Research Database
Displaying 1 - 10 of 10
Predicting large wildfires across western North America by modeling seasonal variation in soil water balance
Year: 2016
A lengthening of the fire season, coupled with higher temperatures, increases the probability of fires throughout much of western North America. Although regional variation in the frequency of fires is well established, attempts to predict the occurrence of fire at a spatial resolution <10 km2 have generally been unsuccessful. We hypothesized that predictions of fires might be improved if depletion of soil water reserves were coupled more directly to maximum leaf area index (LAImax) and stomatal behavior. In an earlier publication, we used LAImax and a process-based forest growth model to…
Publication Type: Journal Article
Synthesis of Knowledge of Extreme Fire Behavior: Volume II for Fire Behavior Specialists, Researchers, and Meteorologists
Year: 2016
The National Wildfire Coordinating Group’s definition of extreme fire behavior indicates a level of fire behavior characteristics that ordinarily precludes methods of direct controlaction. One or more of the following is usually involved: high rate of spread, prolific crowning/ spotting, presence of fire whirls, and strong convection column. Predictability is difficultas such fires often influence their environment to some degree and behave erratically, sometimes dangerously. Alternate terms include “blow up” and “fire storm.” Fire managersexamining fires over the last 100 years have come to…
Publication Type: Report
Forest fuels and potential fire behaviour 12 years after variable-retention harvest in lodgepole pine
Year: 2016
Variable-retention harvesting in lodgepole pine offers an alternative to conventional, even-aged management. This harvesting technique promotes structural complexity and age-class diversity in residual stands and promotes resilience to disturbance. We examined fuel loads and potential fire behaviour 12 years after two modes of variable-retention harvesting (dispersed and aggregated retention patterns) crossed by post-harvest prescribed fire (burned or unburned) in central Montana. Results characterise 12-year post-treatment fuel loads. We found greater fuel load reduction in treated than…
Publication Type: Journal Article
The impact of aging on laboratory fire behaviour in masticated shrub fuelbeds of California and Oregon, USA
Year: 2016
Mastication of shrubs and small trees to reduce fire hazard has become a widespread management practice, yet many aspects of the fire behaviour of these unique woody fuelbeds remain poorly understood. To examine the effects of fuelbed aging on fire behaviour, we conducted laboratory burns with masticated Arctostaphylos spp. and Ceanothus spp. woody debris that ranged from 2 to 16 years since treatment. Masticated fuels that were 10 years or older burned with 18 to 29% shorter flame heights and 19% lower fireline intensities compared with the younger fuelbeds across three different fuel loads…
Publication Type: Journal Article
Fuels and Fire Behavior Dynamics in Bark Beetle-Attacked Forests in Western North America and Implications for Fire Management
Year: 2012
Declining forest health attributed to associations between extensive bark beetle-caused tree mortality, accumulations of hazardous fuels, wildfire, and climate change have catalyzed changes in forest health and wildfire protection policies of land management agencies. These changes subsequently prompted research to investigate the extent to which bark beetle-altered fuel complexes affect fire behavior. Although not yet rigorously quantified, the results of the investigations, in addition to a growing body of operational experience and research, indicates that predictable changes in surface,…
Publication Type: Journal Article
Atmospheric Interactions with Wildland Fire Behaviour II. Plume and Vortex Dynamics
Year: 2012
This paper is the second of two reviewing scientific literature from 100 years of research addressing interactions between the atmosphere and fire behaviour. These papers consider research on the interactions between the fuels burning at any instant and the atmosphere, and the interactions between the atmosphere and those fuels that will eventually burn in a given fire. The first paper reviews the progression from the surface atmospheric properties of temperature, humidity and wind to horizontal and vertical synoptic structures and ends with vertical atmospheric profiles. This second paper…
Publication Type: Journal Article
Mastication and Prescribed Fire Influences on Tree Mortality and Predicted Fire Behavior in Ponderosa Pine
Year: 2012
The purpose of this study was to provide land managers with information on potential wildfire behavior and tree mortality associated with mastication and masticated/fire treatments in a plantation. Additionally, the effect of pulling fuels away from tree boles before applying fire treatment was studied in relation to tree mortality. Fuel characteristics and tree mortality data were gathered before and after treatments in a 25-year-old ponderosa pine (Pinus ponderosa C. Lawson) plantation. A random block design was used with three treatments plus a control at each of four blocks. Four plots…
Publication Type: Journal Article
Atmospheric Interactions with Wildland Fire Behaviour I. Basic Surface Interactions, Vertical Profiles and Synoptic Structures
Year: 2012
This paper is the first of two reviewing scientific literature from 100 years of research addressing interactions between the atmosphere and fire behaviour. These papers consider research on the interactions between the fuels burning at any instant and the atmosphere, and the interactions between the atmosphere and those fuels that will eventually burn in a given fire. This first paper reviews the progression from the surface atmospheric properties of temperature, humidity and wind to horizontal and vertical synoptic structures and ends with vertical atmospheric profiles. (The companion paper…
Publication Type: Journal Article
Surface Fire Intensity Influences Simulated Crown Fire Behavior in Lodgepole Pine Forests with Recent Mountain Pine Beetle-Caused Tree Mortality
Year: 2012
Recent bark beetle outbreaks have had a significant impact on forests throughout western North America and have generated concerns about interactions and feedbacks between beetle attacks and fire. However, research has been hindered by a lack of experimental studies and the use of fire behavior models incapable of accounting for the heterogeneous fuel complexes. We populated the Wildland-Urban Interface Fire Dynamics Simulator with data from 11 field sites to investigate the effect of mountain pine beetle (MPB)-caused tree mortality on simulated crown fire behavior across a range of surface…
Publication Type: Journal Article
Wildfire exposure to analysis on the national forests in the Pacific Northwest, USA
Year: 2012
We analyzed wildfire exposure for key social and ecological features on the national forests in Oregon and Washington. The forests contain numerous urban interfaces, old growth forests, recreational sites, and habitat for rare and endangered species. Many of these resources are threatened by wildfire, especially in the east Cascade Mountains fire-prone forests. The study illustrates the application of wildfire simulation for risk assessment where the major threat is from large and rare naturally ignited fires, versus many previous studies that have focused on risk driven by frequent and small…
Publication Type: Journal Article