Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 31-39). Also available on the World Wide Web.

Thesis (M.S.)--Mississippi State University. Department of Animal and Dairy Sciences. / Title from title screen. Includes bibliographical references.

Grasslands are characterized by recurring disturbances such as fire and grazing occurring against a background of topoedaphic heterogeneity and climatic variability. The result is a complex, multi-scaled disturbance regime, in which fire and grazing often have interactive roles, yet they have usually been studied independently. Relationships between climate, fire and simulated grazing (=mowing) were explored to determine the roles these disturbances play in shaping patterns and processes in southern mixed-grass prairie. A field experiment investigated the potential effects of these disturbances on above and belowground plant productivity, patch dynamics, and soil respiration over a 2-year period characterized by drought (1998) and normal (1999) rainfall. Spring burning and mowing had interactive effects on aboveground net primary production (ANPP). Consistent with published single factor studies, burning without mowing doubled ANPP, whereas mowing in the absence of burning had neutral effects. However, subsequent mowing on burned plots reduced ANPP gains to levels comparable with all unburned plots. Drought reduced ANPP by 22% relative to a normal rainfall year. In contrast to the traditional model of root response to defoliation, burning and mowing each stimulated root length recruitment measured with minirhizotrons. However, subsequent mowing on burned plots did not produce additional root recruitment. Fire and mowing appear to interact by affecting different components of root recruitment (production and mortality, respectively). Root biomass recovered from ingrowth cores were not correlated with minirhizotron results, and responded only to drought, suggesting that methodological differences have contributed to the varied root responses reported in the literature. Drought suppressed soil respiration, diminished soil moisture, and enhanced soil temperature, whereas fire and/or mowing had little effect. Results suggest that any fire or mowing effects on soil respiration in southern mixed-grass prairie may be highly constrained by moisture limitations during dry periods. In summary, patch level response to fire is a pulse of root recruitment followed by increased ANPP, unless subsequent grazing offsets these gains. Grazing alone produces a pulse of root recruitment, perhaps to replace consumed foliage. This study demonstrates the interactive nature of fire and grazing in grasslands, and the perils of single-factor studies.

The introduction of pen-reared Attwater's prairie-chickens (APC, Tympanuchus cupido attwateri) into the wild to supplement existing populations has met with marginal success. Flight characteristics, predator avoidance behavior, and rearing methods are possible factors contributing to post-release mortality of pen-reared birds. To evaluate flight characteristics and predator avoidance behavior of pen-reared APC's released onto the Attwater Prairie Chicken National Wildlife Refuge, flight characteristics and predator avoidance behavior of pen-reared APC's was compared to wild greater prairie-chickens (GPC, T. c. pinnatus) in Minnesota and Kansas using a radar gun and a trained dog. There was no difference (P = 0.134) in flight speed for pen-reared APC and wild GPC. However, wild GPC had greater (P < 0.001) flight distances than did pen-reared APC. Wild GPC and pen-reared APC that had survived in the wild for at least a year flushed at a greater (P < 0.001) distance from an approaching human than did pen-reared APC that had been released for less than 3 months. A trained dog was able to approach closer (P < 0.001) to APC than GPC before birds flushed, and APC did not fly as far as GPC after being flushed by the dog. Pen-reared APC displayed flight endurance deficiencies and were more approachable by humans and a dog before they flushed when compared to wild GPC, which could explain their increased mortality when released into the wild. To determine if APC chicks could be reared without daily human contact, pelleted food, and water in founts, a greenhouse was used to rear chicks in a semi-natural environment. Planted vegetation and commercial insects provided hiding cover and a food source for the APC chicks. An underground heat source provided chick warmth, and water misters and a sprinkler system simulated dew (a water source for chicks) and rain. The greenhouse provided chicks protection from predators and adverse weather conditions (before they could thermo-regulate) while exposing chicks to natural sunlight, day length, and temperature fluctuations. This technique allowed chicks to be reared in a semi-natural environment which reinforced their natural foraging behavior for food and water, and reinforced their hiding and avoidance behaviors, creating a wilder pen-reared bird.

