Download or read book Simulating the Effects of Climate Change Wildfire and Fuel Treatment on Sierra Nevada Forests written by Shuang Liang and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sierra Nevada forests represent a major ecological and economic resource for the state of California. Changes in climate and disturbance regimes, compounded with changes in forest structure from fire-exclusion, pose a critical challenge to managing Sierran forests for sustained carbon (C) sequestration and ecosystem services. My dissertation research sought to improve our understanding of how changing climate and disturbance will affect forest ecosystems in the Sierra Nevada by accounting for species-specific dynamics and interacting spatial processes that were underrepresented in landscape projections. Given the diverse tree species and forest types that differ in their optimal climate for growth and tolerance of stressors, I simulated forest dynamics in the Sierra Nevada under projected future climate and area burned as well as alternative management strategies with a species-specific, spatially explicit forest landscape model. First, I quantified how projected climate-wildfire interactions would affect forest communities and associated C dynamics. Here, results suggest that, across the Sierra Nevada, forest communities may not change as intact unit over the 21st Century and potential exists for substantial community change and C sequestration decline beyond this century. Then, I assessed the long-term successional trajectory and the ability of the system to sequester C beyond the 21st Century. Assuming climate and wildfire distributions equilibrate at late-century conditions, the results show a committed decline in forest cover and C carrying capacity, suggesting a steep reduction in the contribution of Sierra Nevada forest to the terrestrial C sink. Finally, I quantified how large-scale restoration treatments would alter the effects of changing climate and wildfire on forest C balance. I found that widespread application of fuel treatments would confer greater forest C stock stability. This work offers an improved understanding of how changing environmental conditions will affect the forest ecosystems in the Sierra Nevada and provides insights into using large-scale management strategy to manage the Sierran landscape under novel conditions.

Download or read book Forest Management Wildfire and Climate Impacts on the Hydrology of Sierra Nevada Mixed conifer Watersheds written by and published by . This book was released on 2001 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this dissertation aims to 1) assess the water balance of headwater catchments in the Sierra Nevada and determine if fuel treatments implemented in 2012 impacted runoff, 2) use a hydro-ecologic model to simulate the effects of fuel treatments and modeled wildfire at a larger fireshed scale, and 3) to investigate the interaction of vegetation disturbance and projected temperature increases through 2100 to determine relative impacts on hydrologic fluxes. The high variability in annual precipitation, combined with low post-treatment precipitation, masked any detectable changes in headwater catchment runoff from fuel treatments. Model results, however, do show the potential of increased runoff with treatments at both the headwater and fireshed scales, particularly in the high precipitation region of the American River Basin, where vegetation is less water-limited. While the potential for increasing runoff with fuel treatments exists, and may be a co-benefit of reduced fire risk, high-precision equipment for measuring stream discharge may be necessary to verifiable detect these increases. Although increasing temperatures adversely affect snowpack storage, changes in runoff and evapotranspiration are limited to the highest potential temperature increases towards the end of the century, and have less of an impact than vegetation disturbances.

Download or read book Wildland Fires and Air Pollution written by Andrzej Bytnerowicz and published by Elsevier. This book was released on 2008-10-06 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction between smoke and air pollution creates a public health challenge. Fuels treatments proposed for National Forests are intended to reduce fuel accumulations and wildfire frequency and severity, as well as to protect property located in the wild land-urban interface. However, prescribed fires produce gases and aerosols that have instantaneous and long-term effects on air quality. If fuels treatment are not conducted, however, then wild land fires become more severe and frequent causing worse public health and wellfare effects. A better understanding of air pollution and smoke interactions is needed in order to protect the public health and allow for socially and ecologically acceptable use of fire as a management tool. Wildland Fires and Air Pollution offers such an understanding and examines innovative wide-scale monitoring efforts (field and remotely sensed), and development of models predicting spatial and temporal distribution of air pollution and smoke resulting from forests fires and other sources. Collaborative effort of an international team of scientists High quality of invited chapters Full colour

Download or read book The Effects of Fire and Fuels Reduction Treatments on Fire Hazard and Soil Carbon Respiration in a Sierra Nevada Pine Plantation written by Leda Nikola Kobziar and published by . This book was released on 2006 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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

