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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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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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We developed species distribution models with dryland-focused predictors to project environmental suitability changes across the entirety of three pinyon and six juniper species ranges. We identify areas of robust suitability change by combining suitability projections from multiple emissions scenarios and time periods. PJ species’ suitabilities respond to many temperature and moisture covariates expected to change in the future. Projected responses among PJ species are highly variable, ranging from modest declines with concurrent gains for overall little net change to wide-ranging declines with no gains for overall range contractions. Environmental suitability is projected to decline broadly across the arid United States Southwest and remain relatively stable across the northern Great Basin and Colorado Plateau. Our results suggest unique responses of PJ species to future climate change. We found that species were projected to experience more losses than gains in suitability, for overall range shrinks rather than shifts. Land managers have the capacity to increase woodland resilience to drought, and our results can inform rangeland-wide management planning and conservation efforts in PJ woodlands.
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To assess the effects of seeding on the genetic diversity of wildland populations, we conducted a genetic survey of bluebunch wheatgrass (Pseudoroegneria spicata) populations within the perimeter of a recent megafire in southeastern Oregon and southwestern Idaho, United States. We genotyped 760 samples with 10 polymorphic loci. We found similar genetic diversity in populations four to 5 years after seeding compared to unseeded populations that were either burned or unburned. Furthermore, genetic diversity neither increased nor decreased with distance from the fire’s edge, suggesting that wind dispersal from neighboring remnant populations plays a minor role in immediate post-fire recovery compared to resprouting and germination from the seed bank. Though no change was detected in the short term, this survey of genetic variation after a post-fire seeding provides an empirical baseline that can be used to track changes in genetic diversity of these wildland populations over time.
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We measured soil organic carbon (SOC) and its particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) constituents in the surface soils of sites that had sagebrush canopies but differed in whether their understories had been invaded by cheatgrass or not, in both warm and relatively colder ecoregions of the western USA. MAOC stocks were 36.1% less in the 0–10 cm depth and 46.1% less in the 10–20 cm depth in the cheatgrass-invaded stands compared to the uninvaded stands of the warmer Colorado Plateau, but not in the cooler and more carbon-rich Wyoming Basin ecoregion. In plots where cheatgrass increased SOC, it was via unstable POC. These findings indicate that cheatgrass effects on the distribution of soil carbon among POC and MAOC fractions may vary among ecoregions, and that cheatgrass can reduce forms of carbon that are otherwise considered stable and ‘secure’, i.e. sequestered.
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Managed burning of forests can provide benefits to society including mitigated wildfire risk, improved habitat, and more. However, adverse outcomes of escaped fire or smoke pose risks. I reviewed the evolution of the law regulating forest management burns, explored the current legal architecture, and analyzed the economic incentives for involved actors, in order to identify policy options. Liability standards through most of the twentieth century increasingly placed risk burden on landowners and burners, but increased recognition of the benefits of burns led many States to reverse this trend and limit the liability for a subset of qualified burns. Still, there is broad uncertainty about the liability, which can lead to increased costs for all sides. In view of the societal benefits of burning, States may consider how best to provide legal clarity, how to balance associated risks, and where to place the liability burden.
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Our research found that persistent administrative and coordination challenges exist within and among federal agencies in the post-fire response and recovery space. Challenges included cross- jurisdictional coordination of key emergency response programs, program rules that affect post-fire project timing and effectiveness, the absence of a formal federal post-fire response strategy, and program funding issues. These factors revealed and exacerbated scale mismatches between existing agency capacities and the post-fire landscapes that result from unprecedentedly longer, larger, and more severe wildfires occurring in the western USA. Non-federal and nongovernmental organizations were instrumental in overcoming these challenges through coordinating response and recovery efforts across both federal and private lands. To improve the federal post-fire response capacity, study participants stressed the importance of broader cross-jurisdictional use of federal resources, longer timeframes for recovery activities, and reforming the federal funding process.
