2012 Sagebrush & Fire Field Day
June 7, 2012, Idaho Falls, Idaho
We had a great day at the SageSTEP Roberts study site and other study areas that were burned by the Jefferson wildfire. Thanks to everyone who participated! Photos and notes from the tour are provided below or by clicking on these links:
The Jefferson Wildfire
The Jefferson Fire ignited on the afternoon of July 13, 2010 within the Department of Energy's (DOEs) Idaho National Laboratory (INL). Due to the passage of a low pressure trough which resulted in strong winds (Gusting to 45 mph), high temperatures (88°) and low relative humidity's (12%) the fire quickly spread to the northeast burning through the INL/BLM boundary and consuming 108,855 acres of sagebrush steppe habitat (25,585 acres of public lands administered by the Bureau of Land Management's Upper Snake Field Office). In its course the fire impacted 66,210 acres of remaining intact sagebrush habitat. Vegetation prior to the burn was comprised of Wyoming big sagebrush (Artemisia tridentata wyomingensis) and basin big sagebrush (Artemisia tridentata tridentata) in the overstory with Indian ricegrass (Achnatherum hymenoides), needle and thread grass (Hesperostipa comata), bottlebrush squirreltail (Elymus elymoides), longleaf phlox (Phlox longifolia), hoods phlox (Phlox Hoodii), scarlet globemallow (Sphaeralcea coccinea), and assorted milkvetch and aster species in the understory.
Dr. Gene Schupp, Plant Ecologist, Utah State University
Lee Davis, Research Associate, Utah State University
Juley Hankins Smith, Rangeland Management Specialist, Bureau of Land Management
The Roberts site was treated with prescribed fire, sagebrush mowing and herbicide treatments in fall 2007. In July 2010, the Jefferson wildfire burned through the prescribed burn plot, mow plot, and part of the herbicide plot (but not the control). This gave us an unanticipated opportunity to learn more about the effects of fuels treatments on wildfire behavior and subsequent recovery.
|SageSTEP Roberts study site control plot, 2012.|
- Increase in perennial grass in all treatments
- 2009, 2010, 2011 were all unusually wet springs
- Imazapic (Plateau; applied at 5-6 oz/acre) effect has lasted 3-4 years and in the 5th post-treatment growing season (2012) effect is less evident
- Basal gap research: Even when cover is consistent, gaps between plants can increase in size and cheatgrass is more likely to invade larger gaps. Only the burn treatment increases gap size.
|2012 images of plots where prescribed burn and mow treatments were implemented prior to the Jefferson fire. Mustard and halogeton are dominant in many areas.|
|These images show a 30m x 30m subplot in the mow treatment that was sprayed with imazapic (Plateau) pre-emergent herbicide in 2007. The subplot is in the center of the top photo and the bottom photo is a close-up view inside the subplot. This year (2012), some weeds are showing up in the subplot, but there is still an obvious difference from the unsprayed area.|
Treatment plot size is smaller than typical BLM treatments, but larger than typical research plots.
We want to find thresholds b/c managers to don’t have to seed after every fire/disturbance
We need to evaluate sites for 10-15 years to see long-term effects. Also, now we have the opportunity to look at how treatment areas respond to wildfire (e.g. Did mow + two years post-treatment recovery = different response to wildfire than control).
Is this the type of are BLM would normally treat? No, it was not degraded enough and the agency only has money to treat the most degraded areas.
We’re looking to restore landscapes that are not already completely degraded (which is often the only option for BLM).
Would private landowners treat this type of landscape? Yes, they might talk to NRCS about help treating to improve understory. They would likely use herbicide or mow, not prescribed fire.
This site had 20-25% sagebrush cover prior to treatment. Managers might not want to reduce that but ranchers probably would. (This site has lower sagebrush cover than other sagebrush sites in the SageSTEP study network.)
Comment: “Long-term” in these systems could be multiple lifetimes. We don’t usually have a long enough perspective.
Will these areas that are now weedy ever be seeded? There is a clause in the MOUs for seeding if determined necessary, but so far it hasn’t been used because we want to learn how well sites recover on their own.
There were never many perennial forbs here. Why has halogeton increased? Fire? Lack of wildlife? No one knows the answer to this.
Dr. Steve Bunting, Fuels Ecologist, University of Idaho
Fuels Table Handout (PDF, 65 KB): Fuels data from study sites including Roberts and other similar sites.
Pages 30-31 in the post-treatment fuels guide show what these areas (see burn and mow plot photos above) looked like after fuels treatments and before the wildfire.
Fuels guides and these types of tables can help people set fuel parameters for running fuel models for wildfire and prescribed fire. They can also help determine shrub and other cover to make rapid estimates for a variety of management purposes.
We are lucky because normally scientists don’t have pre-fire data from the exact location where a fire occurs, but we do for this site. We can learn a lot from this site without having to try and find a comparable control nearby.
Jason Williams, Hydrologist, Agricultural Research Service
Williams discussed the impacts of fuels treatments and wildfire on water runoff and erosion of sagebrush rangelands. His handout (PDF, 4 MB) uses photos and data to illustrate these impacts and their implications for land managers.
Invertebrates in Sagebrush Systems
Dr. Jim McIvers, Ecologist, Oregon State University
Arthropod pitfall trap used to measures invertebrate composition in an area. Scientists use this information to understand changes in invertebrate communities and the relationships between invertebrates and vegetation on treated and untreated sagebrush landscapes.
