alaskan tundra ecotones was completed using records from the Alaska Large Fire Database and an analysis of future fire potential was performed based on future climate scenarios and the Canadian Fire Weather Indices (FWI). The authors analyze tundra fire potential in different tundra areas and conclude that most areas will see substantial increase in the number of high-fire-potential days in the next few decades. This figure shows, for example, the Seward Peninsula and Southwest areas with historical (1951-2005) fire weather indices and modeled with 3 different climate projections to 2095. Although the Seward Peninsula FWI only exceeded 20 twice in the historical record (1977 & 2005), it is projected to exceed 20 much more frequently in the next decades. Read the full article: French, N. H. F., L. K. Jenkins, T. V. Loboda, M. Flannigan, R. Jandt, L. L. Bourgeau-Chavez, and M. Whitley, 2015: Fire in arctic tundra of Alaska: past fire activity, future fire potential, and significance for land management and ecology. Int. J. Wildland Fire, http://dx.doi.org/10.1071/WF14167.
Here in interior Alaska a lot of us have been thinking about the potential for fire growth lately: as in how big could these fires actually get in 2015? The graph below (thanks to Rick Thoman from the Alaska Climate Center-UAF for tracking this data) shows how the cumulative acres burned compares with the Season-of-Never-Ending-Smoke 2004. As you can see, we’re well on our way to a new record year, barring a significant turn of weather patterns. It just so happens a very interesting presentation on modeling fire growth was presented to the May 2015 American Meterological Society Conference and that paper is now available and posted on the Alaska Fire Science Consortium website: MODELING FIRE GROWTH POTENTIAL BY EMPHASIZING SIGNIFICANT GROWTH EVENTS:CHARACTERIZING A CLIMATOLOGY OF FIRE GROWTH DAYS IN ALASKA’S BOREAL FOREST by Robert Ziel, Jane Wolken, Tom St. Clair, and Marsha Henderson.
The authors show that MODIS hotspot data can be used as fire growth data to evaluate multi-day fire growth models such as FS-Pro since 97% of MODIS hotspot data correlated with final fire perimeters. Predicting fire growth potential based on thresholds for weather and fuel moisture conditions required a climatological analysis of the conditions occurring throughout the interior Boreal ecoregion, and an analysis was conducted on the conditional frequency of the fire events (represented by MODIS detects) that occur under the range of weather and fuel moisture conditions found in the climatology.
Training modules on using the Wildland Fire Decision Support System (WFFDSS) in Alaska are now available on the AFSC website. Find a video, from 5 to 30 minutes long, on the section you’re interested in or download a step-by-step annotated Powerpoint taking you all the way from Login to Publishing a decision.
Eric Miller, BLM Alaska Fire Service Fire Ecologist, assists with a lot of prescribed burns on military training ranges in Alaska where the primary fuel is standing dead grass (photo) and this question was often on his mind. He found that existing fine dead fuel moisture tables underestimated the moisture content in dead grass. Six years and 74 prescribed burn days later he had collected 409 grass samples and 285 weather observations, enough to build several empirical- and process-based fuel moisture models. He gave a presentation on his findings at the Alaska Fire Science workshop in April 2015 and prepared a 1-page research brief on the highlights of his study.
Eric introduced a simple “Rule of Thumb” for predicting dead grass moisture content in the field: MC = rH/5 + 4 You can find the new fuel moisture and ignition probability calculators based on Eric’s field campaign, along with other useful tools like a dead grass fuel loading photoseries and CFFDRS calculator, on his website: http://www.taigafire.org/