Research Database
Displaying 21 - 40 of 104
Pyrogenic carbon decomposition critical to resolving fire’s role in the Earth system
Year: 2022
Recently identified post-fire carbon fluxes indicate that, to understand whether global fires represent a net carbon source or sink, one must consider both terrestrial carbon retention through pyrogenic carbon production and carbon losses via multiple pathways. Here these legacy source and sink pathways are quantified using a CMIP6 land surface model to estimate Earth’s fire carbon budget. Over the period 1901–2010, global pyrogenic carbon has driven an annual soil carbon accumulation of 337 TgC yr−1, offset by legacy carbon losses totalling −248 TgC yr−1. The residual of these values…
Publication Type: Journal Article
Future climate risks from stress, insects and fire across US forests
Year: 2022
Forests are currently a substantial carbon sink globally. Many climate change mitigation strategies leverage forest preservation and expansion, but rely on forests storing carbon for decades to centuries. Yet climate-driven disturbances pose critical risks to the long-term stability of forest carbon. We quantify the climate drivers that influence wildfire and climate stress-driven tree mortality, including a separate insect-driven tree mortality, for the contiguous United States for current (1984–2018) and project these future disturbance risks over the 21st century. We find that current…
Publication Type: Journal Article
Tamm review: The effects of prescribed fire on wildfire regimes and impacts: A framework for comparison
Year: 2020
Prescribed fire can result in significant benefits to ecosystems and society. Examples include improved wildlifehabitat, enhanced biodiversity, reduced threat of destructive wildfire, and enhanced ecosystem resilience.Prescribed fire can also come with costs, such as reduced air quality and impacts to fire sensitive species. To planfor appropriate use of prescribed fire, managers need information on the tradeoffs between prescribed fire andwildfire regimes. In this study, we argue that information on tradeoffs should be presented at spatial andtemporal scales commensurate with the scales at…
Publication Type: Journal Article
High‐severity wildfire leads to multi‐decadal impacts on soil biogeochemistry in mixed‐conifer forests
Year: 2020
During the past century, systematic wildfire suppression has decreased fire frequency and increased fire severity in the western United States of America. While this has resulted in large ecological changes aboveground such as altered tree species composition and increased forest density, little is known about the long‐term, belowground implications of altered, ecologically novel, fire regimes, especially on soil biological processes. To better understand the long‐term implications of ecologically novel, high‐severity fire, we used a 44‐yr high‐severity fire chronosequence in the Sierra…
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
Reburn in the Rain Shadow
Year: 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…
Publication Type: Report
Recovery of ectomycorrhizal fungus communities fifteen years after fuels reduction treatments in ponderosa pine forests of the Blue Mountains, Oregon
Year: 2018
Managers use restorative fire and thinning for ecological benefits and to convert fuel-heavy forests to fuel-lean landscapes that lessen the threat of stand-replacing wildfire. In this study, we evaluated the long-term impact of thinning and prescribed fire on soil biochemistry and the mycorrhizal fungi associated with ponderosa pine (Pinus ponderosa). Study sites were located in the Blue Mountains of northeastern Oregon where prescribed fire treatments implemented in 1998 and thinning treatments in 2000 included prescribed fire, mechanical thinning of forested areas, a combination of…
Publication Type: Journal Article
Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity
Year: 2018
Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the…
Publication Type: Journal Article
Pyro-Ecophysiology: Shifting the Paradigm of Live Wildland Fuel Research
Year: 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…
Publication Type: Journal Article
The influence of fire history on soil nutrients and vegetation cover in mixed-severity fire regime forests of the eastern Olympic Peninsula, Washington, USA
Year: 2018
The rain shadow forests of the Olympic Peninsula exemplify a mixed-severity fire regime class in the midst of a highly productive landscape where spatial heterogeneity of fire severity may have significant implications for below and aboveground post-fire recovery. The purpose of this study was to quantify the impacts of wildfire on forest soil carbon (C) and nitrogen (N) pools and assess the relationship of pyrogenic carbon (PyC) to soil processes in this mixed-severity ecosystem. We established a 112-year fire chronosequence with nine similar forest stands ranging in time since lastfire (TSF…
Publication Type: Journal Article
Telling Fire’s Story through Narrative and Art
Year: 2017
Modern works by highly skilled narrative authors and artists have become increasingly useful for telling the story of wildland fire in the United States. Using unconventional means—and with partial funding by the Joint Fire Science Program—creative individuals have spawned some colorful and heartfelt messages that convey insightful information about wildland fire, climate, and other elements of nature to an increasingly receptive public. Recent narrative works by well-known authors, such as Stephen J. Pyne, and creative art pieces by well-established and emerging artists have helped depict…
Publication Type: Report
Relational risk assessment and management: investigating capacity in wildfire response networks
Year: 2017
