Background
Rural communities are increasingly impacted by smoke produced by wildfires and forest management activties. Understanding local influences on smoke adaptation and mitigation is critical to social adaptation as fire risk continues to rise.
Aims
Background. Prescribed burning is a widely-used fire management strategy for maintaining socioeconomic and ecological resilience by mitigating the impacts of wildfires. Monitoring the effectiveness of prescribed burns on future fire spread, however, is challenged by limited data availability and quality.
We created the first annually resolved records of historical fire occurrence coupled with precise estimates of tree establishment for the northern half of the west slope of the Oregon Cascades, a region that is home to some of the most productive forests on earth.
Fire is strongly linked to outdoor recreation in the United States. Recreational uses of fires, whether in designated campgrounds or the backcountry, include warmth, cooking, and fostering a comfortable atmosphere. However, through inattention, negligence, or bad luck, recreational fires sometimes ignite wildfires. From 1992 through 2020, such ignitions accounted for an estimated 12% of human-caused wildfires and 8% of the area burned by those wildfires in Washington, Oregon, and California. 76% of the recreation-caused ignitions occurred on public lands: 50% on lands managed by the U.S. Forest Service, 15% on other federal lands, and 11% on state, county, or local lands.
With the aim of informing strategies to limit the risk of recreation-caused ignitions, we evaluated whether the density of wildfires ignited by recreation or ceremony on U.S. Forest Service lands, and the size of such wildfires, is influenced by proximity to designated campgrounds, visitor density, previous and current drought conditions, and the type of vegetation surrounding the ignition point. With respect to recreation-caused ignitions, we tested the common assumption that large wildfires tend to be enabled by wet conditions in the prior growing season where vegetation is not continuous, and by dry conditions in the current growing season where vegetation is abundant and the climate generally limits flammability. We accounted for the potential effects of ecoregion on these associations given that vegetation composition, climate, and historical fire-return intervals and sizes vary among ecoregions.
Background
Post-wildfire debris flows (PFDFs) frequently threaten life, property and infrastructure in California. To date, there is no comprehensive assessment of their spatial distribution, seasonality, atmospheric drivers and interannual variability across the state.
Aims
Reduced fire frequency is recognized as a main cause of piñon–juniper (Pinus–Juniperus L.) expansion in western North American sagebrush steppe and grasslands. Piñon–juniper woodland control using prescribed fire and mechanical treatments have increased the past three decades with the goal of restoring sagebrush steppe plant communities.
The January 2025 Los Angeles wildfires released large amounts of air pollutants and exposed millions of residents to smoke containing hazardous volatile organic compounds (VOCs).
Structure fires in the wildland–urban interface (WUI) are becoming more frequent and destructive, yet their emissions of air pollutants remain poorly quantified and are not included in national inventories. Here we present a conterminous-scale inventory of WUI-related structure fire emissions in the United States from 2000 to 2020.