The overall objective of my thesis research was to develop methodologies for assessing effects of mining effluents on pristine and sensitive northern rivers. I used a multi-trophic level approach in field studies to evaluate current monitoring methods and to determine whether metal mining activities had affected two otherwise pristine rivers that flow into the South Nahanni River, NWT; a World Heritage Site. Upstream reference conditions in the rivers were compared to sites downstream and further downstream of mines. The endpoints evaluated included concentrations of metals in river water, sediments and liver and flesh of slimy sculpin (Cottus cognatus); benthic algal and macroinvertebrate abundance, richness, diversity, and community composition; and various slimy sculpin measures. Elevated concentrations of copper (p=0.002)and iron (p=0.001) in liver tissue of sculpin from the Flat River were associated with high concentrations of mine-derived iron in river water and copper in sediments that were above national guidelines. In addition, sites downstream of the mine on the Flat River had increased algal abundances (p=0.002) and altered benthic macroinvertebrate communities ((p<0.001) whereas the sites downstream of the mine on Prairie Creek had increased benthic macroinvertebrate taxa richness (p=0.050) and improved sculpin condition (males: p=0.008; females: p=0.001). Biological differences in both rivers were consistent with mild enrichment of the rivers downstream of current and historical mining activity. Although the effects of mining activities on riverine biota in these northern rivers are currently limited, results of this research show that there is potential for effects to occur with proposed growth in mining activities.<p> Laboratory exposures were conducted using slimy sculpin, identified as a sentinel fish species in pristine northern rivers, to identify alternative methods for assessing toxicity of contaminants of concern in mining effluents. Ammonia was selected for the exposures based on effluent characteristics of northern mining effluents. Ammonia is known to be an important toxicant in aquatic environments. Although ammonia toxicity has been well studied in many fish species, effects of chronic exposure of slimy sculpin, a critical biomonitoring species for northern aquatic habitats, are not well known. Slimy sculpin were exposed to six concentrations of un-ionized ammonia relevant to concentrations found in northern mining effluents: control (0 ppm), 0.278 ppm, 0.556 ppm, 0.834 ppm, 1.112 ppm, and 1.668 ppm. An LC50 of 1.529 ppm was calculated from mortality data. Histopathological examination of gills indicated significant tissue damage, measured as lamellar fusion and epithelial lifting, at 0.834, 1.112, and 1.668 ppm. Using gill endpoints, NOEC and LOEC were calculated as 0.556 ppm and 0.834 ppm respectively. An EC50 of 0.775 ppm was determined for lamellar fusion and an EC50 of 0.842 ppm for epithelial lifting. Hemorrhage of gills was present in mortalities which occurred at 1.668 ppm of un-ionized ammonia. A significant decrease in liver somatic index (LSI) was seen in both male and female fish at 0.834 and 1.112 ppm, respectively. Gonadosomatic index (GSI) in female fish significantly increased at 1.668 ppm un-ionized ammonia with an associated significant increase in total whole body testosterone concentrations. GSI in male fish also significantly increased at 1.668 ppm but no differences were seen in testosterone concentrations. No significant differences were seen in gonad histopathological assessments or condition factor. Results from this study indicate that ammonia concentrations commonly reported in northern mine effluents hold potential to affect the health of slimy sculpin including acute, chronic, histological and endocrine endpoints. <p> Results from both the field study and laboratory exposures provide direction for future monitoring programs in pristine northern rivers and emphasize the importance of monitoring tools to detect change in these ecosystems. I recommend that monitoring of northern pristine rivers focus on a multi-trophic monitoring approach including indicators in algal and benthic macroinvertebrate communities due to their responsiveness. Laboratory exposures using slimy sculpin should be considered to obtain toxicological information for northern contaminants of concern. Gill histopathology endpoints may be a more sensitive indicator for detecting effects in slimy sculpin exposed to ammonia than traditional chronic endpoints. I also recommend monitoring of metal burdens in periphyton and benthic invertebrates for assessment of exposure to mine effluent and causal association in areas of low fish abundance.

A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.

Hairy prairie-clover (Dalea villosa Nutt. (Spreng) var. villosa), a rare plant species, grows in the Canadian Prairies. Populations of Dalea in Canada are threatened by the loss of sand dune habitat because of changes in land use and altered ecological processes such as grazing and fire. Local populations of Dalea are further threatened by one or more specific threats, including herbivory from native and domestic ungulates and invasion of habitats by exotic plants. The overall objective of this thesis was to gain more knowledge about Dalea and to determine the impact of threats and management practices to the Saskatchewan populations and their habitats. Observational studies were conducted at each of two sites in Saskatchewan supporting Dalea. First, at the Dundurn Sandhills site, structural equation modeling was used to examine landscape, ecological, and management factors associated with high rates of herbivory on Dalea and with reductions in the long-term survival and productivity of Dalea. The conditions which deer (Odocoileus hemionus and Odocoileus virginianus) or cattle (Bos taurus) were responsible for the most intense rates of herbivory to Dalea plants and patches were determined. Generally, deer appeared responsible for the most herbivory, whereas cattle grazing on Dalea increased with stocking densities. At the same time, new hypotheses about ecological processes affecting Dalea productivity in the Dundurn Sandhills were explored. In particular, it appeared that deer may be responding to cattle grazing in Dalea habitat by avoiding those areas, and that mid-season germination and recruitment of many Dalea plants may occur following precipitation events. Second, at the Mortlach site, the costs and benefits of using grazing management to control leafy spurge (Euphorbia esula L. var. esula) were assessed, especially in consideration of the potential negative effects of intense herbivory on Dalea productivity. Aspects of the grazing regime including stocking density and the livestock species influenced herbivory on Dalea and its reproductive output, but there were no apparent links between the abundance of leafy spurge abundance and the reproductive output of Dalea. The findings of these two studies are relevant for the conservation and management of Dalea in Saskatchewan.

