Research Database
Displaying 121 - 140 of 145
Interval squeeze: altered fire regimes and demographic responses interact to threaten woody species persistence as climate changes
Year: 2015
Projected effects of climate change across many ecosystems globally include more frequent disturbance byfire and reduced plant growth due to warmer (and especially drier) conditions. Such changes affect species– particularly fire-intolerant woody plants – by simultaneously reducing recruitment, growth, and survival.Collectively, these mechanisms may narrow the fire interval window compatible with populationpersistence, driving species to extirpation or extinction. We present a conceptual model of these combinedeffects, based on synthesis of the known impacts of climate change and altered fire…
Publication Type: Journal Article
Enhancing adaptive capacity for restoring fire-dependent ecosystems: the Fire Learning Network’s Prescribed Fire Training Exchanges
Year: 2015
Prescribed fire is a critical tool for promoting restoration and increasing resilience in fire-adapted ecosystems, but there are barriers to its use, including a shortage of personnel with adequate ecological knowledge and operational expertise to implement prescribed fire across multijurisdictional landscapes. In the United States, recognized needs for both professional development and increased use of fire are not being met, often because of institutional limitations. The Fire Learning Network has been characterized as a multiscalar, collaborative network that works to enhance the adaptive…
Publication Type: Journal Article
Modeling wildfire regimes in forest landscapes: abstracting a complex reality
Year: 2015
Fire is a natural disturbance that is nearly ubiquitous in terrestrial ecosystems. The capacity to burn exists virtually wherever vegetation grows. In some forested landscapes, fire is a principal driver of rapid ecosystem change, resetting succession ( McKenzie et al. 1996a ) and changing wildlife habitat (Cushman et al. 2011 ), hydrology ( Feikema et al. 2013 ), element cycles ( Smithwick 2011 ), and even landforms (Pierce et al. 2004 ). In boreal forests, for example, recurring wildfi res are the main cause of compositional and spatial patterns ( Wein and MacLean 1983 ), where a fi re-…
Publication Type: Book Chapter
Sources and implications of bias and uncertainty in a century of US wildfire activity data
Year: 2015
Analyses to identify and relate trends in wildfire activity to factors such as climate, population, land use or land cover and wildland fire policy are increasingly popular in the United States. There is a wealth of US wildfire activity data available for such analyses, but users must be aware of inherent reporting biases, inconsistencies and uncertainty in the data in order to maximise the integrity and utility of their work. Data for analysis are generally acquired from archival summary reports of the federal or interagency fire organisations; incident-level wildfire reporting systems of…
Publication Type: Journal Article
The climate space of fire regimes in north-western North America
Year: 2015
Aim Studies of fire activity along environmental gradients have been undertaken, but the results of such studies have yet to be integrated with fire-regime analysis. We characterize fire-regime components along climate gradients and a gradient of human influence. Location We focus on a climatically diverse region of north-western North America extending from northern British Columbia, Canada, to northern Utah and Colorado, USA. Methods We used a multivariate framework to collapse 12 climatic variables into two major climate gradients and binned them into 73 discrete climate domains. We…
Publication Type: Journal Article
A bird’s-eye view: Land-use planning and assessments in Oregon and Washington
Year: 2015
Developing forest lands and agricultural lands for other uses has wide-ranging implications. Land development can affect production from forest and agricultural lands, wildlife habitat quality, the spread of invasive species, water quality, wildfire control, and infrastructure costs. In its attempts to mitigate these effects, Oregon implemented statewide land-use planning laws in the early 1970s. Washington established less prescriptive laws in the 1990s. Policymakers, land managers, and various interest groups want to know the effect these laws have had on land use. Scientists with the…
Publication Type: Report
Landscape restoration of a forest with a historically mixed-severity fire regime: What was the historical landscape pattern of forest and openings?
Year: 2014
Forest management of dry forests in the western US that historically experienced mixed-severity fire regimes is increasingly focused on landscape-scale restoration. However, this restoration effort is constrained by historic range of variation (HRV) reference conditions that lack information concerning the spatial configuration of these forests at intermediate scales (approximately 0.01–100 ha). I used reconstruction methods to map historical (1860) pattern of ponderosa pine-Douglas-fir forests along twenty 1 km long transects on Colorado’s Front Range and compared pre-settlement opening and…
Publication Type: Journal Article
The role of defensible space for residential structure protection during wildfires
Year: 2014
With the potential for worsening fire conditions, discussion is escalating over how to best reduce effects on urban communities. A widely supported strategy is the creation of defensible space immediately surrounding homes and other structures. Although state and local governments publish specific guidelines and requirements, there is little empirical evidence to suggest how much vegetation modification is needed to provide significant benefits. We analysed the role of defensible space by mapping and measuring a suite of variables on modern pre-fire aerial photography for 1000 destroyed and…
Publication Type: Journal Article
Severity of an uncharacteristically large wildfire, the Rim Fire, in forests with relatively restored frequent fire regimes
Year: 2014
The 2013 Rim Fire, originating on Forest Service land, burned into old-growth forests within Yosemite National Park with relatively restored frequent-fire regimes (¡Ý2 predominantly low and moderate severity burns within the last 35 years). Forest structure and fuels data were collected in the field 3-4 years before the fire, providing a rare chance to use pre-existing plot data to analyze fire effects. We used regression tree and random forests analysis to examine the influence of forest structure, fuel, fire history, topographic and weather conditions on observed fire severity in the Rim…
Publication Type: Journal Article
Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA
Year: 2014
