Research Database
Displaying 161 - 180 of 209
Spatiotemporal dynamics of fine dead surface fuel moisture content in a Colorado mixed-conifer forest
Year: 2025
BackgroundDead fine fuel moisture content (FMC) is critical for predicting fire behavior and effects. Spatiotemporal variation in FMC occurs due to to variability in atmospheric conditions at the fuel interface, which is influenced by interacting factors including local forest structure and topography. Previous research has primarily examined these patterns over coarse spatial scales and relied on few factors to explain variability.AimsIn this study, we monitored the spatiotemporal variability in FMC and characterized how controls of FMC vary over a fire…
Publication Type: Journal Article
Active-fire landscapes demonstrate structural resistance to subsequent fire and drought
Year: 2025
A key tenet of contemporary management in dry, fire-adapted forests of western North America is the reintroduction of a frequent and low- to moderate-severity fire regime. Where this fire regime has been fully or partially restored, it is critical to evaluate the degree to which these landscapes demonstrate forest structural resistance (i.e., the capacity to retain intrinsic structures through time) under novel climates and disturbances. In this study, we used overlapping airborne lidar datasets spanning active-fire landscapes in the Sierra Nevada, California, to evaluate how tree densities,…
Publication Type: Journal Article
Decreasing landscape carbon storage in western US forests with 2 °C of warming
Year: 2025
Changing climate is altering the amount of carbon that can be sustained in forest ecosystems. Increasing heat and drought is already causing increased mortality and decreased regeneration in some locations. These changes have implications for landscape carbon storage with ongoing climate change. We used a climate analogs approach to project aboveground forest carbon density under +2 °C warming above pre-industrial climate for western US forests. We calculated analogs for current climate and under +2 °C warming and associated carbon density for each time period. We found that in most…
Publication Type: Journal Article
Multiple Fire Index Examination of Future Climate Change Affecting Wildfire Seasonality and Extremes in the Contiguous United States
Year: 2025
Climate change is impacting wildfires in the contiguous United States; thus, projections of fire danger under climate change have the potential to inform responses to changing wildfire risks. We calculate fire indices for 13 dynamically downscaled regional climate models, then count days exceeding relevant fire danger thresholds, and compare future changes for mid- and late-twenty-first century relative to a historical reference period. We then compare the responses of the fire indices to highlight areas of agreement and disagreement on the sign and magnitude of future change in fire danger…
Publication Type: Journal Article
Carbon costs of different pathways for reducing fire hazard in the Sierra Nevada
Year: 2025
Restoring a low-intensity, frequent-fire regime in fire-prone forests offers a promising natural climate solution. Management interventions that include prescribed fire and/or mechanical treatments have effectively reduced fire hazards in the Western United States, yet concerns remain regarding their impact on forest carbon storage. This study used results from a long-term, replicated field experiment to assess the impacts of a restored disturbance regime on carbon dynamics in a Sierra Nevada, mixed conifer forest. The carbon consequences of the treatments were compared to a dynamic baseline…
Publication Type: Journal Article
Power and planning: a critical discourse analysis of tribal and non-tribal Oregon wildfire protection plans
Year: 2025
BackgroundSince the late 1800s, the US government has largely removed Indigenous fire stewardship practices from the landscape by implementing a top-down fire suppression system that criminalized traditional fire practices and denaturalized the role of fire in forested environments. A century of routine fire suppression produced dense, homogenous forests capable of sustaining high-intensity wildfire that exceeds the suppression capabilities of land management organizations in many regions, spurring federal leaders to modify management approaches. As part of this change,…
Publication Type: Journal Article
When the wilderness burns: an analysis of current fire management and the case for prescribed fire in designated wilderness in the United States
Year: 2025
BackgroundUnited States wilderness areas face increasing challenges from altered fire regimes and climate change, and land managers face ever more complex decisions about fire use. While federal policies permit various fire management strategies in wilderness, including prescribed fire, managers predominantly rely on suppression despite broad support to restore and sustain fire's natural role in these landscapes. Consequently, wilderness fire regimes continue to diverge from historical norms. To better understand wilderness fire management, we used surveys and interviews with…
Publication Type: Journal Article
Episodic occurrence of favourable weather constrains recovery of a cold desert shrubland after fire
Year: 2021
1. Key to the long-term resilience of dryland ecosystems is the recovery of foundation plant species following disturbance. In ecosystems with high interannual weather variability, understanding the influence of short-term environmental conditions on establishment of foundation species is essential for identifying vulnerable landscapes and developing restoration strategies. We asked how annual environmental conditions affect post-fire establishment of Artemisia tridentata, a shrub species that dominates landscapes across much of the western United States, and evaluated the influence of…
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
Evidence for widespread changes in the structure, composition, and fire regimes of western North American forests
Year: 2021
Implementation of wildfire- and climate-adaptation strategies in seasonally dry forests of western North America is impeded by numerous constraints and uncertainties. After more than a century of resource and land use change, some question the need for proactive management, particularly given novel social, ecological, and climatic conditions. To address this question, we first provide a framework for assessing changes in landscape conditions and fire regimes. Using this framework, we then evaluate evidence of change and lack of change in contemporary conditions relative to those maintained by…
Publication Type: Journal Article
Adapting western North American forests to climate change and wildfires: ten common questions
Year: 2021
