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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Living with Wildfire in Arizona

Dolan, Corrine, Rogstad, Alix January 2007 (has links)
226 pp. / UACE Firewise publications (8 total) / The Living with Wildfire in Arizona educational materials synthesize the most recent scientific and technically known information available on fire ecology for the ecosystems of Arizona, including mixed conifer forests, ponderosa pine forests, pinyon-juniper and oak woodlands, chaparral, grasslands and desert scrub, and riparian areas. The materials are meant to educate homeowners living in the wildland urban interface areas as to the natural function of fire in each ecosystem and what significant changes have impacted fire behavior over time. Information includes the natural role of fire, how and why fire behavior has changed over time, and the role that humans play in affecting that change in protecting themselves and their property.
22

Introducing Two New Weed Control Tools: A "Smart" Spray Wand and a Wildland Weed Treatment Time Model

Dayton, Bryan E. 01 May 2015 (has links)
Millions are spent managing invasive weeds on public lands each year. Wildland invasive weed treatment bids are based primarily on acreage or hours but can be influenced by variables that increase treatment time and cost. Often neither the agency contracting the treatment nor the contractor has a clear idea of the amount of time that will be involved based on these variables. This makes it difficult to develop an accurate budget or bid for invasive weed control projects. It also limits managers in seeking funding and justifying treatment costs. A model has been developed that can predict herbicide application time due to four variables, weed canopy cover, slope, land cover, and weed visibility. Other variables were explored. The “smart” spray wand (SSW) is a new precision tool used to develop this model. The SSW is a spray wand with an integrated GPS and a flow meter for use with any type of spray system. The wand records the GPS location, herbicide flow,application time, and associated data of each treatment spray point. This information provided necessary data for the treatment time model. Weed control total treatment time (TTot) was hypothesized to include both treatment time (Tt) and rest time (Rt). The development and benefits of a wildland weed treatment time model are discussed. An accurate treatment time model could 1) establish an accurate standard for contractors and land managers, 2) assist in planning and managing limited treatment resources, and 3) justify funding requests and expenditures. The primary influence of the model is due to weed canopy cover (p=<2.2e-16, R2=0.5607), with smaller impacts by other variables. If canopy cover, slope, land cover, and weed visibility can be obtained for a weed control project, the model can be used.
23

Reducing Reliance on Supplemental Winter Feeding in Elk (Cervus canadensis): An Applied Management Experiment at Deseret Land and Livestock Ranch, Utah

Mangus, Dax L 01 August 2011 (has links)
Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of winter-feeding programs as a necessary step for decreasing the risk of disease spread due to high animal densities associated with feeding during winter. My research evaluated the use of behavioral training to reduce reliance on supplemental winter feeding of elk, while minimizing population reductions and human-wildlife conflicts. My study was conducted at Deseret Land & Livestock (DLL) in Rich County, UT, where managers at DLL have over 20 years of data on elk feeding during winters of varying intensities. I tested the effectiveness of range improvements, strategic cattle grazing, dispersed supplemental feeding, hunting, and herding to distribute and hold elk in desired areas during winter. I compared elk numbers on the feed ground during this study with historic data on DLL, and also contrasted elk responses with other comparable feed sites in Wyoming that served as controls. In 2 mild winters we completely eliminated elk feeding without incident and were able to reduce the quantity and duration of feeding during 1 severe winter. Since the conclusion of my study, DLL has further reduced quantity and duration of feeding during severe winters, and has completely eliminated feeding in light winters. Based on a Before After Control Impact (BACI) analysis, the reduction in the proportion of the elk population fed at the study site was significantly less than the proportion of the elk populations fed at the control sites in Wyoming (P = 0.057). Based on these results, I anticipate wildlife managers can decrease dependence on costly supplemental winter feeding and reduce the risks of disease while keeping human-wildlife conflicts at a minimum. This research illustrates an adaptive method that can enable wildlife managers to keep elk populations in northern Utah at or near their current size, while constraining disease outbreak and transmission risks within "acceptable" levels.
24