Warmer and drier climate over the past few decades has brought larger fire sizes and increased annual area burned in forested ecosystems of western North America, and continued increases in annual area burned are expected due to climate change. As warming continues, fires may also increase in severity and produce larger contiguous patches of severely burned areas. We used remotely sensed burn-severity data from 125 fires in the northern Cascade Range of Washington, USA, to explore relationships between fire size, severity, and the spatial pattern of severity. We examined relationships between…
Publication Type: Journal Article
Wildfire, Wildlands, and People: Understanding and preparing for wildfire in the wildland-urban interface
Year: 2013
Fire has historically played a fundamental ecological role in many of America’s wildland areas. However, the rising number of homes in the wildland-urban interface (WUI), associated impacts on lives and property from wildfire, and escalating costs of wildfire management have led to an urgent need for communities to become "fire-adapted." We present maps of the conterminous United States that illustrate historical natural fire regimes, the wildland-urban interface, and the number and location of structures burned since 1999. We outline a sampler of actions, programs, and community planning and…
Publication Type: Report
Building community-agency trust in fire affected communities in Australia and the United States
Year: 2013
As a result of the increasing environmental and social costs of wildfire, fire management agencies face ever-growing complexity in their management decisions and interactions with the public. The success of these interactions with community members may be facilitated through building community–agency trust in the process of providing public input opportunities and community engagement and education activities. Without trust, the public may become frustrated in their interactions with the agency and withhold support for management decisions. This study takes a comparative case approach using…
Publication Type: Journal Article
Fire regimes of quaking aspen in the Mountain West
Year: 2013
Quaking aspen, the most widespread tree species in North America, reproduces primarily by resprouting from roots. In some stands, mortality from fire encourages sprouting and prevents conifers from eventually replacing aspen. In other areas, aspen can form stable communities that do not require fire to regenerate or persist. USGS fire ecologist Doug Shinneman and colleagues reviewed literature about aspen populations and fire, summarized research findings, and suggested a classification system for aspen across the western mountainous United States. The scientists proposed five aspen “fire…
Publication Type: Journal Article
Spatially extensive reconstructions show variable-severity fire and heterogeneous structure in historical western United States dry forests
Year: 2012
Aim Wildfire is often considered more severe now than historically in dry forestsof the western United States. Tree-ring reconstructions, which suggest that historicaldry forests were park-like with large, old trees maintained by low-severity fires,are from small, scattered studies. To overcome this limitation, we developed spatiallycomprehensive reconstructions across 927,000 ha in four landscapes, using anew method based on land surveys from c. 1880.Location Dry forests of the western United States.Methods We reconstructed forest structure for four large dry-forest landscapesusing forest…
Publication Type: Journal Article
Characterizing Fire-on-Fire Interactions in Three Large Wilderness Areas
Year: 2012
The interaction of fires, where one fire burns into another recently burned area, is receiving increased attention from scientists and land managers wishing to describe the role of fire scars in affecting landscape pattern and future fire spread. Here, we quantify fire-on-fire interactions in terms of frequency, size, and time-since-previous fire (TSPF) in three large wilderness areas in Montana and Idaho, USA, from 1984 to present, using spatially consistent large fire perimeter data from the Monitoring Trends in Burn Severity (MTBS) dataset. The analysis is supplemented with less consistent…
Publication Type: Journal Article
Fuel Variability Following Wildfire in Forests with Mixed Severity Fire Regimes, Cascade Range, USA
Year: 2012
Publication Type: Journal Article
Ecological effects of alternative fuel-reduction treatments: highlights of the National Fire and Fire Surrogate study (FSS)
Year: 2012
The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical + fire treatments. Variables within the vegetation, fuelbed, forest floor and soil, bark beetles, tree diseases and wildlife were measured in 10-ha stands, and ecological response was compared among treatments at the site level, and across sites, to…
Publication Type: Journal Article
Carbon Dynamics of Forests in Washington, USA: 21st Century Projections Based on Climate-Driven Changes in Fire Regimes
Year: 2012
During the 21st century, climate-driven changes in fire regimes will be a key agent of change in forests of the U.S. Pacific Northwest (PNW). Understanding the response of forest carbon (C) dynamics to increases in fire will help quantify limits on the contribution of forest C storage to climate change mitigation and prioritize forest types for monitoring C storage and fire management to minimize C loss. In this study, we used projections of 21st century area burned to explore the consequences of changes in fire regimes on C dynamics in forests of Washington State. We used a novel empirical…
Publication Type: Journal Article
Reducing hazardous fuels on nonindustrial private forests: factors influencing landowner decisions
Year: 2011
In mixed-ownership landscapes, fuels conditions on private lands have implications for fire risk on public lands and vice versa. The success of efforts to mitigate fire risk depends on the extent, efficacy, and coordination of treatments on nearby ownerships. Understanding factors in forest owners’ decisions to address the risk of wildland fire is therefore important. This research uses logistic regression to analyze mail survey data and identify factors in forest owners’ decisions to reduce hazardous fuels in the ponderosa pine (Pinus ponderosa) ecosystem on the east side of Oregon. Results…
Publication Type: Journal Article
Fire as a restoration tool: A decision framework for predicting the control or enhancement of plants using fire
Year: 2010
Wildfires change plant communities by reducing dominance of some species while enhancing the abundance of others. Detailed habitat-specific models have been developed to predict plant responses to fire, but these models generally ignore the breadth of fire regime characteristics that can influence plant survival such as the degree and duration of exposure to lethal temperatures. We provide a decision framework that integrates fire regime components, plant growth form, and survival attributes to predict how plants will respond to fires and how fires can be prescribed to enhance the likelihood…
Publication Type: Journal Article