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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.
461

A historical record of land cover change of the lesser prairie-chicken range in Kansas

Spencer, David A. January 1900 (has links)
Master of Science / Department of Geography / Melinda Daniels / The Lesser Prairie-Chicken (Tympanuchus pallidicinctus) is a prairie grouse of conservation concern in the Southern Great Plains. In response to declining population numbers and ongoing threats to its habitat, the Lesser Prairie-Chicken was listed as threatened under the Endangered Species Act in May 2014. In western Kansas, the Lesser Prairie-Chicken occupies the Sand Sagebrush Prairie, Mixed-grass Prairie, and Short-grass/CRP Mosaic Ecoregions. Since the beginning of the 20th century, the overall range and population has declined by 92% and 97% respectively. Much of this decline is attributed to the loss and fragmentation of native grasslands throughout the Lesser Prairie-Chicken range. Whereas much of the loss and degradation of native grassland have been attributed to anthropogenic activities such as conversion of grassland to cropland and energy exploration, federal legislation since the 1980s to convert cropland on highly erodible soils to perennial grasses through the U.S. Department of Agriculture (USDA) Conservation Reserve Program (CRP) may curtail or reverse these trends. My objective was to document changes in the areal extent and connectivity of grasslands in the identified Lesser Prairie-Chicken range in Kansas from the 1950s to 2013 using remotely sensed data. I hypothesized that the total amount of grassland decreased between the 1950’s and 2013 because of an increase in agricultural practices, but predicted an increase of grassland between 1985 and 2013 in response to the CRP. To document changes in grassland, land cover maps were generated through spectral classification of LANDSAT images and visual analysis of aerial photographs from the Army Map Service and USDA Farm Service Agency. Landscape composition and configuration were assessed using FRAGSTATS to compute a variety of landscape metrics measuring changes in the amount of grassland present as well as changes in the size and configuration of grassland patches. Since 1985, the amount of grassland in the Lesser Prairie-Chicken range in Kansas has increased by 210,9963.3 ha, a rise of 11.9%, while the mean patch size and area-weighted mean patch size of grassland increased 18.2% and 23.0% respectively, indicating grassland has become more connected during this time in response to the CRP. Prior to the implementation of CRP, the amount of grassland had been decreasing since 1950, as 66,722.0 ha of grassland was converted to croplands. The loss of grassland had a considerable effect on the patch size of grasslands, as mean patch size and area-weighted mean patch size decreased by 8.8% and 11.1% respectively. The primary driver of grassland loss between 1950 and 1985 was the emergence of center pivot irrigation, which had its greatest impact in western and southwestern parts of the range in Kansas. In particular, while the amount of grassland in Range 5, a region of the Lesser Prairie-Chicken range found in southwest Kansas, has increased overall since the 1950s by 4.7%, the area-weighted mean patch size has decreased by 53.0% in response to center pivot irrigation fragmenting the landscape. While the CRP has been successful in increasing and connecting grassland throughout the Lesser Prairie-Chicken range to offset the loss of grassland since the 1950s, continuation of the CRP faces an uncertain future in the face of rising commodity prices, energy development, and reduction in program scope leaving open the possibility that these areas that have created habitat for Lesser Prairie-Chickens could be lost. As time progresses, a reduction in the scope of the CRP would reduce the amount of habitat available to Lesser Prairie-Chickens, threatening the persistence of their population.
462

Lesser prairie-chicken reproductive success, habitat selection, and response to trees

Lautenbach, Joseph Mark January 1900 (has links)
Master of Science / Department of Biology / David A. Haukos / The lesser prairie-chicken (Tympanuchus pallidicinctus) is a species of prairie grouse native to the southwest Great Plains. Population declines and threats to populations of lesser prairie-chickens led U.S. Fish and Wildlife Service to list the species as “threatened” under the protection of the Endangered Species Act in May 2014. Lesser prairie-chickens are found within three distinct ecoregions of Kansas and Colorado and portions of the species’ range are affected by tree encroachment into grasslands. The effect of trees on lesser prairie-chickens is poorly understood. I evaluated habitat selection and reproductive success and across the northern portion of the species’ range. I captured female lesser prairie-chickens within the three different ecoregions in Kansas and Colorado to track nest and brood survival and measure nest and brood habitat. My findings show that there are regional and annual variations in nest and brood survival. Mean nest survival during 2013 and 2014 was estimated to be 0.388 (95% CI = 0.343 – 0.433) for a 35-day exposure period. Brood survival during 2013 and 2014 was estimated to be 0.316 (95% CI = 0.184 – 0.457) for 56 days. Chick survival was the lowest during the first week of life and is probably a limiting factor for population growth. Chick and brood survival decreased as Julian hatch date increased. Across the northern portion of the species’ range, females consistently select visual obstruction between 2-3 dm. Vegetation at the nest changes between regions and years to reflect environmental and regional conditions. Broods consistently selected habitats with greater percent cover of forbs than was expected at random across all study sites. Broods also selected against areas of bare ground. The threshold of lesser prairie-chicken use was 2 trees/ha throughout the year. No nests were located within areas with greater densities. Lesser prairie-chickens had a greater probability of use at greater distances from trees and at lower tree densities. To provide adequate nesting habitat managers should provide 2-3 dm of visual obstruction. Providing forb cover with visual obstruction between 2.5-5 dm near nesting habitat should provide adequate habitat for broods. Removing trees in core habitats and expand removal efforts outward should expand potential habitat for lesser prairie-chickens.
463