Download or read book A Comparison of Fuel Reduction Methods for Wildfire Risk Management and Climate Change Resiliency in Mixed Conifer Forests in the Sierra Nevada written by Heather Navle and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wildfires in the mixed conifer forests of California's Sierra Nevada have been a common and natural disturbance for thousands of years, historically occurring every 3 to 30 years. The flora and fauna of the mixed conifer forest have evolved to depend on low to moderate severity wildfires for reproduction, foraging, and habitat. However, the Sierra Nevada has experienced dramatic environmental changes over the past ~150 years as a result of three main factors: wildfire suppression, climate change, and habitat loss. Because of the threat wildfires pose to human lives, property and timber harvest, they have been suppressed to an extent that has completely altered mixed conifer ecosystems. One of the changes to these ecosystems is increased vegetative fuel density, which can result in stand-replacing mega fires. To mitigate these high-severity mega wildfires, forest managers incorporate various fuel reduction methods into forest management plans. These impacts can have negative effects on forest ecosystems, degrading ecosystem characteristics that are critical for adapting to climate change. Thus, the two main objectives of this paper are to compare and contrast four different fuel reduction methods based on their effectiveness to (I) reduce wildfire risk and (II) promote climate change resiliency. The four fuel reduction methods are: low thinning, canopy thinning, selective thinning, and prescribed fire. These four fuel reduction methods have been compared in syntheses tables for the two main objectives. Qualitative and quantitative metric data, based on a literature review, were used to compare the optimal effects of each fuel reduction method. It was found that prescribed fire or thinning with prescribed fire resulted in the most optimal effects when considering both reduced wildfire risk and climate change resilience. However, tree mortality and the risk of fire escaping controlled boundaries are increased during prescribed fire operations. Additionally, results showed that all four fuel reduction methods displayed both positive and negative effects, depending on the metric used to evaluate the objective, which suggests that appropriate application of fuel reduction methods is highly variable depending on the goals and the environment. For example, canopy thinning alone may have desirable effects when prescribed fire is financially unfeasible or unsafe due to proximity to buildings. Applying prescribed fire is the most optimal fuel reduction method in most forest conditions; however, it is recommended that forest managers evaluate forest structure, density, and tree species prior to selecting the most appropriate fuel reduction method for their situation.

Download or read book Estimating Wildfire Behavior and Effects written by Frank A. Albini and published by . This book was released on 1976 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a brief survey of the research literature on wildfire behavior and effects and assembles formulae and graphical computation aids based on selected theoretical and empirical models. The uses of mathematical fire behavior models are discussed, and the general capabilities and limitations of currently available models are outlined.

Download or read book The Effects of Fire and Mechanical Fuel Treatments on Wildfire in the Mixed conifer Forest of the Sierra Nevada written by Andrew James Amacher and published by . This book was released on 2007 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Climate Fire and Forest Management in the Sierra Nevada written by Jens Turner Stevens and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Montane coniferous forests in western North America are experiencing rapid environmental change, due in part to increasing fire severity and decreasing winter snowpack. Many of these forests experienced frequent low-severity fires prior to intensive logging and fire suppression during the nineteenth and twentieth centuries, which have led to increased fuel loads and increased dominance by fire-sensitive, shade-tolerant tree species. Forest managers seeking to mitigate increases in fire size and severity are increasingly implementing fuel-reduction treatments, which target small trees and surface fuels for removal. However, the ecological effects of these treatments on subsequent wildfire behavior, forest resilience, understory plant community dynamics, and plant invasions have not been well documented. In Chapter 1, I utilized a large-scale natural experiment to investigate the effects of recent fuel treatments on subsequent wildfire severity and structural resilience, in twelve different yellow pine and mixed-conifer forest sites in the mountains of eastern California. By quantifying forest structure in treated and adjacent untreated stands, both after wildfire and without wildfire, I demonstrated that treatments reduced the amount of structural change caused by wildfire, as a result of their moderating effect on fire severity. Two years post-wildfire, treated stands resembled pre-wildfire stands, in that they had greater tree litter cover, more tree seedling regeneration, less shrub cover and recruitment, and less bare soil relative to untreated stands, which generally burned at very high severity. In Chapter 2, I used the same network of twelve sites to test whether the gradient of disturbance severity, from untreated and unburned stands to high-severity wildfire stands, generated predictable patterns of understory plant community composition and diversity. I incorporated information on the evolutionary history of the native flora to show that increasing disturbance severity favored understory species with southern biogeographic affinity. Analysis of leaf functional traits indicated that increases in microclimatic water deficit in high-severity stands favored species with reduced specific leaf area relative to their leaf Nitrogen concentration. Native plant diversity at the stand scale was greatest in treated stands that subsequently burned in a wildfire, however this diversity peak was due to increased plot-scale alpha diversity relative to undisturbed stands, and increased between-plot beta diversity relative to high-severity wildfire stands. Conversely, exotic plant diversity peaked in high-severity wildfire stands that had not been previously treated. In Chapter 3, I investigated the population-level response of non-native species to interactions between forest harvesting strategies, prescribed fire, and winter snowpack depth using a transplant experiment with two non-native shrubs: Scotch broom (Cytisus scoparius L. (Link)) and Spanish broom (Spartium junceum L.). Both species had the strongest positive population growth responses to canopy thinning, rather than clearcuts or dense canopies. Despite positive effects of prescribed fire on seed germination, frequent prescribed fire was shown to decrease population growth rates for both species. However, experimental snowpack reductions led to increased winter survival by both species, which translated into strong positive effects on population growth rates. Under a future climate scenario where winter snowpack levels increase in elevation, middle-elevation forests that experience fuel treatments may therefore be at increased risk of invasion by non-native plants due to synergies between climate and management regimes.

