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

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.

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

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.

Reburn in the Rain Shadow

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

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.

Fuel Treatments: Are we doing enough?

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.

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

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.

NWFSC Fire Facts: What are? Measures of Fire Behavior

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