Author: Matthew I. CockingPublisher:
ISBN:
Category : Conifers
Languages : en
Pages : 178
Book Description
The Effects of Native Conifer Encroachment and Importance of High-severity Wildfire in Fire-excluded California Black Oak Ecosystems of Northern California
Author: Matthew I. CockingPublisher:
ISBN:
Category : Conifers
Languages : en
Pages : 178
Book Description
Ecosystems of California
Author: Harold MooneyPublisher: Univ of California Press
ISBN: 0520278801
Category : Nature
Languages : en
Pages : 1008
Book Description
This long-anticipated reference and sourcebook for CaliforniaÕs remarkable ecological abundance provides an integrated assessment of each major ecosystem typeÑits distribution, structure, function, and management. A comprehensive synthesis of our knowledge about this biologically diverse state, Ecosystems of California covers the state from oceans to mountaintops using multiple lenses: past and present, flora and fauna, aquatic and terrestrial, natural and managed. Each chapter evaluates natural processes for a specific ecosystem, describes drivers of change, and discusses how that ecosystem may be altered in the future. This book also explores the drivers of CaliforniaÕs ecological patterns and the history of the stateÕs various ecosystems, outlining how the challenges of climate change and invasive species and opportunities for regulation and stewardship could potentially affect the stateÕs ecosystems. The text explicitly incorporates both human impacts and conservation and restoration efforts and shows how ecosystems support human well-being. Edited by two esteemed ecosystem ecologists and with overviews by leading experts on each ecosystem, this definitive work will be indispensable for natural resource management and conservation professionals as well as for undergraduate or graduate students of CaliforniaÕs environment and curious naturalists.
Fire in California's Ecosystems
Author: Jan W. van WagtendonkPublisher: Univ of California Press
ISBN: 0520961919
Category : Science
Languages : en
Pages : 567
Book Description
Fire in California’s Ecosystems describes fire in detail—both as an integral natural process in the California landscape and as a growing threat to urban and suburban developments in the state. Written by many of the foremost authorities on the subject, this comprehensive volume is an ideal authoritative reference tool and the foremost synthesis of knowledge on the science, ecology, and management of fire in California. Part One introduces the basics of fire ecology, including overviews of historical fires, vegetation, climate, weather, fire as a physical and ecological process, and fire regimes, and reviews the interactions between fire and the physical, plant, and animal components of the environment. Part Two explores the history and ecology of fire in each of California's nine bioregions. Part Three examines fire management in California during Native American and post-Euro-American settlement and also current issues related to fire policy such as fuel management, watershed management, air quality, invasive plant species, at-risk species, climate change, social dynamics, and the future of fire management. This edition includes critical scientific and management updates and four new chapters on fire weather, fire regimes, climate change, and social dynamics.
Post-fire Effects in Chaparral and Oak Ecosystems of Northern California
Author: Abigail M. JonesPublisher:
ISBN:
Category : Chaparral
Languages : en
Pages : 80
Book Description
The issue of wildfires, hazard fuels management, and post-fire tree mortality has become an increasingly common topic in the western United States. This thesis is composed of two studies, with the first study, Chapter 1, examining fuel treatment effectiveness and the second study, Chapter 2, striving to characterize post-fire mortality in oaks. Prior to wildfire, fuel reduction projects may take place to decrease the likelihood of high severity fire around human infrastructure and communities. Within California’s chaparral ecosystems, common treatment types include hand-thinning, prescribed burning, mechanical mastication, and mechanical mastication followed with prescribed burning. Because chaparral has a longer historical fire return interval and these ecosystems do not need frequent fire disturbance, the efficacy of these treatment types is debated. Our study had the rare opportunity to collect data on fine woody fuel loading, shrub density, and vegetation both immediately before and one year following wildfire in northern California’s Whiskeytown National Recreation Area. Using these comparisons, our goal was to determine the post-fire response of each treatment type and determine an effective fuels treatment in chaparral to mitigate fire behavior, while maintaining ecosystem integrity and supporting native species habitat. The severity of the wildfire was moderate across the study site and did not differ among treatments. Post-fire live shrub density and live shrub height also were not influenced by treatment type, but oak dominated sites had greater live shrub density after wildfire. Fine woody fuel loading levels differed by treatment type, with prescribed burned units having the greatest levels in both chaparral and oak sites. Fine woody fuel consumption was lowest in hand-thinned units. Total plant species richness increased in all treatment types following wildfire, largely driven by an increase in exotic species, as native plant cover decreased and exotic species cover increased across all treatments. This study suggests that areas of chaparral may need to be retreated sooner than this timeframe to reduce fire severity. However, retreating these systems may not be economically feasible and it remains unclear if treatments will meet fuel and fire behavior objectives. Land managers are concerned about post-fire mortality of trees and rely on statistical models of tree mortality in post-fire decision making. While many studies have evaluated the accuracy of these models in conifers, the performance of these models on hardwood species, specifically oak species, has been understudied. Models, such as FOFEM and FVS-FFE, can help land managers to predict which trees will die following fire and can help in hazard tree removal and post-fire salvage logging operations. These models, however, have been exclusively developed using western United States conifer species, bringing into question the veracity of these models for hardwood species. The purpose of this study was to test current mortality models using observations from wildfire and prescribed burn sites in northern California for two oak species, California black oak (Quercus kelloggii) and canyon live oak (Quercus chrysolepis). Our findings suggest that both modeling approaches performed well, but Random Forest was better at predicting probability of mortality for an imbalanced dataset. When using imbalanced datasets, logistic regression can underpredict mortality, which can have negative repercussions for land managers dealing with recently burned ecosystems containing oaks.