Download or read book Science Basis for Changing Forest Structure to Modify Wildfire Behavior and Severity written by and published by . This book was released on 2004 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forest Pattern Surface Fire Regimes and Climatic Change in the Sierra Nevada California written by Carol Miller and published by . This book was released on 1998 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide to Fuel Treatments in Dry Forests of the Western United States written by Morris C. Johnson and published by . This book was released on 2007 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book U S Geological Survey Professional Paper written by Zhiliang Zhu and published by . This book was released on 1984 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Fire and Fuels Extension to the Forest Vegetation Simulator written by Elizabeth D. Reinhardt and published by . This book was released on 2003 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) simulates fuel dynamics and potential fire behavior over time, in the context of stand development and management. Existing models of fire behavior and fire effects were added to FVS to form this extension. New submodels representing snag and fuel dynamics were created to complete the linkages. This report contains four chapters. Chapter 1 states the purpose and chronicles some applications of the model. Chapter 2 details the model's content, documents links to the supporting science, and provides annotated examples of the outputs. Chapter 3 is a user's guide that presents options and examples of command usage. Chapter 4 describes how the model was customized for use in different regions. Fuel managers and silviculturists charged with managing fire-prone forests can use the FFEFVS and this document to better understand and display the consequences of alternative management actions.

Download or read book Challenges to Sierra Nevada Forests and Their Local Communities written by Cynthia L. Schmidt and published by . This book was released on 2014 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global forests are experiencing dramatic changes due to changes in climate as well as anthropogenic activities. Increased warming is causing the advancement of some species upslope and northward, while it is also causing widespread mortality due to increased drought conditions. In addition, increasing human population in mountain regions is resulting in elevated risk of human life and property loss due to larger and more severe wildfires. My research focuses on assessing the current vulnerability of forests and their communities in the Sierra Nevada, and how forests are projected to change in the future based on different climate change scenarios. In the first chapter I use Landsat satellite imagery to identify and attribute cause of forest disturbance between 1985 and 2011, primarily focusing on disturbances due to insect, diseases and drought. The change-detection algorithm, Landtrendr, was successfully used to identify forest disturbance, but identifying cause of disturbance was challenging due to the spectral similarities between disturbance types. Landtrendr was most successful in identifying disturbance due to insect, disease and drought in the San Bernardino National Forest, where there is little forest management activity. In the second chapter, I assess whether state or local land use policies in high-fire prone regions exist to reduce the vulnerability of residential developments to wildfire. Three specific land-use tools associated with reducing wildfire vulnerability are identified: (1) buffers around developments; (2) clustered developments; (3) restricting construction on slopes greater than 25%. The study also determines whether demographic and physical characteristics of selected California counties were related to implementing land use policies related to reducing wildfire vulnerability. Results indicate that land use policies related to preventing wildfire-related losses focus on building materials, road access, water availability and vegetation management, not the three identified land-use tools. San Diego County, the county that has experienced the most devastating fires, had the highest percentage of residential developments with both clustering and buffering. The third chapter focuses on future forest conditions. I used a Dynamic Global Vegetation Model (DGVM) to assess future vegetation dynamics and productivity under changing climate and atmospheric CO2 concentrations in the Sierra Nevada. Model results suggest that Temperate Broadleaved Evergreen Plant Functional Types (PFTs) will move upslope and eastward, replacing Temperate Needleleaved PFTs. Boreal Needleleaved Evergreen PFTs, found primarily at higher elevations, will decline dramatically as temperatures continue to increase. Gross Primary Productivity (GPP) will increase as atmospheric CO2 concentration increases, due primarily to the increase in the more productive broadleaved PFTs. Forest ecosystems play an important role in maintaining climate stability at the regional and global scales as a vital carbon sink, so understanding the role of disturbance and climate change will be vital to both scientists and policy makers in the future.

