Research Database
Displaying 1 - 20 of 57
Rapid Declines in Southern Sierra Nevada Fisher Habitat Driven by Drought and Wildfire
Year: 2025
Aim: Forest disturbances are a natural ecological process, but climate and land-use change are altering disturbance regimes at an unprecedented rate, posing significant threats to biological communities and the species of concern. Our aim was to develop an automated habitat monitoring system for the Southern Sierra Nevada Distinct Population Segment of fisher (Pekania pennanti) in California, USA, to investigate long-term habitat trends and the effects of a recent megadrought and numerous megafires on fisher habitat.Location: Southern Sierra Nevada, California, USA.Methods: We used…
Publication Type: Journal Article
Collapse and restoration of mature forest habitat in California
Year: 2025
Mature and old-growth forests provide critically important ecosystems services and wildlife habitats, but they are being lost at a rapid rate to uncharacteristic mega-disturbances. We developed a simulation system to project time-to-extinction for mature and old-growth forest habitat in the Sierra Nevada, California, USA. The simulation parameters were derived from a 1985–2022 empirical time-series of habitat for the southern Sierra Nevada fisher (Pekania pennanti), an endangered native mammal and old-forest obligate that has seen a 50 % decline in its habitat over the past…
Publication Type: Journal Article
Finding floral and faunal species richness optima among active fire regimes
Year: 2025
Changing fire regimes have important implications for biodiversity and challenge traditional conservation approaches that rely on historical conditions as proxies for ecological integrity. This historical-centric approach becomes increasingly tenuous under climate change, necessitating direct tests of environmental impacts on biodiversity. At the same time, widespread departures from historical fire regimes have limited the ability to sample diverse fire histories. We examined 2 areas in California's Sierra Nevada (USA) with active fire regimes to study the responses of bird, plant, and bat…
Publication Type: Journal Article
A Systematic Review of Trends and Methodologies in Research on the Effects of Wildfires on the Avifauna in Temperate Forests
Year: 2025
Perceptions of the relationships between forest ecosystems and wildfires have evolved. The ecological role of wildfires is now recognised as essential for maintaining the functionality of fire-adapted forests. Although research on the impact of fire on fauna has grown notably, there is a lack of consensus on its global effects due to the variable responses of faunal communities across taxa. This review provides a bibliometric synthesis of wildfires and their impact on avifauna in temperate forests. It identifies patterns and gaps in research methodologies and offers recommendations for future…
Publication Type: Journal Article
Return on investments in restoration and fuel treatments in frequent-fire forests of the American west: A meta-analysis
Year: 2024
Arid forests in the American West contend with overly dense stands and a need to reduce fuels and restore more natural fire regimes. Forest restoration efforts include fuel treatments, such as thinning and prescribed burning, that can reduce ground and ladder fuels. Restoration and fuel treatments have emerged as leading wildfire risk-reduction strategies in the American West, yet little is known about the cost-effectiveness of such programs. To evaluate forest restoration and fuel treatment benefits and costs, we conducted a meta-analysis of benefit-cost ratios for restoration benefit types…
Publication Type: Journal Article
Accelerated forest restoration may benefit spotted owls through landscape complementation
Year: 2024
Animals often rely on the presence of multiple, spatially segregated cover types to satisfy their ecological needs; the juxtaposition of these cover types is called landscape complementation. In ecosystems that have been homogenized because of human land use, such as fire-suppressed forests, management activities have the potential to increase the heterogeneity of cover types and, therefore, landscape complementation. We modeled changes to California spotted owl (Strix occidentalis occidentalis) nesting/roosting habitat, foraging habitat and habitat co-occurrence (i.e. landscape…
Publication Type: Journal Article
Hazardous wildfire smoke events can alter dawn soundscapes in dry forests of central and eastern Washington, United States
Year: 2024
As global wildfire activity increases, wildlife are facing greater exposure to hazardous smoke pollution – with unknown consequences for biodiversity. Research on the effects of smoke on wild animals is extremely limited, in part due to the inherent logistical challenges of observing how animals respond to smoke in real time. Passive acoustic monitoring may be a powerful tool to safely and effectively monitor biodiversity before, during, and after major smoke events. In this study, we used data…
Publication Type: Journal Article
Forest pollinator richness declines with distance into burned areas
Year: 2024
The effects of prescribed fire on forest pollinator communities are complex and incompletely understood. One of the least-studied questions concerns how these organisms are affected by the size, or spatial scale, of fire. We sought to address this by sampling bees (Hymenoptera: Apoidea), butterflies (Lepidoptera), and hover flies (Diptera: Syrphidae) at different distances along 500 m transects into forests burned every three years in the southeastern United States. We found combined pollinator richness to decline significantly with distance, being about 23.9 % lower near the centers of burn…
Publication Type: Journal Article
Before the fire: predicting burn severity and potential post-fire debris-flow hazards to conservation populations of the Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus)
Year: 2024
Background: Colorado River Cutthroat Trout (CRCT; Oncorhynchus clarkii pleuriticus) conservation populations may be at risk from wildfire and post-fire debris flows hazards. Aim: To predict burn severity and potential post-fire debris flow hazard classifications to CRCT conservation populations before wildfires occur. Methods: We used remote sensing, spatial analyses, and machine learning to model 28 wildfire incidents (2016–2020) and spatially predict burn severity from pre-wildfire environmental factors to evaluate the likelihood…
Publication Type: Journal Article
Changing fire regimes and nuanced impacts on a critically imperiled species
Year: 2024
