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Impact of Artificial Aeration on Nutrients in a Small Eutrophic Lake
(North Dakota State University, 2015) Balangoda, Anusha Rupika
The Heinrich- Martin Dam Impoundment (HMDI), located in northcentral LaMoure County, North Dakota, is an important water body for fishing, boating, and other recreational activities. To eliminate the thermal stratification and low dissolved oxygen (DO) zone near the bottom, an artificial aeration system was installed and operated by the North Dakota Game and Fish Department (NDG&F). This study was conducted to investigate whether aeration improved water quality of HMDI and to evaluate aeration as a tool to effectively manage eutrophication in lakes of this type. Field monitoring and laboratory analyses were conducted during three consecutive summers, in 2010, 2011 and 2012, to evaluate the impact of aeration on the spatial and temporal variation of physical, chemical, and biological water quality. Variables monitored included total and dissolved forms of inorganic nitrogen (N) and phosphorus (P), chlorophyll a, turbidity, water temperature and dissolved oxygen (DO). Field sampling was carried out during aerated conditions in 2010 and 2012 and under non-aerated conditions in 2011. The study revealed no significant differences between aeration and non-aeration conditions in soluble reactive phosphorus (SRP), total phosphorus (TP), or total nitrogen (TN) concentrations in the water column. In contrast, mean ammonia-nitrogen concentration at the near-bottom layers during non-aerated conditions decreased significantly under artificial aeration, while mean nitrate and nitrite concentrations increased significantly under aeration. Under aerated conditions, dissolved inorganic nutrients, TN, TP, temperature, and algae were homogenously distributed throughout the water column. Aeration expanded aerobic habitats for fish and distributed bio-available nutrients, stimulating algal growth throughout the water column. These results indicate that the existing aeration system vertically mixed nutrients throughout the water column of the HMDI. Chlorophyll a results showed that aeration distributed algae throughout the water column and circulated available nutrients for their growth. In addition, the results indicated that aeration improved water quality as measured by Secchi depth, turbidity, DO and algal biomass based on recommended levels by NDDoH. In a nitrogen-limited, phosphorus-rich water body, like HMDI, lowering phosphorus (P) load rather than nitrogen (N) load is recommended as a means of reducing algal biomass.
Aquatic Macroinvertebrate Response to Shifts in Hydroclimatic Variability and Ecohydrological Conditions in Prairie-Pothole Wetlands: Implications for Biodiversity Conservation
(North Dakota State University, 2020) McLean, Kyle Ian
Ecosystem degradation and subsequent biodiversity loss has plagued freshwater environments globally. Wetland ecosystems, such as the depressional wetlands found in the Prairie Pothole Region of North America, have been heavily impacted by historical land-use change and continue to be vulnerable to continued landscape modifications and climate change. Using existing literature, I summarized how recent shifts in climate coupled with historic and contemporary landscape modifications have driven a shift in wetland ecohydrological variability. However, clear trends in biodiversity were often limited by the spatial and temporal resolution of published research. I used 24 years (1992–2015) of hydrologic and aquatic-macroinvertebrate data from a complex of 16 prairie-pothole wetlands located in North Dakota to relate wetland ecohydrological variability to biodiversity. I used structural equation modeling techniques to test a set of causal hypotheses linking a wetland’s hydrogeologic setting and local climate conditions (i.e., the Wetland Continuum) to changes in hydrology, water chemistry, and biology, with an emphasis on aquatic-macroinvertebrate community response. I then examined the temporal synchrony of aquatic-macroinvertebrate populations to examine the relative importance of landscape-scale controls (e.g., climate, metacommunity dynamics) and wetland-specific controls on community assembly. Using this information, I then quantified among-wetland and amongyear changes in aquatic-macroinvertebrate beta diversity to investigate patterns of biotic homogenization. I found that spatial and temporal variability in aquatic-macroinvertebrate composition was strongly influenced by ponded-water dynamics. In addition to hydrologic controls, the high levels of temporal coherence of aquatic-macroinvertebrate compositional turnover supported the hypothesis that wetland biodiversity is also dependent on metacommunity dynamics. Analyses of spatio-temporal patterns in beta diversity did not reveal climate driven homogenization of aquatic-macroinvertebrate taxa among wetlands. However, shifts towards more permanently ponded water regimes corresponded with lasting shifts in aquatic-macroinvertebrate community composition. The communities of temporarily ponded wetlands maintained high levels of both temporal and spatial beta diversity. My collective findings indicate that the conservation of aquatic-macroinvertebrate diversity is dependent on the conservation of heterogenous, wellconnected, wetland complexes.
An Agent-Based Model for the Water Allocation and Management of Hydraulic Fracturing
(North Dakota State University, 2022) Lin, Tong
An agent-based model (ABM) is developed to simulate the impacts on streamflow and groundwater levels by the dramatic increase of hydraulic fracturing (HF) water use. To develop the agent-based model, institution theory is used to model the regulation policies, while evolutionary programming allows agents to select appropriate strategies when applying for potential water use permits. Cognitive maps endow agents’ ability and willingness to compete for more water sales. All agents have their influence boundaries that restrict their competitive behavior toward their neighbors but not to non-neighboring agents. The decision-making process is constructed and parameterized with both quantitative and qualitative information. By linking institution theory, evolutionary programming, and cognitive maps, our approach is a new exploration of modeling the dynamics of coupled human-natural systems (CHNS) to address the high complexity of the decision-making process involved in the CHNS. The ABM is calibrated with HF water-use data, and the calibration results show that it is reliable in simulating water depot number, depot locations, and depot water uses. The SWAT (Soil and Water Assessment Tool) model of the Little Muddy River basin and the MODFLOW of the Fox Hill-Hell Creek regional aquifer are coupled with the ABM to simulate the changes in streamflow and groundwater level, respectively, under different scenarios such as HF water demand, climate, and regulatory policies. The integrated modeling framework of ABM, SWAT, and MODFLOW can be used to support making scientifically sound policies in water allocation and management for hydraulic fracturing.