Failures in effective communication and coordination within the network of responding organizations and agencies during a wildfire can lead to problematic or dangerous outcomes. Although risk assessment and management concepts are usually understood with regards to biophysical attributes in the wildfire context, these concepts can be extended to understanding risk for problematic communication and coordination embedded within social and organizational relationships. In this research, we propose leveraging existing network and social coordination theory to investigate how pre-fire…
Publication Type: Report
Emissions from prescribed burning of timber slash piles in Oregon
Year: 2017
Emissions from burning piles of post-harvest timber slash (Douglas-fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5), black carbon, ultraviolet absorbing PM, elemental/organic carbon, filter-based metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins/dibenzofurans (PCDD/PCDF), and volatile organic compounds (VOCs) were sampled to determine emission factors, the amount of pollutant formed per amount…
Publication Type: Journal Article
The Science of Fuel Treatments
Year: 2017
High fuel loads can significantly contribute to the intensity and severity of fires. Fuels include plant material, such as leaves, bark, needles, branches, and vegetation. Land managers use various methods to reduce fuel levels. The two most common fuel treatment methods include forest thinning and prescribed fire. The pace of implementing such fuel treatments has increased over the last several decades. Scientific studies of fuel treatments supported by the Joint Fire Science Program (JFSP) highlight significant findings on the effectiveness of these treatments in various fuel types.
Publication Type: Report
Policy Scenarios for fire-adapted communities: Understanding stakeholder risk-perceptions, using Fuzzy Cognitive Maps
Year: 2017
Collaborative groups are most effective when the varied stakeholder groups within them understand the risks of wildfire and take proactive steps to manage these risks. Implementing policies for fire risk mitigation and adaptation, however, remains difficult because risks and policy alternatives are not understood or supported uniformly across diverse stakeholders. To facilitate greater understanding and collaboration across diverse groups, we developed a novel approach, based on Fuzzy Cognitive Maps (FCM), in which we systematically collected mental model representations from a range of…
Publication Type: Report
Fire Science Exchange Network
Year: 2017
The Joint Fire Science Program (JFSP) Fire Science Exchange Network is a national collaboration of 15 regional fire science exchanges that provides the most relevant, current wildland fire science information to federal, state, local, tribal, and private stakeholders within ecologically similar regions. The network brings fire managers, practitioners, and scientists together to address regional fire management needs and challenges.
Publication Type: Report
Joint Fire Science Program Smoke Science Plan Conclusion: Smoke Science Accomplishments Under the Plan
Year: 2017
The Smoke Science Plan (SSP) was the guidance and organizational tool of the Joint Fire Science Program for smoke research from 2011 until 2016. It helped to guide the funding and management of 41 research and development projects under four thematic areas. Since its inception in 2011, 29 smoke science projects have been funded. An additional 12 legacy projects, addressing research needs identified in the SSP, were added to the portfolio for a total of 41 projects considered as part of the SSP.
Publication Type: Report
Bridging the gap: Joint Fire Science Program Outcomes
Year: 2017
The Joint Fire Science Program (JFSP) has funded an impressive number of research projects over the years. However, the number of projects does not necessarily provide an accurate picture of the program’s effectiveness. Over the last decade, researchers have collected data and conducted several studies to determine whether the results of JFSP-funded projects are reaching potential users and informing management decisions and actions. Those studies have helped identify issues and influence changes within the program. Early studies pointed out the need for a boundary-spanning organization to…
Publication Type: Report
Forest management scenarios in a changing climate: trade-offs between carbon, timber, and old forest
Year: 2016
Balancing economic, ecological, and social values has long been a challenge in the forests of the Pacific Northwest, where conflict over timber harvest and old-growth habitat on public lands has been contentious for the past several decades. The Northwest Forest Plan, adopted two decades ago to guide management on federal lands, is currently being revised as the region searches for a balance between sustainable timber yields and habitat for sensitive species. In addition, climate change imposes a high degree of uncertainty on future forest productivity, sustainability of timber harvest,…
Publication Type: Journal Article
Scanning the Future of Wildfire: Resilience Ahead...Whether We Like It or Not?
Year: 2016
The field of so-called “futures research” provides researchers and stakeholders in a given subject area or system a way to map out and plan for alternate possible scenarios of the future. A recent research project supported by the Joint Fire Science Program brought together futures researchers and wildfire specialists to envision what the future holds for wildfire impacts and how the wildfire community may respond to the complex suite of emerging challenges. The consensus of the project’s foresight panel suggests that an era of resilience is ahead: but that this resilience may come either…
Publication Type: Report