Research Database
Displaying 61 - 80 of 210
Using PODs to integrate fire and fuels planning
Year: 2023
BackgroundPotential Wildfire Operational Delineations (PODs) were developed as a pre-season planning tool to promote safe and effective fire response. Past research on PODs has identified uses in an incident management context. There has been little research on how PODs are being utilised in non-incident management contexts to align forest and wildfire planning objectives.AimsWe sought to understand how actors are adopting and adapting the PODs framework to inform non-incident management, and to identify facilitators, barriers and recommendations.…
Publication Type: Journal Article
Reduced fire severity offers near-term buffer to climate-driven declines in conifer resilience across the western United States
Year: 2023
Increasing fire severity and warmer, drier postfire conditions are making forests in the western United States (West) vulnerable to ecological transformation. Yet, the relative importance of and interactions between these drivers of forest change remain unresolved, particularly over upcoming decades. Here, we assess how the interactive impacts of chang-ing climate and wildfire activity influenced conifer regeneration after 334 wildfires, using a dataset of postfire conifer regeneration from 10,230 field plots. Our findings highlight declining regeneration capacity across the West over the…
Publication Type: Journal Article
Proportion of forest area burned at high-severity increases with increasing forest cover and connectivity in western US watersheds
Year: 2023
Context In western US forests, the increasing frequency of large high-severity fires presents challenges for society. Quantifying how fuel conditions influence high-severity area is important for managing risks of large high-severity fires and understanding how they are changing with climate change. Fuel availability and heterogeneity influence high-severity fire probability, but heterogeneity is insensitive to some aspects of forest connectivity that are important to potential high-severity fire transmission and thus high-severity area. Objectives To quantify the effects of fuel availability…
Publication Type: Journal Article
Less fuel for the next fire? Short-interval fire delays forest recovery and interacting drivers amplify effects
Year: 2023
As 21st-century climate and disturbance dynamics depart from historic baselines, ecosystem resilience is uncertain. Multiple drivers are changing simultaneously, and interactions among drivers could amplify ecosystem vulnerability to change. Subalpine forests in Greater Yellowstone (Northern Rocky Mountains, USA) were historically resilient to infrequent (100–300 year), severe fire. We sampled paired short-interval (<30-year) and long-interval (>125-year) post-fire plots most recently burned between 1988 and 2018 to address two questions: (1) How do short-interval fire, climate,…
Publication Type: Journal Article
Higher burn severity stimulates postfire vegetation and carbon recovery in California
Year: 2023
As the climate continues to warm, the severity of wildfires is increasing. However, the potential impact of higher burn severity on ecosystem resilience and regional carbon balance is still not clear. There are ongoing debates regarding whether increased burn severity stimulates or delays postfire vegetation and carbon recovery. In this study, we utilized remote sensing data to analyze burn severity and vegetation observations, as well as model simulations to assess wildfire carbon emissions and ecosystem carbon fluxes. Our focus was on examining the dynamics of vegetation and carbon flux…
Publication Type: Journal Article
The contribution of Indigenous stewardship to an historical mixed-severity fire regime in British Columbia, Canada
Year: 2022
Indigenous land stewardship and mixed-severity fire regimes both promote landscape heterogeneity, and the relationship between them is an emerging area of research. In our study, we reconstructed the historical fire regime of Ne Sextsine, a 5900-ha dry, Douglas-fir-dominated forest in the traditional territory of the T’exelc (Williams Lake First Nation) in British Columbia, Canada. Between 1550 and 1982 CE, we found median fire intervals of 18 years at the plot-level and 4 years at the study site-level. Ne Sextsine was characterized by an historical mixed-severity fire regime, dominated by…
Publication Type: Journal Article
The impacts of wildfires of different burn severities on vegetation structure across the western United States rangelands
Year: 2022
Large wildfires have increased in western US rangelands over the last three decades. There is limited information on the impacts of wildfires with different severities on the vegetation in these rangelands. This study assessed the impacts of large wildfires on rangeland fractional cover including annual forbs and grasses (AFG), perennial forbs and grasses (PFG), shrubs (SHR) and trees (TREE) across the western US, and explored relationships between changes in fractional cover and prefire soil moisture conditions. The Expectation Maximization (EM) algorithm was used to group wildfires into…
