Research Database
Displaying 141 - 160 of 210
Fire severity and cumulative disturbance effects in the post-mountain pine beetle lodgepole pine forests of the Pole Creek Fire
Year: 2016
Recent large scale mountain pine beetle (Dendroctonus ponderosae Hopkins, MPB) outbreaks have created concern regarding increased fuel loadings and exacerbated fire behavior and have prompted a desire to understand the effects of sequential disturbances on the landscape. However, previous research has focused on quantifying fuel loadings and using operational fire behavior models, rather than direct field measurements, to understand changes in fire severity following MPB. The 2012 Pole Creek Fire in central Oregon partially occurred in gray stage (8–15 years post-MPB epidemic) lodgepole pine…
Publication Type: Journal Article
Patterns of conifer regeneration following high severity wildfire in ponderosa pine - dominated forests of the Colorado Front Range
Year: 2016
Many recent wildfires in ponderosa pine (Pinus ponderosa Lawson & C. Lawson) - dominated forests of the western United States have burned more severely than historical ones, generating concern about forest resilience. This concern stems from uncertainty about the ability of ponderosa pine and other co-occurring conifers to regenerate in areas where no surviving trees remain. We collected post-fire conifer regeneration and other data within and surrounding five 11-18 year-old Colorado Front Range wildfires to examine whether high severity burn areas (i.e., areas without surviving trees)…
Publication Type: Journal Article
Response of understory vegetation to salvage logging following a high-severity wildfire
Year: 2016
Timber is frequently salvage-logged following high-severity stand-replacing wildfire, but the practice is controversial. One concern is that compound disturbances could result in more deleterious impacts than either disturbance individually, with mechanical operations having the potential to set back recovering native species and increase invasion by non-native species. Following the 2002 Cone Fire on the Lassen National Forest, three replicates of five salvage treatments were applied to 15 units formerly dominated by ponderosa pine, covering a range of disturbance intensities from unsalvaged…
Publication Type: Journal Article
Forest fire policy: change conventional thinking of smoke management to prioritize long-term air quality and public health
Year: 2016
Wildland fire smoke is inevitable. Size and intensity of wildland fires are increasing in the western USA. Smoke-free skies and public exposure to wildland fire smoke have effectively been postponed through suppression. The historic policy of suppression has systematically both instilled a public expectation of a smoke-free environment and deferred emissions through increased forest fuel loads that will lead to an eventual large spontaneous release. High intensity fire smoke is impacting a larger area including high density urban areas. Policy change has largely attempted to provide the…
Publication Type: Journal Article
U.S. wildfire governance as social-ecological problem
Year: 2016
There are fundamental spatial and temporal disconnects between the specific policies that have been crafted to address our wildfire challenges. The biophysical changes in fuels, wildfire behavior, and climate have created a new set of conditions for which our wildfire governance system is poorly suited to address. To address these challenges, a reorientation of goals is needed to focus on creating an anticipatory wildfire governance system focused on social and ecological resilience. Key characteristics of this system could include the following: (1) not taking historical patterns as givens…
Publication Type: Journal Article
Tree mortality and structural change following mixed-severity fire in Pseudotsuga forests of Oregon’s western Cascades, USA
Year: 2016
Mixed-severity fires are increasingly recognized as common in Pseudotsuga forests of the Pacific Northwest and may be an important mechanism for developing or maintaining their structural diversity and complexity. Questions remain about how tree mortality varies and forest structure is altered across the disturbance gradient imposed by these fires. Therefore, we sampled live and dead trees at 45–1.0 ha plots, each with four 0.10 ha nested subplots, stratified across an unburned, low, moderate and high-severity fire gradient. Burned plots were primarily sampled 10 and 22 years post-fire,…
Publication Type: Journal Article
Post-fire morel (Morchella) mushroom abundance, spatial structure, and harvest sustainability
Year: 2016
Morel mushrooms are globally distributed, socially and economically important reproductive structures produced by fungi of the genus Morchella. Morels are highly prized edible mushrooms and significant harvests are collected throughout their range, especially in the first year after fire, when some morel species fruit prolifically. Few studies have quantified post-fire morel mushroom abundance, despite their widespread human use. The purpose of this study is to provide the first ever estimate of post-fire morel mushroom abundance in Sierra Nevada mixed-conifer forest. Specifically, we…
Publication Type: Journal Article
Post-fire morel (Morchella) mushroom abundance, spatial structure, and harvest sustainability
Year: 2016
Morel mushrooms are globally distributed, socially and economically important reproductive structures produced by fungi of the genus Morchella. Morels are highly prized edible mushrooms and significant harvests are collected throughout their range, especially in the first year after fire, when some morel species fruit prolifically. Few studies have quantified post-fire morel mushroom abundance, despite their widespread human use. The purpose of this study is to provide the first ever estimate of post-fire morel mushroom abundance in Sierra Nevada mixed-conifer forest. Specifically, we…
Publication Type: Journal Article
Did the 2002 Hayman Fire, Colorado, USA, Burn with Uncharacteristic Severity?
Year: 2016
There is considerable interest in evaluating whether recent wildfires in dry conifer forests of western North America are burning with uncharacteristic severity—that is, with a severity outside the historical range of variability. In 2002, the Hayman Fire burned an unlogged 3400 ha dry conifer forest landscape in the Colorado Front Range, USA, that had been the subject of previous fire history and forest age structure research. We opportunistically leveraged pre-existing data from this research, in combination with post-fire aerial imagery, to provide insight into whether the Hayman Fire’s…
Publication Type: Journal Article
Does increased forest protection correspond to higher fire severity in frequent-fire forests of the western United States?