Envisioning 3D learning environments in environmental education: an exploration of the Konza Prairie

Webb, Natalie January 1900 (has links)
Master of Landscape Architecture / Landscape Architecture/Regional and Community Planning / Howard D. Hahn / “There is an alarming gap between awareness and action on [environmental issues]” (Sheppard, 2005). Public awareness of how to cope and change with these issues is lacking (Sheppard, 2004; Nicholson-Cole, 2005; Dockerty et al., 2005), but new visualization technologies can begin to bridge the gap through environmental education. Environmental education focuses on the user exploring an environment, environmental issues, problem solving and ways to mitigate these issues. While the younger generations (middle to high school students) are much more aware of current and future environmental issues than older generations, the solutions to these problems may not be so apparent. By combining the need to educate young adults about climate change, regional ecosystem climate mitigation, and ecological management for technologically driven youth, middle and high school students can better understand their environment’s impact on climate-change regulation. Through literature synthesis, documentation of existing visualization exhibits and technologies, and preliminary technology exploration, a production process, criteria, framework, and technology recommendations were established. These components informed the final storyboards, which visually organized a proposal to build a 3D learning environment focused on the Konza Prairie and its ecological management practices.
464

Interactions between grassland birds and their snake predators: the potential for conservation conflicts in the Tallgrass prairie

Klug, Page Elizabeth January 1900 (has links)
Doctor of Philosophy / Department of Biology / Kimberly A. With / The loss, fragmentation, and degradation of grasslands have resulted in widespread declines in grassland birds. Nest predation is the leading cause of avian reproductive failure; therefore minimizing nest predation can lessen the severity of bird declines. Snakes are important predators of bird nests, but little is known about how snakes may enhance predation risk. To address this issue, I studied the habitat use, movement behavior, population genetic structure, and connectivity of snakes in the grasslands of northeastern Kansas. I addressed the connectivity of eastern yellowbelly racer (Coluber constrictor flaviventris) populations by using a landscape genetics approach at a broad scale (13,500 km2). I also radio-tracked the yellowbelly racer and Great Plains ratsnake (Pantherophis emoryi) at Konza Prairie Biological Station to understand their spatial ecology while simultaneously evaluating nest survival in grassland birds. Individual racers had limited dispersal (<3 km), but substantial admixture occurred within 30 km and populations were in migration-drift equilibrium and had high allelic diversity; therefore, racers must be abundant and continuously distributed for gene flow to be fluid throughout the region. Racers may be more likely to encounter bird nests, as they had more frequent movements and traversed greater distances on average than ratsnakes, which exhibited long periods of inactivity between directed movements. As for grassland birds, nest survival rates decreased with increasing shrubs and decreasing vegetation height. Discriminant function analysis revealed that successful nests were likely to occur in tall vegetation but reduced shrub cover, whereas higher shrub cover characterized snake habitats. Because snakes often use shrubs, nests in areas of increased shrubs may be at higher risk of predation by snakes. Targeted removal of shrubs may increase nest success by minimizing the activity of predators attracted to shrubs. Although predator removal is often a strategy for protecting bird populations, it may not be feasible in this instance, especially since snakes are a native component of the grassland community. Efforts to reduce snake predation on grassland bird nests should therefore focus on managing habitat within grasslands (i.e., shrubs) that influence snake activity, as no natural or anthropogenic habitat barriers currently limit snake movement across the landscape.
465

How to Combat Rabbits, Gophers, Prairie Dogs, Coyotes, Ants, and Grasshoppers

Paschall, Arthur L. 15 November 1917 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
466

