Research Database
Displaying 101 - 120 of 151
Using mental models to understand trade-offs in wildfire risk mitigation
Year: 2019
Throughout much of the Pacific Northwest, the interplay between environmental and social change not only contributes to wildfire risk, but also complicates efforts to mitigate it. As fire-prone landscapes become increasingly economically and culturally diverse, wildfire risk mitigation decisions have implications for a correspondingly broader set of values, resulting in greater potential for trade-offs (that is, actions that enhance some values but adversely affect others)....
Publication Type: Report
Spatial and temporal assessment of responder exposure to snag hazards in post-fire environments
Year: 2019
Researchers and managers increasingly recognize enterprise risk management as critical to addressing contemporary fire management challenges. Quantitative wildfire risk assessments contribute by parsing and mapping potentially contradictory positive and negative fire effects. However, these assessments disregard risks to fire responders because they only address social and ecological resources and assets. In this study, we begin to overcome this deficiency by using a novel modeling approach that integrates remote sensing, field inventories, imputation-based vegetation modeling, and empirical…
Publication Type: Journal Article
Examining post-fire vegetation recovery with Landsat time series analysis in three western North American forest types
Year: 2019
Background: Few studies have examined post-fire vegetation recovery in temperate forest ecosystems with Landsat time series analysis. We analyzed time series of Normalized Burn Ratio (NBR) derived from LandTrendr spectral-temporal segmentation fitting to examine post-fire NBR recovery for several wildfires that occurred in three different coniferous forest types in western North America during the years 2000 to 2007. We summarized NBR recovery trends, and investigated the influence of burn severity, post-fire climate, and topography on post-fire vegetation recovery via random forest (RF)…
Publication Type: Journal Article
Cost-effective fuel treatment planning: a theoretical justification and case study
Year: 2019
Modelling the spatial prioritisation of fuel treatments and their net effect on values at risk is an important area for applied work as economic damages from wildfire continue to grow. We model and demonstrate a cost-effective fuel treatment planning algorithm using two ecosystem services as benefits for which fuel treatments are prioritised. We create a surface of expected fuel treatment costs to incorporate the heterogeneity in factors affecting the revenue and costs of fuel treatments, and then prioritise treatments based on a cost-effectiveness ratio to maximise the averted loss of…
Publication Type: Journal Article
Post-fire management affects species composition but not Douglas-fir regeneration in the Klamath Mountains
Year: 2019
Ensuring adequate conifer regeneration after high severity wildfires is a common objective for ecologists and forest managers. In the Klamath region of Oregon and California, a global hotspot of botanical biodiversity, concerns over regeneration have led to post-fire management on many sites, which involves salvage logging followed by site preparation, conifer planting, and manual shrub release. To quantify the impacts of post-fire management, we sampled 62 field sites that burned at high severity nearly 20 years ago in the Klamath-Siskiyou Mountain bioregion, stratifying by management and…
Publication Type: Journal Article
Exploring the influence of local social context on strategies for achieving Fire Adapted Communities
Year: 2019
There is a growing recognition that the social diversity of communities at risk from wildland fire may necessitate divergent combinations of policies, programs and incentives that allow diverse populations to promote fire adapted communities (FACs). However, there have been few coordinated research efforts to explore the perceived utility and effectiveness of various options for FACs among residents, professionals, and local officials in disparate communities with different social contexts. The research presented here attempts to systematically explore the combination of local social factors…
Publication Type: Journal Article
Evaluating Model Predictions of Fire Induced Tree Mortality Using Wildfire-Affected Forest Inventory Measurements
Year: 2019
Forest land managers rely on predictions of tree mortality generated from fire behavior models to identify stands for post-fire salvage and to design fuel reduction treatments that reduce mortality. A key challenge in improving the accuracy of these predictions is selecting appropriate wind and fuel moisture inputs. Our objective was to evaluate postfire mortality predictions using the Forest Vegetation Simulator Fire and Fuels Extension (FVS-FFE) to determine if using representative fire-weather data would improve prediction accuracy over two default weather scenarios. We used pre- and post-…
Publication Type: Journal Article
Influence of fire refugia spatial pattern on post-fire forest recovery in Oregon’s Blue Mountains
Year: 2019
Context Fire regimes in many dry forests of western North America are substantially different from historical conditions, and there is concern about the ability of these forests to recover following severe wildfire. Fire refugia, unburned or low-severity burned patches where trees survived fire, may serve as essential propagule sources that enable forest regeneration. Objectives To quantify the influence of fire refugia spatial pattern and other biophysical factors on the process of post-fire tree regeneration; in particular examining both the proximity and density of surrounding refugia to…
Publication Type: Journal Article
Rapid growth of the US wildland-urban interface raises wildfire risk
Year: 2018
The wildland-urban interface (WUI) is the area where houses and wildland vegetation meet or intermingle, and where wildfire problems are most pronounced. Here we report that the WUI in the United States grew rapidly from 1990 to 2010 in terms of both number of new houses (from 30.8 to 43.4 million; 41% growth) and land area (from 581,000 to 770,000 km2; 33% growth), making it the fastest-growing land use type in the conterminous United States. The vast majority of new WUI areas were the result of new housing (97%), not related to an increase in wildland vegetation. Within the perimeter of…
Publication Type: Journal Article
How does forest recovery following moderate-severity fire influence effects of subsequent wildfire in mixed-conifer forests?
