Research Database
Displaying 21 - 40 of 172
Modeling Neighborhoods as Fuel for Wildfire: A Review
Year: 2025
Wildfire’s destruction of homes is an increasingly serious global problem. Research indicates that characterizing home hardening and defensible space at the individual structure level may reduce loss through enriched understanding of structure susceptibility in the built environment. However, improved data and methods are required to accurately characterize these features at scale. This paper does three things: (1) Identifies features correlated with structure loss. (2) Compares methods of characterizing structure susceptibility, including home assessments and emerging fire spread models. (3…
Publication Type: Journal Article
Planted seedling regeneration using gap-based silviculture without herbicide in a wildfire-impacted forest of the Sierra Nevada
Year: 2025
Gap-based silviculture, which we define as the creation and maintenance of multi-aged stands through the periodic harvesting of discrete canopy gaps, provides a potential mechanism for converting previously high-graded stands into more heterogeneous, multi-aged structures. An advantage of small canopy gaps, relative to even-aged regeneration methods, is their potential to suppress shrub competition while allowing seedling growth without the use of herbicides or other means of managing shrub competition. While this idea has been proposed in principle, it has not been tested. The objective of…
Publication Type: Journal Article
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
Mobile radar provides insights into hydrologic responses in burn areas
Year: 2025
Background. Wildfires often occur in mountainous terrain, regions that pose substantial challenges to operational meteorological and hydrologic observing networks. Aims. A mobile, postfire hydrometeorological observatory comprising remote-sensing and in situ instrumentation was developed and deployed in a burnt area to provide unique insights into rainfall-induced post-fire hazards. Methods. Mobile radar-based rainfall estimates were produced throughout the burn area at 75-m resolution and compared with rain gauge accumulations and basin response variables. Key results. The mobile radar was…
Publication Type: Journal Article
Shaping Land Use Patterns in the Wildland-Urban Interface: The Role of State and Local Governments in Reducing Exposure to Wildfire Risks
Year: 2025
Development in the wildland-urban interface is increasing exposure to wildfire risks in the western United States. Yet, among the components of risk—hazard, vulnerability, and exposure—mitigating exposure has arguably been most difficult. In this report, we describe the set of interconnected state and local policies that affect development and risk exposure, including local land use planning and zoning, state policies governing insurance, building codes, and infrastructure spending, as well as the role of states as intermediaries between the federal government and localities. We discuss…
Publication Type: Report
Informing proactive wildfire management that benefits vulnerable communities and ecological values
Year: 2024
- In response to mounting wildfire risks, land managers across the country will need to dramatically increase proactive wildfire management (e.g. fuel and forest health treatments). While human communities vary widely in their vulnerability to the impacts of fire, these discrepancies have rarely informed prioritizations for wildfire mitigation treatments. The ecological values and ecosystem services provided by forests have also typically been secondary considerations.
- To identify locations across the conterminous US where proactive wildfire management is likely to be effective…
Publication Type: Journal Article
Centering socioecological connections to collaboratively manage post- fire vegetation shifts
Year: 2024
Climate change is altering fire regimes and post-fire conditions, contributing to relatively rapid transformation of landscapes across the western US. Studies are increasingly documenting post-fire vegetation transitions, particularly from forest to non- forest conditions or from sagebrush to invasive annual grasses. The prevalence of climate-driven, post-fire vegetation transitions is likely to increase…
Publication Type: Journal Article
Moderating effects of past wildfire on reburn severity depend on climate and initial severity in Western US forests
Year: 2024
Rising global fire activity is increasing the prevalence of repeated short-interval burning (reburning) in forests worldwide. In forests that historically experienced frequent-fire regimes, high-severity fire exacerbates the severity of subsequent fires by increasing prevalence of shrubs and/or by creating drier understory conditions. Low- to moderate-severity fire, in contrast, can moderate future fire behavior by reducing fuel loads. The extent to which previous fires moderate future fire severity will powerfully affect fire-prone forest ecosystem trajectories over the next century. Further…
Publication Type: Journal Article
When do contemporary wildfires restore forest structures in the Sierra Nevada?
