Research Database
Displaying 561 - 580 of 1416
Predicting increasing high severity area burned for three forested regions in the western United States using extreme value theory
Year: 2019
More than 70 years of fire suppression by federal land management agencies has interrupted fire regimes in much of the western United States. The result of missed fire cycles is a buildup of both surface and canopy fuels in many forest ecosystems, increasing the risk of severe fire. The frequency and size of fires has increased in recent decades, as has the area burned with high severity in some ecosystems. A number of studies have examined controls on high severity fire occurrence, but none have yet determined what controls the extent of high severity fire. We developed statistical models…
Publication Type: Journal Article
Post-fire management affects species composition but not Douglas-fir regeneration in the Klamath Mountains
Year: 2019
Ensuring adequate conifer regeneration after high severity wildfires is a common objective for ecologists and forest managers. In the Klamath region of Oregon and California, a global hotspot of botanical biodiversity, concerns over regeneration have led to post-fire management on many sites, which involves salvage logging followed by site preparation, conifer planting, and manual shrub release. To quantify the impacts of post-fire management, we sampled 62 field sites that burned at high severity nearly 20 years ago in the Klamath-Siskiyou Mountain bioregion, stratifying by management and…
Publication Type: Journal Article
Increasing trends in high-severity fire in the southwestern USA from 1984 to 2015
Year: 2019
In the last three decades, over 4.1 million hectares have burned in Arizona and New Mexico and the largest fires in documented history have occurred in the past two decades. Changes in burn severity over time, however, have not been well documented in forest and woodland ecosystems in the southwestern US. Using remotely sensed burn severity data from 1621 fires (>404 ha), we assessed trends from 1984 to 2015 in Arizona and New Mexico in (1) number of fires and total area burned in all vegetation types; (2) area burned, area of high-severity, and percent of high-severity fire in all forest…
Publication Type: Journal Article
Tradeoffs between US national forest harvest targets and fuel management to reduce wildfire transmission to the wildland urban interface
Year: 2019
US public land management agencies are faced with multiple, often conflicting objectives to meet management targets and produce a wide range of ecosystem services expected from public lands. One example is managing the growing wildfire risk to human and ecological values while meeting programmatic harvest targets for economic outputs mandated in agency budgets. Studies examining strategic management tradeoffs on federal lands and program efficiencies are rare. In this study we used the 79 western US national forests to examine tradeoffs between forest management scenarios targeting wildfire…
Publication Type: Journal Article
Predicting post-fire attack of red turpentine or western pine beetle on ponderosa pine and its impact on mortality probability in Pacific Northwest forests
Year: 2019
In ponderosa pine forests of western North America, wildfires are becoming more frequent and affecting larger areas, while prescribed fire is increasingly used to reduce fuels and mitigate potential wildfire severity. Both fire types leave trees that initially survive their burn injuries, but will eventually die. Predicting delayed tree mortality has received considerable research attention to aid in post-fire planning and management. The amount of crown scorched is recognized as the most useful variable for discriminating between trees that live or die, but models gain discrimination with…
Publication Type: Journal Article
Spatial and temporal assessment of responder exposure to snag hazards in post-fire environments
Year: 2019
Researchers and managers increasingly recognize enterprise risk management as critical to addressing contemporary fire management challenges. Quantitative wildfire risk assessments contribute by parsing and mapping potentially contradictory positive and negative fire effects. However, these assessments disregard risks to fire responders because they only address social and ecological resources and assets. In this study, we begin to overcome this deficiency by using a novel modeling approach that integrates remote sensing, field inventories, imputation-based vegetation modeling, and empirical…
Publication Type: Journal Article
Traditional knowledge of fire use by the Confederated Tribes of Warm Springs in the eastside Cascades of Oregon Share via EmailShare on FacebookShare on LinkedIn
Year: 2019
We examined traditional knowledge of fire use by the Ichishikin (Sahaptin), Kitsht Wasco (Wasco), and Numu (Northern Paiute) peoples (now Confederated Tribes of Warm Springs, CTWS) in the eastside Cascades of Oregon to generate insights for restoring conifer forest landscapes and enhancing culturally-valued resources. We examined qualitative and geospatial data derived from oral history interviews, participatory GIS focus groups, archival records, and historical forest surveys to characterize cultural fire regimes (CFRs) –an element of historical fire regimes– of moist mixed conifer (MMC),…
Publication Type: Journal Article
What drives ponderosa pine regeneration following wildfire in the western United States?