Wildland Fire in Ecosystems
Author: The Relationship Between Forest Fires and Forest Dynamics in California's North Coast Bioregion: how Altered Fire Regimes Have Affected the Vegetative Outcomes of Oak Woodlands and Mixed Conifer Forests
Author: Max BencomoPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Wildfire is a necessary part of ecosystem function in California, but fire suppression and the spread of invasive species have endangered many ecosystems. The North Coast bioregion of California has seen dramatic shifts in forest ecology and vegetative density, largely due to the disruption of historic fire regimes. Historic fire regimes were previously maintained through indigenous land management, but the arrival of European settlers in the 1850's initiated the changes reflected in current fire regimes. Not only is the North Coast bioregion the hotbed of recent fire activity, it is experiencing decreased counts of heterogeneity within forests while also seeing increased amounts of fuel loads that contribute to more severe fires. This paper utilizes a comparative analysis of mixed conifer forest and oak woodland ecozones, describing the vegetative outcomes of their altered fire regimes. Through the synthesis of case studies, government reports, impact assessments, and management plans, I investigated the current state of these landscapes and developed recommendations for future management. The combination of fire suppression and increasing invasive populations have led to numerous shifts in forest systems. Invasive species heavily influence forest fuel loads and can change ecosystem structure, which can subsequently alter the area's fire regime. Once a fire regime has changed it can imperil the livelihood of historic plant populations. Conifer forests are seeing shifts from resilient species to more fire-sensitive species, which can lead to the decimation of entire populations by high-severity fires. Oak woodlands are also suffering from fire regime changes, as conifers are encroaching and overtaking the forest canopy, drowning out oaks and reducing them to shrub species. Both mixed conifer forests and oak woodlands are threatened by changes in their respective fire regimes. These shifts in vegetation patterns can be amended through integrative management initiatives, notably the application of prescribed burns to aid the restoration of historical fire regimes.
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.
Introduction to Prescribed Fire in Southern Ecosystems
Author: Thomas A. WaldropPublisher: Government Printing Office
ISBN: 9780160943959
Category : Gardening
Languages : en
Pages : 32
Book Description
Prescribed burning is an important tool throughout Southern forests, grasslands, and croplands. The need to control fire became evident to allow forests to regenerate. This manual is intended to help resource managers to plan and execute prescribed burns in Southern forests and grasslands. A new appreciation and interest has developed in recent years for using prescribed fire in grasslands, especially hardwood forests, and on steep mountain slopes. Proper planning and execution of prescribed fires are necessary to reduce detrimental effects, such as the impacts on air and downstream water quality. Check out these related products: Trees at Work: Economic Accounting for Forest Ecosystem Services in the U.S. South can be found here: https://bookstore.gpo.gov/products/trees-work-economic-accounting-forest-ecosystem-services-us-south Soil Survey Manual 2017 is available here: https://bookstore.gpo.gov/products/soil-survey-manual-march-2017 Quantifying the Role of the National Forest System Lands in Providing Surface Drinking Water Supply for the Southern United States is available here: https://bookstore.gpo.gov/products/quantifying-role-national-forest-system-lands-providing-surface-drinking-water-supply Fire Management Today print subscription is available here: https://bookstore.gpo.gov/products/fire-management-today Wildland Fire in Ecosystems: Fire and Nonnative Invasive Plants can be found here: https://bookstore.gpo.gov/products/wildland-fire-ecosystems-fire-and-nonnative-invasive-plants
Fire Effects Guide
Author: Fire Effects on Soils and Restoration Strategies
Author: A CerdaPublisher: CRC Press
ISBN: 1439843333
Category : Science
Languages : en
Pages : 630
Book Description
This book has been published a decade after Fires Effects on Ecosystems by DeBano, Neary, and Folliott (1998), and builds on their foundation to update knowledge on natural post-fire processes and describe the use and effectiveness of various restoration strategies that may be applied when human intervention is warranted. The chapters in this book,