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The Northwest Fire Science Consortium works to accelerate the awareness, understanding, and adoption of wildland fire science. We connect managers, practitioners, scientists, and local communities and collaboratives working on fire issues on forest and range lands in Washington and Oregon.

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JFSP Regions

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NWFSC is one of
fifteen regional exchanges
sponsored by the Joint Fire Science Program.

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Fire and tree death: understanding and improving modeling of fire-induced tree mortality

Authored by S.M. Hood; Published 2018

Each year wildland fires kill and injure trees on millions of forested hectares globally, affecting plant and animal biodiversity, carbon storage, hydrologic processes, and ecosystem services. The underlying mechanisms of fire-caused tree mortality remain poorly understood, however, limiting the ability to accurately predict mortality and develop robust modeling applications, especially under novel future climates. Virtually all post-fire tree mortality prediction systems are based on the same underlying empirical model described in Ryan and Reinhardt (1988 Can. J. For. Res. 18 1291–7), which was developed from a limited number of species, stretching model assumptions beyond intended limits. We review the current understanding of the mechanisms of fire-induced tree mortality, provide recommended standardized terminology, describe model applications and limitations, and conclude with key knowledge gaps and future directions for research. We suggest a two-pronged approach to future research: (1) continued improvements and evaluations of empirical models to quantify uncertainty and incorporate new regions and species and (2) acceleration of basic, physiological research on the proximate and ultimate causes of fire-induced tree mortality to incorporate processes of tree death into models. Advances in both empirical and process fire-induced tree modeling will allow creation of hybrid models that could advance understanding of how fire injures and kills trees, while improving prediction accuracy of fire-driven feedbacks on ecosystems and landscapes, particularly under novel future conditions.


Advancing the Science of Wildland Fire Dynamics Using Process-Based Models

Authored by C.H. Hoffman; et al.; Published 2018

As scientists and managers seek to understand fire behavior in conditions that extend beyond the limits of our current empirical models and prior experiences, they will need new tools that foster a more mechanistic understanding of the processes driving fire dynamics and effects. Here we suggest that process-based models are powerful research tools that are useful for investigating a large number of emerging questions in wildland fire sciences. These models can play a particularly important role in advancing our understanding, in part, because they allow their users to evaluate the potential mechanisms and interactions driving fire dynamics and effects from a unique perspective not often available through experimentation alone. For example, process-based models can be used to conduct experiments that would be impossible, too risky, or costly to do in the physical world. They can also contribute to the discovery process by inspiring new experiments, informing measurement strategies, and assisting in the interpretation of physical observations. Ultimately, a synergistic approach where simulations are continuously compared to experimental data, and where experiments are guided by the simulations will profoundly impact the quality and rate of progress towards solving emerging problems in wildland fire sciences.


Prescribed fire policy barriers: Findings from a JFSP project on challenges and strategies on federal lands across the West

Webinar from Northwest Fire Science Consortium and Southern Rockies Fire Science Network

Courtney Schultz, Associate Professor of Forest and Natural Resource Policy and Director of the Public Lands Policy Group in the Department of Forest and Rangeland Stewardship at Colorado State University and Heidi Huber-Stearns, Associate Director of the Ecosystem Workforce Program, University of Oregon presented on "Prescribed fire policy barriers: Findings from a JFSP project on challenges and strategies on federal lands across the West." Watch the video on our YouTube channel.


Evaluation of burn mosaics on subsequent wildfire behavior, severity and fire management strategies

Webinar from Northwest Fire Science Consortium

Susan Prichard, research scientist at the University of WA; Nick Povak, ORISE postdoctoral fellow with USFS Pacific Northwest Research Station; and Paul Hessburg, research landscape ecologist with USFS Pacific Northwest Research Station presented on "Evaluation of burn mosaics on subsequent wildfire behavior, severity and fire management strategies." Watch the video on our YouTube channel.


Policy Design to Support Forest Restoration: The Value of Focused Investment and Collaboration

Authored by C.A. Schultz; Published 2018

To address rapid change and complex environmental management challenges, governance approaches must support collective action across actors and jurisdictions, and planning at appropriate spatial extents to affect ecological processes. Recent changes in U.S. national forest policy incorporate new tools to facilitate collaborative landscape restoration, providing an opportunity to examine the relationship between policy design and governance change. Based on 151 interviews with agency personnel and partners, and a survey of 425 agency staff members, we investigated how two new policy approaches affected the governance of forest restoration and also looked at the other factors that most significantly affected policy implementation. Our findings reveal that, under these policies, multi-year funding commitments to specific landscapes, combined with requirements to work collaboratively, resulted in larger scales of planning, improved relationships, greater leveraged capacity, and numerous innovations compared to the past. A history of collaborative relationships, leadership, and agency capacity were the most significant variables that affected the implementation of policies designed to support collaborative landscape restoration. Our findings suggest that policies that provide focused investment to undertake landscape approaches to restoration, along with specific requirements for interagency and partner collaboration, are yielding positive results and may represent a new era in forest policy in the United States.


