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Characterizing fuelbed structure, depth, and mass in a grassland using terrestrial laser scanning.Umphries, Tara Amber 24 July 2013 (has links)
Fuelbed depth and loading are fundamental parameters for predicting fire behavior and effects. This thesis considers the application of Terrestrial Laser Scanning (TLS) for characterizing the structure, measuring depth and mass in a grassland fuelbed. It examines whether TLS can be used to quantify the vertical structure of a bunchgrass community in terms of bunch and seed head, and to describe spatial variability in height and fuel mass at fine grain (0.25m2). In the experiment, fuels are mechanically manipulated to enhance variability. Height and mass are modified independently at three levels using a randomized design. Results show that vertical strata (bunches and seed head) are measurable within the TLS height profile and changes in height due to treatments can be detected. There are statistically significant but small absolute differences (± 1-6cm) between TLS-derived and field-measured heights with no systematic bias observed. TLS-derived height measurements have a higher precision than field-measured heights, but the accuracy of measurements is uncertain given ambiguity in field measurements. In the untreated grassland, fuel mass is associated with TLS-derived bunch height and standard deviation of height; a linear model using these metrics explains ~30 percent of the variability in biomass. In the treated grassland, a linear model using median height and standard deviation of height accounts for ~40 percent of the variability in biomass. In the biomass-only treatment, bunch height and canopy cover are the best combination of explanatory variables for biomass accounting for ~ 42 percent; median height and standard deviation of height account for 24 percent of biomass variability in the height-only treatment. Collectively, these results suggest that TLS can be used to quantify the spatial variability in heights (and hence, volumes) occupied by fuels in a grassland where biomass is concentrated in distinct strata. However, prediction of biomass leaves room for improvement, with the most substantial gains likely to be made with better cover/density metrics. Even with improved density metrics, improvements are likely to be modest because variability in the bunchgrass system is low and the TLS is not very sensitive to small changes in cover.
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ESTIMATION AND MODELING OF FOREST ATTRIBUTES ACROSS LARGE SPATIAL SCALES USING BIOMEBGC, HIGH-RESOLUTION IMAGERY, LIDAR DATA, AND INVENTORY DATA.Golinkoff, Jordan Seth 02 July 2013 (has links)
The accurate estimation of forest attributes at many different spatial scales is a critical problem. Forest landowners may be interested in estimating timber volume, forest biomass, and forest structure to determine their forest's condition and value. Counties and states may be interested to learn about their forests to develop sustainable management plans and policies related to forests, wildlife, and climate change. Countries and consortiums of countries need information about their forests to set global and national targets to deal with issues of climate change and deforestation as well as to set national targets and understand the state of their forest at a given point in time.
This dissertation approaches these questions from two perspectives. The first perspective uses the process model Biome-BGC paired with inventory and remote sensing data to make inferences about a current forest state given known climate and site variables. Using a model of this type, future climate data can be used to make predictions about future forest states as well. An example of this work applied to a forest in northern California is presented. The second perspective of estimating forest attributes uses high resolution aerial imagery paired with light detection and ranging (LiDAR) remote sensing data to develop statistical estimates of forest structure. Two approaches within this perspective are presented: a pixel based approach and an object based approach. Both approaches can serve as the platform on which models (either empirical growth and yield models or process models) can be run to generate inferences about future forest state and current forest biogeochemical cycling.
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Control by Vegetation Disturbance on Gully Rejuvenation Following WildfireHyde, Kevin 17 July 2013 (has links)
Gully rejuvenation (GR) following wildfire influences landform evolution and generates flooding and debris that alters aquatic habitat and threatens human activities. Fire severity, defined as the degree of vegetation loss by wildfire, is a hypothesized control on this erosion response. I investigated three related aspects of the relationship between fire severity and GR: The capacity of vegetation disturbance to explain the occurrence or non-occurrence of GR; the spatial structure of burn mosaics relative to post-fire erosion; and the relationship between fire severity and threshold conditions required for channel initiation. I surveyed 269 burned catchments and mapped 111 cases of GR across sites in Montana and Idaho. I created the Vegetation Disturbance Index (VDI) derived from LANDSAT images to quantify fire severity and implemented geospatial and statistical analysis to quantify relationships between VDI and post-fire erosion response. Vegetation disturbance strongly explained GR with additional influences from upslope geometry and pre-fire shrub cover. As fire severity increased, the percent of the catchment area covered by continuous patches of high severity burn increased non-linearly. Trends in patch structure defined a threshold of fire severity after which the probability of GR was strongly correlated with the development of large, continuous severely burned patches. Fire severity systematically influenced the relationship between source area and steepness. Threshold conditions for channel initiation, specifically source area steepness and curvature, decreased as vegetation disturbance increased. These results provide inferential evidence that vegetation disturbance exerts first-order controls over post-fire erosion processes. The results of the patch-pattern analysis suggest that progressive loss of vegetation due to wildfire leads to critical thresholds of hydrologic connectivity after which runoff and erosion accelerate. The source area analysis suggests that forces of convergent flow are not fully expressed until a significant proportion of vegetation has been consumed such that flow resistance is minimized. The VDI as a continuous metric of vegetation disturbance may contribute to improved quantitative analysis of landform evolution relative to vegetation disturbance, ecological effects of fire, and ecosystem response to climate change. The assessment methodology outlined herein provides a first step towards a systematic quantification of the potential for GR following wildfire.