Download or read book Assessing the Effects of Climate Change and Fuel Treatments on Forest Dynamics and Wildfire in Dry Mixed Conifer Forests of the Inland West written by and published by . This book was released on 2018 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past century in the western United States, warming has produced larger and more severe wildfires than previously recorded. General circulation models and their ensembles project continued increases in temperature and the proportion of precipitation falling as rain. Warmer and wetter conditions may change forest successional trajectories by modifying rates of vegetation establishment, competition, growth, reproduction, and mortality. Many questions remain regarding how these changes will occur across landscapes and how disturbances, such as wildfire, may interact with changes to climate and vegetation. Forest management is used to proactively modify forest structure and composition to improve fire resilience. Yet, research is needed to assess how to best utilize mechanical fuel reduction and prescribed fire at the landscape scale. Human communities also exist within these landscapes, and decisions regarding how to manage forests must carefully consider how management will affect such communities. In this work, three aspects of forest management are analyzed: (1) climate effects on forest composition and wildfire activity; (2) efficacy of fuel management strategies toward reducing wildfire spread and severity; and, (3) local resident perspectives on forest management. Using a forest landscape model, simulations of forest dynamics were used to investigate relationships among climate, wildfire, and topography with long-term changes in biomass for a fire-prone dry-conifer landscape in eastern Oregon. Under climate change, wildfire was more frequent, more expansive, and more severe, and ponderosa pine expanded its range into existing shrublands and high-elevation zones. There was a near-complete loss of native high-elevation tree species, such as Engelmann spruce and whitebark pine. Loss of these species were most strongly linked to burn frequency; this effect was greatest at high elevations and on steep slopes. Fuel reduction was effective at reducing wildfire spread and severity compared to unmanaged landscapes. Spatially optimizing mechanical removal of trees in areas at risk for high-severity wildfire was equally effective as distributing tree removal across the landscape. Tripling the annual area of prescribed burns was needed to affect landscape-level wildfire spread and severity, and distributing prescribed burns across the study area was more effective than concentrating fires in high-risk areas. I conclude that forest management can be used to reduce wildfire activity in dry-mixed conifer forests and that spatially optimizing mechanical treatments in high-risk areas can be a useful tool for reducing the cost and ecological impact associated with harvest operations. While reducing the severity and spread of wildfire may slow some long-term species shifts, high sub-alpine tree mortality occurred under all climate and fuel treatment scenarios. Thus, while forest management may prolong the existence of sub-alpine forests, shifts in temperature, precipitation, and wildfire may overtake management within this century. The use of PPGIS was useful for delineating the range of forest management preferences within the local community, for identifying areas of agreement among residents who have otherwise polarized views, and for generating modeling inputs that reflect views that may not be obtained through extant official channels for public participation. Because the local community has concerns about the use of prescribed fire, more education and outreach is needed. This may increase public acceptance of the amounts of prescribed fire needed to modify wildfire trajectories under future climate conditions.

Download or read book An Analysis of Wildfire Fuel Treatments as a Carbon Offset Project Type written by Peter Kelly and published by . This book was released on 2011 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulating the Effects of Climate Change and Ecological Restoration on Wildfire Behavior in Southwestern Ponderosa Pine Forests written by Kristen Honig and published by . This book was released on 2010 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: