Research and Publications
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Fuel-treatments targeting shrubs and fire-prone exotic annual grasses (EAGs) are increasingly used to mitigate increased wildfire risks in arid and semiarid environments, and understanding their response to natural factors is needed for effective landscape management. Using field-data collected over four years from fuel-break treatments in semiarid sagebrush-steppe, we asked 1) how the outcomes of EAG and sagebrush fuel treatments varied with site biophysical properties, climate, and weather, and 2) how predictions of fire behavior using the Fuel Characteristic Classification System fire model related to land-management objectives of maintaining fire behavior expected of low-load, dry-climate grasslands. Generalized linear mixed effect modeling with build-up model selection was used to determine best-fit models, and marginal effects plots to assess responses for each fuel type. EAG cover decreased as antecedent-fall precipitation increased and increased as antecedent-spring temperatures and surface soil clay contents increased. Herbicides targeting EAGs were less effective where pre-treatment EAG cover was >40 % and antecedent spring temperatures were >9.5 °C. Sagebrush cover was inversely related to soil clay content, especially where clay contents were >17 %. Predicted fire behavior exceeded management objectives under 1) average fire weather conditions when EAG or sagebrush cover was >50 % or >26 %, respectively, or 2) extreme fire weather conditions when EAG or sagebrush cover was >10 % or >8 %, respectively. Consideration of the strong effects of natural variability in site properties and antecedent weather can help in justifying, planning and implementing fuel-treatments.
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Large-scale disturbances, such as megafires, motivate restoration at equally large extents. Measuring the survival and growth of individual plants plays a key role in current efforts to monitor restoration success. However, the scale of modern restoration (e.g., >10,000 ha) challenges measurements of demographic rates with field data. In this study, we demonstrate how unoccupied aerial system (UAS) flights can provide an efficient solution to the tradeoff of precision and spatial extent in detecting demographic rates from the air. We flew two, sequential UAS flights at two sagebrush (Artemisia tridentata) common gardens to measure the survival and growth of individual plants. The accuracy of Bayesian-optimized segmentation of individual shrub canopies was high (73–95%, depending on the year and site), and remotely sensed survival estimates were within 10% of ground-truthed survival censuses. Stand age structure affected remotely sensed estimates of growth; growth was overestimated relative to field-based estimates by 57% in the first garden with older stands, but agreement was high in the second garden with younger stands. Further, younger stands (similar to those just after disturbance) with shorter, smaller plants were sometimes confused with other shrub species and bunchgrasses, demonstrating a need for integrating spectral classification approaches that are increasingly available on affordable UAS platforms. The older stand had several merged canopies, which led to an underestimation of abundance but did not bias remotely sensed survival estimates. Advances in segmentation and UAS structure from motion photogrammetry will enable demographic rate measurements at management-relevant extents.
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Public agencies and organizations often deliver financial assistance through cost sharing, in which recipients contribute some portion toward total costs. However, cost sharing might raise equity concerns if it reduces participation among populations with lower incomes. Here, we revisit a past study using a richer dataset (n=1,689) to assess whether stated income levels affect survey respondents’ willingness to participate in a cost share program for vegetation reduction to mitigate wildfire risk in western Colorado. Results show that residents with lower incomes are less likely to participate even though they can choose to contribute 0% toward a cost share. Residents reporting incomes less than $50,000 are 11 percentage points less likely to participate than those reporting incomes of $200,000 or more. They also are willing to pay a lower share (26 percentage points less) if they do participate. Results indicate potential economic equity concerns from the use of such programs.
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This study found three primary themes across relevant legislative proposals: (1) reforms to simplify permitting and regulatory approval processes (primarily in Australia); (2) efforts to mitigate the risk of legal liability for escaped burns (primarily in California); and (3) recent recognition of and support for cultural burns (primarily in California).
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To contextualize decision factors within the decision making process, we offer a Wildfire Decision Framework that has value for policy makers seeking to improve decision making, managers improving their process and wildfire social science researchers.
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Consider several of the most devastating fire disasters of the last century. In August 2023, the wildfire-initiated urban conflagration of Lahaina, Hawaii, damaged or destroyed more than 2,200 structures and killed 98 people. In December 2021, the Marshall Fire sparked conflagrations in Superior and Louisville, Colorado, destroying 1,084 structures and killing two. In September 2020, the Almeda Drive Fire in the communities of Talent and Phoenix, Oregon, destroyed 2,600 homes and killed three. In November 2018, the Camp Fire initiated ignitions in Paradise, California, destroyed 18,804 buildings, and killed 85. In November 2016, fires spread through Gatlinburg and Pigeon Forge, Tennessee, destroying 2,460 structures and killing 14. These fire disasters burned in vastly different environments. But all had human causes (power lines contributed to at least three), were near communities, occurred during extreme wind events, then inflicted their damage as urban conflagrations. Almost all destruction occurred within the first 12 hours after ignition. These fires immediately overwhelmed wildland and structural firefighting efforts, which were largely ineffective during the initial and extreme phase of the fire. Further, all these fires occurred since 2016. It’s clear that structures and whole communities were vulnerable to ignition and burning—irrespective of what initiated the fires.
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Sagebrush steppe is one of the most threatened ecosystems in North America. Adult density of songbirds within sagebrush steppe is a metric used to evaluate conservation actions. However, relying on only adult density to guide conservation may be misleading. Information on how conservation actions influence the nest density and nest survival of songbird species, in addition to adult density, are needed. We evaluated the relationships between nest density, nest survival, and adult density of Brewer’s sparrow (Spizella breweri) and vesper sparrow (Pooecetes gramineus) over 3 breeding seasons in central Montana. Our findings suggest that adult pairs of both species were often present in higher numbers than nests, and this relationship was most prominent for Brewer’s sparrows. However, our results do not support density dependence when considering nest survival. This discrepancy suggests that songbirds may not breed every year and that density dependence may be operating on nest densities within these populations differently than we examined. This study provides information on relationships between population demographics for 2 songbird species in grazed sagebrush steppe that will improve monitoring and management activities of conservation efforts.
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Potential Operational Delineations (PODs) a strategic collaborative spatial wildfire planning framework and decision support tool for wildfire response and mitigation. Background, primer, and use of sections included.
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This study found that Potential Wildfire Operational Delineations (PODs) were helpful for validating fuels treatment plans and supporting communication among agency staff, and with private landowners and collaborators. Challenges included lack of technical knowledge and skills, unclear leadership direction, potential misalignment with other forest management goals and community and agency buy-in to using PODs.
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Reducing PODs (potential operational delineations) to a network of suppression-focused fuel breaks may dilute the intent and diminish the richness of the framework. Using PODs and fuel breaks to perpetuate fire exclusion is not likely to be effective and may set us up for failure. In many forest types, we may need to rethink design of fuel breaks along POD boundaries to support expansion of proactive use of fire.