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Hair today, gone tomorrow: the degradation and conservation of archaeological hair fibersSager, Rebecca M. 15 May 2009 (has links)
The research of this work describes the degradation and conservation of
archaeological hair fibers. Chapter I will be a brief overview, with Chapter II following
with a literary review and definition of terms. Chapter III focuses on research centered
on the structure of hair fibers and their physical and chemical attributes. It will also
focus on the archaeological and historical evidence of hair fiber use by humans. This
research will help form the backbone of the paper and experiments performed.
The next chapter focuses on the degradation of hair fibers in different
environments. Hair fibers left in underwater, open air, burial, and arid environments are
monitored for degree of degradation and brittleness. The hair fiber types used are four
commonly found hair fibers types: coarse wool, fine wool, mohair, and human hair.
After deposition, conservation using silicone oil treatment is tested on the
degraded hair fibers. When silicone oil treatment proves to be a viable conservation
method, the technique is then be applied to two artifacts. The two artifacts used are a
Victorian era watch fob made from human hair and hair fibers mixed with tar from the
excavation of Kittern in Bulgaria.
Chapter VII deals with the conclusions of the experiments as a whole. The
degradation of the fibers in different environmental conditions show that burial in acidic sandy clay is the most detrimental to hair fibers, while hair fibers from arid, dry
environments are brittle, but well preserved aesthetically. The silicone oil treatments are
shown to be viable treatment methods with positive results for all of the fibers tested,
including two artifacts, a Victorian watch fob made from human hair fibers and hair
fibers mixed with a tar-like substance from the shipwreck Kittern in Bulgaria.
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A study of the relationship between conservation education and scuba diver behavior in the Flower Garden Banks National Marine SanctuaryBelknap, Julia 15 May 2009 (has links)
Scuba diver impacts on coral reefs are causing many threats to reefs. One
solution is to change divers’ behaviors through on-site environmental education. The
Flower Garden Banks National Marine Sanctuary developed an education program in an
effort to achieve this goal. The purpose of this study was to describe the education
program, understand how it affected divers’ knowledge of and value orientation toward
coral reefs, and examine two teaching approaches conducted in a recreation/tourism
setting.
Two theories were tested in this study. Orams’ model was used to develop the
“Naturalist Onboard” program and describe how the model played out in a diver
education situation. The work Bransford’s team did was tested to see how their teaching
approach works in a recreation/tourism setting.
Evaluating this program was achieved through pre- and post-questionnaires,
participant observation and semi-structured interviews. They were used in the first
article to provide a description of how Orams’ model played out in the real world. In the second article they were used to determine: 1) the value orientation of the divers, 2) how
much knowledge divers gained via participation in this program, 3) the relationship
between value orientation and knowledge gained, and 4) the degree their value
orientations affect knowledge acquisition. In the final article they were used to see how
two teaching approaches affected divers’ knowledge and value orientations about coral
reefs, and how the divers responded to the two approaches.
The program aroused divers’ curiosity, engaged their emotions, and motivated
them to minimize their impacts while visiting the coral reef. However, suggestions for
making changes in their behavior at home were not received well. Most divers had a
“biocentric” value orientation and gained a significant amount of knowledge. These
divers were also more open to learning and changing their behaviors. There was no
significant difference between the two approaches regarding the divers’ knowledge and
value orientation. This may be due to validity threats. Due to time constraints and
divers’ lack of interest in actively acquiring knowledge, the constructivist teaching
approach did not work well in this setting.