Year: 2024
Background: Following a century of fire suppression in western North America, managers use forest restoration treatments to reduce fuel loads and reintroduce key processes like fire. However, annual area burned by wildfire frequently outpaces the application of restoration treatments. As this trend continues under climate change, it is essential that we understand the effects of contemporary wildfires on forest ecosystems and the extent to which post-fire structures are meeting common forest restoration objectives. In this study, we used airborne lidar to evaluate fire effects across yellow…
Publication Type: Journal Article
A Dynamic Spatiotemporal Understanding of Changes in Social Vulnerability to Wildfires at Local Scale
Year: 2024
Research on wildfires and social vulnerability has gained significant importance due to the increasing frequency and severity of wildfires around the world. This study investigates the dynamic changes in social vulnerability to wildfires over a decade in Idaho, USA, utilizing GIS-based tools and a quasi-experimental design. We assess the evolving nature of social vulnerability at a local scale, emphasizing both spatial and temporal dynamics. Initially, we identified social vulnerability trends in relation to varying levels of wildfire risk. The research then employs propensity score matching…
Publication Type: Journal Article
A fast spectral recovery does not necessarily indicate post-fire forest recovery
Year: 2024
BackgroundClimate change has increased wildfire activity in the western USA and limited the capacity for forests to recover post-fire, especially in areas burned at high severity. Land managers urgently need a better understanding of the spatiotemporal variability in natural post-fire forest recovery to plan and implement active recovery projects. In burned areas, post-fire “spectral recovery”, determined by examining the trajectory of multispectral indices (e.g., normalized burn ratio) over time, generally corresponds with recovery of multiple post-fire vegetation types, including trees and…
Publication Type: Journal Article
Fuel constraints, not fire weather conditions, limit fire behavior in reburned boreal forests
Year: 2024
Fire frequency in boreal forests has increased via longer burning seasons, drier conditions, and higher temperatures. However, fires have historically self-regulated via fuel limitations, mediating the effects of changes in climate and fire weather. Early post-fire boreal forests (10–15 years postfire) are often dominated by mixed conifer-broadleaf or broadleaf regeneration, considered less flammable due to the higher foliar moisture of broadleaf trees and shrubs compared to their more intact conifer counterparts. However, the strength of self-regulation in the context of changing fire…
Publication Type: Journal Article
The geography of social vulnerability and wildfire occurrence (1984–2018) in the conterminous USA
Year: 2024
Wildfire is increasing in frequency, extent, and severity in many parts of the USA. Considering the unequal burden of natural hazards on socially vulnerable populations, we ask here, how are characteristics of social vulnerability associated with wildfire occurrence nationwide, at different scales and across differing levels of wildland–urban interface development? To answer this question, we first identify all non-urban census tracts in the USA that have experienced a wildfire since 1984. Using 26 different measures of social vulnerability, we compare these tracts to non-urban census tracts…
Publication Type: Journal Article
Patterns, drivers, and implications of postfire delayed tree mortality in temperate conifer forests of the western United States
Year: 2024
Conifer forest resilience may be threatened by increasing wildfire activity and compound disturbances in western North America. Fire refugia enhance forest resilience, yet may decline over time due to delayed mortality—a process that remains poorly understood at landscape and regional scales. To address this uncertainty, we used high-resolution satellite imagery (5-m pixel) to map and quantify delayed mortality of conifer tree cover between 1 and 5 years postfire, across 30 large wildfires that burned within three montane ecoregions in the western United States. We used statistical models to…
Publication Type: Journal Article
Prefire Drought Intensity Drives Postfire Recovery and Mortality in Pinus monticola and Pseudotsuga menziesii Saplings
Year: 2024
Increasing frequency of droughts and wildfire are sparking concerns that these compounded disturbance events are pushing forested ecosystems beyond recovery. An improved understanding of how compounded events affect tree physiology and mortality is needed given the reliance of fire management planning on accurate estimates of postfire tree mortality. In this study, we use a toxicological dose-response approach to quantify the impact of variable-intensity drought and fire on the physiology and mortality of Pinus monticola and Pseudotsuga menziesii saplings. We show that the…
Publication Type: Journal Article
A Review of the Occurrence and Causes for Wildfires and Their Impacts on the Geoenvironment
Year: 2024
Wildfires have short- and long-term impacts on the geoenvironment, including the changes to biogeochemical and mechanical properties of soils, landfill stability, surface- and groundwater, air pollution, and vegetation. Climate change has increased the extent and severity of wildfires across the world. Simultaneously, anthropogenic activities—through the expansion of urban areas into wildlands, abandonment of rural practices, and accidental or intentional fire-inception activities—are also responsible for a majority of fires. This paper provides an overall review and critical appraisal of…
Climate Change and Fire, Fire Effects and Fire Ecology, Smoke and Air Quality, Soils and Woody Debris
Publication Type: Journal Article
Evidence of increasing wildfire damage with decreasing property price in Southern California fires
Year: 2024
Across the Western United States, human development into the wildland urban interface (WUI) is contributing to increasing wildfire damage. Given that natural disasters often cause greater harm within socio-economically vulnerable groups, research is needed to explore the potential for disproportionate impacts associated with wildfire. Using Zillow Transaction and Assessment Database (ZTRAX), hereafter “Zillow”, real estate data, we explored whether lower-priced structures were more likely to be damaged during the most destructive, recent wildfires in Southern California. Within fire…
Publication Type: Journal Article
Model analysis of post-fire management and potential reburn fire behavior
Year: 2024
Recent trends in wildfire area burned have been characterized by large patches with high densities of standing dead trees, well outside of historical range of variability in many areas and presenting forest managers with difficult decisions regarding post-fire management. Post-fire tree harvesting, commonly called salvage logging, is a controversial management tactic that is often undertaken to recoup economic loss and, more recently, also to reduce future fuel hazard, especially when coupled with surface fuel reduction. It is unclear, however, whether the reductions in future fuels translate…
Publication Type: Journal Article
Disentangling drivers of annual grass invasion: Abiotic susceptibility vs. fire-induced conversion to cheatgrass dominance in the sagebrush biome
Year: 2024
Invasive annual grasses are often facilitated by fire, yet they can become ecologically dominant in susceptible locations even in the absence of fire. We used an extensive vegetation plot database to model susceptibility to the invasive annual grass cheatgrass (Bromus tectorum L.) in the sagebrush biome as a function of climate and soil water availability variables. We built random forest models predicting cheatgrass presence or dominance (>15 % relative cover) under unburned (37,219 plots) and burned conditions (6340 plots). We mapped predicted probability of cheatgrass…
Publication Type: Journal Article
Social Inequity and Wildfire Response: Identifying Gaps and Interventions in Ventura County, California
Year: 2024
As climate change increases the frequency and severity of wildfires across the Western U.S., there is an urgent need for improved wildfire preparedness and responses. Socially marginalized communities are particularly vulnerable to wildfire effects because they disproportionately lack access to the resources necessary to prepare for and recover from wildfire and are frequently underrepresented in the wildfire planning process. As an exemplar of how to understand and improve preparedness in such communities, this research identified communities in Ventura County facing heightened…
Publication Type: Journal Article