This dissertation examines the multifaceted and pervasive impact of globalisation on the Canadian public policy environment through a detailed analysis of the monopoly marketing of prairie wheat. The study argues that forces associated with globalisation, working through regionally differentiated configurations of farmer opinion and interest groups amidst varying partisan settings, are key to understanding the changing nature of policy-making processes, structures, and outcomes in the wheat marketing arena. The forces associated with globalisation include the increased presence of transnational corporations, the expansion of international trade regimes, increased interaction and cooperation between Canadian provincial governments and US state governments, the international harmonisation of regulations, advances in transportation technology, and heightened levels of education, knowledge, and information. In attempting to understand how globalisation influences the wheat policy arena, the examination uses a comparative analysis focusing on Alberta, Saskatchewan, and Manitoba. The inter-governmental harmony that had prevailed since the 1940s on the matter of Canadian Wheat Board's (CWB's) wheat monopoly was replaced by conflict by the 1990s as the forces of globalisation washed across the Canadian prairies. The dissertation shows that where the absence of these forces once reinforced the CWB's wheat monopoly, the presence of these forces now poses a formidable challenge to its continuation. Farmer opinion data indicates that a trend away from monopoly selling toward open marketing is present throughout the prairies. Like the presence of the forces of globalisation, anti-monopoly opinion is particularly strong in Alberta. The dissertation will also show how the conflict over monopoly wheat marketing was projected into the policy arena through differentiated sets of interest group configurations and partisan environments. In doing so, the examination points out that institutions, while often providing resistance to change, can also serve as conduits facilitating change. The analysis shows that the public policy network involved with the marketing of prairie wheat, as well as actors within this network, have become increasingly internationalised. The examination indicates that domestic governmental regulation and control have been severely undermined in the wheat marketing arena as north-south ties increasingly undermine and replace the east-west unity previously forged by the National Policy.

Anthropogenic disturbances to Alberta’s landscape have resulted in the widespread removal of indigenous plant communities. Steep slopes and limited topsoil are often barriers when trying to reestablish vegetation; however, native rhizomatous grass species have a number of traits that make them ideally suited to revegetate challenging sites. A field study evaluated the establishment of three species of native perennial rhizomatous grasses (Calamagrostis canadensis, Calamovilfa longifolia, and Hierochloe odorata) from three propagation methods. Initial results suggest that these species were able to establish and survive on these sites despite poor soil conditions. Establishment was poor in seeded plots (24.1%), but improved with root cuttings (75.9%) and nursery-grown plugs (96.3%). The use of vegetative establishment methods could increase the successful application of native grass species, and encourage their use in landscape design and restoration projects. / Thank you to Imperial Oil and the Glenbow Ranch Park Foundation for providing financial and material support for this project.

The present study analyzed the evolutionary history of Erigeron trifidus Hook. by addressing two main questions: 1) Is the current hypothesis of the origin of the species by hybridization between E.compositus and E.lanatus supported by molecular data? and 2)Is the species monophyletic? An analysis of uni-and-biparentally inherited molecular markers from three species throughout the range of E.trifidus yielded data that supports the hybridization hypothesis. First, a restriction site analysis of cpDNA revealed 4 haplotypes. In most cases, cpDNA haplotypes were the same as in E.lanatus, suggesting E.lanatus as the maternal parent. Sequencing and cloning the nuclear ETS region revealed the presence of multiple repeat types in most individuals sampled. This further supports the hybrid origin hypothesis in that E.trifidus contained only repeat types present in one or the other of the putative parents. In addition, E.trifidus displayed the highest percentage of intrainidividual repeat type polymorphism, a common trait of hybrid species. Erigeron trifidus populations collected in the northern region appear to be monophyletic as they all exhibited a particular pattern of repeat type variation, a pattern absent in Ram Mountain and Waterton Lakes National Park populations. As E.lanatus has never been recorded from Ram Mountain, it is likely that the populations identified as E.trifidus are instead a different agamospermous variant of E.compositus. In Waterton Lakes National Park, populations of E.trifidus are thought to be the product of local hybridization but the identity of the putative parents remains uncertain. Therefore, E.trifidus is concluded to be polyphyletic. / viii, 66 leaves : ill. (some col.) ; 28 cm.

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