Research Database
Displaying 41 - 60 of 91
Towards an Integrated Approach to Wildfire Risk Assessment: When, Where, What and How May the Landscapes Burn
Year: 2023
This paper presents a review of concepts related to wildfire risk assessment, including the determination of fire ignition and propagation (fire danger), the extent to which fire may spatially overlap with valued assets (exposure), and the potential losses and resilience to those losses (vulnerability). This is followed by a brief discussion of how these concepts can be integrated and connected to mitigation and adaptation efforts. We then review operational fire risk systems in place in various parts of the world. Finally, we propose an integrated fire risk system being developed under the…
Publication Type: Journal Article
Fire frequency and vulnerability in California
Year: 2023
Wildfires pose a large and growing threat to communities across California, and understanding fire vulnerability and impacts can enable more effective risk management. Government hazard maps are often used to identify at-risk areas, but hazard zones and fire experience may have different implications for communities. This analysis of three decades of fire footprints, hazard maps, and census and real estate data shows that communities with high fire experience differ substantially from communities with high fire hazard. High-hazard communities average higher incomes than low- and no-hazard…
Publication Type: Journal Article
Harnessing Natural Disturbances: A Nature-Based Solution for Restoring and Adapting Dry Forests in the Western USA to Climate Change
Year: 2023
Natural disturbances (wildfires, droughts, beetle outbreaks) shaped temperate forests for millennia, including dry forests of the western USA. Could they now best restore and adapt dry forests to climate change while protecting nearby communities? Mechanical fuel-reduction treatments (e.g., thinning) reduce landscape heterogeneity and appear ineffective since <1% of the treated area encounters fire each year and fires are still increasing. We propose and analyze a nature-based solution (NbS), using natural disturbances, to see whether it is feasible, how long it might take, and whether it…
Publication Type: Journal Article
Social drivers of vulnerability to wildfire disasters: A review of the literature
Year: 2023
The increase of wildfire disasters globally has highlighted the need to understand and mitigate human vulnerability to wildfire. In response, there has been a substantial uptick in efforts to characterize and quantify wildfire vulnerability. Such efforts have largely focused on quantifying potential wildfire exposure and frequently overlooked the individual and community vulnerability to wildfire. Here, we review the emergent literature on social vulnerability to wildfire by synthesizing factors related to exposure, sensitivity, and adaptive capacity that contribute to a population’s or…
Publication Type: Journal Article
Recent Douglas-fir Mortality in the Klamath Mountains Ecoregion of Oregon: Evidence for a Decline Spiral
Year: 2023
Recent increases in Douglas-fir (Psuedotsuga menziesii var. menziesii) mortality in the Klamath Mountains ecoregion raise concerns about the long-term resilience of Douglas-fir in the ecoregion and increased potential for uncharacteristic wildfire. We used data from the USDA Forest Service Aerial Detection Survey and ninety-six field plots to explore the relationships between physiographic and climate variables and Douglas-fir mortality. Our results provide strong evidence for a decline spiral in which Douglas-fir growing on hot, dry sites (predisposing factor) are further stressed by drought…
Publication Type: Journal Article
Plant-water sensitivity regulates wildfire vulnerability
Year: 2022
Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50%…
Publication Type: Journal Article
Tree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
Year: 2022
1. The future of dry forests around the world is uncertain given predictions that rising temperatures and enhanced aridity will increase drought-induced tree mortality. Using forest management and ecological restoration to reduce density and competition for water offers one of the few pathways that forests managers can potentially minimize drought-induced tree mortality. Competition for water during drought leads to elevated tree mortality in dense stands, although the influence of density on heat-induced stress and the durations of hot or dry conditions that most impact mortality remain…
Publication Type: Journal Article
Rapid Growth of Large Forest Fires Drives the Exponential Response of Annual Forest-Fire Area to Aridity in the Western United States
Year: 2022
Annual forest area burned (AFAB) in the western United States (US) has increased as a positive exponential function of rising aridity in recent decades. This non-linear response has important implications for AFAB in a changing climate, yet the cause of the exponential AFAB-aridity relationship has not been given rigorous attention. We investigated the exponential AFAB-aridity relationship in western US forests using a new 1984–2019 database of fire events and 2001–2020 satellite-based records of daily fire growth. While forest-fire frequency and duration grow linearly with aridity, the…
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
Relationships between building features and wildfire damage in California, USA and Pedrógão Grande, Portugal
Year: 2022
Background: Buildings in communities near wildlands, in the wildland–urban interface (WUI), can experience wildfire damage.Aims: To quantitatively assess the relationship between building features and damage, a building wildfire resistance index is developed and validated with the 2013–2017 CAL FIRE (DINS) database from California, USA, and the 2017 Pedrógão Grande Fire Complex post-fire investigation from Portugal.Methods: Three statistical dependence tests are compared to evaluate the relationship between selected building features and…