Evaluating Tree Seedling Survival and Growth in a Bottomland Old-field Site: Implications for Ecological Restoration

Boe, Brian Jeffrey 08 1900 (has links)
In order to assess the enhancement of seedling survival and growth during drought conditions, five-hundred bare-root seedlings each of Shumard oak (Quercus shumardii Buckl.) and green ash (Fraxinus pennsylvanica Marsh.) were planted each with four soil amendments at a Wildlife Management Area in Lewisville, Texas. The treatments were a mycorrhizal inoculant, mulch fabric, and two superabsorbent gels (TerraSorb® and DRiWATER®). Survival and growth measurements were assessed periodically for two years. Research was conducted on vegetation, soil, and site history for baseline data. Both superabsorbent gels gave significant results for Shumard oak survival, and one increased green ash diameter. For overall growth, significant results were found among DRiWATER®, mycorrhizae, and mulch treatments.
467

De l'influence des crues sur les services écosystémiques des prairies inondables : Application à la production fourragère dans le delta du fleuve Tana, au Kenya / ON THE INFLUENCE OF FLOODS ON ECOSYSTEM SERVICES OF FLOODPLAIN GRASSLANDS : An application to fodder production in the Tana River Delta, Kenya

Léauthaud-Harnett, Crystèle 22 February 2013 (has links)
En Afrique Sub-Saharienne, les zones humides forment d'importantes zones de pâturages pour bon nombre de pastoralistes. Le régime d'inondation de ces plaines influence leur fonc tionnement et leur productivité. Pour comprendre et maitriser ces régimes, il est donc essentiel d'évaluer l'impact de l'infrastructure hydro-électrique sur les dynamiques d'inondations en aval des barrages. Pourtant, le manque de données disponibles, l'absence de modèles validés et la forte variabilité environnementale rendent cet exercice difficile. Cette thèse contribue à quantifier l'impact du changement des ressources hydriques sur la productivité fourragère des prairies inondables dans le Delta du fleuve Tana, au Kenya. 1/ Les caractéristiques de croissance et la productivité d'une prairie inondable à Echinochloa stagnina (Retz) P. Beauv. ont été déterminées pour différents régimes de fauche, d'irrigation et conditions d'inondations. Ensuite, un modèle de croissance adapté à des Graminées en C4, tropicales et pérennes, de prairies inondables a été développé. Il constitue, à notre connaissance, le premier modèle éco-physiologique adapté à ce type de prairies. 2/ Des processus hydrologiques importants pour le fonctionnement des écosystèmes (étendue, période, durée et fréquence d'inondation) ont été caractérisés grâce à un modèle de bilan hydrologique et à l'utilisation de techniques de télédétection, et cela en dépit de la faible instrumentalisation du bassin, du peu de données topographiques et d'un fort couvert nuageux. 3/ Une analyse préliminaire de l'impact de différents scénarios d'inondations sur la production fourragère a été effectuée en utilisant des indicateurs de services écosystémiques. Cette thèse participe à l'amélioration de nos connaissances des services écosystémiques des zones humides par la construction de modèles et par l'évaluation de scénarios dans une région du monde où ce type de données est rare. / Wetlands are a vital resource for many pastoralists in Sub-Saharan Africa as they provide dry-season grazing zones. As floods are essential for wetland ecosystems, the assessment of water abstraction and hydroelectric infrastructure on downstream flooding dynamics is crucial. Yet, scarce data, environmental variability and the lack of models make this challenging. This research contributes to quantifying the influence of changing water resources on fodder pro- duction of floodplain grasslands in the Tana River Delta, Kenya. 1/ Growth characteristics of floodplain grasslands of Echinochloa stagnina (Retz) P. Beauv. for different flood and manage- ment options were determined and a quantification of their productivity achieved. This kind of data is scarce for floodplain grasslands. A plant growth model adapted to tropical floodplain conditions and perennial C4 grasses was developed, and is the first known physiologically based model for floodplain grasslands. 2/ Hydrological processes of ecological importance (flood extent, timing, duration, frequency) were characterized in a poorly gauged basin using a water-balance model combined with remote-sensing techniques, despite precise knowledge of discharge rates, topography and a high cloud cover. 3/ A preliminary analysis explored different flooding scenarios and their impact on fodder production through the use of simple ecosystem service indicators. This PhD contributes to the repertoire of wetland ecosystem ser- vices by building biophysically based simulation models and exploring possible scenarios in a region of the world and an ecosystem where these type of evaluations are rare.
468