Year: 2019
Ponderosa pine (Pinus ponderosa Lawson & C. Lawson) is a prominent tree species in forests of the western United States. Wildfire activity in ponderosa pine dominated or co-dominated forests has increased dramatically in recent decades, with these recent wildfires often burning in an uncharacteristic manner due to past land management activities and changing climate. The structure and function of vegetative communities that develop following recent wildfires are highly contingent on ponderosa pine regeneration, making it important that the factors influencing this regeneration be…
Publication Type: Journal Article
The emergence of network governance in U.S. National Forest Administration: Causal factors and propositions for future research
Year: 2019
Since its establishment in the early twentieth century, the U.S. Forest Service has periodically evolved its approach to decision-making and management for the millions of hectares of national forest under its authority. Starting in the 1990s, a complex governance regime emerged in which non-Forest Service entities—such as state and other federal agencies, non-governmental organizations, public utilities, rural communities, and others—contribute resources and legitimacy to processes that include decision-making, project funding and implementation, monitoring, and changes to management rules…
Publication Type: Journal Article
Effects of season and interval of prescribed burns on pyrogenic carbon in ponderosa pine stands in the southern Blue Mountains, Oregon, USA
Year: 2019
In ponderosa pine (Pinus ponderosa) forests of the western United States, prescribed burns are used to reduce fuel loads and restore historical fire regimes. The season of and interval between burns can have complex consequences for the ecosystem, including the production of pyrogenic carbon (PyC). PyC plays a crucial role in soil carbon cycling, displaying turnover times that are orders of magnitude longer than unburned organic matter. This work investigated how the season of and interval between prescribed burns affects soil organic matter, including the formation and retention of PyC, in a…
Publication Type: Journal Article
Social fragmentation and wildfire management: Exploring the scale of adaptive action
Year: 2019
The research presented in this article responds to the deficit described above by exploring the ways that interaction between residents, land managers, fire professionals, and government officials’ influences local approaches to wildfire management. We use the term social dynamics in reference to the patterns, influences and perspectives characterizing the interaction between human actors surrounding wildfire management, including their influence on the scale at which management can occur. We conducted focus groups with a variety of professionals, residents, and government officials in a…
Publication Type: Journal Article
Cost-effective fuel treatment planning: a theoretical justification and case study
Year: 2019
Modelling the spatial prioritisation of fuel treatments and their net effect on values at risk is an important area for applied work as economic damages from wildfire continue to grow. We model and demonstrate a cost-effective fuel treatment planning algorithm using two ecosystem services as benefits for which fuel treatments are prioritised. We create a surface of expected fuel treatment costs to incorporate the heterogeneity in factors affecting the revenue and costs of fuel treatments, and then prioritise treatments based on a cost-effectiveness ratio to maximise the averted loss of…
Publication Type: Journal Article
Fire behaviour and smoke modelling: model improvement and measurement needs for next-generation smoke research and forecasting systems
Year: 2019
There is an urgent need for next-generation smoke research and forecasting (SRF) systems to meet the challenges of the growing air quality, health and safety concerns associated with wildland fire emissions. This review paper presents simulations and experiments of hypothetical prescribed burns with a suite of selected fire behaviour and smoke models and identifies major issues for model improvement and the most critical observational needs. The results are used to understand the new and improved capability required for the next-generation SRF systems and to support the design of the Fire and…
Publication Type: Journal Article
Integrating Subjective and Objective Dimensions of Resilience in Fire-Prone Landscapes
Year: 2019
Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives and definitions of resilience is a complex and often unrecognized challenge to applying resilience concepts to social–ecological systems (SESs) management. Using wildfire as an example, we develop a framework to expose and separate two important dimensions of resilience: the inherent properties that maintain structure, function, or states of an SES and the human perceptions of desirable or valued components…
