In Canada, the endangered prairie skink (Plestiodon septentrionalis) exists only in southwestern Manitoba. Habitat loss is the most significant threat faced by the prairie skink in Canada, with leafy spurge (Euphorbia esula) invasion identified as one of the suspected factors contributing to habitat loss. The objectives of this study were to determine microhabitat preferences and effect of leafy spurge on prairie skinks in southwestern Manitoba. To determine microhabitat preferences, occupied sites were compared to unoccupied sites. Artificial cover was identified as the most important microhabitat element. To determine the impacts of spurge on microhabitat, ground temperatures in invaded were compared to un-invaded sites. No significant differences in temperature or skink density were observed between invaded and un-invaded site; however, skinks were more likely to use spurge when cover was present, than when no cover was present. Artificial cover may improve microhabitat by providing refuge from predators and microhabitat for prey.

The role of shelterbelts within prairie agriculture is changing. In the past, shelterbelts have been promoted and adopted for soil stabilization and their ability to protect farmsteads and livestock from harsh prairie climates. In today’s agricultural landscape advances in production technology, an increase in farm size, and changes to policy have changed the circumstances in which decisions related to shelterbelts are made. The objective of this research is to identify the costs, benefits and the barriers to adoption and retention of shelterbelts that influence agricultural producers and landowners’ management decisions related to shelterbelts in the Canadian Prairies. In the summer of 2013, surveys of producers and landowners from throughout the province of Saskatchewan (and several from Alberta) were conducted. Using the information collected in the surveys, the costs and benefits (both economic and non-economic), and potential barriers to adoption and retention of shelterbelts that influence producer’s management decisions were identified and analyzed. This research identified that overall shelterbelts removal is increasing and that there are many barriers to adoption and retention for agricultural producers related to the economic costs. In addition, it was found that many of the benefits of shelterbelts are non-economic and more difficult for producers and landowners to recognize within their operations. Going forward, shelterbelts have the potential to play a major role in climate change mitigation by sequestering significant amounts of atmospheric carbon dioxide (CO2) into the soil and as biomass carbon in aboveground and belowground parts of planted shelterbelt trees or shrubs within the agricultural landscape. In addition, shelterbelts provide many ecological goods and services to landowners and society. In conclusion, understanding the context in which producers are making decisions related to shelterbelts within their operations is important from an agricultural production, climate change, and policy perspective.

As the need to understand climate induced changes increases, so too does the need to understand the long-term spatial-temporal characteristics of snow cover and snow water equivalence (SWE). Snow cover and SWE are useful indicators of climate change. In this research, we combine methods from spatial statistics, geographic information systems (GIS), time-series analysis, ecosystems classification, cluster analysis, and remote sensing, to provide a unique perspective on the spatial-temporal interactions of SWE. We show that within the Canadian Prairies, extreme SWE are becoming more spatially constrained, and may cause some regions to be more prone to flooding. As well, we find that the temporal characteristics of SWE are not captured by current ecological management units, highlighting the need for Canadian ecological management units that consider winter conditions. We then address this need by developing methods designed to generate geographically distinct SWE regimes. These regimes are used to partition the landscape into winter-based management units, and compared with conventional summer based units. We find that regional variations in the ability of current ecological units to capture SWE characteristics exist, and suggest that SWE regimes generated as a result of this analysis should be used as guidelines for developing winter-based management units in conjunction with current ecological stratifications.

Prescribed burning is an important management tool for the restoration and maintenance of tallgrass prairies. To improve fire behaviour prediction in tallgrass prairies, I assessed three different aspects of fire behaviour - heat of combustion, fuel load and rate of spread. Heat of combustion was found to vary amongst certain tallgrass species but the relatively small differences in means is unlikely to contribute significantly to fire behaviour. Average fuel loads in Ontario tallgrass prairie sites were found to be higher than current default value used in fire behaviour prediction. Three rapid fuel load assessment techniques were tested. Finally, the predictions of three fire behaviour prediction systems - the FBP System, BehavePlus and an Australian grassfire spread model, were compared with actual fire behaviour observations. The FBP System was found to perform poorly while both BehavePlus and the Australian model exhibited relatively strong relationships between observed and predicted rates of spread.

Prescribed burning is an important management tool for the restoration and maintenance of tallgrass prairies. To improve fire behaviour prediction in tallgrass prairies, I assessed three different aspects of fire behaviour - heat of combustion, fuel load and rate of spread. Heat of combustion was found to vary amongst certain tallgrass species but the relatively small differences in means is unlikely to contribute significantly to fire behaviour. Average fuel loads in Ontario tallgrass prairie sites were found to be higher than current default value used in fire behaviour prediction. Three rapid fuel load assessment techniques were tested. Finally, the predictions of three fire behaviour prediction systems - the FBP System, BehavePlus and an Australian grassfire spread model, were compared with actual fire behaviour observations. The FBP System was found to perform poorly while both BehavePlus and the Australian model exhibited relatively strong relationships between observed and predicted rates of spread.