Establishing Weed Prevention Areas and evaluating Their Impact

Christensen, Stephanie 01 May 2011 (has links)
The spread of invasive weeds continues to be a serious economic and environmental threat. Weed prevention has the potential to stop weeds before they become well established in an area conserving time, energy, and resources. Unfortunately, weed prevention is often overlooked. Weed Prevention Areas (WPAs) are a relatively new tool developed to help improve the application of weed prevention. They are cooperatively managed areas that focus on implementing prevention and early detection strategies at a community level. The purpose of this research was to establish baseline data that will be used to evaluate the overall effectiveness of the WPA concept, as well as to produce materials to assist individuals with the development of a WPA. Two rural communities, with new WPAs, were each paired with a non-WPA community for data collection purposes. On-the-ground GPS vegetation inventories were conducted to determine the initial abundance and distribution of selected invasive weed species. This information was then used to demonstrate how to prioritize species and sites within a WPA in order to utilize limited resources more efficiently. A mail-back survey was also conducted to evaluate landowners' current opinions and activities in regards to prevention and control. In general, weed prevention was viewed as an important part of integrated weed management, but fewer than half of all respondents applied prevention strategies on their property. The failure to implement prevention strategies was attributed to limited funding and resources, a lack of weed prevention knowledge, and a high level of perceived risk. The knowledge gained from this research was then used to create Step-By-Step Guidelines for Establishing a Weed Prevention Area. These Guidelines provide interested individuals the resources necessary to successfully organize a WPA in their community. In addition, four wildland weed mapping methods were evaluated to identify their strengths and weaknesses. There was no difference in the estimation of patch size or location between the buffered point, screen-drawn, and perimeter walked methods. In most situations, time and distance factors favor the selection of either the buffered point or screen-drawn method. If patch shape is an important consideration, the perimeter-walked or buffered point method should be selected.
25

Landowner perception, awareness, and adoption of wildfire programs in the Southern United States

Jarrett, Adam R. 15 May 2009 (has links)
Non-industrial Private Forests (NIPF) landowners constitute a major component of the forested land portfolio in the Southeastern United States. The lands they possess provide a variety of social benefits but many aspects of how these landowners manage their properties exist. The goal of this research was to determine overall landowner awareness regarding wildfire programs and education and identify interrelationships among management strategies, demographic variables, and experiences. Specifically, it was hypothesized that landowner program awareness, interest in biomass utilization, and wildfire mitigation strategies would be influenced by the type of information they received, management activities, and other factors. Seven logit models were constructed to analyze these interrelationships. Results revealed that the type and quality of information landowners received was important in most cases. Landowners not receiving any information were less likely to take action to prevent or mitigate wildfire damage to their property. Wildfire education was highly valued by participants. Knowledge of existing biomass utilization programs was almost non-existent. However, the desire to obtain information on this topic was high. In general, state agencies were utilized more than federal agencies, and landowners felt that cost-share programs and marketability of removed biomass would encourage participation in wildfire prevention activities.
26

Return of Historical Fire: Impacts of Burn Severity and Heterogeneity on Mexican Fox Squirrels

Doumas, Sandra L. January 2010 (has links)
After decades of suppression, fire is returning to forests of western United States. Understanding responses of wildlife species to fire is essential to native species conservation because contemporary fires may not have the same effects on forest structure and landscape patterns as historical fires. I used radio-telemetry to investigate effects of fire severity and heterogeneity on habitat selection of Mexican fox squirrels, Sciurus nayaritensis chiricahuae. Vegetation within home ranges was characterized by more open understory and larger trees than random locations. Squirrels used areas burned at low severity more than unburned areas and those burned at higher severities. Squirrels used areas of moderate burn heterogeneity more than areas of low or high heterogeneity. Return of low-severity fire can help restore habitat for Mexican fox squirrels and other native species in forests with a historical regime of low-severity fire and contribute to understanding of the role of fire in forest ecosystems.
27

The North American Monsoon System in Southern Arizona

Brandt, Richard Raymond January 2006 (has links)
The North American Monsoon System (NAMS) is a dominant factor in climate in the southwestern United States and northwestern Mexico. Despite the influence of the NAMS and the intense research efforts it receives, its predictability, its variability, and the details of its influence on the environment are not well understood. This dissertation is comprised of three papers, which collectively address these three aspects of this complex climate phenomenon through an examination of various data and analyses at multiple spatial and temporal scales, while focusing on impacts in southern Arizona. In the first paper, a modified definition of the NAMS is established to delineate dates for monsoon onset, bursts, breaks, and retreat. The results are applied to an atmospheric compositing study in the second paper and to an applied study of monsoon-wildland fire relationships in the third paper. In the second paper, geopotential height patterns that affect moisture advection are identified. Onset, retreat, and break timing and duration are impacted by shifts in the latitude of the mid-level anticyclone and by lower-level gradients and contour orientation. Analyses in the third paper reveal the some of the complex effects of monsoon onset, variations in break timing and duration, and monsoon retreat on fire occurrence. This research contributes to the current knowledge of the NAMS in general and to the specific regional impacts of the monsoon. The results can (1) improve meteorological forecasts through the recognition of synoptic and sub-synoptic patterns related to the NAMS and (2) help fire managers by expanding the current understanding of the regional controls of wildland fire.
28