Reason for SageSTEP wildlife research: wildlife managers manage habitat, not animals. SageSTEP is looking at how changes in habitat affect animals to inform management decisions.
Ants: Workers are not directly impacted by treatments and we have not seen any short-term impacts in 4 years post-treatment.
Spiders: Directly impacted by treatments so lots of short-term mortality, but also a good rebound some time after treatments.
Butterflies: Not active during the fall (treatment time). Treatments change habitat and the next generation returns in the spring and adjusts to the changes. Improvements in butterfly habitat-removal of woody vegetation increases soil moisture and increases fobs. In general, positive short-term response but a decline in some plots for unknown reasons.
Jim’s comforting thoughts: Butterfly, spider and ant species at our plots are native and some have not even been named by science. In spite of heavy disturbance, these native species are doing okay and that is encouraging.
Why aren’t we doing bird work in sagebrush plots? Because of a lack of funding, but work in Phase 1 woodlands (low tree cover) can be somewhat applicable to sagebrush landscapes. Songbirds have high site fidelity so we haven’t seen a lot of impact on these species, but we probably will when the current generation dies (they live 6-7 years on average).
Public Opinion of Fuels Management
Dr. Mark Brunson, Social Scientist, Utah State University
SageSTEP social scientists have conducted a longitudinal study to understand citizens' concerns and their priorities for management of sagebrush and woodland landscapes in the Great Basin. Questionnaires were sent out in 2006 and 2010. Dr. Brunson discussed this research and a good summary of this work can be found in SageSTEP News Issue 15.
Dr. Matt Germino, Ecologist, USGS, Forest and Rangeland Ecosystem Science Center
After the Jefferson fire, Germino instigated a study more than 20 miles downwind from the ignition point to evaluate how much erosion was happening, the wind speeds required to move soils and how rain and other events affect wind erosion.
Germino states the following as predictors of post-fire wind erosion:
- fire size, soil
- pre-fire vegetation
Wind erosion events are related to fire size and these events have increased with increased wildfire size.
|Wind erosion study site more than 20 miles from the Jeffersion wildfire ignition point. Dominant vegetation two years after the fire is rabbit brush and halogeton. Notice the pedestalling around burned sagebrush stumps.|
Results of this study show:
- About 2cm of soil has been swept away from this site.
- Soil was more or less bare for ~10 months following fire, increasing erosion potential.
- When vegetation cover reaches ~10%, wind erosion goes down
- Timing of wildfires affects erosion. Snow prevents wind erosion.
Physical soil crust in study area with high wind erosion.
What can we do to prevent erosion?
- Break up the landscape so wildfires cannot spread as far and burn such large areas.
- Improve ecologic health of rangelands with more herbaceous understory.
Studies of post-fire wind erosion in sagebrush steppe near the Roberts/Jefferson fire site
Please contact Matt Germino for pdfs.
Sankey J, Germino MJ, Sankey T, Hoover A (In Press) Fire effects on the spatial patterning of soil properties in sagebrush steppe, USA: Meta-analysis. International Journal of Wildfire.
Sankey J, Germino M, Glenn N, Benner S (In Press) Bioavailable nutrients transported by wind in an eroding cold desert. Aeolian Research.
Hasselquist N, Germino MJ, Sankey J, Glenn N, Ingram J. 2011. High potential for nutrient redistribution in aeolian sediment fluxes following wildfire in sagebrush steppe. Biogeosciences 8: 3649-3659.
Sankey J, Germino MJ, Glenn NJ. 2012. Dust supply varies with sagebrush microsites and time since burning in experimental erosion events. Journal of Geophysical Research-Biogeosciences 117:1-13.
Sankey J, Eitel J, Glenn N, Germino M, Vierling L. 2011. Quantifying relationships of burning, roughness, and potential dust emission with laser altimetry of soil surfaces at submeter scales. Geomorphology doi:10.1016/j.geomorph.2011.08.016.
Hoover A, Germino MJ. 2012. Post-fire, Resource-Island Effects on Bromus tectorum and Pseudoroegneria spicata: Evidence From a Common-Garden Study. Rangeland Ecology and Management 65:160-170.
Sankey J, Glenn NF, Germino MJ, Gironella A, Thackray G. 2010. Relationships of aeolian erosion and deposition with LiDAR-derived landscape surface roughness following wildfire Geomorphology 119, 135-145.
Sankey J, Germino MJ, Glenn NF. 2009. Relationships of post-fire aeolian transport to soil and atmospheric moisture, Aeolian Research 1: 75-85.
Sankey J, Germino MJ, Glenn NF. 2009. Aeolian sediment transport following wildfire in sagebrush steppe. Journal of Arid Environments 73: 912-919.
Ben Dyer, Fire Ecologist, Bureau of Land Management, Upper Snake Field Office
Following containment of the Jefferson fire, resource personnel conducted a field tour of the burn to determine key areas where rehabilitation treatments would be most beneficial. Four areas were identified that had higher burn severities, elevated rates of erosion, and had been heavily impacted by historic livestock grazing resulting in lower ecological condition. It was determined that revegetation of these areas with desirable, native species would be necessary to provide long-term competition against noxious weeds and invasive species, and to return the area to a pre-disturbance, native vegetation condition. A total of 12,500 acres were treated using a combination of drill, aerial, and hand planting methods.
The following information was provided at this stop on the tour:
Drill seed rows from BLM ES&R treatments. Monitoring one year after seeding shows this to be a productive site. See Ben Dyer's handout for more information about treatments and results at this site.