We review science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes. As part of the review, we address common questions associated with climate adaptation and realignment treatments that run counter to a broad consensus in the literature. These include: (1) Are the effects of fire exclusion overstated? If so, are treatments unwarranted and even counterproductive? (2) Is forest thinning alone sufficient to mitigate wildfire hazard? (3) Can forest thinning and…
Publication Type: Journal Article
The "strings attached" to community difference and potential pathways to fire adaptiveness in the wildland urban interface
Year: 2021
This article identifies specific social characteristics in two wildland urban interface communities that may have significant impacts on the ability of those communities to adapt to wildfire. Researchers used a mixed-methods approach to triangulate results to identify potential views and motives surrounding three important behaviors and values related to crafting potential strategies to mitigate wildfire risk. The analysis of quantitative data in the form of responses to Likert-type questions and qualitative data in the form of responses to questions asked during focus group sessions yielded…
Publication Type: Journal Article
Wildfire and climate change adaptation of western North American forests: a case for intentional management
Year: 2021
We review science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes. As part of the review, we address common questions associated with climate adaptation and realignment treatments that run counter to a broad consensus in the literature. These include the following: (1) Are the effects of fire exclusion overstated? If so, are treatments unwarranted and even counterproductive? (2) Is forest thinning alone sufficient to mitigate wildfire hazard? (3) Can forest…
Publication Type: Journal Article
Wildfire and climate change adaptation of western North American forests: a case for intentional management
Year: 2021
Forest landscapes across western North America (wNA) have experienced extensive changes over the last two centuries, while climatic warming has become a global reality over the last four decades. Resulting interactions between historical increases in forested area and density and recent rapid warming, increasing insect mortality, and wildfire burned areas, are now leading to substantial abrupt landscape alterations. These outcomes are forcing forest planners and managers to identify strategies that can modify future outcomes that are ecologically and/or socially undesirable. Past forest…
Publication Type: Journal Article
Fire and Forests in the 21st Century: Managing Resilience Under Changing Climates and Fire Regimes in USA Forests
Year: 2021
Higher temperatures, lower snowpacks, drought, and extended dry periods have contributed to increased wildfire activity in recent decades. Climate change is expected to increase the frequency of large fires, the cumulative area burned, andfire suppression costs and risks in many areas of the USA. Fire regimes are likely to change due to interactions among climate, fire, and other stressors and disturbances; resulting in persistent changes in forest structure and function. The remainder of the twenty-first century will present substantial challenges, as natural resource managers are faced with…
Publication Type: Book Chapter
Network governance in the use of prescribed fire: roles for bridging organizations and other actors in the Western United States
Year: 2021
Dangerous wildfire conditions continue to threaten people and ecosystems across the globe and cooperation is critical to meeting the outsized need for increased prescribed burning in wildfire risk reduction work. Despite the benefits of using prescribed fire to mitigate wildfire risks, prescribed fire implementation is still challenging. Collaboration and capacity-building can help address policy and capacity barriers inhibiting prescribed fire. We conducted 53 interviews across four case studies in the western United States where federal land management agencies and cooperative actors are…
Publication Type: Journal Article
Disturbance shapes the US forest governance frontier: A review and conceptual framework for understanding governance change
Year: 2021
Conflict in US forest management for decades centered around balancing demands from forested ecosystems, with a rise in place-based collaborative governance at the end of the twentieth century. By the early 2000s, it was becoming apparent that not only had the mix of players involved in forest management changed, but so had the playing field, as climate-driven disturbances such as wildfire and insect and disease outbreaks were becoming more extensive and severe. In this conceptual review paper, we argue that disturbance has become the most prominent driver of governance change on US national…
Publication Type: Journal Article
Repeated fall prescribed fire in previously thinned Pinus ponderosa increases growth and resistance to other disturbances
Year: 2021
In western North America beginning in the late 19th century, fire suppression and other factors resulted in denseponderosa pine (Pinus ponderosa) forests that are now prone to high severity wildfire, insect attack, and rootdiseases. Thinning and prescribed fire are commonly used to remove small trees, fire-intolerant tree species, andshrubs, and to reduce surface and aerial fuels. These treatments can be effective at lowering future fire severity,but prescribed burns must be periodically repeated to maintain favorable conditions and are feasible only outsidethe historical summer wildfire…
Publication Type: Journal Article
Repeated fall prescribed fire in previously thinned Pinus ponderosa increases growth and resistance to other disturbances
Year: 2021
In western North America beginning in the late 19th century, fire suppression and other factors resulted in dense ponderosa pine (Pinus ponderosa) forests that are now prone to high severity wildfire, insect attack, and root diseases. Thinning and prescribed fire are commonly used to remove small trees, fire-intolerant tree species, and shrubs, and to reduce surface and aerial fuels. These treatments can be effective at lowering future fire severity, but prescribed burns must be periodically repeated to maintain favorable conditions and are feasible only outside the historical summer wildfire…
Publication Type: Journal Article
High-severity wildfire reduces richness and alters composition of ectomycorrhizal fungi in low-severity adapted ponderosa pine forests
Year: 2021
Ponderosa pine (Pinus ponderosa) forests are increasingly experiencing high-severity, stand-replacing fires.Whereas alterations to aboveground ecosystems have been extensively studied, little is known about soil fungal responses in fire-adapted ecosystems. We implement a chronosequence of four different fires that varied in time since fire, 2 years (2015) to 11 years (2006) and contained stands of high severity burned P. ponderosa in easternWashington and compared their soil fungal communities to adjacent unburned plots. Using Illumina Miseq(ITS1), we examined changes in soil nutrients,…
Publication Type: Journal Article