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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.
1

Simulation of the effects of climate change on forage and cattle production in Saskatchewan

Sykes, Cheri 19 February 2008
Multiple global climate models suggest that the Canadian Prairies will experience temperature increases due to climate warming. This could influence pasture and grazing production. Three climate scenarios CGCM2 A21, CSIROMk2 B11 and HadCM3 A21 were used to predict daily weather data to 2099 and incorporated into the GrassGro decision support tool to project pastoral production during 30-year increments, 2010 to 2099. Simulations were compared with the World Meterological Organization baseline years, 1961-1990 at two sites (Saskatoon and Melfort) and two soil textures (loam topsoil / loam subsoil and sandy-loam / sandy-clay-loam). Two tame grasses [crested wheatgrass (CWG; <i>Agropyron cristatum</i>) and hybrid bromegrass (HBG; <i>Bromus inermis x Bromus riparius</i>) and a mixed native pasture (<i>Festuca hallii; Elymus lanceolatus; Pascopyrum smithii; Nassella viridula</i>) were studied at each location.<p> Soil moisture was greater for loam/loam than sandy-loam/sandy-clay-loam resulting in more plant available moisture in all climate scenarios at both locations. However, plant available moisture alone was unable to explain changes in pasture dry matter (DM) production. The results projected from CGCM2 A21 were more favorable to plant and livestock production than those of CSIROMk2 B11 and HadCM3 A21. CGCM2 A21 simulated increases in mean DM production of HBG at both locations during spring each 30-yr period (P<0.05) but an overall decline (P<0.05) in mean average daily gain (ADG) of steers at Melfort, whereas at Saskatoon there was an increase in ADG (P<0.05). CWG decreased in DM production at Melfort during summer and increased at Saskatoon with CGCM2 A21 but there was an overall decrease in ADG of steers during each 30-yr period relative to baseline. It was concluded that HBG was better able to stabilize production under various future climatic conditions than CWG. There was a shift in species dominance from <i>Festuca hallii</i> to <i>Elymus lanceolatus</i> in the mixed native pasture at both locations associated with the increase in summer temperatures. This suggests that various grass species may respond differently to climate change.These results indicate that climate change will cause significant changes in soil moisture, productivity and quality of tame pastures, liveweight of grazing cattle and species composition of native pasture.
2

Assessment of the second generation prairie agrometeorological model's performance for spring wheat on the Canadian Prairies

Gervais, Mark D. 14 January 2009 (has links)
To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters. / February 2009
3

Simulation of the effects of climate change on forage and cattle production in Saskatchewan

Sykes, Cheri 19 February 2008 (has links)
Multiple global climate models suggest that the Canadian Prairies will experience temperature increases due to climate warming. This could influence pasture and grazing production. Three climate scenarios CGCM2 A21, CSIROMk2 B11 and HadCM3 A21 were used to predict daily weather data to 2099 and incorporated into the GrassGro decision support tool to project pastoral production during 30-year increments, 2010 to 2099. Simulations were compared with the World Meterological Organization baseline years, 1961-1990 at two sites (Saskatoon and Melfort) and two soil textures (loam topsoil / loam subsoil and sandy-loam / sandy-clay-loam). Two tame grasses [crested wheatgrass (CWG; <i>Agropyron cristatum</i>) and hybrid bromegrass (HBG; <i>Bromus inermis x Bromus riparius</i>) and a mixed native pasture (<i>Festuca hallii; Elymus lanceolatus; Pascopyrum smithii; Nassella viridula</i>) were studied at each location.<p> Soil moisture was greater for loam/loam than sandy-loam/sandy-clay-loam resulting in more plant available moisture in all climate scenarios at both locations. However, plant available moisture alone was unable to explain changes in pasture dry matter (DM) production. The results projected from CGCM2 A21 were more favorable to plant and livestock production than those of CSIROMk2 B11 and HadCM3 A21. CGCM2 A21 simulated increases in mean DM production of HBG at both locations during spring each 30-yr period (P<0.05) but an overall decline (P<0.05) in mean average daily gain (ADG) of steers at Melfort, whereas at Saskatoon there was an increase in ADG (P<0.05). CWG decreased in DM production at Melfort during summer and increased at Saskatoon with CGCM2 A21 but there was an overall decrease in ADG of steers during each 30-yr period relative to baseline. It was concluded that HBG was better able to stabilize production under various future climatic conditions than CWG. There was a shift in species dominance from <i>Festuca hallii</i> to <i>Elymus lanceolatus</i> in the mixed native pasture at both locations associated with the increase in summer temperatures. This suggests that various grass species may respond differently to climate change.These results indicate that climate change will cause significant changes in soil moisture, productivity and quality of tame pastures, liveweight of grazing cattle and species composition of native pasture.
4