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Texas is one of 17 states with both 1862 and 1890 Extension programs. The purpose of this study was to examine the partnership amongst agents of Texas AgriLife Extension Service and the Cooperative Extension Program, in counties that have both Extension programs. Seventy-eight agents participated in the study, of which, 73% (N=57) were employed by Texas AgriLife Extension Service and 24% (N=19) were employed by the Cooperative Extension Program. Cohen's D Effect Size was used to determine the practical significance of differences among agents' perception of the relevance of Texas AgriLife Extension Service, Cooperative Extension Program at Prairie View A&M University, along with the agents' understanding of the partnership, willingness to partner and knowledge of the Operational Guidelines. As part of the study, agents also identified strengths, weaknesses, and opportunities of having two programs in the State and provided recommendations for strengthening the partnership. Among agents, there was a high degree of relevance for Texas AgriLife Extension Service, while there was a moderate degree of relevance for the Cooperative Extension Program-Prairie View A&M. Cohen's D Effect size suggested a large practical difference amongst agents in their perception of both Extension programs. Findings indicated a moderate degree of knowledge of the Operational Guidelines and understanding of the partnership amongst agents. Cohen's D Effect size value (d =.1.29) and (d =1.30) suggested a large practical differences amongst agents, from the two programs, in relation to their willingness to partner and understanding of the partnership respectively. Strengths of having two Extension programs identified by agents were the Extension programs ability to reach new and diverse audiences and address community and state needs. Weaknesses identified were agents competing against one another for audiences, two programs causing confusion to clientele, and a lack of understanding on how to collaborate. Opportunities of having two Extension programs identified were collaborating on programs, reaching diverse audiences, and the ability to provide more services. Agents provided recommendations of better communication to understanding the partnership and how to partner, clearer job descriptions to prevent duplication and competition, and making the citizens the priority instead of the Extension programs.

The contagious nature of the black-tailed prairie dog (Cynomys ludovicianus) jump-yip display may provide information to signalers and receivers regarding the vigilance of neighbours. Videotaping jump-yip bouts and the behaviour of both bout initiators and respondents within those bouts provided evidence that: 1) individuals became vigilant immediately following jump-yip production, but exhibited minimal changes in their immediate post-jump-yip behaviour with changes in the characteristics of the preceding bout, 2) bout initiators spent more time actively foraging and exhibited vigilance behaviours less frequently with greater levels of response in the preceding jump-yip bout, 3) respondents spent more time actively foraging and less time vigilant following bouts with greater response. These results suggest that black-tailed prairie dogs base behavioural decisions at least in part on the characteristics of their jump-yip bouts and thus the jump yip display may provide information about the vigilance of group members. / October 2007

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. / May 2007

This thesis focuses on Canadian Prairie communities and how architecture plays a role in promoting community engagement and interaction. The ideal components of a healthy rural town include its identity, sense of community and a strong relationship to the landscape, all of which are threatened by both internal and external influences. The large urban centers in close proximity to rural communities are a major influence over the direction of development. The growth of the urban fabric is understood only after studying the historical factors that have shaped its foundation, as well as its relationship to larger regional forces. These forces have changed the urban morphology — shifting from an emphasis centered on community to one that is more focused upon economic development. This change does not suggest that these elements are completely separate from one another, but instead that the emphasis has shifted – bringing with it a whole new set of priorities. Increased development along major arterial highways is favoured over downtown growth; vehicular transportation dominates over the pedestrian; subdivisions are planned and built by developers to maximize economic gain rather than foster a sense of community; and community-based projects are no longer the norm. Unfortunately this has resulted in a loss of citizen participation and engagement. An in-depth urban analysis of the town is central to the development of future design and development strategies. Case studies of comparable cities, towns or villages will help guide the development of design principles, strategies and processes necessary to promote a healthy rural community. By exploring the complexities of rural development, strategies and interventions that address these issues can be articulated and applied.

This thesis focuses on Canadian Prairie communities and how architecture plays a role in promoting community engagement and interaction. The ideal components of a healthy rural town include its identity, sense of community and a strong relationship to the landscape, all of which are threatened by both internal and external influences. The large urban centers in close proximity to rural communities are a major influence over the direction of development. The growth of the urban fabric is understood only after studying the historical factors that have shaped its foundation, as well as its relationship to larger regional forces. These forces have changed the urban morphology — shifting from an emphasis centered on community to one that is more focused upon economic development. This change does not suggest that these elements are completely separate from one another, but instead that the emphasis has shifted – bringing with it a whole new set of priorities. Increased development along major arterial highways is favoured over downtown growth; vehicular transportation dominates over the pedestrian; subdivisions are planned and built by developers to maximize economic gain rather than foster a sense of community; and community-based projects are no longer the norm. Unfortunately this has resulted in a loss of citizen participation and engagement. An in-depth urban analysis of the town is central to the development of future design and development strategies. Case studies of comparable cities, towns or villages will help guide the development of design principles, strategies and processes necessary to promote a healthy rural community. By exploring the complexities of rural development, strategies and interventions that address these issues can be articulated and applied.

A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.