Publication Type: Journal Article
Use of Science and Modeling by Practitioners in Landscape-Scale Management Decisions
Year: 2019
Scientific knowledge and tools have central roles in contemporary federal forest programs that promote restoration in large landscapes and across ownerships. Although we know much about the role of science in decisionmaking and ways that science can be better linked to practice, we know less about manager perspectives about science and science tools, and the perceived role of both in planning. We surveyed Forest Service resource managers in the western United States to address this knowledge gap. Respondents engaged most frequently with science via reading research publications; direct…
Publication Type: Journal Article
Near-future forest vulnerability to drought and fire varies across the western United States
Year: 2019
Recent prolonged droughts and catastrophic wildfires in the western United States have raised concerns about the potential for forest mortality to impact forest structure, forest ecosystem services, and the economic vitality of communities in the coming decades. We used the Community Land Model (CLM) to determine forest vulnerability to mortality from drought and fire by the year 2049. We modified CLM to represent 13 major forest types in the western United States and ran simulations at a 4‐km grid resolution, driven with climate projections from two general circulation models under one…
Publication Type: Journal Article
Fire deficits have increased drought‐sensitivity in dry conifer forests; fire frequency and tree‐ring carbon isotope evidence from Central Oregon
Year: 2019
A century of fire suppression across the Western US has led to more crowded forests and increased competition for resources. Studies of forest thinning or stand conditions after mortality events have provided indirect evidence for how competition can promote drought stress and predispose forests to severe fire and/or bark beetle outbreaks. Here we demonstrate linkages between fire deficits and increasing drought stress through analyses of annually resolved tree‐ring growth, fire scars, and carbon isotope discrimination (Δ13C) across a dry mixed‐conifer forest landscape. Fire deficits across…
Publication Type: Journal Article
Understory vascular plant responses to retention harvesting with and without prescribed fire
Year: 2019
Wildfire is the predominant natural disturbance in the boreal forests of western Canada. Natural disturbance-based forest management involves the use of retention harvesting to retain stand structural diversity post-harvest; however, this partial harvesting technique does not cause combustion of the forest floor as does fire. Application of prescribed burning to areas treated with retention harvesting might emulate the influence of wildfires more effectively than harvesting alone. We compared understory vascular plant diversity, abundance, and composition between forest stands subjected to…
Publication Type: Journal Article
Making the Transition from Science Delivery to Knowledge Coproduction in Boundary Spanning: A Case Study of the Alaska Fire Science Consortium
Year: 2019
Boundary organizations facilitate two-way, sustained interaction and communication between research and practitioner spheres, deliver existing science, and develop new, actionable scientific information to address emerging social–ecological questions applicable to decision-making. There is an increasing emphasis on the role of boundary organizations in facilitating knowledge coproduction, which is collaborative research with end users to develop actionable scientific information for decision-making. However, a deeper understanding of how boundary organizations and knowledge coproduction work…
Publication Type: Journal Article
Beyond red crowns: complex changes in surface and crown fuels and their interactions 32 years following mountain pine beetle epidemics in south-central Oregon, USA
Year: 2019
Background Mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB), a bark beetle native to western North America, has caused vast areas of tree mortality over the last several decades. The majority of this mortality has been in lodgepole pine (Pinus contorta Douglas ex Loudon) forests and has heightened concerns over the potential for extreme fire behavior across large landscapes. Although considerable research has emerged concerning influence of MPB on forest fuels, there has been little work in the climax lodgepole pine forests of south-central Oregon, USA. Specifically, we assessed…
Publication Type: Journal Article