Research and Publications
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Our study aimed to document the expansion of PBAs and provide insight into their structure, function, and impacts. Leaders from 135 known PBAs across the United States were invited to participate in an online survey. Survey results demonstrate a widespread emergence of PBAs in the United States, successfully mobilizing thousands of volunteers to collectively burn more than 34,000 ha annually. PBAs demonstrated that they are reducing myriad barriers to prescribed burning while meeting their goals to broaden access to the use of fire using a neighbors-helping-neighbors model to provide training, pool resources, and reduce the costs of prescribed burning. By including volunteers with diverse levels of experience and backgrounds, PBAs are changing the narrative of who has access to the use of fire.
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Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of conditions conducive to extreme-impact wildfires from 1990 to 2022 across California. More than three-quarters of extreme-impact wildfires—defined as the top 20 largest, most destructive, or deadliest events on record—originated within 1 km from the wildland-urban interface. The deadliest and most destructive wildfires—90% of which were human-caused—primarily occurred in the fall, while the largest wildfires—56% of which were human-caused—mostly took place in the summer. By integrating human activity and climate change impacts, we provide a holistic understanding of human-centric wildfire risk, crucial for policy development.
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To assess relationships between fire spread rates and landscape burn severity patterns, we used satellite fire detections to create day-of-burning maps for 623 fires comprising 4267 single-day events within forested ecoregions of the southwestern United States. We related satellite-measured burn severity and a suite of high-severity patch metrics to daily area burned. Extreme fire spread events (defined here as burning > 4900 ha/day) exhibited higher mean burn severity, a greater proportion of area burned severely, and increased like adjacencies between high-severity pixels. Furthermore, increasing daily area burned also resulted in greater distances within high-severity patches to live tree seed sources. High-severity patch size and total high-severity core area were substantially higher for fires containing one or more extreme spread events than for fires without an extreme event. Larger and more homogenous high-severity patches produced during extreme events can limit tree regeneration and set the stage for protracted forest conversion. These landscape outcomes are expected to be magnified under future climate scenarios, accelerating fire-driven forest loss and long-term ecological change.
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Significant and lasting soil carbon change in rangeland ecosystems requires ecological state change. Although within-ecological state, soil carbon dynamics can occur, they are driven primarily by short-term fluctuations in weather, specifically precipitation, and are insufficient to provide reliable estimates of change to support policy and management decisions. Changes in grazing management typically do not result in ecological state change, apart from the vegetation structural change associated with long-term overgrazing. Dominant vegetation attributes such as shrub-to-grass ratios, cool season versus warm season plant production, and annual versus perennial growth habit define ecological state and are detectable accurately and cost-effectively using existing remote-sensing technology. These vegetation attributes, along with stationary soil properties, allow for mapping at scales consistent with a variety of policy and management decisions and provide a logical basis for developing a credible sampling framework for verification. Furthermore, state-transition models of ecological state dynamics are designed to provide information that can be used to support inventories and management decisions for soil carbon and other ecosystem services.
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We continued to monitor streamflow and precipitation at an existing hydrologic monitoring network at the Grizzly Creek Fire, CO. Through analysis of this long-term dataset, managers may better plan for infrastructure impacts multiple years post-fire. Next, to evaluate the performance of existing post-fire decision criteria and assess potential improvements, we developed the Post-fire Decision Criteria Assessment Framework. We applied this framework to the Grizzly Creek Fire, CO (2020) and specifically evaluated the decision criteria for highway safety closures applied by the Colorado Department of Transportation (CDOT) to Interstate (I-) 70 within Glenwood Canyon, CO between Dotsero and Glenwood Springs in the first three years post-fire (2021-2023). We defined the infrastructure impact (referred to as ‘impact’) as any instance where I-70 was closed by the Colorado Department of Transportation beyond the end of the precipitation event for maintenance or cleanup associated with flooding or sediment. We
identified a total of 20 safety closure decisions reported by CDOT over the study period and classified each decision into one of three performance categories: true positive (preemptive closure and impact occurred), false positive (preemptive closure and no impact occurred), and false negative (no preemptive closure but impact occurred, resulting in emergency closure). We found that the performance of the safety closure decision criteria varied over the study period in alignment with the Colorado Department of Transportation’s aim of protecting travelers’ safety while reducing unnecessary safety closures without impact. Decisions that resulted in compromised traveler safety or unnecessary closures were considered poor performance. We identified that precipitation-based metrics including precipitation event depth and short-term intensity (i.e. 15-minute) were significant indicators of impact to I-70. Soil moisture-based metrics may be a good secondary indicator but further analysis with a larger dataset is needed. This framework is applicable across burned watersheds and to other infrastructure impacts of interest, such as for water intake shutdown.
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Rural residents think of smoke as an acceptable risk. Efforts to adapt to potential health impacts are minimal, though inaction is driven by diverse reasoning and tradeoffs. Local social context particularly elements related to government distrust, forest management, and independence – heavily influences interest in uptake of different adaptation strategies as well as affecting access to, and interpretation of, information about smoke risks. Rural approaches to, and understandings of, smoke adaptation vary spatially and temporally. Public interest in broader forest management efforts can be leveraged to engage residents in conversations about proactive smoke adaptation. Implications. Smoke adaptation strategies in rural communities must meld evidence of their effectiveness with community preferences grounded in local context to overcome inaction.
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The National Wildfire Coordinating Group (NWCG) Wildland Urban Interface Mitigation Field Guide, PMS 053 provides mitigation practitioners at all experience levels with recommendations on the most effective and efficient ways to accomplish mitigation work in communities at risk to wildfire damage or destruction. The content in this guide was written in coordination with the NWCG Standards for Mitigation in the Wildland Urban Interface, PMS 052.
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We present a mixed integer programming model for prioritizing fuel treatments within a landscape fuel break network to maximize protection against wildfires, measured by the total fire size reduction or the sum of Wildland Urban Interface areas avoided from burning. This model uses a large dataset of simulated wildfires in a large landscape to inform fuel break treatment decisions. Its mathematical formulation is concise and computationally efficient, allowing for customization and expansion to address more complex and challenging fuel break management problems in diverse landscapes. We constructed test cases for Southern California of the United States to understand model outcomes across a wide range of fire and fuel management scenarios. Results suggest optimal fuel treatment layouts within the Southern California’s fuel break network responding to various model assumptions, which offer insights for regional fuel break planning. Comparative tests between the proposed optimization model and a rule-based simulation approach indicate that the optimization model can provide significantly better solutions within reasonable solving times, highlighting its potential to support fuel break management and planning decisions.
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This brief summarizes a recent study that assessed factors driving perceived defensibility through the lens of wildland firefighters to learn more about how they evaluate the risks associated with different structures. It provides insight into structure defensibility in action, and the factors that firefighters may consider when they engage a fire near structures.
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This review explores Integrated Fire Management as both an adaptation and mitigation strategy for altered fire regimes. It provides an overview of the progress and challenges associated with implementing Integrated Fire Management across different regions worldwide. The review also proposes five core objectives and outlines a roadmap of incremental steps for advancing Integrated Fire Management as a strategy to adapt to ongoing and future changes in fire regimes, thereby maximizing its potential to benefit both people and nature.