THE ECOLOGY AND FUTURE DISTRIBUTION OF WEST NILE VIRUS IN THE CANADIAN PRAIRIE PROVINCES

2013 June 1900 (has links)
This thesis describes aspects of the ecology of West Nile virus (WNV) including factors contributing to the distribution of WNV, possible future distribution, and effects of WNV on host abundance in the Canadian prairies provinces: Alberta, Saskatchewan, and Manitoba. Using mosquito surveillance data collected between 2005 and 2008, models integrating abiotic and biotic factors were constructed to predict the weekly and monthly scales of WNV infection rate in Culex tarsalis, which is the primary vector of WNV in the Canadian prairies. At the weekly scale, the WNV infection rate in Cx. tarsalis increased with increasing Cx. tarsalis abundance and mean temperature lagged from 1 to 8 weeks, but decreased with an increasing mean precipitation lagged from 2 to 6 weeks. Furthermore, precipitation was a ‘distorter variable’ which altered the association between Cx. tarsalis abundance and the WNV infection rate. Study at the monthly scale showed that higher mean temperature and time lagged mean temperature elevated were associated with increased numbers of Cx. tarsalis and higher WNV infection rates. However, increasing precipitation was associated with higher abundance of Cx. tarsalis and lower WNV infection rate. In addition, this study found that increased temperature fluctuation and wetland land cover were associated with decreased WNV infection rate in Cx. tarsalis. Climate change could drive dramatic alterations in the spatial and temporal distribution and overall incidence of vector-borne diseases. The constructed models and biological thresholds were used to predict the distribution of Cx. tarsalis and WNV infection rate in the prairie provinces under a range of potential future climate and habitat conditions. In the current endemic regions, the projected WNV infection rate under the median outcome scenario in 2050 was 18 times higher than under current climate conditions. Seasonal occurence of Cx. tarsalis infected with WNV extended from June to August to include May and September. Moreover, models predicted northward range expansion for Cx. tarsalis and WNV. The declines of susceptible bird abundance caused by WNV may further influence the bird community composition and, in turn, affect the incidence of WNV through a dilution effect. The North American Breeding Bird Survey data was used to evaluate the effect of WNV on the abundance of selected birds in the Canadian prairies, as well as the effects of bird community composition on the WNV risk. There was no significant decline in bird abundances of selected birds following the emergence of WNV. These findings suggest that the effect of WNV on selected bird abundance and bird community composition is insignificant. In addition, there is no evidence to support the association between bird community composition and WNV infection rate in Cx.tarsalis in the Canadian prairies. Lastly, findings in this thesis and current knowledge were integrated to create a decision making flowchart for the prevention of WNV infection in the prairie provinces.
5

A Spatial Model of Agricultural Land Use with Climate Change for the Canadian Prairies

Robertson, Susan Unknown Date
No description available.
6

Assessment of the second generation prairie agrometeorological model's performance for spring wheat on the Canadian Prairies

Gervais, Mark D. 14 January 2009 (has links)
To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters.
7

Agronomic and environmental impacts of corn production under different water management strategies in the Canadian Prairies

Cordeiro, Marcos R. C. January 2012 (has links)
A major challenge facing agriculture is to improve water use and minimize environmental impact while increasing productivity levels. This study, carried out in Winkler, Manitoba, tested four water management treatments: no drainage and no irrigation (NDNI as control), no drainage with overhead irrigation (NDIR), free drainage with overhead irrigation (FDIR), and controlled drainage with subirrigation (CDSI). Each treatment was replicated in three plots during two growing seasons in 2010 and 2011. The monitored variables included soil moisture content, water table depth variation, drainage outflow volume and quality, weather parameters, and agronomic indices. In 2010, yields were 8.48 (NDNI), 10.36 (NDIR), 10.10 (FDIR), and 9.22(CDSI) Mg ha-1 with only the mean yield difference for the NDIR and the CDSI treatments being statistically significant (p = 0.014). In 2011, yields were 9.25 (NDNI), 10.47 (NDIR), 11.28 (FDIR), and 9.49 (CDSI) Mg ha-1 with no statistically significant differences in yield. In 2010, the exports of NO3-N (138 kg ha-1), PO4-P (0.6 kg ha-1) and salts (2.34 Mg ha-1) from the FDIR treatment were significantly larger (p <0.05) than exports from CDSI, which were 0.07 kg ha-1, 0.08 kg ha-1, and 0.41 Mg ha-1, respectively. In 2011, the exports of NO3-N (36 kg ha-1), PO4-P (0.27 kg ha-1), and salts (1.1 Mg ha-1) from FDIR were significantly larger (p < 0.05) than the exports from CDSI which were 10 kg ha-1, 0.08 kg ha-1, and 0.39 Mg ha-1, respectively. These results indicate that irrigation was the main factor driving corn yields under the conditions prevailing in the Canadian Prairies, while subsurface drainage had a beneficial impact when the beginning of the season was wet. Also, this study showed the advantage of controlled drainage over free drainage in reducing the nutrients and salt exports.
8

Assessment of the second generation prairie agrometeorological model's performance for spring wheat on the Canadian Prairies

Gervais, Mark D. 14 January 2009 (has links)
To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters.
9

Voice Map Trekking

Klassen, Michael John 21 January 2008 (has links)
The site analysis and mapping methods in the design and planning professions follow a standardized quantitative and qualitative analyis of place that favors a design process which can limit creativity and render it difficult to do anything with the normative. This work is an exploration of the development of a design approach and method that uses voice mapping as a basis for design. The voice maps contain oral histories and personal accounts of landscape experiences. Voice mapping is employed not only as a method or for site analysis but also as a generator or ideas. Voice Map Trekking is explored through a trek in the Canadian Arctic and across the Canadian Prairies. Two specific landscapes were chosen as bases for testing concepts - one near St. Gertrude SK and the other near Morinville AB. / February 2008
10

Voice Map Trekking

Klassen, Michael John 21 January 2008 (has links)
The site analysis and mapping methods in the design and planning professions follow a standardized quantitative and qualitative analyis of place that favors a design process which can limit creativity and render it difficult to do anything with the normative. This work is an exploration of the development of a design approach and method that uses voice mapping as a basis for design. The voice maps contain oral histories and personal accounts of landscape experiences. Voice mapping is employed not only as a method or for site analysis but also as a generator or ideas. Voice Map Trekking is explored through a trek in the Canadian Arctic and across the Canadian Prairies. Two specific landscapes were chosen as bases for testing concepts - one near St. Gertrude SK and the other near Morinville AB. / February 2008

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