Knowing the control of landscape position in greenhouse gas (GHG) emission from the Prairie pothole region is necessary to provide reliable emission estimates needed to formulate strategies for reducing emission from the region. Presented here are results of a study investigating the control of landscape position on the flux of nitrous oxide (N2O) and methane (CH4) from an agricultural soil. Field flux of N2O and CH4 and associated soil parameters from the Upper, Middle, Lower and Riparian slope positions were monitored from spring to fall of 2005, and spring of 2006, at the Manitoba Zero-Tillage Research Association (MTRZA) farm, 17.6km North of Brandon, MB. The field site consisted of a transect of 128 chambers segmented into the four landscape positions, with either all chambers or a subset of the chambers (32) sampled on select days. Spring thaw is an important period for annual inventory of N2O emission, thus, soil samples were also collected from the four slope positions in fall 2005, and treated in the laboratory to examine how antecedent moisture and landscape position affect the freeze-thaw emission of N2O from soil. Daily emissions of N2O and CH4 for 2005 were generally higher than for 2006, the former being a wetter year. There was high temporal variability in N2O and CH4 emission, with high fluxes associated with events like spring thaw and fertilizer application in the case of N2O, and rapid changes in soil moisture and temperature in the case of CH4. There was a high occurrence of hotspots for N2O emission at the Lower slope, associated with its high soil water-filled porosity (WFP) and carbon (C) availability. The Riparian zone was not a source of N2O emission, despite its soil WFP and organic C being comparable with the Lower slope. The hotspot for CH4 emission was located at the Riparian zone, associated with its high soil WFP and C availability. The Upper and Middle slope positions gave low emission or consumed CH4, associated with having low soil WFP and available C. This pattern in N2O and CH4 emission over the landscape was consistent with examination of entire 128 chambers on the transect or the 32 subset chambers. Significantly lowering the antecedent moisture content of soil by drying eliminated the freeze-thaw emission of N2O, despite the addition of nitrate to the soil. This was linked to drying slightly reducing the denitrifying enzyme activity (DEA) of soil. The highest and earliest freeze-thaw emission of N2O was from the Riparian zone, associated with its high antecedent moisture content, DEA and total organic C content. The addition of nitrate to soil before freezing failed to enhance freeze-thaw emission of N2O from the Upper, Middle and Lower slope positions, but increased emission three-fold for the Riparian zone. Despite the greater potential of the Riparian zone to produce N2O at thaw compared to the Upland slopes, there was no spring-thaw emission of N2O from the zone on the field. This was because this zone did not freeze over the winter, due to insulation by high and persistent snow cover, vegetation and saturated condition. The denitrifying potential and freeze-thaw N2O emission increased in going from the Upper to the Lower slope position, similar to the pattern of N2O emission observed on the field. The localization of hotspots for N2O and CH4 emission within the landscape was therefore found to be driven by soil moisture and C availability. When estimating GHG emission from soil, higher emission index for N2O and CH4 should be given to poorly-drained cropped and vegetated areas of the landscape, respectively. The high potential of the Riparian zone for spring-thaw emission of N2O should not be discountenanced when conducting annual inventory of N2O emission at the landscape scale. When fall soil moisture is high, snow cover is low, and winter temperature is very cold, freeze-thaw emission of N2O at the Riparian zones of the Prairie pothole region may be very high.

This study engaged with the architecture of the ‘Initial Structure’ at Newman College, 1915-1918, so as to establish this building’s place in the oeuvre of Walter Burley Griffin (1876-1937). Griffin’s architecture at Newman College was unparalleled in Melbourne yet it has never been the subject of a comprehensive study. Further, a measure for Griffin’s creative method and architectural style has not been developed to date although much scholarship has been devoted to the identification of events and works in Griffin’s career. Furthermore a substantive analysis of the architecture of Walter Burley Griffin was lacking that defined and distinguished his work from that of the so-called ‘Prairie School’, and of Frank Lloyd Wright. / Walter Burley Griffin was the conceptual designer of Newman College, while Marion Mahony Griffin (1871-1961), his wife and architectural practice partner was its facilitator. An evaluation of Griffin’s university education, 1895-1899, drew out the compositional concepts of parti, types and architectonics, as his own preferred means of working. Griffin’s mature style in the college design was also indebted to his architectural practice and experiences in Chicago, 1899-1914. An initial assumption in this study was that Griffin was eclectic, as were the American predecessors he admired, Thomas Jefferson and Henry Hobson Richardson, as were Griffin’s contemporaries, Louis Henri Sullivan and Frank Lloyd Wright. Thus the sources of Griffin’s architectural ideas, elements, and methods of composition, have been traced in this study. / American campus designs were surveyed and comparisons made with the other three late 19th Century college buildings at the University of Melbourne to distinguish Griffins’ innovations in college planning, construction and form at Newman College. The description of the commissioning, committee-work and program for the Newman College building revealed the social and political idealism that linked Griffin with his supporters among Melbourne’s Roman Catholic community. Griffin worked with ‘structure’ in mind, both compositional and constructional. Particular partis, typologies and architectonic patterns have been 3 identified in the compositional structures of the college building design. Similarly Griffin’s adaptations of new and exploratory building techniques were investigated. / Griffin’s sources were not only American. He derived inspiration equally from seminal European and Asian precedents, which provided instances of an underlying compositional structure. In the architecture of Newman College the composite plans, mixed construction techniques and materials, and richly layered forms allowed Griffin scope to express ideal college purposes, spiritual universality, and organic wholeness.

Thesis (Ph.D.)--Tufts University, 2005. / Adviser: J. Michael Reed. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 126-135). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 1984. / Vita. Includes bibliographical references (leaves 626-650). Also issued in print.

Thesis (M.S.)--Wildlife and Fisheries Sciences Dept., South Dakota State University, 2009. / Includes bibliographical references (leaves 74-85). Also available via the World Wide Web.