Thesis (M. S. - Soil, Water, and Environmental Science)--University of Arizona, 2002. / Includes bibliographical references (leaves 50-52).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [i]-iii).

No description available.

Thesis (Ph.D.) - University of Glasgow, 1996. / Ph.D. thesis submitted to the Environmental Sciences Department, Scottish Agricultural College, 1996. Includes bibliographical references. Print version also available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 102-105.

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirement for the degree of Master of Science (Environmental Sciences) at the School of Geography, Archaeology & Environmental Studies March 2017 / Accurate estimates and mapping of grass quality is important for effective rangeland management. The purpose of this research was to map different grass species as well as nutrient Phosphorus (P) and Sodium (Na) concentration across grass communities using Sentinel-2 imagery in Telperion game reserve. The main objectives of the study were to: map the most common grass communities at the Telperion game reserve using Sentinel-2 imagery using artificial neural network (ANN) classifier and to evaluate the use of Sentinel-2 (MSI) in quantifying grass phosphorus and sodium concentration across different grass communities. Grass phosphorus and sodium concentrations were estimated using Random Forest (RF) regression algorithm, normalized difference vegetation index (NDVI) and the simple ratios (SR) which were calculated from all two possible band combination of Sentinel-2 data. Results obtained demonstrated woody vegetation as the dominant vegetation and Aristida congesta as the most common grass species. The overall classification accuracy = 81%; kappa =0.78 and error rate=0.18 was achieved using the ANN classifier. Regression model for leaf phosphorus concentration prediction both NDVI and SR data sets yielded similar results (R2 =0.363; RMSE=0.017%) and (R2 =0.36 2; RMSE=0.0174%). Regression model for leaf sodium using NDVI and SR data sets yielded dissimilar results (R2 =0.23; RMSE=16.74 mg/kg) and (R2 =0.15; RMSE =34.08 mg/kg). The overall outcomes of this study demonstrate the capability of Sentinel 2 imagery in mapping vegetation quality (phosphorus and sodium) and quantity. The study recommends the mapping of grass communities and both phosphorus and sodium concentrations across different seasons to fully understand the distribution of different species across the game reserve as well as variations in foliar concentration of the elements. Such information will guide the reserve managers on resource use and conservation strategies to implement within the reserve. Furthermore, the information will enable conservation managers to understand wildlife distribution and feeding patterns. This will allow integration of effective conservation strategies into decisions on stocking capacity. / MT 2017

The northern Great Plains of Saskatchewan is one of the most significantly modified landscapes in Canada. While the majority of anthropogenic disturbance to Saskatchewans grasslands is the result of agricultural practices, oil and gas activity are of increasing concern to grassland conservation efforts. Although such developments require formal regulatory approval (Environmental Impact Assessment), follow-up and monitoring of the effects of oil and gas development on grasslands is not common practice. In the absence of empirical based follow-up and monitoring, the actual environmental effects of petroleum and natural gas (PNG) development on grassland ecology and the spatial extent of development are largely unknown.<p> This thesis examines the spatial and temporal extent of PNG development and its effects on grassland ecology within a PFRA (Prairie Farm Rehabilitation Administration) pasture in southwest Saskatchewan. The extent of the changes to infrastructure and the actual impacts from development within the study area were documented from 1955 to 2006. The actual impacts of oil and gas activity on grassland ecology were determined by analyzing ground cover characteristics, soil properties, and community composition at lease sites and compared to reference pasture sites. Associated with construction practices, lease sites had low herbaceous, Lycopodiaceae, litter, organic horizon (Ah) thickness, and soil compaction values. Lease sites were also found to have low desirable species diversity, range health values, and greater undesirable species presence. Impacts from development were amplified at active, highly productive lease sites. The impacts associated with PNG development were also found to persist for more than 50 years, and extend 20m 25m beyond the physical footprint of infrastructure. This research will contribute to monitoring and mitigation measures for oil and gas development within Saskatchewan and Canadian grasslands.

The northern Great Plains of Saskatchewan is one of the most significantly modified landscapes in Canada. While the majority of anthropogenic disturbance to Saskatchewans grasslands is the result of agricultural practices, oil and gas activity are of increasing concern to grassland conservation efforts. Although such developments require formal regulatory approval (Environmental Impact Assessment), follow-up and monitoring of the effects of oil and gas development on grasslands is not common practice. In the absence of empirical based follow-up and monitoring, the actual environmental effects of petroleum and natural gas (PNG) development on grassland ecology and the spatial extent of development are largely unknown.<p> This thesis examines the spatial and temporal extent of PNG development and its effects on grassland ecology within a PFRA (Prairie Farm Rehabilitation Administration) pasture in southwest Saskatchewan. The extent of the changes to infrastructure and the actual impacts from development within the study area were documented from 1955 to 2006. The actual impacts of oil and gas activity on grassland ecology were determined by analyzing ground cover characteristics, soil properties, and community composition at lease sites and compared to reference pasture sites. Associated with construction practices, lease sites had low herbaceous, Lycopodiaceae, litter, organic horizon (Ah) thickness, and soil compaction values. Lease sites were also found to have low desirable species diversity, range health values, and greater undesirable species presence. Impacts from development were amplified at active, highly productive lease sites. The impacts associated with PNG development were also found to persist for more than 50 years, and extend 20m 25m beyond the physical footprint of infrastructure. This research will contribute to monitoring and mitigation measures for oil and gas development within Saskatchewan and Canadian grasslands.

Thesis (Ph. D.)--University of Chicago, Department of the Geophysical Sciences, 2002. / Includes bibliographical references. Also available on the Internet.

No description available.