Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 556
Book Description
Lake Tahoe Basin Management Unit, South Shore Fuel Reduction and Healthy Forest Restoration
Author: Research Paper PNW.
Author: Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 108
Book Description
Upper Truckee River Restoration and Golf Course Reconfiguration Project
Author: Fire Behavior and Effects Relating to Suppression, Fuel Treatments, and Protected Areas on the Antelope Complex: Wheeler Fire
Author: Long-term Effects of Fire Hazard Reduction Treatments in the Southern Cascades and Northern Sierra Nevada, California
Author: Lindsay Aney ChionoPublisher:
ISBN:
Category :
Languages : en
Pages : 162
Book Description
Historic fire regimes in the dry conifer forests of the southern Cascade and northern Sierra Nevada regions of California were characterized by relatively frequent fires of low and mixed severity. Human management practices since the mid-19th century have altered the disturbance role of fire in these dry yellow pine and mixed conifer forest ecosystems. Fire suppression, high-grade timber harvesting, and livestock grazing have reduced the frequency of burning and caused a shift in the structure and species composition of forest vegetation. These changes, including high levels of accumulated fuel and increased structural homogeneity and dominance of shade-tolerant tree species, combined with a warming climate, have rendered many stands susceptible to high-severity fire. In many forests of the western United States, wildfires are increasingly difficult and costly to control, and human communities are regularly threatened during the fire season. Treating wildland fuels to reduce wildfire hazards has become a primary focus of contemporary forest management, particularly in the wildland-urban interface. The specific objectives of treatment are diverse, but in general, treatments address accumulated surface fuels, the fuel ladders that carry fire into the forest canopy, and surface and canopy fuel continuity. These modifications to forest fuels can alleviate the severity of a future wildfire and support suppression activities through improved access and reduced fire intensity. While fuel reduction treatments are increasingly common in western forests, the long-term structural and ecological effects of treatment remain poorly understood. This dissertation uses a chronosequence of treated stands to examine the temporal influence of treatment on forest structure, the understory plant community, and wildfire hazard. The first chapter examines the effects of fuels reduction treatment on stand structure, overstory species composition, and ground and surface fuels. The stand structures and reduced surface fuel loads created by fuels modification are temporary, yet few studies have assessed the lifespan of treatment effects. The structural legacies of treatment were still present in the oldest treatment sites. Treatments reduced site occupancy (stand density and basal area) and increased quadratic mean diameter by approximately 50%. The contribution of shade-tolerant true firs to stand density was also reduced by treatment. Other stand characteristics, particularly timelag fuel loads, seedling density, and shrub cover, exhibited substantial variability, and differences between treatment age classes and between treatment and control groups were not statistically significant. The second chapter evaluates fuel treatment longevity based on potential wildfire behavior and effects on vegetation. Forest managers must divide scarce resources between fuel treatment maintenance, which is necessary to retain low hazard conditions in treated stands, and the construction of new treatments. Yet the most basic questions concerning the lifespan of treatment effectiveness have rarely been engaged in the literature. In this study, field-gathered fuels and vegetation data were used to aid fuel model selection and to parameterize a fire behavior and effects model, Fuels Management Analyst Plus. In addition, a semi-qualitative, semi-quantitative protocol was applied to assess ladder fuel hazard in field sampling plots. Untreated sites exhibited fire behavior that would challenge wildfire suppression efforts, and projected overstory mortality was considerable. In contrast, estimated fire behavior and severity were low to moderate in even the oldest fuel treatments, those sampled 8-26 years after treatment implementation. Findings indicate that in the forest types characteristic of the northern Sierra Nevada and southern Cascades, treatments for wildfire hazard reduction retain their effectiveness for more than 10-15 years and possibly beyond a quarter century. Fuel treatment activities disturb the forest floor, increase resource availability, and may introduce non-native plant propagules to forest stands. Non-native plant invasions can have profound consequences for ecosystem structure and function. For these reasons, there is concern that treatment for fire hazard reduction may promote invasion by exotic species. Several short-term studies have shown small increases in non-native abundance as a result of treatment, but the long-term effects have rarely been addressed in the literature. The final chapter examines treatment effects on the understory plant community and on cover of the forest floor, as mineral soil exposure has been linked to invasion. Regression tree analysis provided insights into the influence of treatment and site characteristics on these variables. Treatments increased forb and graminoid cover, but temporal trends in abundance were opposite. An initial increase in forb cover in the most recently treated sites was followed by a gradual decline, while mean graminoid cover was highest in the oldest treatments. Shrubs dominated live plant abundance. Shrub cover showed few temporal trends, but was negatively associated with canopy cover. Mineral soil exposure was increased by treatment and declined slowly over time, remaining elevated in the oldest treatments. Non-native plant species were very rare in the treatment sites sampled in this study. Despite the availability of bare mineral soil and the proximity of transportation corridors, a source of non-native propagules, non-natives were recorded in only 2% of sampling plots. This study suggests that forest disturbance associated with treatment for hazardous fuels reduction may not produce significant invasions in these forest types.
