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In 2024, there were five Thursdays in February. To celebrate this rare event, the Fire Lab is hosting a series of five seminars that highlight new tools and research for managers. The “February Five” will occur during our regularly scheduled seminar series timeslot – Thursdays at 11am Mountain Time. Please join us on Teams. Select the titles below for connection information and to view recordings after the event.
FastFuels and QUIC-Fire: 3D fuel and fire modeling systems supporting prescribed fire
Feb 1, 2024: Russell Parsons, Research Ecologist
The Fire Weather Alert System
Feb 8, 2024: Jason Forthofer, Research Mechanical Engineer; Natalie Wagenbrenner, Research Meteorologist
Estimating forest characteristics such as carbon and tree growth over space and time using TreeMap, FIADB, and FVS
Feb 15, 2024: Karin Riley, Research Ecologist and John Shaw, Forest Inventory and Analysis
Behave7 Fire Modeling System: A Long Time Coming
Feb 22, 2024: Faith Ann Heinsch, Physical Scientist; LaWen Hollingsworth, Fire Behavior Specialist; Greg Dillon, Director, Fire Modeling Institute
Wildfire risk and mitigation opportunities in the US sagebrush biome
Feb 29, 2024: Karen Short, Research Ecologist
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This study indicates that wildfire smoke leads to a 4 to 6 percent reduction in birthweight, and these effects are most pronounced among mothers exposed to smoke during the second or the third trimesters of pregnancy. It also found that these effects attenuate (or diminish) with respect to distance to a wildfire, becoming ineffectual three miles and further from the burn source. In contrast, it found that even if infants had been close to a wildfire while in utero, there was no statistically significant effect on their birthweight if they were outside the smoke’s path.
This study evaluated the long-term (13 years post-treatment) effectiveness of prescribed fire and mechanical tree removal to re-establish sagebrush steppe vegetation and associated spatial patterns in ground surface conditions and soil hydrologic properties of two woodland-encroached sites. Specifically, we assessed the effects of tree removal on: (1) vegetation and ground cover at the hillslope scale (990 m2 plots) and (2) associated spatial patterns in point-scale ground surface conditions and soil hydrologic properties along transects extending from tree bases and into the intercanopy areas between trees. Both sites were in mid to late stages of woodland encroachment with extensive bare conditions (~60–80% bare ground) throughout a degraded intercanopy area (~75% of the domain) surrounding tree islands (~25% of domain, subcanopy areas). All treatments effectively removed mature tree cover and increased hillslope vegetation. Enhanced herbaceous cover (4–15-fold increases) in burned areas reduced bare interspace (bare area between plants) by at least 4-fold and improved intercanopy hydraulic conductivity (> than 2-fold) and overall ecohydrologic function. Mechanical treatments retained or increased sagebrush and generally increased the intercanopy herbaceous vegetation. Intercanopy ground surface conditions and soil hydrologic properties in mechanical treatments were generally similar to those in burned areas but were also statistically similar to the same measures in untreated areas in most cases. This suggests that vegetation and ground surface conditions in mechanical treatments are trending toward a significantly improved hydrologic function over time. Treatments had limited impact on soil hydrologic properties within subcanopy areas; however, burning did reduce the soil water repellency strength and the occurrence of strong soil water repellency underneath trees by three- to four-fold. Overall, the treatments over a 13-year period enhanced the vegetation, ground surface conditions, and soil hydrologic properties that promote infiltration and limit runoff generation for intercanopy areas representing ~75% of the area at the sites. However, ecological tradeoffs in treatment alternatives were evident. The variations in woodland responses across sites, treatments, and measurement scales in this long-term study illustrate the complexity in predicting vegetation and hydrologic responses to tree removal on woodland-encroached sagebrush sites and underpin the need and value of multi-scale long-term studies.
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This study found that climate change accompanied by experimentally increased biomass (i.e., the effects of invasions that increase community biomass or management that increases productivity through fertilization or respite from grazing) increased drought frequency and duration and advanced drought onset. Results suggest that the replacement of perennial temperate semiarid grasslands by shrubs, or increased biomass, can increase ecological drought in both current and future climates.
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In recent decades, many bumble bee species have declined due to changes in habitat, climate, and pressures from pathogens, pesticides, and introduced species. The western bumble bee (Bombus occidentalis), once common throughout western North America, is a species of concern and will be considered for listing by the U.S. Fish and Wildlife Service (USFWS) under the Endangered Species Act (ESA). We attempt to improve alignment of data collection and research with USFWS needs to consider redundancy, resiliency, and representation in the upcoming species status assessment. We reviewed existing data and literature on western bumble bee, highlighting information gaps and priority topics for research. Priorities include increased knowledge of trends, basic information on several life‐history stages, and improved understanding of the relative and interacting effects of stressors on population trends, especially the effects of pathogens, pesticides, climate change, and habitat loss. An understanding of how and where geographic range extent has changed for the two subspecies of western bumble bee is also needed.