Ashland Oregon Prescribed Fire Training Exchange

Save the date—details will be available in January.


Central Oregon Prescribed Fire Training Exchange

Save the date—details will be available in January.


Living with Wildland Fire in America: Building New Bridges between Policy, Science, and Management

Authored by J.A. Hall; Published 2018

In his October 26, 2017 commentary in these pages, Dr. Tom Zimmerman highlights a number of ongoing and future challenges faced by wildland fire management. To address these challenges he also identifies an important role for science and in particular management-relevant wildland fire research. Here, we first briefly elaborate on Dr. Zimmerman’s challenges and how they relate to new opportunities for the role of science. Second, we focus on three additional institutional or “cultural” barriers or divides that should be acknowledged and addressed when forging a path forward for wildland fire research and its necessary companion: science delivery. As commenters on these matters, we represent only a small portion—even within the federal wildland fire science community—of those responsible for or interested in the funding, execution, and delivery of actionable science to end users. Nevertheless, we represent key programs with specific missions to serve federal wildland fire-related management and policy information needs.


Tree traits influence response to fire severity in the western Oregon Cascades, USA

Authored by J.D. Johnston; Published 2018

Wildfire is an important disturbance process in western North American conifer forests. To better understand forest response to fire, we used generalized additive models to analyze tree mortality and long-term (1 to 25 years post-fire) radial growth patterns of trees that survived fire across a burn severity gradient in the western Cascades of Oregon. We also used species-specific leaf-area models derived from sapwood estimates to investigate the linkage between photosynthetic capacity and growth response. Larger trees and shade intolerant trees had a higher probability of surviving fire. Trees that survived fire tended to experience a reduction in growth immediately following fire, with the most pronounced growth suppression found in trees within stands burned at high severity. Radial growth response to fire over time differed markedly as a function of tree size. Smaller trees that survived fire generally experienced enhanced radial growth relative to small trees in unburned stands. Conversely, larger trees that survived fire experienced significant and persistent reductions in growth relative to large trees in unburned stands. There was a linear relationship between diameter and tree leaf area in stands burned at low severity, but a non-linear relationship between diameter and leaf area in stand burned at high severity. Generalized additive models are well suited to modeling non-linear mortality and growth responses to fire. This research provides a better understanding of how fire severity influences tree-growth, forest succession, as well as the long-term resilience of forests to disturbances.


Reburn in the Rain Shadow

Authored by N. Vizcarra; Published 2018

Wildfires consume existing forest fuels but also leave behind dead shrubs and trees that become fuel to future wildfires. Harvesting firekilled trees is sometimes proposed as an economical approach for reducing future fuels and wildfire severity. Postfire logging, however, is controversial. Some question its fuel reduction benefits and its ecological impacts.

David W. Peterson, a research forester with the USDA Forest Service, and his colleagues investigated the long-term effects of postfire logging on woody fuels in 255 coniferous forest stands that burned with high fire severity in 68 wildfires between 1970 and 2007 in eastern Washington and Oregon. They found that postfire logging significantly reduced future surface woody fuel levels in forests regenerating following wildfires.

The researchers also investigated the long-term response of understory vegetation to two postfire logging treatments—commercial salvage logging with and without additional fuel reduction logging—on a long-term postfire logging experiment in northeastern Oregon.

They found that postfire logging produced minimal persistent impacts on understory vegetation, suggesting that understory vegetation can be resilient to postfire logging, particularly when best management practices, like logging over snow, are used to limit damage to soils and understory vegetation.


Embracing Complexity to Advance the Science of Wildland Fire Behavior

Authored by K.M. Yedinak; Published 2018

Wildland fire behavior research has largely focused on the steady-state interactions between fuels and heat fluxes. Contemporary research is revealing new questions outside the bounds of this simplified approach. Here, we explore the complex interactions taking place beyond steady-state assumptions through acknowledging the manufactured separation of research disciplines in fire science and the dynamic interactions that unfold when these separations are removed. Through a series of examples spanning at least four research disciplines and three ranges of spatial scale, we illustrate that by precisely defining parameters in a way that holds across scales and relaxing one steady-state simplification, we begin to capture the inherent variability that has largely eluded the fire behavior community. Through exploring examples of “deep interdependence,” we make the case that fire behavior science is well equipped to launch forward into more complex lines of inquiry.


Pyro-Ecophysiology: Shifting the Paradigm of Live Wildland Fuel Research

Authored by M.W. Jolly; Published 2018

The most destructive wildland fires occur in mixtures of living and dead vegetation, yet very little attention has been given to the fundamental differences between factors that control their flammability. Historically, moisture content has been used to evaluate the relative flammability of live and dead fuels without considering major, unreported differences in the factors that control their variations across seasons and years. Physiological changes at both the leaf and whole plant level have the potential to explain ignition and fire behavior phenomena in live fuels that have been poorly explained for decades. Here, we explore how these physiological changes violate long-held assumptions about live fuel dynamics and we present a conceptual model that describes how plant carbon and water cycles independently and interactively influence plant flammability characteristics at both the leaf and whole plant scale. This new ecophysiology-based approach can help us expand our understanding of potential plant responses to environmental change and how those physiological changes may impact plant flammability. Furthermore, it may ultimately help us better manage wildland fires in an uncertain future.