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The Conservation of Seventeenth Century Archaeological GlassArcak, Cory 2009 August 1900 (has links)
The primary goal of the conservator is to stabilize and conserve artifacts with the best possible treatment available. Ideally, these treatments are noninvasive and reversible, and maintain the integrity of the object as a top priority. In this respect, it is the responsibility of the conservator to research other possible treatments when traditional methods prove to be insufficient to properly stabilize and conserve an object. Sometimes choosing to treat with a seemingly unorthodox method is the only chance for the objects survival. Though glass is considered one of the most stable archaeological materials, noninvasive, reversible treatments are not always possible given the level of deterioration glass objects undergo within the archaeological setting, specifically the underwater or waterlogged archaeological setting.
This research is a consideration and investigation of the use of silicone polymers and silanes as consolidation materials for 17th-century glass recovered from aqueous environments. Working within the Conservation Research Laboratory and the Archaeological Preservation Research Laboratory at Texas A and M University, a newly developed polymer passivation technique utilizing materials acquired from the Dow Corning Corporation was applied to archaeological glass recovered from the 1686 shipwreck La Belle, excavated in Matagorda Bay off the coast of Texas by the Texas Historical Commission from 1996 to 1997.
The successful application of a hydroxyl ended silicone polymer Q-1 3563, combined with a methyltrimethoxysilane intermediate crosslinker, Q-9 1315, at a 15% solution by weight and catalyzed with dibutyltin diacetate (DBTDA Fascat 4200) occurred in 1999. This project was the first large scale application of silicone polymers and silanes to 17th-century archaeological glass recovered from a marine site. Through this investigation we answered a number of questions regarding the use and application of the silicone technologies and confirmed that these materials are a viable resource for glass consolidation and conservation in terms of the suggested conservation guidelines of the IIC. The silicone technology was successfully applied to numerous types, forms, colors and degradation levels of glass. This included successful application to composite artifacts and the retreatment of objects unsuccessfully treated with a "traditional" method.
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The utilization of genetic markers to resolve modern management issues in historic bison populations: implications for species conservationHalbert, Natalie Dierschke 17 February 2005 (has links)
The saga of the American bison (Bison bison) is a well-known story of death, destruction, and greed circumvented by early conservationists. The foresight of 5 cattlemen and the Canadian and U.S. governments at the apex of the population bottleneck in the 1880s led to the eventual establishment of several federal bison populations, from which virtually all of the 300,000 extant bison are descended.
A survey of 54 microsatellite loci spanning each autosomal and both sex chromosomes was used to compare levels of genetic variation among 10 of the 11 federal bison populations in the U.S. Although most populations contain moderate levels of genetic variation, the majority of genetic variation is contained within only 4 of the federal populations surveyed. The distribution and partitioning of genetic variation confirm historical records of founding lineages and transfers among populations.
Previously published mitochondrial and nuclear markers were used to survey federal bison populations for evidence of domestic cattle introgression. While only 1 population was found to contain low levels of domestic cattle mitochondrial DNA, 7 of the 10 surveyed populations had detectable introgression of nuclear genes from domestic cattle. From this, 2 federal bison populations were identified that have both high levels of genetic variation and no evidence of introgression of domestic cattle genes.
The data obtained from this study were used to examine consequences of past and present management practices in closed bison populations. In the case of the Texas State Bison Herd, observed chronic small population size, low levels of genetic variation, low natality rates, and high juvenile mortality rates combined with the results of population modeling indicate a high risk of extinction within the next 50 years unless new genetic variation is introduced into the herd. Alternatively, analysis of population substructure and nonrandom culling reveal the necessity for further investigation into the long-term effects of current management practices in the Yellowstone National Park bison population. This study illustrates that while bison may be considered a conservation success story, long-term survival of protected federal populations requires the development of effective genetic management strategies.
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Conservation of waterlogged linoleumCoke, BobbyeJo Evon 17 February 2005 (has links)
Linoleum has been around for over a hundred years. With its invention by Frederick Walton in the 1860s a new means of durable floor covering was introduced to the world. This new invention was promoted as durable, hygienic, and easy to maintain. In agreement with the Lake Champlain Maritime Museum, a study was commissioned to seek the best means to conserve linoleum from a canal boat excavated in the summer of 2002 in Lake Champlain. The Sloop Island Canal Boat is part of an excavation project that is studying the ways of life on the lake. Conserving waterlogged linoleum is a new area of study in conservation, and there is very little information dealing with the topic. This study will provide a baseline for the conservation of linoleum.