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
Comparing Geography and Severity of Managed Wildfires in California and the Southwest USA before and after the Implementation of the 2009 Policy Guidance
Year: 2022
Managed wildfires, i.e., naturally ignited wildfires that are managed for resource benefits, have the potential to reduce fuel loads, minimize the effects of future wildfires, and restore critical natural processes across many forest landscapes. In the United States, the 2009 federal wildland fire policy guidance was designed to provide greater flexibility in the use of managed wildfires, but the effects of this policy on wildfires in the western US are not yet fully understood. Our goal was to compare managed and full suppression wildfires and to also analyze the differences between managed…
Publication Type: Journal Article
Mapping the ethical landscape of wildland fire management: setting an agendum for research and deliberation on the applied ethics of wildland fire
Year: 2022
Background: Virtually every decision within wildland fire management includes substantial ethical dimensions. As pressures increase with ever-growing fires, it is becoming increasingly important to develop tools for assessing and acting on the values intrinsic to wildfire management. Aims: This paper aims to foster an applied ethics of wildland fire by bringing values to the forefront of wildland fire management debates, highlighting areas where ethical issues have been previously discussed, and providing a framework to assist in future discussion. Methods: Through a literature review and…
Publication Type: Journal Article
Extreme Winds Alter Influence of Fuels and Topography on Megafire Burn Severity in Seasonal Temperate Rainforests under Record Fuel Aridity
Year: 2022
Nearly 0.8 million hectares of land were burned in the North American Pacific Northwest (PNW) over two weeks under record-breaking fuel aridity and winds during the extraordinary 2020 fire season, representing a rare example of megafires in forests west of the Cascade Mountains. We quantified the relative influence of weather, vegetation, and topography on patterns of high burn severity (>75% tree mortality) among five synchronous megafires in the western Cascade Mountains. Despite the conventional wisdom in climate-limited fire regimes that regional drivers (e.g., extreme aridity, and…
Publication Type: Journal Article
Potential operational delineations: new horizons for proactive, risk-informed strategic land and fire management
Year: 2022
Background The PODs (potential operational delineations) concept is an adaptive framework for cross-boundary and collaborative land and fire management planning. Use of PODs is increasingly recognized as a best practice, and PODs are seeing growing interest from federal, state, local, tribal, and non-governmental organizations. Early evidence suggests PODs provide utility for planning, communication, coordination, prioritization, incident response strategy development, and fuels mitigation and forest restoration. Recent legislative action codifies the importance of PODs by devoting…
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
Interactions Between Fire Refugia and Climate-Environment Conditions Determine Mesic Subalpine Forest Recovery After Large and Severe Wildfires
Year: 2022
Infrequent stand-replacing wildfires are characteristic of mesic and/or cool conifer forests in western North America, where forest recovery within high-severity burn patch interiors can be slow, yet successful over long temporal periods (decades to centuries). Increasing fire frequency and high-severity burn patch size, under a warming climate, however, may challenge post-fire forest recovery, promoting landscape-level shifts in forest structure, composition, and distribution of non-forest patches. Crucial to a delay and/or impediment to this shift, fire refugia (i.e., remnant seed sources)…
Publication Type: Journal Article
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
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
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
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
Cascadia Burning: The historic, but not historically unprecedented, 2020 wildfires in the Pacific Northwest, USA
Year: 2022
Wildfires devastated communities in Oregon and Washington in September 2020, burning almost as much forest west of the Cascade Mountain crest (“the westside”) in 2 weeks (~340,000 ha) as in the previous five decades (~406,00 ha). Unlike dry forests of the interior western United States, temperate rain forests of the Pacific Northwest have experienced limited recent fire activity, and debates surrounding what drove the 2020 fires, and management strategies to adapt to similar future events, necessitate a scientific evaluation of the fires. We evaluate five questions regarding the 2020 Labor…
Publication Type: Journal Article