Year: 2016
There is a widespread view among land managers and others that the protected status of many forestlands in the western United States corresponds with higher fire severity levels due to historical restrictions on logging that contribute to greater amounts of biomass and fuel loading in less intensively managed areas, particularly after decades of fire suppression. This view has led to recent proposals—both administrative and legislative—to reduce or eliminate forest protections and increase some forms of logging based on the belief that restrictions on active management have increased fire…
Publication Type: Journal Article
1984–2010 trends in fire burn severity and area for the conterminous US
Year: 2016
Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were…
Publication Type: Journal Article
Places where wildfire potential and social vulnerability coincide in the coterminous United States
Year: 2016
The hazards-of-place model posits that vulnerability to environmental hazards depends on both biophysical and social factors. Biophysical factors determine where wildfire potential is elevated, whereas social factors determine where and how people are affected by wildfire. We evaluated place vulnerability to wildfire hazards in the coterminous US. We developed a social vulnerability index using principal component analysis and evaluated it against existing measures of wildfire potential and wildland–urban interface designations. We created maps showing the coincidence of social vulnerability…
Publication Type: Journal Article
Tree mortality based fire severity classification for forest inventories: a Pacific Northwest national forests example
Year: 2016
Determining how the frequency, severity, and extent of forest fires are changing in response to changes in management and climate is a key concern in many regions where fire is an important natural disturbance. In the USA the only national-scale fire severity classification uses satellite image change-detection to produce maps for large (>400 ha) fires, and is generated by the Monitoring Trends in Burn Severity (MTBS) program. It is not clear how much forested area burns in smaller fires or whether ground-based fire severity estimates from a statistical sample of all forest lands might…
Publication Type: Journal Article
A spatial database for restoration management capability on national forests in the Pacific Northwest USA
Year: 2016
Description: Understanding the capacity to reduce wildfire risk and restore dry forests on Western national forests is a key part of prioritizing new accelerated restoration programs initiated by the Forest Service. Although a number of social and biophysical factors influence the ability to implement restoration programs, one key driver is the suite of forest plan land designations and associated management directions. These land use designations and conservation reserves, which are intended to provide an array of ecosystem services (recreation, wildlife, water, timber, research, etc.), were…
Publication Type: Report
Recovery and adaptation after wildfire on the Colorado Front Range (2010-2012)
Year: 2016
Following the loss of homes to wildfire, when risk has been made apparent, homeowners must decide whether to rebuild, and choose materials and vegetation, while local governments guide recovery and rebuilding. As wildfires are smaller and more localised than other disasters, it is unclear if recovery after wildfire results in policy change and adaptation, decreasing assets at risk, or if recovery encourages reinvestment in hazard-prone areas. We studied three wildfires on the Colorado Front Range from2010 to 2012 that each destroyed over 150homes, describing policy response and characterising…
Publication Type: Journal Article
Relating Fire-Caused Change in Forest Structure to Remotely Sensed Estimates of Fire Severity
Year: 2016
Fire severity maps are an important tool for understanding fire effects on a landscape. The relative differenced normalized burn ratio (RdNBR) is a commonly used severity index in California forests, and is typically divided into four categories: unchanged, low, moderate, and high. RdNBR is often calculated twice—from images collected the year of the fire (initial assessment) and during the summer of the year after the fire (extended assessment). Both collection times have been calibrated to field measurements, but field data with both pre-fire and post-fire observations of matched plots are…
Publication Type: Journal Article
The economic benefit of localised, short-term, wildfire-potential information
Year: 2015
Wildfire-potential information products are designed to support decisions for prefire staging of movable wildfire suppression resources across geographic locations. We quantify the economic value of these information products by defining their value as the difference between two cases of expected fire-suppression expenditures: one in which daily information about spatial variation in wildfire-potential is used to move fire suppression resources throughout the season, and the other case in which daily information is not used and fire-suppression resources are staged in their home locations all…
Publication Type: Journal Article
Fire severity in southwestern Colorado unaffected by spruce beetle outbreak
Year: 2015
Recent large and severe outbreaks of native bark beetles have raised concern among the general public and land managers about potential for amplified fire activity in western North America. To date, the majority of studies examining bark beetle outbreaks and subsequent fire severity in the U.S. Rocky Mountains have focused on outbreaks of mountain pine beetle (MPB, Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests, but few studies, particularly field studies, have addressed the effects of the severity of spruce beetle (Dendroctonus rufipennis Kirby) infestation on subsequent…
Publication Type: Journal Article
Recovery of small pile burn scars in conifer forests of the Colorado Front Range
Year: 2015
The ecological consequences of slash pile burning are a concern for land managers charged with maintaining forest soil productivity and native plant diversity. Fuel reduction and forest health management projects have created nearly 150,000 slash piles scheduled for burning on US Forest Service land in northern Colorado. The vast majority of these are small piles (<5 m diameter). Similar to larger piles, we found that burning small piles had significant immediate effects on soil nutrients and physical and chemical properties and native plant cover. To evaluate the need to rehabilitate…
Publication Type: Journal Article
Topography, fuels, and fire exclusion drive fire severity of the Rim Fire in an old-growth mixed-conifer forest, Yosemite National Park, USA
Year: 2015
The number of large, high-severity fires has increased in the western United States over the past 30 years due to climate change and increasing tree density from fire suppression. Fuel quantity, topography, and weather during a burn control fire severity, and the relative contributions of these controls in mixed-severity fires in mountainous terrain are poorly understood. In 2013, the Rim Fire burned a previously studied 2125 ha area of mixed-conifer forest in Yosemite National Park. Data from 84 plots sampled in 2002 revealed increases in tree density, basal area, and fuel buildup since 1899…
Publication Type: Journal Article