Research Database
Displaying 81 - 100 of 238
Severity patterns of the 2021 Dixie Fire exemplify the need to increase low-severity fire treatments in California’s forests
Year: 2022
Publication Type: Journal Article
Frequency of disturbance mitigates high-severity fire in the Lake Tahoe Basin, California and Nevada
Year: 2022
Because of past land use changes and changing climate, forests are moving outside of their historical range of variation. As fires become more severe, forest managers are searching for strategies that can restore forest health and reduce fire risk. However, management activities are only one part of a suite of disturbance vectors that shape forest conditions. To account for the range of disturbance intensities and disturbance types (wildfire, bark beetles, and management), we developed a disturbance return interval (DRI) that represents the average return period for any disturbance, human or…
Publication Type: Journal Article
Professional wildfire mitigation competency: a potential policy gap
Year: 2022
Studies show that effective strategies to mitigate the risk of structural damage in wildfires include defensible spaces and home hardening. Structures in the western United States are especially at risk. Several jurisdictions have adopted codes that require implementation of these strategies. However, construction and landscaping professionals are generally not required to obtain credentials indicating their competency in mitigating the risk of structural damage in a wildfire. We discuss the implications of this policy gap and propose a solution to bolster competency of professionals in…
Publication Type: Journal Article
Burn severity and pre-fire seral state interact to shape vegetation responses to fire in a young, western Cascade Range forest
Year: 2022
Wildfire size and frequency are increasing across the western U.S., affecting large areas of young, second-growth forest originating after logging and burning. Despite their prevalence in the western Cascade landscape, we have a poor understanding of how these young stands respond to fire or how their responses differ from older, undisturbed forests, which are well studied. We explore these questions using pre- and early post-fire data from a young (<30-year-old), naturally regenerating forest in western Oregon that was burned preemptively to limit spread of the 2018 Terwilliger Fire. We…
Publication Type: Journal Article
Governing wildfires: toward a systematic analytical framework
Year: 2022
Despite recent research, a systematic approach to understanding wildfire governance is lacking. This article addresses this deficit by systematically reviewing governance theories and concepts applied so far in the academic literature on wildfires as a step toward achieving their more effective and holistic management. We engage our findings with the wider governance literature to unlock new thinking on wildfires as a process and outcome. This comparative approach enables us to propose a novel framework for analyzing wildfire governance based on four pillars: (1) actor participation in…
Publication Type: Journal Article
A systematic review of empirical evidence for landscape-level fuel treatment effectiveness
Year: 2022
Background Adverse effects of wildfires can be mitigated within fuel treatments, but empirical evidence of their effectiveness across large areas is needed to guide design and implementation at the landscape level. We conducted a systematic literature review of empirically based studies that tested the influence of landscape-level fuel treatments on subsequent wildfires in North America over the past 30 years to evaluate how treatment type and configuration affect subsequent wildfire behavior or enable more effective wildfire response. Results We identified 2240 papers, but only 26 met our…
Publication Type: Journal Article
Post-fire landscape evaluations in Eastern Washington, USA: Assessing the work of contemporary wildfires
Year: 2022
In the western US, wildfires are modifying the structure, composition, and patterns of forested landscapes at ratesthat far exceed mechanical thinning and prescribed fire treatments. There are conflicting narratives as to whetherthese wildfires are restoring landscape resilience to future climate and wildfires. To evaluate the landscape-levelwork of wildfires, we assessed four subwatersheds in eastern Washington, USA that experienced large wildfires in2014, 2015, or 2017 after more than a century of fire exclusion and extensive timber harvest. We compared preandpost-fire landscape conditions…
Publication Type: Journal Article
Multi-Objective Scheduling of Fuel Treatments to Implement a Linear Fuel Break Network
Year: 2022
We developed and applied a spatial optimization algorithm to prioritize forest and fuel management treatments within a proposed linear fuel break network on a 0.5 million ha Western US national forest. The large fuel break network, combined with the logistics of conducting forest and fuel management, requires that treatments be partitioned into a sequence of discrete projects, individually implemented over the next 10–20 years. The original plan for the network did not consider how linear segments would be packaged into projects and how projects would be prioritized for treatments over time,…
Publication Type: Journal Article
Evidence for widespread changes in the structure, composition, and fire regimes of western North American forests
Year: 2021
Implementation of wildfire- and climate-adaptation strategies in seasonally dry forests of western North America is impeded by numerous constraints and uncertainties. After more than a century of resource and land use change, some question the need for proactive management, particularly given novel social, ecological, and climatic conditions. To address this question, we first provide a framework for assessing changes in landscape conditions and fire regimes. Using this framework, we then evaluate evidence of change and lack of change in contemporary conditions relative to those maintained by…
Publication Type: Journal Article
High-severity wildfire reduces richness and alters composition of ectomycorrhizal fungi in low-severity adapted ponderosa pine forests
Year: 2021
Ponderosa pine (Pinus ponderosa) forests are increasingly experiencing high-severity, stand-replacing fires.Whereas alterations to aboveground ecosystems have been extensively studied, little is known about soil fungal responses in fire-adapted ecosystems. We implement a chronosequence of four different fires that varied in time since fire, 2 years (2015) to 11 years (2006) and contained stands of high severity burned P. ponderosa in easternWashington and compared their soil fungal communities to adjacent unburned plots. Using Illumina Miseq(ITS1), we examined changes in soil nutrients,…
Publication Type: Journal Article
A Mixed Methods Literature Review and Framework for Decision Factors That May Influence the Utilization of Managed Wildfire on Federal Lands, USA
Year: 2021
