Research Database
Displaying 21 - 40 of 142
Thinning and Managed Burning Enhance Forest Resilience in Northeastern California
Year: 2024
Understanding and quantifying the resilience of forests to disturbances are increasingly important for forest management. Historical fire suppression, logging, and other land uses have increased densities of shade tolerant trees and fuel buildup in the western United States, which has reduced the resilience of these forests to natural disturbances. One way to mitigate this problem is to use fuel treatments such as stand thinning and prescribed burning. In this study, we investigated changes in forest structure in the Lassen and Plumas National Forests of northern California following a large…
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
Spatial and temporal analysis of vulnerability disparity of minorities to wildfires in California
Year: 2024
Wildfires typically have devastating impacts on communities, both in urban and rural areas, resulting in property loss, psychological distress, physical injuries, and loss of life. A notable gap in the literature is the spatial and temporal disproportionate impact of wildfires on underrepresented communities. This lack of attention is concerning, as these underrepresented populations are likely to be more vulnerable to the devastating consequences of wildfire disasters, exacerbating pre-existing social, economic, and environmental disparities. This study aims to address this gap by conducting…
Publication Type: Journal Article
Stand diversity increases pine resistance and resilience to compound disturbance
Year: 2024
BackgroundDrought, fire, and insects are increasing mortality of pine species throughout the northern temperate zone as climate change progresses. Tree survival may be enhanced by forest diversity, with growth rates often higher in mixed stands, but whether tree defenses are likewise aided remains in question. We tested how forest diversity-productivity patterns relate to growth and defense over three centuries of climate change, competition, wildfire, and bark beetle attack. We used detailed census data from a fully mapped 25.6-ha forest dynamics plot in California, USA to…
Publication Type: Journal Article
The impacts of rising vapour pressure deficit in natural and managed ecosystems
Year: 2024
An exponential rise in the atmospheric vapour pressure deficit (VPD) is among the most consequential impacts of climate change in terrestrial ecosystems. Rising VPD has negative and cascading effects on nearly all aspects of plant function including photosynthesis, water status, growth and survival. These responses are exacerbated by land–atmosphere interactions that couple VPD to soil water and govern the evolution of drought, affecting a range of ecosystem services including carbon uptake, biodiversity, the provisioning of water resources and crop yields. However, despite the…
Publication Type: Journal Article
Wildfire management decisions outweigh mechanical treatment as the keystone to forest landscape adaptation
Year: 2024
BackgroundModern land management faces unprecedented uncertainty regarding future climates, novel disturbance regimes, and unanticipated ecological feedbacks. Mitigating this uncertainty requires a cohesive landscape management strategy that utilizes multiple methods to optimize benefits while hedging risks amidst uncertain futures. We used a process-based landscape simulation model (LANDIS-II) to forecast forest management, growth, climate effects, and future wildfire dynamics, and we distilled results using a decision support tool allowing us to examine tradeoffs between alternative…
Publication Type: Journal Article
Rethinking cost-share programs in consideration of economic equity: A case study of wildfire risk mitigation assistance for private landowners
Year: 2024
Public agencies and organizations often deliver financial assistance through cost sharing, in which recipients contribute some portion toward total costs. However, cost sharing might raise equity concerns if it reduces participation among populations with lower incomes. Here, we revisit a past study using a richer dataset (n=1,689) to assess whether stated income levels affect survey respondents' willingness to participate in a cost share program for vegetation reduction to mitigate wildfire risk in western Colorado. Results show that residents with lower incomes are less likely to…
Publication Type: Journal Article
Association of social vulnerability factors with power outage burden in Washington state: 2018–2021
Year: 2024
Major power outages have risen over the last two decades, largely due to more extreme weather conditions. However, there is a lack of knowledge on the distribution of power outages and its relationship to social vulnerability and co-occurring hazards. We examined the associations between localized outages and social vulnerability factors (demographic characteristics), controlling for environmental factors (weather), in Washington State between 2018–2021. We additionally analyzed the validity of PowerOutage.us data compared to federal datasets. The population included 27 counties served by 14…
Publication Type: Journal Article
Long-term frequent fire and cattle grazing alter dry forest understory vegetation
Year: 2024
Understanding fire and large herbivore interactions in interior western forests is critical, owing to the extensive and widespread co-occurrence of these two disturbance types and multiple present and future implications for forest resilience, conservation and restoration. However, manipulative studies focused on interactions and outcomes associated with these two disturbances are rare in forested rangelands. We investigated understory vegetation response to 5-year spring and fall prescribed fire and domestic cattle grazing exclusion in ponderosa pine stands and reported long-term responses,…
Publication Type: Journal Article
A systematic scoping review of the Social Vulnerability Index as applied to natural hazards
Year: 2024
Social vulnerability approaches seek to identify social, economic, and political drivers that exacerbate environmental risks, and inform adaptation strategies that redress uneven vulnerabilities. Social Vulnerability Indices (SVIs), one such approach, have exponentially increased in use since their inception in 2003. This paper contributes the most comprehensive and rigorous systematic assessment of SVIs to date, as applied in hazard and disaster contexts. We evaluate how 246 peer-reviewed articles, published online between 2003 and 2021, conceptualized, constructed, and applied SVIs across…
Publication Type: Journal Article
Evacuation decisions of tourists in wildfire scenarios
