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Full-Text Articles in Physical Sciences and Mathematics

Effect Of Water Velocity And Temperature On Energy Use, Behavior, And Mortality Of Pallid Sturgeon Scaphirhynchus Albus Larvae, Joseph Thomas Mrnak Jan 2019

Effect Of Water Velocity And Temperature On Energy Use, Behavior, And Mortality Of Pallid Sturgeon Scaphirhynchus Albus Larvae, Joseph Thomas Mrnak

Electronic Theses and Dissertations

Pallid Sturgeon Scaphirhynchus albus are a federally endangered species endemic to the Missouri River basin. Natural reproduction has been limited for decades and a recruitment bottleneck is hypothesized to occur during the larval stage of development. Understanding factors that affect survival of Pallid Sturgeon larvae is key given their critical status and ongoing recovery efforts. In this study, I evaluated the effects of water velocity and temperature on energy use, behavior, and mortality of endogenously feeding Pallid Sturgeon larvae (< 25 mm TL). In the first experiment, I examined the effect of water velocity (0 – 8.3 cm s−1) on larval growth, energy density, swimming activity, and mortality. Larval growth rate at 16.3 °C was similar across …


Long-Term Impacts Of Manure And Inorganic Fertilization On Soil Physical, Chemical And Biological Properties, Asmita Gautam Jan 2019

Long-Term Impacts Of Manure And Inorganic Fertilization On Soil Physical, Chemical And Biological Properties, Asmita Gautam

Electronic Theses and Dissertations

The intensive use of mineral fertilizers to achieve high crop yield has led to soil degradation and poor soil health. Thus, manure application as an alternative to mineral fertilizers can be an effective fertilization strategy to improve soil health and biodiversity. This study aims to assess the impacts of long-term manure and mineral fertilizers on soil physical, chemical and biological properties. The experimental site was initiated in 2003 near Beresford, South Dakota on Egan soil under a randomized complete block design with four replications and six treatments. The study treatments included: three manure rates [low manure (LM), manure application based …


Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson Jan 2019

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …


Effects Of Energy Development On Movements, Home Ranges, And Resource Selection Of White-Tailed Deer In The Western Dakotas, Bailey S. Gullikson Jan 2019

Effects Of Energy Development On Movements, Home Ranges, And Resource Selection Of White-Tailed Deer In The Western Dakotas, Bailey S. Gullikson

Electronic Theses and Dissertations

Oil and natural gas development has increased in recent years and research is needed to assess potential impacts on white-tailed deer (Odocoileus virginianus) populations. Our objectives were to document movements, home ranges, and resource selection of female white-tailed deer in response to energy development in the western Dakotas. Our study areas included Dunn County, North Dakota, an area with current oil and gas development, and Grant County, North Dakota, and Perkins County, South Dakota, areas without current oil and gas development. We captured and fitted 150 female deer with Very High Frequency (VHF) collars across study sites, and …


Isolation And Identification Of Potential Bioinoculants Based On Phosphate Solubilizing And Plant Growth Promoting Benefits, Rachel Raths Jan 2019

Isolation And Identification Of Potential Bioinoculants Based On Phosphate Solubilizing And Plant Growth Promoting Benefits, Rachel Raths

Electronic Theses and Dissertations

Conservative models have shown that as populations rise, food production needs to double by 2050. Population increase and the green revolution have caused fertilizer inputs to increase since the 1960’s, increasing environmental issues and production costs. These intensive practices have led to degraded arable land and there has been an increase in urbanization meaning we need to make best use of the farming land that is available and ensure it is sustainable for future food production. Due to this, there has been a higher demand for research on more environmentally and economically friendly approaches to food production. Plant growth promoting …


Prairie Dogs And Livestock In Rangeland Systems: Balancing Biodiversity And Production In The Northern Mixed-Grass Prairie, Jameson Robert Brennan Jan 2019

Prairie Dogs And Livestock In Rangeland Systems: Balancing Biodiversity And Production In The Northern Mixed-Grass Prairie, Jameson Robert Brennan

Electronic Theses and Dissertations

A major constraint of beef production within the Standing Rock Reservation has been identified as a reduction in rangeland quality due in large part to wide-scale colonization by black-tailed prairie dogs (Cynomys ludovicianus). The desire exists within the community to design a holistic framework which incorporates livestock management with the goal of increasing production and rangeland health while still maintaining increased diversity associated with prairie dogs. Prairie dogs reduce the carrying capacity of cattle on rangelands by up to 50% on occupied hectares through direct consumption of vegetation and waste due to clipping to improve detection of predators. Livestock stocking …


Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer Jan 2019

Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer

Electronic Theses and Dissertations

Wetlands are one of the world's largest known carbon sinks while comprising only a small amount of the Earth's surface. However, the amount of carbon sequestered by wetlands is shrinking as droughts and human disturbance increases. Carbon in wetlands is stored through the contrast of decomposition and sedimentation of organic matter and absorption of CO2 from the atmosphere by soil microbes. Understanding how changing hydrological regimes and increased wildfires will affect wetland soil and microbial processes is important in the face of predicted climate change for future wetland conservation practices. Specifically, I seek to understand the response of southeastern …