Wildfire activity throughout western North America is increasing which can have important consequences for species persistence. Native species have evolved disturbance-adapted traits that confer resilience to natural disturbance provided disturbances operate within their historical range of variability. This resilience can erode as disturbance regimes change and begin operating outside this range. We assessed wildfire impacts during 1987–2018 on the northern spotted owl, an imperiled species with complex relationships with late and early seral forest in the Pacific Northwest, USA. We analyzed…
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
The Economic Value of Fuel Treatments: A Review of the Recent Literature for Fuel Treatment Planning
Year: 2022
This review synthesizes the scientific literature on fuel treatment economics published since 2013 with a focus on its implications for land managers and policy makers. We review the literature on whether fuel treatments are financially viable for land management agencies at the time of implementation, as well as over the lifespan of fuel treatment effectiveness. We also review the literature that considers the broad benefits of fuel treatments across multiple sectors of society. Most studies find that fuel treatments are not financially viable for land management agencies based on revenue…
Publication Type: Journal Article
The importance of Indigenous cultural burning in forested regions of the Pacific West, USA
Year: 2021
Indigenous communities in the Pacific West of North America have long depended on fire to steward their environments, and they are increasingly asserting the importance of cultural burning to achieve goals for ecological and social restoration. We synthesized literature regarding objectives and effects of cultural burning in this region within an ecosystem services framework. Much scholarly literature focuses on why various species harvested from burned areas were important historically, while tribes and recent research increasingly stress a wide range of ecological and cultural benefits…
Publication Type: Journal Article
Post-fire Salvage Logging Science Series
Year: 2021
The publications and media in this hot topic address the effects of salvage logging on plants, biodiversity, and cavity-nesting birds. They also cover a range of research that includes, but is not limited to, the ecological impacts of salvage logging; the effects of salvage logging on soil, sediment production, mountain pine beetles, and riparian systems.
Publication Type: Presentation
Transformation of western hemlock (Tsuga heterophylla) tree crowns by dwarf mistletoe (Arceuthobium tsugense, Viscaceae)
Year: 2020
Dwarf mistletoes (Arceuthobium species) are arboreal, hemiparasitic plants of conifers that can change the structure and function of the tree crown. Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) principally parasitizes western hemlock (Tsuga heterophylla) and effects 10.8% of all western hemlock trees in Oregon, USA. In this study, we climbed 16 western hemlock trees (age 97–321 years, height 33–54.7 m) across a gradient of infection (0%–100% of branches infected) and measured occurrence of all dwarf mistletoe infections, dwarf mistletoe caused deformities, foliage, branch…
Publication Type: Journal Article
Washington State 2020 Forest Action Plan
Year: 2020
Washington has more than 22 million acres of forestland. From the lush rainforests on our coasts, to the rugged sub-alpine forests along the Cascade Crest, to the pine-dominated hillsides surrounding the Columbia Plateau, forests are an integral part of our landscapes and communities, and they provide a wealth of benefits to Washingtonians and the planet. They provide us with sustainable timber and jobs, produce clean air and water, sequester carbon, and support world-class outdoor recreation. Our forests, however, face unprecedented threats that require bold action. Climate change is…
Publication Type: Government Report
Expansion of the invasive European mistetoe in California, USA
Year: 2020
The horticulturist Luther Burbank introduced the European mistletoe (Viscum album L.) to Sebastopol, Sonoma County, California, USA, around 1900 to grow as a Christmas ornament crop and tincture for medicinal use. The mistletoe has since spread from the point of introduction on apple to other hardwood trees, especially non-native hardwoods in yards and farms of the region. Mistletoe surveys were previously conducted in 1971,1986, and 1991. We re-surveyed the region in 2019, with emphasis on the 1991 perimeter, and documented the current farthest distribution of V. album. This represents a 120…
Publication Type: Journal Article
Mixed-severity wildfire and habitat of an old-forest obligate
Year: 2019
The frequency, extent, and severity of wildfire strongly influence the structure and function of ecosystems. Mixed‐severity fire regimes are the most complex and least understood fire regimes, and variability of fire severity can occur at fine spatial and temporal scales, depending on previous disturbance history, topography, fuel continuity, vegetation type, and weather. During high fire weather in 2013, a complex of mixed‐severity wildfires burned across multiple ownerships within the Klamath‐Siskiyou ecoregion of southwestern Oregon where northern spotted owl (Strix occidentalis caurina)…
Publication Type: Journal Article
Towards an understanding of the evolutionary role of fire in animals
Year: 2018
Wildfires underpin the dynamics and diversity of many ecosystems worldwide, and plants show a plethora of adaptive traits for persisting recurrent fires. Many fire-prone ecosystems also harbor a rich fauna; however, knowledge about adaptive traits to fire in animals remains poorly explored. We review existing literature and suggest that fire is an important evolutionary driver for animal diversity because (1) many animals are present in fire-prone landscapes and may have structural and phenotypic characters that contribute to adaptation to these open landscapes; and (2) in some cases, animals…
Publication Type: Journal Article
Wildfires managed for restoration enhance ecological resilience
Year: 2018
Expanding the footprint of natural fire has been proposed as one potential solution to increase the pace of forest restoration programs in fire‐adapted landscapes of the western USA. However, studies that examine the long‐term socio‐ecological trade‐offs of expanding natural fire to reduce wildfire risk and create fire resilient landscapes are lacking. We used the model Envision to examine the outcomes that might result from increased area burned by what we call “restoration” wildfire in a landscape where the ecological benefits of wildfire are known, but the need to suppress high‐risk fires…
Publication Type: Journal Article