Research Database
Displaying 1 - 20 of 52
Small-scale fire refugia increase soil bacterial and fungal richness and increase community cohesion nine years after fire
Year: 2025
Small-scale variation in wildfire behavior may cause large differences in belowground bacterial and fungal communities with consequences for belowground microbial diversity, community assembly, and function. Here we combine pre-fire, active-fire, and post-wildfire measurements in a mixed-conifer forest to identify how fine-scale wildfire behavior, unburned refugia, and aboveground forest structure are associated with belowground bacterial and fungal communities nine years after wildfire. We used fine-scale mapping of small (0.9–172.6 m2) refugia to sample soil-associated burned and…
Publication Type: Journal Article
Characterizing post-fire delayed tree mortality with remote sensing: sizing up the elephant in the room
Year: 2024
BackgroundDespite recent advances in understanding the drivers of tree-level delayed mortality, we lack a method for mapping delayed mortality at landscape and regional scales. Consequently, the extent, magnitude, and effects of delayed mortality on post-fire landscape patterns of burn severity are unknown. We introduce a remote sensing approach for mapping delayed mortality based on post-fire decline in the normalized burn ratio (NBR). NBR decline is defined as the change in NBR between the first post-fire measurement and the minimum NBR value up to 5 years post-fire for each pixel…
Publication Type: Journal Article
Fire refugia are robust across Western US forested ecoregions, 1986–2021
Year: 2023
In the Western US, area burned and fire size have increased due to the influences of climate change, long-term fire suppression leading to higher fuel loads, and increased ignitions. However, evidence is less conclusive about increases in fire severity within these growing wildfire extents. Fires burn unevenly across landscapes, leaving islands of unburned or less impacted areas, known as fire refugia. Fire refugia may enhance post-fire ecosystem function and biodiversity by providing refuge to species and functioning as seed sources after fires. In this study, we evaluated whether the…
Publication Type: Journal Article
Refuge-yeah or refuge-nah? Predicting locations of forest resistance and recruitment in a fiery world
Year: 2023
Climate warming, land use change, and altered fire regimes are driving ecological transformations that can have critical effects on Earth's biota. Fire refugia—locations that are burned less frequently or severely than their surroundings—may act as sites of relative stability during this period of rapid change by being resistant to fire and supporting post-fire recovery in adjacent areas. Because of their value to forest ecosystem persistence, there is an urgent need to anticipate where refugia are most likely to be found and where they align with environmental conditions that support post-…
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
Where and why do conifer forests persist in refugia through multiple fire events?
Year: 2021
Changing wildfire regimes are causing rapid shifts in forests worldwide. In particular, forested landscapes that burn repeatedly in relatively quick succession may be at risk of conversion when pre-fire vegetation cannot recover between fires. Fire refugia (areas that burn less frequently or severely than the surrounding landscape) support post-fire ecosystem recovery and the persistence of vulnerable species in fire-prone landscapes. Observed and projected fire-induced forest losses highlight the need to understand where and why forests persist in refugia through multiple fires. This…
Publication Type: Journal Article
Disjunct and decoupled? The persistence of a fire-sensitive conifer soecies in a historically frequent-fire landscape
Year: 2020
Local and regional species extirpations may become more common as changing climate and disturbance regimesaccelerate species’ in situ range contractions. Identifying locations that function as both climate and disturbancerefugia is critical for biodiversity conservation. Here, we investigate the persistence of a disjunct, fire-sensitiveconifer population, yellow-cedar (Callitropsis nootkatensis), in the historically frequent-fire landscape of the BlueMountains in eastern Oregon, USA. We used tree rings to reconstruct multi-century fire histories, which werethen used to compare historical mean…
Publication Type: Journal Article
Contributions of fire refugia to resilient ponderosa pine and dry mixed-conifer forest landscapes
Year: 2019
Altered fire regimes can drive major and enduring compositional shifts or losses of forest ecosystems. In western North America, ponderosa pine and dry mixed‐conifer forest types appear increasingly vulnerable to uncharacteristically extensive, high‐severity wildfire. However, unburned or only lightly impacted forest stands that persist within burn mosaics—termed fire refugia—may serve as tree seed sources and promote landscape recovery. We sampled tree regeneration along gradients of fire refugia proximity and density at 686 sites within the perimeters of 12 large wildfires that occurred…
Publication Type: Journal Article
Influence of fire refugia spatial pattern on post-fire forest recovery in Oregon’s Blue Mountains
Year: 2019
Context Fire regimes in many dry forests of western North America are substantially different from historical conditions, and there is concern about the ability of these forests to recover following severe wildfire. Fire refugia, unburned or low-severity burned patches where trees survived fire, may serve as essential propagule sources that enable forest regeneration. Objectives To quantify the influence of fire refugia spatial pattern and other biophysical factors on the process of post-fire tree regeneration; in particular examining both the proximity and density of surrounding refugia to…
Publication Type: Journal Article
Spatiotemporal patterns of unburned areas within fire perimeters in the northwestern United States from 1984 to 2014
Year: 2018
A warming climate, fire exclusion, and land cover changes are altering the conditions that produced historical fire regimes and facilitating increased recent wildfire activity in the northwestern United States. Understanding the impacts of changing fire regimes on forest recruitment and succession, species distributions, carbon cycling, and ecosystem services is critical, but challenging across broad spatial scales. One important and understudied aspect of fire regimes is the unburned area within fire perimeters; these areas can function as fire refugia across the landscape during and after…
Publication Type: Journal Article
Fire Refugia: What Are They, and Why Do They Matter for Global Change?
Year: 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…
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
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
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
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
Secretarial Order 3336 Science Priorities: The Role of Science Past, Present, and Future
Year: 2016
Within sagebrush (Artemisia spp.) ecosystems, which are home to more than 350 species of plants and animals, potentially more frequent and severe fires are causing an increased threat to human safety, property, rural economies, and wildlife habitat. In particular, the habitat of the greater sage-grouse (Centrocercus urophasianus), an iconic sagebrush-dependent species, is at risk. In response to this reality, on January 15, 2015, Secretary Sally Jewell signed Secretarial Order 3336 (S.O. 3336), titled “Rangeland Fire Prevention, Management, and Restoration.” The main purpose of the order is…
Publication Type: Report