Current and future wildfire risk in the peri-urban Acadian Forest Region

Whitman, Ellen M. 06 August 2013 (has links)
The majority of the world’s population now lives in urban areas, and the peri-urban has grown simultaneously, creating new Wildland-Urban Interface (WUI) where development comes into contact – and intermingles with – wildlands. WUI has an elevated wildfire risk. This study examines current and future wildfire risk in the Acadian Forest Region, and consists of two papers. The first manuscript of this thesis describes a model to delineate WUI at a site-scale for municipal risk management, using fire behaviour modelling. The second manuscript uses climate and fire behaviour modelling, projecting an increase in fire weather severity in the Acadian Forest Region under climate change, indicating increased future fire susceptibility. Shifts in tree species composition may offset this risk, as tree species become a negative fire risk driver. The relative importance of fire risk drivers was solicited from experts to assess the net impact on fire risk. Together these papers identify an increasing fire risk in the region under climate change, depending on site-level tree species composition dynamics, and an opportunity for municipal management of fire risk. Delineation of WUI and risk management are necessary, given increasing future fire risk and uncertainty under climate change.
29

INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD

Adam, Brittany A 01 January 2015 (has links)
A challenge for fire researchers is obtaining data from those fires that are most dangerous and costly. While it is feasible to instrument test beds, test plots, and small prescribed burns for research, it is uncommon to successfully instrument an active wildland fire. With a focus on very specific facets of wildland fire, researchers have created many unique models utilizing matchsticks, cardboard, liquid fuel, excelsior, plywood, live fuels, dead fuels, and wood cribs of different packing densities. Such scale models, however, only serve as valid substitutes for the full-scale system when all functional relations of the scale model are made similar to corresponding relations of the original phenomena. The field of study of large wildland fires therefore was in need of a framework that researchers could use to relate the results from many previous experiments to full-scale wildland fires; this framework was developed during the research for this dissertation. This further work developing laws for instability scaling in wildland settings was founded on the established work in dynamic similitude of G.I. Taylor, H. C. Hottel, F. A. Williams, R. I. Emori, K. Saito and Y. Iguchi. Additionally, in this work, a new dynamic flame parameter was incorporated into the scaling laws for fires that had not previously been assessed and proved to provide additional, important insight into flame spread. The new dynamic parameter enabled improved St-Fr correlations and was established for a wide range of fire sizes and fuel types.
30

Herpetofauna and Riparian Microhabitat of Urban and Wildland Reaches Along the Salt River, Arizona

January 2011 (has links)
abstract: Worldwide, riverine floodplains are among the most endangered landscapes. In response to anthropogenic impacts, riverine restoration projects are considerably increasing. However, there is a paucity of information on how riparian rehabilitation activities impact non-avian wildlife communities. I evaluated herpetofauna abundance, species richness, diversity (i.e., Shannon and Simpson indices), species-specific responses, and riparian microhabitat characteristics along three reaches (i.e., wildland, urban rehabilitated, and urban disturbed) of the Salt River, Arizona. The surrounding uplands of the two urbanized reaches were dominated by the built environment (i.e., Phoenix metropolitan area). I predicted that greater diversity of microhabitat and lower urbanization would promote herpetofauna abundance, richness, and diversity. In 2010, at each reach, I performed herpetofauna visual surveys five times along eight transects (n=24) spanning the riparian zone. I quantified twenty one microhabitat characteristics such as ground substrate, vegetative cover, woody debris, tree stem density, and plant species richness along each transect. Herpetofauna species richness was the greatest along the wildland reach, and the lowest along the urban disturbed reach. The wildland reach had the greatest diversity indices, and diversity indices of the two urban reaches were similar. Abundance of herpetofauna was approximately six times lower along the urban disturbed reach compared to the two other reaches, which had similar abundances. Principal Component Analysis (PCA) reduced microhabitat variables to five factors, and significant differences among reaches were detected. Vegetation structure complexity, vegetation species richness, as well as densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrows had a positive correlation with at least one of the three herpetofauna community parameter quantified (i.e., herpetofauna abundance, species richness, and diversity indices), and had a positive correlation with at least one herpetofauna species. Overall, rehabilitation activities positively influenced herpetofauna abundance and species richness, whereas urbanization negatively influenced herpetofauna diversity indices. Based on herpetofauna/microhabitat correlations established, I developed recommendations regarding microhabitat features that should be created in order to promote herpetofauna when rehabilitating degraded riparian systems. Recommendations are to plant vegetation of different growth habit, provide woody debris, plant Populus, Salix, and Prosopis of various ages and sizes, and to promote small mammal abundance. / Dissertation/Thesis / M.S. Applied Biological Sciences 2011

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