There is increasing discussion in the academic and agency literature, as well as popular media, about the need to address the existing deficit of beneficial fire on landscapes. One approach allowable under United States federal wildland fire policy that could help address this condition is by deliberately managing wildfire with a strategy other than full suppression (hereafter referred to as ‘managed wildfire’). To improve the understanding of the managed fire decision-making process, we conducted a mixed methods review of the existing literature. This review spanned 1976 to 2013 and used…
Publication Type: Journal Article
Disturbance shapes the US forest governance frontier: A review and conceptual framework for understanding governance change
Year: 2021
Conflict in US forest management for decades centered around balancing demands from forested ecosystems, with a rise in place-based collaborative governance at the end of the twentieth century. By the early 2000s, it was becoming apparent that not only had the mix of players involved in forest management changed, but so had the playing field, as climate-driven disturbances such as wildfire and insect and disease outbreaks were becoming more extensive and severe. In this conceptual review paper, we argue that disturbance has become the most prominent driver of governance change on US national…
Publication Type: Journal Article
Climate and wildfire adaptation of inland Northwest US forests
Year: 2021
After a century of intensive logging, federal forest management policies were developed in the 1990s to protect remaining large trees and old forests in the western US. Today, due to rapidly changing ecological conditions, new threats and uncertainties, and scientific advancements, some policy provisions are being re-evaluated in interior Oregon and Washington. The case for re- evaluation is clearest where small- to large-sized, immature, fast-growing, fire-intolerant trees have filled in forests after both a long period of fire exclusion and the harvest of large, old trees. This infilling…
Publication Type: Journal Article
Using Landsat Imagery to Assess Burn Severity of National Forest Inventory Plots
Year: 2021
As the frequency and size of wildfires increase, accurate assessment of burn severityis essential for understanding fire effects and evaluating post-fire vegetation impacts. Remotelysensedimagery allows for rapid assessment of burn severity, but it also needs to be field validated.Permanent forest inventory plots can provide burn severity information for the field validation ofremotely-sensed burn severity metrics, although there is often a mismatch between the size andshape of the inventory plot and the resolution of the rasterized images. For this study, we used twodistinct datasets: (1)…
Publication Type: Journal Article
U.S. Geological Survey Wildland Fire Science Strategic Plan, 2021-26
Year: 2021
The USGS Wildland Fire Science Strategic Plan (hereafter, Strategic Plan) was developed by USGS fire scientists and executive leadership, and was informed by discussions with external stakeholders. The Strategic Plan is aligned with the needs of the fire science stakeholder community—fire, land, natural resource, and emergency managers from Federal, State, Tribal, and community organizations and members of the broad scientific community. The Strategic Plan also defines critical, core fire science capabilities for understanding fire-related and fire-responsive earth system processes and…
Publication Type: Report
Riparian and adjacent upland forests burned synchronously during dry years in eastern Oregon (1650-1900 CE), USA
Year: 2020
Riparian forests link terrestrial and freshwater communities and therefore understanding the landscape context of fire regimes in these forests is critical to fully understanding the landscape ecology. However, few direct studies of fire regimes exist for riparian forests, especially in the landscape context of adjacent upland forests or studies of long-term climate drivers of riparian forest fires. We reconstructed a low-severity fire history from tree rings in 38 1-ha riparian plots and combined them with existing fire histories from 104 adjacent upland plots to yield 2633 fire scars…
Publication Type: Journal Article
Wildfire decision support tools: an exploratory study of use in the United States
Year: 2020
In the United States, many decision support tools exist to provide fire managers with weather and fire behaviour information to inform and facilitate risk-based decision-making. Relatively little is known about how managers use these tools in the field and when and how they may serve to influence decisions. To address this gap, we conducted exploratory interviews with 27 wildfire management and fire weather professionals across the United States. Results reveal that barriers to the use of decision support tools are structural and social. Specifically, fire weather and behaviour models may not…
Publication Type: Journal Article
Fuel treatment effectiveness in the context of landform, vegetation, and large, wind‐driven wildfires
Year: 2020
Large wildfires (>50,000 ha) are becoming increasingly common in semi‐arid landscapes of the western United States. Although fuel reduction treatments are used to mitigate potential wildfire effects, they can be overwhelmed in wind‐driven wildfire events with extreme fire behavior. We evaluated drivers of fire severity and fuel treatment effectiveness in the 2014 Carlton Complex, a record‐setting complex of wildfires in north‐central Washington State. Across varied topography, vegetation and distinct fire progressions, we used a combination of simultaneous autoregression (SAR) and random…
Publication Type: Journal Article
How does tree regeneration respond to mixed‐severity fire in the western Oregon Cascades, USA?
Year: 2020
Dendroecological studies of historical tree recruitment patterns suggest mixed‐severity fire effects are common in Douglas‐fir/western hemlock forests of the Pacific Northwest (PNW), USA, but empirical studies linking observed fire severity to tree regeneration response are needed to expand our understanding into the functional role of fire in this forest type. Recent increases in mixed‐severity fires offered this opportunity, so we quantified the abundance, spatial distribution, species richness, and community composition of regenerating trees across a mixed‐severity fire gradient (unburned–…
Publication Type: Journal Article
Persistent effects of fire severity on ponderosa pine regeneration niches and seedling growth
Year: 2020
Several recent studies have documented how fire severity affects the density and spatial patterns of tree regenerationin western North American ponderosa pine forests. However, less is known about the effects of fireseverity on fine-scale tree regeneration niche attributes such as understory plant composition and cover, surfacefuel abundance, and soil properties, or how these attributes in turn affect regenerating ponderosa pine growth.Using 1-m2 plots centered on 360 ponderosa pine seedlings that regenerated naturally after the Pumpkin Fire in2000 in Arizona, we quantified regeneration niche…
Publication Type: Journal Article