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Cheatgrass and medusahead invasions pose a serious threat to Great Basin ecosystems. Managers and scientists are hopeful that strains of the bacterium Pseudomonas fluorescens will be able to selectively inhibit root growth of annual weeds in more complex rangeland ecosystems. These weed-suppressive bacteria (WSB) are now commercially available in many states and have been applied on tens of thousands of acres across the Great Basin, yet results are variable and largely unpublished, indicating that much remains to be understood about when, where and why WSB are or are not effective. This webinar features six speakers: Matt Germino, USGS and Great Basin LCC; David Pyke, USGS; Richard Lee, BLM; Mike Gregg, USFWS; Jane Mangold, Montana State University, and Brynne Lazarus, USGS.
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This webinar illuminated the challenges and opportunities posed by landscape-level species management in the desert southwest. Moderator: Matt McKinney, Director of the Center for Natural Resources and Environmental Policy at the University of Montana. Panelists: Alexa Sandoval, Director, New Mexico Department of Game and Fish; John Swett, Program Manager, Lower Colorado River Multi-Species Conservation Program; Jim deVos, Assistant Director, Wildlife Management, Arizona Game and Fish Department; Bill McDonald, Executive Director, Malpai Borderlands Group. This webinar is one in a series for the “Species Conservation and Endangered Species Act Initiative,” the Chairman’s Initiative of Wyoming Governor and Western Governors’ Association Chairman Matt Mead.
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Restoration of the foundational species, big sagebrush (Artemisia tridentata Nutt.), of the sagebrush steppe biome has not kept pace with the loss of habitat, demanding new tools to improve its restoration. Seed enhancement technology (SET) is one approach that is increasingly being tested in native plant restoration as a means to overcome establishment barriers. Like many semiarid shrubs, sagebrush faces establishment barriers from inadequate moisture, competition from faster-growing grasses, and limited available nutrients. We performed a series of laboratory trials testing whether nutrient amendments could be applied to sagebrush seed using a SET to increase root length and biomass, thereby potentially increasing seedling survival. We initially tested 11 amendments applied directly to bare seeds; of these, a high-phosphorus fertilizer resulted in a 2.7x increase in root biomass and 71-mm increase in root length over the control. We then tested incorporating this fertilizer at multiple concentrations into a pellet SET and a ground dust. Although the fertilizer, particularly at higher concentrations, conferred some enhancement to seedling biomass, the pellet treatments had substantially lower emergence and survival than bare seed and dust treatments. These results indicate the potential for a “root-enhancement” SET to benefit sagebrush and other species like it; they also illustrate some of the challenges of SET development for native species. Sagebrush has small seeds that typically need light to germinate. Further work is needed to develop an appropriate technology that does not negatively impact emergence but still provides enough nutrients for enhanced root growth. Field testing is also needed to determine if increases in root growth translate into greater survival. Given the low success rate of sagebrush seeding in restoration projects, however, we suggest that it is worth considering root-enhancement SET alongside other efforts to improve sagebrush establishment success.
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This study analyzed trends in surface air temperature and temperature extremes in the Great Basin during 1901–2010. Researchers found that annual average daily minimum temperature increased significantly during the study period, with daily maximum temperature increasing only slightly. The results of this study suggest that continuation of the overall warming trend would lead to markedly warmer conditions in upcoming decades.
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Large forest fires have far-reaching impacts on the environment, human health, infrastructure and the economy. Forest fires become large when all forest types across a landscape are dry enough to burn. Mesic forests are the slowest to dry and can act as a barrier to fire growth when they are too wet to burn. Therefore, identifying the factors influencing fire occurrence in mesic forests is important for gauging fire risk across large landscapes. We quantified the key factors influencing the likelihood that an active wildfire would propagate through mesic forest. We analyzed 35 large forest fires (> 2500 ha) that occurred in Victoria, Australia where mesic and drier eucalypt forests are interspersed across mountainous terrain. We used a random forest model to evaluate 15 meteorological, topographic and disturbance variables as potential predictors of fire occurrence. These variables were extracted for points within burnt and unburnt patches of mesic forest. The likelihood of an active wildfire spreading through mesic forest increased by 65 % as vapor pressure deficit (VPD, i.e., atmospheric dryness) rose from 2.5 to 7 kPa. Other variables had substantially less influence (< 20 % change in fire occurrence) and their effects were further reduced when VPD was very high (> 6.5 kPa). Mesic forests were less likely to burn in areas with lower aridity, shallower slopes, and more sheltered topographic positions. Mesic forests 13–15 years following stand-replacing disturbance had 6 % higher chance of burning than long undisturbed forests (50 years post-disturbance). Overall, we show that topography and disturbance history cannot substantially counter the effects of high VPD. Therefore, the effectiveness of mesic forest as a barrier to the development of large forest fires is weakening as the climate warms. Our analysis also identifies areas less likely to burn, even under high VPD conditions. These areas could be prioritized as wildfire refugia.