Zen of the plains: discovering space, place and self

Olstad, Tyra A. January 1900 (has links)
Doctor of Philosophy / Department of Geography / Kevin Blake / With their windswept ridges and wind-rent skies, prairies and plains have often been denigrated as nothing but nothing—empty, meaningless, valueless space. Mountains and forests, oceans and deserts have been praised and protected while vast expanses of undulating grasslands have been plowed under, grazed over, used, abused, maligned. Once the largest ecosystem on the North American continent, wild prairies now persist mainly in overlooked or unwanted fragments. In part, it’s a matter of psychology; some people see plains as visually unpleasing (too big, too boring) or physically alienating (too dry, too exposed). It’s also part economics; prairies seem more productive, more valuable as anything but tangles of grass and sage. But at heart, it’s a matter of sociocultural and individual biases; people seeking bucolic or sublime landscapes find “empty,” treeless skyscapes flat and dull, forgettable. Scientific, social, and especially aesthetic appreciation for plains requires a different perspective—a pause in place—an exploration of the horizon as well as an examination of the minutiae, few people have strived to understand and appreciate undifferentiated, untrammeled space. This research seeks to change that by example, using conscientious, systematic reflection on first-hand experience to explore questions fundamental to phenomenology and geography—how do people experience the world? How do we shape places and how do places shape us?—in the context of plains landscapes. Written and illustrated from the perspective of a newcomer, a scholar, a National Park Service ranger, a walker, a watcher, a person wholly and unabashedly in love with wild places, the creative non-fiction narratives, photoessays, and hand-drawn maps address themes of landscape aesthetics, sense of place, and place-identity by tracing the natural, cultural, and managerial histories of and personal relationships with Arizona’s Petrified Forest National Park, South Dakota’s Badlands National Park, Kansas’s Konza Prairie Long-Term Ecological Research Station, and Wyoming’s Fossil Butte National Monument. Prosaic and photographic meditations on wildness and wilderness, travel and tourism, preservation and conservation, days and seasons, expectations and acceptance, even dreams and reality intertwine to evoke and illuminate the inspiring aesthetic of spacious places—Zen of the plains.
469

Devenir des stocks de carbone organique des sols après déforestation et mise en culture : une analyse diachronique en contexte amazonien / Fate of soil organic carbon stocks after deforestation and cultivation : a diachronic approach in amazonian context