Year: 2024
This paper investigates the factors affecting evacuation behaviour of tourists in wildfire scenarios by conducting a scoping review using the Preferred Reporting Items for Systematic reviews and Meta-Analysis approach - here using only its extension for scoping reviews. A total of 524 scientific papers were identified in the Web of Science and Scopus and 23 studies were fully reviewed. Key variables affecting the evacuation behaviour of tourists included property attachment, past experience and preparedness, safety culture, risk perception, individual and group socio-demographics, interaction…
Publication Type: Journal Article
Exploring spatial heterogeneity in synergistic effects of compound climate hazards: Extreme heat and wildfire smoke on cardiorespiratory hospitalizations in California
Year: 2024
Extreme heat and wildfire smoke events are increasingly co-occurring in the context of climate change, especially in California. Extreme heat and wildfire smoke may have synergistic effects on population health that vary over space. We leveraged high-resolution satellite and monitoring data to quantify spatially varying compound exposures to extreme heat and wildfire smoke in California (2006–2019) at ZIP Code Tabulation Area (ZCTA) level. We found synergistic effects between extreme heat and wildfire smoke on daily cardiorespiratory hospitalizations at the state level. We also found spatial…
Publication Type: Journal Article
Socially vulnerable US Pacific Northwest communities are more likely to experience wildfires
Year: 2024
Quantitative wildfire risk assessments increasingly are used to prioritize areas for investments in wildfire risk mitigation actions. However, current assessments of wildfire risk derived from fire models built primarily on biophysical data do not account for socioeconomic contexts that influence community vulnerability to wildfire. Research indicates that despite accounting for only a small proportion of high wildfire hazard areas, communities with fewer socioeconomic resources to devote to wildfire prevention and response may experience outsized exposure and impacts. We examined the…
Publication Type: Journal Article
‘Mind the Gap’—reforestation needs vs. reforestation capacity in the western United States
Year: 2024
Tree establishment following severe or stand-replacing disturbance is critical for achieving U.S. climate change mitigation goals and for maintaining the co-benefits of intact forest ecosystems. In many contexts, natural post-fire tree regeneration is sufficient to maintain forest cover and associated ecosystem services, but increasingly the pattern and scale of disturbance exceeds ecological thresholds and active reforestation may be warranted. Our capacity to plant trees, however, is not keeping pace with reforestation needs. This shortfall is uniquely apparent in the western U.S., where…
Publication Type: Journal Article
Coupling fire and energy in the Anthropocene: Deploying scale to analyze social vulnerability to forced electricity outages in California
Year: 2024
Extreme events such as wildfires and winter storms result in disruptions to grid-based electricity delivery. Electricity supply disruptions are both reactive, whereby specific events cause damage to physical infrastructure, or anticipatory where electricity suppliers—namely electric utility companies—preemptively de-energize sections of an electrical grid or distribution network based on elevated potential of extreme conditions that may cause wildfire ignition. De-energization has been promoted as a strategy to mitigate risk of wildfire ignition and spread when active fires may encounter…
Publication Type: Journal Article
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
Ability of seedlings to survive heat and drought portends future demographic challenges for five southwestern US conifers
Year: 2023
Climate change and disturbance are altering forests and the rates and locations of tree regeneration. In semi-arid forests of the southwestern USA, limitations imposed by hot and dry conditions are likely to influence seedling survival. We examined how the survival of 1-year seedlings of five southwestern US conifer species whose southwestern distributions range from warmer and drier woodlands and forests (Pinus edulis Engelm., Pinus ponderosa Douglas ex C. Lawson) to cooler and wetter subalpine forests (Pseudotsuga menziesii (Mirb.) Franco, Abies concolor…
Publication Type: Journal Article
Climate and fire impacts on tree recruitment in mixed conifer forests in Northwestern Mexico and California
Year: 2023
Frequent-fire forests were once heterogeneous at multiple spatial scales, which contributed to their resilience to severe fire. While many studies have characterized historical spatial patterns in frequent-fire forests, fewer studies have investigated their temporal dynamics. We investigated the influences of fire and climate on the timing of conifer recruitment in old-growth Jeffrey pine-mixed conifer forests in the Sierra San Pedro Martir (SSPM) and the eastern slope of Sierra Nevada. Additionally, we evaluated the impacts of fire exclusion and recent climate change on recruitment levels…
Publication Type: Journal Article
Social Vulnerability in USCommunities Affected by WildfireSmoke, 2011 to 2021
Year: 2023
Objectives. To describe demographic and social characteristics of US communities exposed to wildfire smoke.
Methods. Using satellite-collected data on wildfire smoke with the locations of population centers in the coterminous United States, we identified communities potentially exposed to light-, medium-, and heavy-density smoke plumes for each day from 2011 to 2021. We linked days of exposure to smoke in each category of smoke plume density with 2010 US Census data and community characteristics from the Centers for Disease Control and Prevention’s Social Vulnerability Index to describe…
Publication Type: Journal Article
Mechanical thinning restores ecological functions in a seasonally dry ponderosa pine forest in the inland Pacific Northwest, USA
Year: 2023
An increasingly important goal of federal land managers in seasonally dry forests of the western US is restoring forest resilience. In this study, we quantified the degree to which a thinning treatment in a dry forest of eastern Oregon restored aspects of forest resilience by focusing on key functional attributes of our study system. First, we measured several physiological responses of overstory trees that are associated with resilience, including radial growth, resin production, abundance of non-structural carbohydrates (NSC), and leaf area. Second, we investigated understory vegetation…
Publication Type: Journal Article