Research and Publications
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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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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.
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Invasion by nonnative annual plants that form prolific seed banks, including cheatgrass, throughout western North America is a major natural resource concern. Even with known economic and ecological implications, soil seed banks and their potential to impact ecological restoration in arid and semiarid ecosystems are poorly understood. Quantifying the regenerative potential of the soil seed bank—the living seeds in the soil profile and on the soil surface—can help natural resource managers make decisions to increase the likelihood of restoration success. We analyzed the germinable soil seed bank composition and distribution of a rangeland site in western Colorado that experienced a wildfire in 1994 and is dominated by cheatgrass. We collected soil seed bank samples from 118 points in a 100 × 110 m grid to a depth of 5 cm. Each sample was split by depth from 0 to 2 cm and from 2 to 5 cm, and the seed bank was quantified using greenhouse emergence methods. We found that seeds of native species were more dense and evenly distributed (3391 seeds ⋅ m−2than seeds of nonnative species were (1880 seeds ⋅ m−2) in the 0–5 cm seed bank across the site. We also found that seeds of both native and nonnative species were concentrated in the 0–2 cm layer of the seed bank but that native and nonnative seeds were present in substantive densities in the 2–5 cm layer. These findings suggest that the soil seed bank of the site is resilient, and a targeted approach to specifically deplete the seed bank of nonnative annuals could facilitate restoration by the in situ native seed bank.
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The invasive annual grass, medusahead, infests rangelands throughout the West, from the Columbia Plateau to the California Annual Grasslands and the Great Basin. Dominating secondary succession in the sagebrush steppe, medusahead can degrade the habitat of threatened species such as the greater sage-grouse. This research explores the potential of dormant season grazing as an applied management strategy to reduce the negative impacts of medusahead while promoting recovery of perennial vegetation at the landscape scale. In particular, it assessed grazing with four treatments from 2018 to 2020: traditional grazing (May–October), dormant season grazing (October–February), traditional + dormant season grazing (May–February), and no grazing. After 2 yr of grazing treatments, biomass, density, cover, and fuel continuity did not differ between treatments (P > 0.05). However, biomass measurements were significantly different between years, which is likely due to greater than normal precipitation in 2019 and 2020. Between 2018 and 2019, annual grass biomass increased by 81% (666–1 212 kg ha−1) and perennial grass biomass increased by 165% (118–313 kg ha−1). Litter biomass decreased by approximately 15% in every year since 2018 (2 374, 2 012, and 1 678 kg ha−1 in 2018–2020). There were not significant differences in cover or density of annual and perennial grasses between treatments and years. Our results indicate that 2 yr may not be adequate time for dormant season grazing treatments to be effective in reducing the abundance of medusahead and that after 2 yr of treatments, dormant season grazing does not have a detrimental effect on perennial vegetation.