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We investigate priorities and effectiveness of wildfire suppression using a novel empirical strategy that compares 1,500 historical fire perimeters with the spatial distribution of assets at risk to identify determinants of wildfire suppression efforts. We find that fires are more likely to stop spreading as they approach homes, particularly when those homes are of higher value. This effect of threatened assets persists after controlling for physical factors (fuels, landscape, and weather) using outputs from a state-of-the-art wildfire simulation tool, and the probability that fire spread will be halted is affected by characteristics of homes 1–2 km from a fire’s edge. Our results provide evidence that wildfire suppression can substantively affect outcomes from wildfires but that some groups may benefit more from wildfire management than others.
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Pre- and post-season assessments of primary (e.g. psychosocial risk factors, physical fitness and psychological capital) and secondary (e.g. work engagement, job stress and incidence of injury) outcomes facilitated comprehensive evaluation. The psychosocial education intervention program was effective at buffering participant appraisals of 12 of 13 psychosocial risk factors, namely: organizational culture, civility, psychological demands, balance, psychological support, leadership expectations, growth and development, influence, workload management, engagement, protection and safety. Participants in the psychosocial education intervention also reported lower stress relating to organizational support compared with those who not receiving the intervention program. Wildland firefighters receiving either or both intervention programs reported a significantly lower incidence rate of injury (9.9%) compared with the organisation’s 5-year average (16.0%).
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We created a novel, multiple-region, N-mixture community model (MNCM) to examine the relations of riparian area and fragmentation with species richness of breeding birds in mountain ranges within the Great Basin, Nevada, USA. Projections of future riparian contraction suggested that decreases in species richness are likely to be greatest in canyons that currently have moderate (~10–25 ha) amounts of riparian vegetation. Our results suggest that if a goal of management is to maximize the species richness of breeding birds in montane riparian areas in the Great Basin, it may be more effective to focus on total habitat area than on fragmentation of patches within canyons, and that canyons with at least moderate amounts of riparian vegetation should be prioritized.
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o examine the short-term effects of wildfire on belowground processes in the northern Sierra Nevada, we collected soil samples along a gradient from unburned to high fire severity over 10 months following a wildfire. This included immediate pre- and post-fire sampling for many variables at most sites. While season and soil moisture did not substantially alter pH, microbial biomass, net N mineralization, and nitrification in unburned locations, they interacted with burn severity in complex ways to constrain N cycling after fire. In areas that burned, pH increased (at least initially) after fire, and there were non-monotonic changes in microbial biomass. Net N mineralization also had variable responses to wetting in burned locations. These changes suggest burn severity and precipitation patterns can interact to alter N cycling rates following fire.
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Drawing on recent syntheses of the scientific evidence, this paper examines “myths” commonly used to
oppose climate- and wildfire-adaptation of fire-prone forests. We use an established framework
designed to counter science denial by recognizing the fallacy for each myth. Fallacies are false
arguments; there are several kinds of fallacies, including cherry picking (selecting only a portion of
facts to support a conclusion), false dichotomies or oversimplification (claiming only two possible
outcomes), circular arguments, or straw man (misdirection) arguments. Learning to recognize
logical fallacies and other characteristics of science denial is an essential component of any
assessment of arguments for and against proposed actions
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Study found that expected sediment and phosphorus loads were lower under the scenario that emphasized thinning, whereas scenarios that increased prescribed burning resulted in loads that were comparable to scenarios that involved less treatment. These results reflect the finding from the WEPP analysis that prescribed burning is expected to reduce ground cover more than is thinning. Our analysis supports efforts to increase fuel reduction treatments to mitigate future wildfires, but it also suggests that preventative treatments may not avoid a long-term decline in water quality as wildfires increase with climate change.
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Results suggest that dry forest species are undergoing an active range shift driven by both changing recruitment and mortality, and that increasing temperatures and drought threaten the long-term viability of many of these species in their current range. While four of the five species examined were experiencing some declines, Pinus edulis is currently most vulnerable. Management actions such as reducing tree density may be able to mitigate some of these impacts. The framework we present to estimate range-wide demographic rates can be applied to other species to determine where range contractions are most likely.
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Reports from the early 1900s, along with paleo- and dendro-ecological records, indicate similar and potentially even larger wildfires over the past millennium, many of which shared similar seasonality (late August/early September), weather conditions, and even geographic locations. Consistent with the largest historical fires, strong east winds and anomalously dry conditions drove the rapid spread of high-severity wildfire in 2020. We found minimal difference in burn severity among stand structural types related to previous management in the 2020 fires. Adaptation strategies for similar fires in the future could benefit by focusing on ignition prevention, fire suppression, and community preparedness, as opposed to fuel treatments that are unlikely to mitigate fire severity during extreme weather. While scientific uncertainties remain regarding the nature of infrequent, high-severity fires in westside forests, particularly under climate change, adapting to their future occurrence will require different strategies than those in interior, dry forests.
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This study used a coupled ecohydrologic and fire regime model to examine how climate change and CO2 scenarios influence fire regimes. In this semiarid watershed, we found an increase in burned area and burn probability in the mid-21st century (2040s) as the CO2 fertilization effect on vegetation productivity outstripped the effects of climate change-induced fuel decreases, resulting in greater fuel loading. However, by the late-21st century (2070s), climatic warming dominated over CO2 fertilization, thus reducing fuel loading and burned area. Fire regimes were shown to shift from flammability- to fuel-limited or become increasingly fuel-limited in response to climate change. We identified a metric to identify when fire regimes shift from flammability- to fuel-limited: the ratio of the change in fuel loading to the change in its aridity. The threshold value for which this metric indicates a flammability versus fuel-limited regime differed between grasses and woody species but remained stationary over time. Our results suggest that identifying these thresholds in other systems requires narrowing uncertainty in exogenous drivers, such as future precipitation patterns and CO2 effects on vegetation.
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Tree planting has long been promoted to avert climate change and has received renewed impetus in recent years with the Bonn Challenge and related forest restoration initiatives guided by the forest and landscape restoration (FLR) framework. Much of the focus for reforestation and afforestation is on developing countries in Africa, Asia and South America, where large areas of rangelands in drylands and grassy biomes are portrayed as “degraded,” “unused,” and in need of more trees. This perception is rooted in persistent theories on forests and desertification that widely shaped colonial policy and practice and remain influential in today’s science-policy frameworks. From a rangelands perspective, the global FLR thrust raises two main concerns. First, inappropriate understandings of the ecology of drylands and grassy biomes encourage afforestation, grazing restriction and fire suppression, with negative impacts on hydrology, carbon storage, biodiversity, livestock production and pastoral livelihoods. Second, their target-driven approach requires large-scale afforestation and massive funding to achieve. Nearly half of the area pledged to the Bonn Challenge is in fact destined for forestry and other commercial plantations, which threaten pastoral livelihoods and cause ecological damage while having very limited potential to mitigate climate change. As the officially endorsed framework of the Bonn Challenge and related global restoration initiatives, FLR has become a powerful instrument for guiding global restoration efforts and funding. Its proponents have a responsibility to ensure that the framework is evidence-based and underpinned by appropriate ecological models for different ecoregions.