The Effects of Fire and Fuels Reduction Treatments on Fire Hazard and Soil Carbon Respiration in a Sierra Nevada Pine Plantation
Author: Leda Nikola KobziarPublisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 416
Book Description
"Throughout fire-adapted forests of the western US, and in the Sierra Nevada of California specifically, wildfire suppression has produced forest structures conducive to more severe, costly, and ecologically deleterious fires. Recent legislation has identified the necessity of management practices that manipulate forests towards less fire-hazardous structures. In the approximately 30 year old pine plantations of the Stanislaus National Forest, extensive fuels reduction procedures are being implemented. This dissertation addresses whether silvicultural and burning treatments are effective at reducing the intensity and severity of potential fire behavior, and how, along with wildfire, these treatments impact the evolution of carbon dioxide from the soil to the atmosphere. The first chapter addresses the relationships between soil respiration, tree injury, and forest floor characteristics in high and low severity wildfire burn sites in a salvage-logged mixed-conifer forest. The results indicate that fire severity influences soil CO2 efflux and should be considered in ecosystem carbon modeling. In the next chapter, fire models suggest that mechanical shredding of understory vegetation (mastication) is detrimental, and prescribed fire most effective in reducing potential fire behavior and severity in pine plantations. The third chapter documents the impact of alternative fuels treatments on soil carbon respiration patterns in the pine plantations, and shows that mastication produces short-term reductions in respiration rates and soil moisture. The final chapter further examines the relationships of fire-induced tree injuries, forest floor structure, and environmental factors to soil respiration response to fuels treatments. Each chapter is written as an independent manuscript; they collectively serve to expand the limited understanding of the effectiveness and ecological consequences of fire and fuels treatments in coniferous forests."--Abstract
Guide to Fuel Treatments in Dry Forests of the Western United States
Author: Morris C. JohnsonPublisher:
ISBN:
Category : Fire and Fuels Extension, Forest Vegetation Simulator (Computer program)
Languages : en
Pages : 328
Book Description
The Fire and Fuels Extension of the Forest Vegetation Simulator (FFE-FVS) was used to calulate the immediate effects of treatments on surface fuels, fire hazard, potential fire behavior, and forest structure for respresentative dry forest stands in the Western United States. Treatments considered included pile and burn and prescribed fire.
BEHAVE
Author: Patricia L. AndrewsPublisher:
ISBN:
Category : Fire testing
Languages : en
Pages : 134
Book Description
Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.
Living with Fire
Author: Guide to Fuel Treatments in Dry Forests of the Western United States
Author: United States Department of AgriculturePublisher: CreateSpace
ISBN: 9781511544672
Category :
Languages : en
Pages : 328
Book Description
Guide to Fuel Treatments analyzes a range of fuel treatments for representative dry forest stands in the Western United States with overstories dominated by ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and pinyon pine (Pinus edulis). Six silvicultural options (no thinning; thinning from below to 50 trees per acre [tpa], 100 tpa, 200 tpa, and 300 tpa; and prescribed fire) are considered in combination with three surface fuel treatments (no treatment, pile and burn, and prescribed fire), resulting in a range of alternative treatments for each representative stand. The Fire and Fuels Extension of the Forest Vegetation Simulator (FFE-FVS) was used to calculate the immediate effects of treatments on surface fuels, fire hazard, potential fire behavior, and forest structure. The FFEFVS was also used to calculate a 50-year time series of treatment effects at 10-year increments. Usually, thinning to 50 to 100 tpa and an associated surface fuel treatment were shown to be necessary to alter potential fire behavior from crown fire to surface fire under severe fire weather conditions. This level of fuel treatment generally was predicted to maintain potential fire behavior as surface fire for 30 to 40 years, depending on how fast regeneration occurs in the understory, after which additional fuel treatment would be necessary to maintain surface fire behavior. Fuel treatment scenarios presented here can be used by resource managers to examine alternatives for National Environmental Policy Act documents and other applications that require scientifically based information to quantify the effects of modifying forest structure and surface fuels.