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We studied the impact of increased fire frequencies on the composition and abundance of herbaceous and woody species in the Interior Coast Range of northern California. Our study area is one of the most frequently burned areas in California, which allowed us to investigate higher fire frequencies than previously published in the scientific literature for California. We surveyed fifty-four 250-m2 plots to assess changes in plant community composition and postfire regeneration of chaparral shrubs across a wide range of fire frequencies, including plots that have burned up to six times in the past 30 years. Our findings reveal that short-interval fires significantly reduced postfire native woody regeneration, with obligate seeding species experiencing a 99% reduction and facultative species showing an 83% reduction in regeneration in the most frequently burned plots. Moreover, the overall marginal effect of one additional fire since 1985 decreased the proportion of native species cover by 12% and both richness and Shannon diversity by 4%. Consequently, areas with higher fire recurrence supported a more structurally and botanically homogeneous landscape dominated by a homogeneous group of non-native species.
Function over form: The benefits of aspen as surrogate brood-rearing habitat for greater sage-grouse
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Species of conservation concern are often habitat specialists, posing significant risk to those species when specific plant communities are threatened. As a result, practitioners habitually focus conservation efforts on these communities while ignoring ecological mechanisms that explain the wildlife–plant relationships. In doing so, practitioners may overlook alternative vegetation communities that could maintain wildlife populations under alternative conditions (e.g., climate change). Here, we term these areas surrogate habitat, defined as vegetation communities or resource sites that provide similar critical resources as conventional sites, and assess their potential for conservation using a case study of greater sage-grouse on Parker Mountain, Utah (1998–2009). Sage-grouse are a sagebrush-obligate species and a species of conservation concern. Range-wide conservation efforts have long emphasized management of seasonal habitats within semiarid sagebrush ecosystems, specifically management of mesic or wet meadow sites that provide brood-rearing habitat required for population persistence. Despite this requirement, no conventional mesic habitat exists on Parker Mountain, yet it supports one of Utah’s largest sage-grouse populations. Rather, the Parker sagebrush system abuts quaking aspen (Populus tremuloides) stands that may provide brood-rearing habitat analogous to wet meadow sites. It is unclear, however, to what extent sage-grouse use these aspen stands because sage-grouse commonly avoid tall structures (e.g., trees) and their associated avian predators. Thus, we tested whether (1) sage-grouse selected for surrogate habitat (i.e., aspen edge) and (2) selection behaviors related to surrogate habitat had demographic effects on the population. As we predicted, sage-grouse selected for these areas, and the sage-grouse that spent increased time closer to aspen edges did not experience increased mortality. Together, this demonstrates that the aspen–sagebrush edge provided a surrogate for the wet meadows used by other populations. More broadly, this suggests that conservation practitioners should move beyond simplistic wildlife–habitat associations toward a more holistic view of animal ecology focused on the wildlife–resource association, an approach that becomes particularly useful in areas where conventional obligate habitat may be degraded or lost. This work also implores us to examine alternative habitat potential rather than applying one-size-fits-all models to threatened species conservation.
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Rapid increases in wildfire area burned across North American forests pose novel challenges for managers and society. Increasing area burned raises questions about whether, and to what degree, contemporary fire regimes (1984–2022) are still departed from historical fire regimes (pre-1880). We use the North American tree-ring fire-scar network (NAFSN), a multi-century record comprising >1800 fire-scar sites spanning diverse forest types, and contemporary fire perimeters to ask whether there is a contemporary fire surplus or fire deficit, and whether recent fire years are unprecedented relative to historical fire regimes. Our results indicate, despite increasing area burned in recent decades, that a widespread fire deficit persists across a range of forest types and recent years with exceptionally high area burned are not unprecedented when considering the multi-century perspective offered by fire-scarred trees. For example, ‘record’ contemporary fire years such as 2020 burned 6% of NAFSN sites—the historical average—well below the historical maximum of 29% sites that burned in 1748. Although contemporary fire extent is not unprecedented across many North American forests, there is abundant evidence that unprecedented contemporary fire severity is driving forest loss in many ecosystems and adversely impacting human lives, infrastructure, and water supplies.