Publication Type: Journal Article
Human ignitions on private lands drive USFS cross‑boundary wildfire transmission and community impacts in the western US
Year: 2022
Wildfires in the western United States (US) are increasingly expensive, destructive, and deadly. Reducing wildfire losses is particularly challenging when fires frequently start on one land tenure and damage natural or developed assets on other ownerships. Managing wildfire risk in multijurisdictional landscapes has recently become a centerpiece of wildfire strategic planning, legislation, and risk research. However, important empirical knowledge gaps remain regarding cross-boundary fire activity in the western US. Here, we use lands administered by the US Forest Service as a study system to…
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
Stop going around in circles: towards a reconceptualisation of disaster risk management phases
Year: 2021
Purpose The way that disasters are managed, or indeed mis-managed, is often represented diagrammatically as a “disaster cycle”. The cyclical aspects of the disaster (risk) management concept, comprised of numerous operational phases, have, in recent years, been criticised for conceptualising and representing disasters in an overly simplistic way that typically starts with a disaster “event” – and subsequently leads onto yet another disaster. Such cyclical thinking has been proven to not be very useful for the complexities associated with understanding disasters and their risks. This paper…
Publication Type: Journal Article
Evaluating rural Pacific Northwest towns for wildfire evacuation vulnerability
Year: 2021
Wildfire is an annual threat for many rural communities in the Pacific Northwest region of the United States. In some severe events, evacuation is one potential course of action to gain safety from an advancing wildfire. Since most evacuations occur in a personal vehicle along the surrounding road network, the quality of this network is a critical component of a community's vulnerability to wildfire. In this paper, we leverage a high-resolution spatial dataset of wildfire burn probability and mean fireline intensity to conduct a regional-scale screening of wildfire evacuation vulnerability…
Publication Type: Journal Article
Crowded and Thirsty: Fire exclusion leads to greater drought sensitivity in mixed-conifer forests
Year: 2020
Wildfires were a frequent source of disturbance in forests of the Western United States prior to Euro-American settlement. Following a series of catastrophic wildfires in the Northern Rockies in 1910, the U.S. Forest Service adopted a broad wildfire suppression policy that has resulted in forests thick with small trees. These crowded trees compete for nutrients and water and experience increased drought stress in summer.In recent decades, many trees have died following drought, bark beetle outbreaks, and severe wildfire. A link between this mortality and increasing susceptibility to drought…
Publication Type: Report
Riparian and adjacent upland forests burned synchronously during dry years in eastern Oregon (1650-1900 CE), USA
Year: 2020
Riparian forests link terrestrial and freshwater communities and therefore understanding the landscape context of fire regimes in these forests is critical to fully understanding the landscape ecology. However, few direct studies of fire regimes exist for riparian forests, especially in the landscape context of adjacent upland forests or studies of long-term climate drivers of riparian forest fires. We reconstructed a low-severity fire history from tree rings in 38 1-ha riparian plots and combined them with existing fire histories from 104 adjacent upland plots to yield 2633 fire scars…
Publication Type: Journal Article
Tribes & Climate Change
Year: 2020
Native Americans rely on tribally important ecosystem services such as traditional foods, hunting, timber production, non-timber forest resources (recreation, water), and cultural resources. Unfortunately, many of these resources may be highly vulnerable to the impacts of climate change. A research team sought to answer the question: Where and which tribally-important ecosystem services will be affected by climate change in the Pacific Northwest? They used projections from climate and vegetation models and stakeholder input to demonstrate a generalizable approach for assessing possible…
Publication Type: Web project page
Social Vulnerability and Wildfire in the Wildland-Urban Interface: Literature synthesis
Year: 2019
The overall objective of this paper is to clarify areas of debate, clearly define and contrast disparate approaches, and synthesize findings that may help address vulnerability to wildfires and other natural hazards. While land managers and fire personnel might find it pertinent to approach biophysical and social issues separately, addressing both aspects of wildfire hazard can be productive for minimizing risk and empowering communities, neighborhoods, and households to prepare and recover from wildfire events. We aim to provide a practical grasp of social vulnerability research as it…
Publication Type: Report
Social Vulnerability and Wildfire in the Wildland-Urban Interface
Year: 2019
People living in the Pacific Northwest confrontrisks associated with environmentalhazards such as wildfire. Vulnerability towildfire hazard is commonly recognized as beingspatially distributed according to geographic conditionsthat collectively determine the probabilityof exposure. For example, exposure to wildfirehazard is higher for people living in rural, forestedsettings than in a strictly urban neighborhood becauserural housing is built in close proximity tothe threat source, e.g., flammable landscapes suchas forests and chaparral. Yet, even if levels of exposureare held constant, not…
Publication Type: Report