Fuel Loading and Vegetation Response to Mechanical Mastication Fuels Treatments PDF Download

Author: Jeffrey Kane
Publisher:
ISBN:
Category : Forest ecology
Languages : en
Pages : 142

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Author: Alan Wyatt Shakespear
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 45

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Book Description
Pinyon-juniper woodland encroachment threatens ecosystem function and diversity on sagebrush steppe. Decreased fire frequency likely favors proliferation of pinyon-juniper woodlands and subsequent decline in desirable understory species. Increased tree cover produces hazardous canopy fuel loads that contribute to severe crown fires and threaten life and property at the wildland-urban-interface. Mechanical mastication converts large canopy fuels into small woody debris, altering wildfire dynamics from a potential crown fire to a more controllable surface fire. We measured fuel loading and cover on untreated, masticated, and masticated + burned treatments on 30-m transects within 30 X 33-m subplots, representing 45 different sites throughout Utah. All variables were analyzed using mixed-model analysis of covariance with untreated or pretreatment tree cover as the covariate. Shredding trees reduced large-diameter fuels to primarily 10-hour fuels (6.4-25.4 mm diameter). Reduced fuel sizes, fuel redistribution, and fuelbed compactness resulting from mastication treatments can aid wildfire suppression. Masticated + burned treatments effectively reduced woody surface fuel loading to that of pretreatment conditions. Prescribed burning could be used outside the growing season in cool-weather, high-moisture conditions to remove surface fuels, mitigating lethal soil heating and plant mortality. Shrub loading was not adversely affected by mastication treatments, but was significantly reduced with masticated + burned treatments. Masticated and masticated + burned treatments significantly increased herbaceous fuel loading. Treating at lower tree cover values reduced fuel buildup, and provided more opportunity for a positive herbaceous response. Fuel loading estimates measured in this study were provided to populate fire behavior models for mastication treatments on our study sites when such models become available.

Author: Caroline Martorano
Publisher:
ISBN:
Category : Forest thinning
Languages : en
Pages : 40

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Fuel reduction treatments are broadly implemented to reduce the risk of extreme wildfire. Yet, research on the long-term effectiveness and ecological consequences among these treatments is lacking. In this study, I examined short- and long-term changes in fuels and understory vegetation after treatment in chaparral and oak-dominated stands of Whiskeytown National Recreation Area. Treatments included mastication and spring burning, spring burning only, mastication only, and hand-thinning. Treatments were applied randomly to 1 to 2 units within each of 10 blocks. Two plots were established in each treatment unit and fuel and vegetation data was collected and analyzed at the block level (n=10). Results showed all treatments, except spring burn only, reduced live shrub height compared to the control. The combined mastication and spring burn treatment had up to 2.3 times higher live shrub density than the other treatments. Mechanical or manual only treatments promoted reductions in fine dead woody surface fuel loading compared to the control 15 years after treatment. There were subtle changes in the understory plant community, including an increase in species richness in the mastication and spring burn treatment and a decrease in species richness over time. The effects of fuel treatments on fuels and understory vegetation were highly varied with some level of trade-off in effectiveness. Optimal fuel treatments will likely depend on the specific site objectives. However, results from this study indicate that mastication and hand removal treatments can provide substantial decreases in live and dead fuel loading over the long- term without substantial changes to the understory plant community.

Author: Roger D. Fight
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 28

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Author: Leda Nikola Kobziar
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 416

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"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

Author: Morris C. Johnson
Publisher: DIANE Publishing
ISBN: 1428987665
Category : Technology & Engineering
Languages : en
Pages : 310

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Analyzes a range of fuel treatments for representative dry forest stands in the Western U.S. dominated by ponderosa pine, Douglas-fir, & pinyon pine. Six silvicultural options (no thinning; thinning from below to 50 trees per acre [tpa], 100 tpa, 200 tpa, & 300 tpa; & prescribed fire) are considered in combination with the surface fuel treatments (no treatment, pile & burn, & prescribed fire), resulting in a range of alternative treatments for each representative stand. Fuel treatment scenarios presented here can be used by resource managers to examine alternatives for Nat. Environ. Policy Act documents & other applications that require scientifically based info. to quantify the effects of modifying forest structure & surface fuels. Illustrations.

Author:
Publisher:
ISBN:
Category : Colorado
Languages : en
Pages : 37

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Over the past several years, fire managers have increased their use of mastication treatments, the on-site disposal of shrubs and small-diameter trees through chipping and shredding. Mastication is a relatively untested management practice that alters the chemical and physical conditions of the forest floor and may influence vegetation regrowth and fuel development for years or decades. Eighteen sites were established across four ecosystems of the southern Rocky Mountains and the Colorado Plateau: lodgepole pine (Pinus contorta), mixed conifer (Pinus ponderosa, Pseudotsuga menziesii, Pinus flexilis, and Pinus contorta), ponderosa pine (Pinus ponderosa), and pinyon pine/juniper (Pinus edulis/Juniperus sp.). These sites were distributed across a wide geographic range throughout Colorado and represent treatments across several federal, state, and other land agencies. The sites were mulched between 2004 and 2006 and first measured in 2007 or 2008. The mechanical treatment added a substantial amount of 1-hr and 10-hr woody fuel (nutrition in lodgepole pine and pinyon-juniper ecosystems. Though the initial impacts of mastication were subtle, our findings indicate that responses will vary among ecosystems and justify further research to elucidate ecosystem-specific processes and long-term consequences of these treatments.

Author: Faith Ann Heinsch
Publisher:
ISBN:
Category : Conifers
Languages : en
Pages : 23

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Author: United States Department of Agriculture
Publisher: CreateSpace
ISBN: 9781511544672
Category :
Languages : en
Pages : 328

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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.

Author: Jesse K. Kreye
Publisher:
ISBN:
Category :
Languages : en
Pages : 185

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Treatments had little impact on understory vegetation communities or soil nutrients, however reduction in saw palmetto evidenced inthis study may alter future groundcover vegetation as slight increases in grasscover were observed here. The fast recovery of understory vegetation andgenerally low impact to ecosystem attributes suggest resiliency of these pineflatwoods to mechanical treatments, however their effectiveness at reducingfire hazard is likely short-lived. Developing treatment regimes that utilize prescribed burning to reducesurface fuel loading following mastication will require special attention to treatment timing in order to ensure surface litter consumption, while minimizing potential impacts to the overstory and meeting overall management goals.