Fujisaki, Kenji 27 November 2014 (has links)
Le carbone organique des sols (COS) joue un rôle majeur dans le maintien des propriétés des sols, et constitue un important réservoir de carbone sensible aux perturbations anthropiques dont les changements d'usage ou de gestion des terres. En Amazonie, la déforestation libère des gaz à effet de serre (GES) par le brûlis de la végétation mais les stocks de COS sont également susceptibles d'évoluer et de contribuer aux émissions de GES. Nous montrons que ces variations de stocks sont cependant mal comprises à l'échelle du biome, en raison de l'approche par chrono-séquence qui induit de nombreuses incertitudes et du manque de données sur la gestion des agrosystèmes implantés après déforestation. L'étude a été conduite sur un site agronomique diachronique en Guyane, déboisé sans brûlis et avec des restitutions de biomasse forestière au sol, sur lequel ont été implantés 3 systèmes de culture : une prairie et deux systèmes maïs/soja avec ou sans travail du sol. L'objectif a été de déterminer le devenir du carbone forestier et du COS des agrosystèmes. Les fluctuations des stocks ont été mesurées jusqu'à 5 ans après déforestation dans la couche 0-30 cm, un bilan est proposé pour la couche 0-100 cm à 5 ans. La décomposition des débris de bois, apportés au sol suite à la déforestation, a été étudiée via leur perte de masse et leur caractérisation par pyrolyse Rock-Eval. La répartition granulométrique du COS a été mesurée 4 ans après déforestation. L'isotopie δ13C a été utilisée dans le sol sous prairie pour distinguer le carbone d'origine prairiale. L'apport de carbone issu de la déforestation a entrainé une augmentation des stocks de COS, mais de courte durée car les débris de bois se sont rapidement décomposés et n'ont pas induit de stockage durable de COS. Cinq ans après déforestation les stocks de COS sous prairie sont similaires à ceux observés sous forêt, grâce à des apports de carbone importants par les racines, alors que sous cultures les stocks diminuent d'environ 18 %, sans que l'on ait distingué un effet du travail du sol. La décroissance du carbone forestier, qui concerne l'ensemble des fractions granulométriques du sol, a donc été compensée par les apports de carbone sous prairie, ce qui n'est pas le cas sous cultures annuelles. Le modèle RothC a pu être validé dans notre situation même s'il a surestimé légèrement les stocks sous cultures. Nos résultats, replacés dans le contexte amazonien montrent que les diminutions de COS observées ici sont moins importantes que pour l'ensemble des tropiques humides, probablement en raison de la gestion optimale du site et de la courte durée du temps d'observation. / Soil organic carbon is a key component of soil quality, and represents a large part of the terrestrial carbon stock, sensitive to human perturbations including land-use change. In Amazonia, deforestation induces greenhouse gases (GHG) emissions due to vegetation burning, but SOC stocks also change, which can induce GHG emissions. We show that these changes are misunderstood at the biome scale, because of the chronosequence approach that induces uncertainties, and because of the lack of management data of the agrosystems established after deforestation. We studied here an agronomic trial with a diachronic approach in French Guiana, deforested with a fire-free method that returned large amount of forest organic matter. Three agrosystems were set up: a grassland and two annual crop systems (maize/soybean) with and without soil tillage. We aimed to measure the fate of forest carbon and of SOC in the agrosystems. SOC stocks fluctuations were assessed up to 5 years after deforestation in the layer 0-30 cm, and a comparison forest-agroecosystems in the layer 0-100 cm was done at 5 years. Decomposition of woody debris buried in the soil after deforestation was assessed by mass loss approach and Rock-Eval pyrolysis. SOC distribution in granulometric fractions was measured 4 years after deforestation. δ13C methods were used in the grassland soil to distinguish the carbon derived from forest or grassland. We found that carbon inputs from deforestation increased SOC stocks, but only at short-term because woody debris decomposition was fast and did not induce a mid-term SOC storage. Five years after deforestation SOC stocks in grassland are similar to the forest, thanks to carbon inputs from root activity. In the annual crops SOC stocks decrease of about 18 %, and no difference is found according to the soil tillage. The decay of forest soil carbon, which affected the whole granulometric fractions of SOC, is thus offset in grassland but not in annual crops. RothC model could be validated in our study, but slightly overestimated SOC stocks in annual crops. Replaced in the Amazonian context, our results showed that the SOC decrease here was lower than other studies across humid tropics. This can probably be explained by the optimal management of the agrosystems, and the short time lapse studied.
470

An Exploration of the Selkirk Treaty

Hasselstrom, Nathan 04 April 2019 (has links)
In 1817, the fifth Earl of Selkirk and certain Saulteaux chiefs negotiated the Selkirk Treaty to secure the existence of a fragile Euro-Canadian settlement near the confluence of the Red and Assiniboine Rivers. Selkirk died soon after, and his agents and successors disputed the content of the treaty with the Indigenous negotiating parties. The historiography of the Selkirk Treaty has not reached a consensus on these disputes, in part due to the number of ostensibly contradictory sources it draws upon. This thesis argues that these disputes can be best answered, and these ostensibly contradictory sources best reconciled, by situating them and the Selkirk Treaty within the context of the Indigenous and Imperial land frameworks that operated in Red River in 1817. This thesis first identifies unresolved questions in the historiography of the Selkirk Treaty. Using primary sources cited in the historiography, it then outlines the ideas acting within the Indigenous and Imperial land frameworks operative over Red River. It argues these ideas and frameworks remained intact during the negotiation of the Selkirk Treaty. On the basis of these frameworks, this thesis further argues that neither Lord Selkirk nor the Saulteaux negotiators intended the Selkirk Treaty to consist of a permanent alienation of Indigenous land. However, after Selkirk’s death, his agents and successors came to trust the Indenture of the Selkirk Treaty, a written and signed record of the treaty, as the only trustworthy record of the agreement. Selkirk’s agents and successors then read the Indenture as a permanent alienation of land, but this thesis argues that, on the basis of the borders specified in the Indenture, that document alone is inadequate to interpret the Selkirk Treaty. The primary purpose of this thesis is to provide a point of departure for future research into the Selkirk Treaty. At the same time, it is intended as a corrective against assuming the ideas of either Indigenous or Euro-Canadian actors about land rights in colonization zones. It is also meant to act as a caution against relying any more heavily on the Indenture of the Selkirk Treaty than scholars do on the written records of other treaties. It is further hoped that this thesis contributes to a better understanding of Red River’s Métis population in these early years by situating them within the framework of the broader Iron Alliance.

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