Fuel Treatments: Are we doing enough?

Authored by U.S.D.A.Forest Service; Published 2018

Although a natural ecological process, wildfire in unhealthy forests can be uncharacteristically destructive. Fuel treatments—such as thinning, mowing, prescribed fire, or managed wildfire—can help reduce or redistribute the flammable fuels that threaten to carry and intensify fire. Using both field-tested data and computer simulations, Pacific Northwest Research Station scientists are addressing critical questions such as Are we treating enough
of the landscape to restore fire-adapted forests? Are fuel treatments effective at changing fire behavior? Together with land managers, fuel planners, and other partners, our scientists are helping public land management agencies move toward a future of fire-resilient forests and communities.


Disequilibrium of fire-prone forests sets the stage for a rapid decline in conifer dominance during the 21st century

Authored by J.M. Serra-Diaz; Published 2018

The impacts of climatic changes on forests may appear gradually on time scales of years to centuries due to the long generation times of trees. Consequently, current forest extent may not reflect current climatic patterns. In contrast with these lagged responses, abrupt transitions in forests under climate change may occur in environments where alternative vegetation states are influenced by disturbances, such as fire. The Klamath forest landscape (northern California and southwest Oregon, USA) is currently dominated by high biomass, biodiverse temperate coniferous forests, but climate change could disrupt the mechanisms promoting forest stability (e.g. growth, regeneration and fire tolerance). Using a landscape simulation model, we estimate that about one-third of the Klamath forest landscape (500,000 ha) could transition from conifer-dominated forest to shrub/hardwood chaparral, triggered by increased fire activity coupled with lower post-fire conifer establishment. Such shifts were widespread under the warmer climate change scenarios (RCP 8.5) but were surprisingly prevalent under the climate of 1949–2010, reflecting the joint influences of recent warming trends and the legacy of fire suppression that may have enhanced conifer dominance. Our results demonstrate that major forest ecosystem shifts should be expected when climate change disrupts key stabilizing feedbacks that maintain the dominance of long-lived, slowly regenerating trees.


Escaping social-ecological traps through tribal stewardship on national forest lands in the Pacific Northwest, United States of America

Authored by J.W. Long; Published 2018

Tribal communities in the Pacific Northwest of the United States of America (USA) have long-standing relationships to ancestral lands now managed by federal land management agencies. In recent decades, federal and state governments have increasingly recognized tribal rights to resources on public lands and to participate in their management. In support of a new planning initiative to promote sustainable land management, we reviewed scientific publications to examine relationships between tribal social-ecological systems and public lands in the region. We identified key ecocultural resources, impacts to those resources, and associated forest ecosystems, and strategies that have been piloted to redress those impacts. We found that many factors stemming from colonization by Euro-Americans have engendered social-ecological traps that have inhibited tribes from continuing traditional land stewardship activities that supported their well-being and maintained ecological integrity. These long-standing factors include legal and political constraints on tribal access and management; declining quality and abundance of forest resources due to inhibition of both natural disturbance and indigenous tending regimes; competition with nontribal users; species extirpations and introductions of invasive species; and erosion of tribal traditional ecological knowledge and relationships that are important for revitalizing resource use. As a consequence, both supply and demand for these forest resources have been reduced, as have the resilience and diversity of these ecosystems. Simply permitting resource harvest by tribal members does not sufficiently address the underlying constraints in ways that will promote tribal well-being. Escaping these traps will require addressing a gamut of ecological and social constraints through cooperative restoration efforts between land management agencies and tribes, several of which we highlight as examples. Because tribally focused restoration strategies generally align with broader strategies suggested to restore national forests in the region, they can foster both tribal well-being and ecological sustainability.


Fire Refugia: What Are They, and Why Do They Matter for Global Change?

Authored by A.J.H. Meddens; Published 2018

Fire refugia are landscape elements that remain unburned or minimally affected by fire, thereby supporting postfire ecosystem function, biodiversity, and resilience to disturbances. Although fire refugia have been studied across continents, scales, and affected taxa, they have not been characterized systematically over space and time, which is crucial for understanding their role in facilitating resilience in the context of global change. We identify four dichotomies that delineate an overarching conceptual framework of fire refugia: unburned versus lower severity, species-specific versus landscape-process characteristics, predictable versus stochastic, and ephemeral versus persistent. We outline the principal concepts underlying the ecological function of fire refugia and describe both the role of fire refugia and uncertainties regarding their persistence under global change. An improved understanding of fire refugia is crucial to conservation given the role that humans play in shaping disturbance regimes across landscapes.


NWFSC Fire Facts: What are? Measures of Fire Behavior

Authored by N.W.Fire Scien Consortium; Published 2018

There are four main parameters used by fire managers to describe fire behavior. Read more at Fire Facts: What are? Measures of Fire Behavior