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Underwater observation and habitat utilization of three rare darters (Etheostoma cinereum, Percina burtoni, and Percina williamsi) in the Little River, Blount County, TennesseeJett, Robert Trenton 01 May 2010 (has links)
The Little River in Blount County is home to one of the richest darter faunas in East Tennessee. Increases in agriculture and development on several tributaries and the main stem of the Little River are suspected as causes for reduced abundance in fish populations. Earlier research on the Little River identified three species, Etheostoma cinereum (ashy darter), Percina burtoni (blotchside logperch), and P. williamsi (sickle darter), as having low densities. From May – October 2009, snorkel observations were made at 16 predetermined sites along the mainstem of the river to determine abundance and habitat association of these target species, as well as abundance of P. aurantiaca (tangerine darter) for comparison with historic surveys. All fish observed while snorkeling were identified and microhabitat measurements were taken at the location of all target species. Observations included 39 fish species, including 273 P. aurantiaca, 58 P. burtoni, and 7 P. williamsi. Etheostoma cinereum were not encountered during this study. Our observations documented that darter populations during 2009 were significantly different than historic populations, indicating that local populations of the target species have been negatively impacted since the historic survey. E. cinereum has been consistently difficult to collect on the Little River, and previous sampling efforts have observed this species with less frequency in the last 30 years. The absence of this species in this study may be an artifact of habitat degradation due to development and agriculture, two consecutive years of drought in 2007-2008, or potential sampling bias due to high flows in 2009. Habitat measurements documented that P. burtoni were frequently associated with gravel and cobble substrates. This habitat association is indicative of the feeding habits of P. burtoni who use their padded snout to flip small stones and feed on the aquatic insects found underneath. Turbidity was closely associated with river mile, with a consistent increase in turbidity at downstream sites in the watershed.
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Essential Elements of Ecological Literacy and the Pathways to Achieve It: Perspectives of EcologistsMcBride, Brooke Baldauf 05 August 2011 (has links)
<p>National assessments have led many to conclude that the level of ecological literacy among the general population in the United States is too low to enable effective social responses to current environmental challenges. However, the actual meaning of ecological literacy varies considerably between academic fields and has been a topic of intensive deliberation for several decades. Within the field of ecology in particular, a driving purpose behind this ongoing discussion has been to advance a complete, pedagogy-guiding, and broadly applicable framework for ecological literacy, allowing for the establishment of guidelines and tools for assessing educational achievement; yet, a widely accepted framework does not currently exist. What is ecological literacy and how can it be achieved? Through an extensive review of the literature, I traced the evolution of the related concepts of environmental literacy, ecological literacy, and ecoliteracy, and compared and contrasted the numerous proposed frameworks across multiple dimensions of affect, knowledge, skills, and behavior. In addition to characterizing the overall discourse, this analysis facilitated close examination of where we have been, where we are, and where we might be headed with respect to these vital conversations. To explore current perspectives on the topic, I analyzed the open-ended responses of more than 1,000 ecologists and other environmental scientists on the nature of ecological literacy and how it may be achieved. Factor analysis revealed the presence of six common dimensions underlying respondents' views of ecological literacy (cycles and webs, ecosystem services, negative human impacts, critical thinking/application, nature of ecological science, and biogeography) and five common dimensions for how to achieve it (education by mass media, formal/traditional education, financial incentive, participatory/interactive education, and communication/outreach by scientists). Based on these results, I proposed a framework for ecological literacy that, ideally, will provide guidance for the development of updated ecology curricula and assessment tools, a foundation for discussion of alignment between K-12 and higher education, and a mechanism for creating greater synergy between formal and informal learning environments. Further, to assess the impacts of innovative graduate programs designed to train ecologists in promoting ecological literacy, I analyzed pre- and post-fellowship surveys completed by participants in an ecologically focused K-12 outreach program at The University of Montana, as well as the broader impacts of a set of similar programs across the country. These highly beneficial programs are urgently needed to ensure that future leaders of the scientific enterprise are well-equipped with the tools to effectively communicate their science with diverse audiences well beyond their scientific peers. Indeed, ecologists and other natural and social scientists who study the environment have multiple roles to play in promoting a modern vision of ecological literacy in society today.</p>
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