Year: 2018
Given regional increases in fire activity in western North American forests, understanding how fire influences the extent and effects of subsequent fires is particularly relevant. Remotely sensed estimates of fire effects have allowed for spatial portioning into different severity categories based on the degree of fire-caused vegetation change. Fire effects between minimal overstory tree mortality (< 20%) and complete (or nearly complete) overstory tree mortality (> 95%) are often lumped into a single category referred to as moderate severity. In this paper, we investigated how burned…
Publication Type: Journal Article
Reburn in the Rain Shadow
Year: 2018
Wildfires consume existing forest fuels but also leave behind dead shrubs and trees that become fuel to future wildfires. Harvesting firekilled trees is sometimes proposed as an economical approach for reducing future fuels and wildfire severity. Postfire logging, however, is controversial. Some question its fuel reduction benefits and its ecological impacts. David W. Peterson, a research forester with the USDA Forest Service, and his colleagues investigated the long-term effects of postfire logging on woody fuels in 255 coniferous forest stands that burned with high fire severity in 68…
Publication Type: Report
Looking beyond the mean: Drivers of variability in postfire stand development of conifers in Greater Yellowstone
Year: 2018
High-severity, infrequent fires in forests shape landscape mosaics of stand age and structure for decades to centuries, and forest structure can vary substantially even among same-aged stands. This variability among stand structures can affect landscape-scale carbon and nitrogen cycling, wildlife habitat availability, and vulnerability to subsequent disturbances. We used an individual-based forest process model (iLand) to ask: Over 300 years of postfire stand development, how does variation in early regeneration densities versus abiotic conditions influence among-stand structural variability…
Publication Type: Journal Article
Influences of fire–vegetation feedbacks and post‐fire recovery rates on forest landscape vulnerability to altered fire regimes
Year: 2018
In the context of ongoing climatic warming, forest landscapes face increasing risk of conversion to non‐forest vegetation through alteration of their fire regimes and their post‐fire recovery dynamics. However, this pressure could be amplified or dampened, depending on how fire‐driven changes to vegetation feed back to alter the extent or behaviour of subsequent fires. Here we develop a mathematical model to formalize understanding of how fire–vegetation feedbacks and the time to forest recovery following high‐severity (i.e. stand‐replacing) fire affect the extent and stability of forest…
Publication Type: Journal Article
Fuel mass and stand structure 13 years after logging of a severely burned ponderosa pine forest in northeastern Oregon, U.S.A
Year: 2018
Stand structure and fuel mass were measured in 2011, 13 years after logging of a seasonally dry, ponderosa pine-dominated forest that had burned severely in the 1996 Summit Wildfire, Malheur National Forest, northeastern Oregon, U.S.A. Data are compared to those taken one year after post-fire logging (1999), and analyzed in the context of a second fire (Sunshine Fire) that burned through one of the four treatment blocks in 2008. Three treatments were evaluated in a randomized block experiment: unlogged control, commercial harvest (most dead merchantable trees removed), and fuel reduction…
Publication Type: Journal Article
Mortality predictions of fire-injured large Douglas-fir and ponderosa pine in Oregon and Washington, USA
Year: 2017
Wild and prescribed fire-induced injury to forest trees can produce immediate or delayed tree mortality but fire-injured trees can also survive. Land managers use logistic regression models that incorporate tree-injury variables to discriminate between fatally injured trees and those that will survive. We used data from 4024 ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and 3804 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from 23 fires across Oregon and Washington to assess the discriminatory ability of 21 existing logistic regression models and a polychotomous key (Scott…
Publication Type: Journal Article
Predicting post-fire tree mortality for 14 conifers in the Pacific Northwest, USA: Model evaluation, development, and thresholds
Year: 2017
Fire is a driving force in the North American landscape and predicting post-fire tree mortality is vital to land management. Post-fire tree mortality can have substantial economic and social impacts, and natural resource managers need reliable predictive methods to anticipate potential mortality following fire events. Current fire mortality models are limited to a few species and regions, notably Pinus ponderosa and Pseudotsuga menziesii in the western United States. The efficacy of existing mortality models to predict fire-induced tree mortality is central to effective forest management.…
Publication Type: Journal Article
Bridging the divide between fire safety research and fighting fire safely: how do we convey research innovation to contribute more effectively to wildland firefighter safety?
Year: 2017
Creating a safe workplace for wildland firefighters has long been at the centre of discussion for researchers and practitioners. The goal of wildland fire safety research has been to protect operational firefighters, yet its contributions often fall short of potential because much is getting lost in the translation of peer-reviewed results to potential and intended users. When information that could enhance safety is not adopted by individuals, the potential to improve safety – to decipher the wildland fire physical or social environment and to recognise hazards – is lost. We use firefighter…
Publication Type: Journal Article
Towards improving wildland firefighter situational awareness through daily fire behaviour risk assessments in the US Northern Rockies and Northern Great Basin
Year: 2017
Wildland firefighters must assess potential fire behaviour in order to develop appropriate strategies and tactics that will safely meet objectives. Fire danger indices integrate surface weather conditions to quantify potential variations in fire spread rates and intensities and therefore should closely relate to observed fire behaviour. These indices could better inform fire management decisions if they were linked directly to observed fire behaviour. Here, we present a simple framework for relating fire danger indices to observed categorical wildland fire behaviour. Ordinal logistic…
Publication Type: Journal Article
Post-fire vegetation and fuel development influences fire severity patterns in reburns
Year: 2017
In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of…
Publication Type: Journal Article
Human presence diminishes the importance of climate in driving fire activity across the United States
Year: 2017
Growing human and ecological costs due to increasing wildfire are an urgent concern in policy and management, particularly given projections of worsening fire conditions under climate change. Thus, understanding the relationship between climatic variation and fire activity is a critically important scientific question. Different factors limit fire behavior in different places and times, but most fire-climate analyses are conducted across broad spatial extents that mask geographical variation. This could result in overly broad or inappropriate management and policy decisions that neglect to…
Publication Type: Journal Article