Crop Acreage Response Modeling in North Dakota and Greater Midwest
(North Dakota State University, 2017) Chowdhury, Nazea H Khan
Our research consists of two papers. First paper focus on the trend of North Dakota (ND) crop acreage changes and include economic factors (expected prices of crops, input price, crop yield, revenue of crops) and climate factors (precipitation, minimum and maximum temperature, growing degree days, and palmer drought severity index). We are using Geographic Information System (GIS) database for cropland areas throughout ND for the years 1998 through 2013. But we are using five crops for our analysis. We use Seemingly Unrelated Tobit Left Censored Regression and Monte Carlo Simulation techniques for our analysis. We also include renewable fuel standard dummy (year 2005 and 2007). Findings suggest that prices of crop, yield, revenue, input price significant impact on crop acreage. Marginal effects of crop price increase by $1 to own acreage of barley, corn, soybean, wheat, and oilseeds ranges between 50 to 295 acres, 28 to 572 acres, -24 to 45 acres, -198 to -39 acres, and 7 to 48 acres throughout ND and statistically significant except soybean. Elasticity of own-price to acreage of barley, corn, soybean, wheat, and oilseeds are 1.16%, 1.23%, 0.17%, -0.16%, and 0.53%, respectively, and statistically significant except soybean. Second paper mainly focus on three states ND, South Dakota (SD), and Minnesota (MN) causes of crop acres planted changes due to economic factors as well as weather factors. We are using Seemingly unrelated regression and Monte Carlo Simulation technique for that paper. We produce a balanced panel dataset with annual observations of the planted acreages of each of the five crops in each of the three states, along with the relevant price and yield variables for each crop and pertinent precipitation and temperature variables for each year in each state. Monte Carlo Simulation technique used to calculate own-price elasticity of MN state barley, corn, soybean, wheat, and sunflower to their own acreage are -0.506%, 0.197%, 0.116%, 0.566 %, and 11.34%, respectively; in SD state are -0.739%, 0.312%, 0.290%, 0.309%, and 1.72%, respectively and statistically significant except barley crop elasticity. This research findings will help forecast future agricultural land use trends & crop area response.
Life History and Interspecific Co-Persistence of Native Imperiled Fishes in Single Species and Multi-Species Ex Situ Refuges
(North Dakota State University, 2015) Goodchild, Shawn Christopher
Like many imperiled fishes, the endangered Pahrump Poolfish (Empetrichthys latos latos) is managed in ex situ refuges. I investigated life history characteristics of females from two such populations at Lake Harriet and Shoshone Stock Pond. Lake Harriet is a relatively large lake with low fish densities located at relatively low elevation and low latitude, while Shoshone Stock is a small pond with high fish densities at a higher elevation and latitude. Females from the Lake Harriet population were larger, and had greater fat content, reproductive allocation, and ‘clutch’ size than females from the Shoshone Pond population. This divergence, which occurred in three decades, may result in a phenotypic mismatch if the fish are used as a source for restocking their native habitat or stocking new refuges. Poolfish conservation may require establishing new populations; however, many sites are inhabited by non-native fish and/or other protected fish species. Thus, managers may wish to consider establishing multi-species refuges that may even already include undesirable species. I established experimental communities that included allopatric and sympatric communities of Poolfish, Amargosa Pupfish (Cyprinodon nevadensis), and invasive Western Mosquitofish (Gambusia affinis). Pupfish persisted in sympatry with both poolfish and mosquitofish, but had higher juvenile production when maintained in allopatry. By contrast, poolfish juvenile production was high in allopatry, but virtually absent in the presence of other species. To evaluate the generality of these findings, I established experimental allopatric and sympatric communities of poolfish or pupfish with mosquitofish from two populations that differed in body size: Garrett mosquitofish were approximately twice the mass of Wabuska mosquitofish. Poolfish juveniles had high survival in allopatry, but produced virtually no juveniles when sympatric with either of the two mosquitofish populations. Pupfish juvenile survival was higher in allopatry than sympatric with Garrett mosquitofish, which in turn was higher than sympatric with Wabuska mosquitofish. These results were consistent with the earlier experiment suggesting that poolfish were functionally extirpated but pupfish maintained substantial production in the presence of mosquitofish. These findings suggest that poolfish should be maintained in single species refuges, but that multi-species refuges may protect imperiled pupfish species.
Nitrogen Mineralization Dynamics of Post Harvest Crop Residue in No-Till Systems
(North Dakota State University, 2020) Alghamdi, Rashad Saeed
In North Dakota, adoption of conservation tillage practices has resulted in an accumulation of crop residue remaining on the soil surface. North Dakota producers receive a nitrogen credit for long-term no-till but due to previous crop residue this credit may not be realistic for providing partial nutrient needs to subsequent crops in a cool environment with a short growing season. Our objectives were to evaluate the N mineralization potential of common crop residues to determine whether crop residue accumulation in no-till systems can provide sufficient nitrogen quantities needed for subsequent crops. Three lab incubation studies were conducted to provide N mineralization insights for individual crop residues, crop residues over several simulated growing seasons, and crop residue in diversified cropping systems. Differences in soil texture, surface application versus incorporation of residue, freeze and thaw cycles and combinations of residues were all factors examined. Results indicated that crop residue decomposition and N release from the residue treatments generally immobilized N but were not significantly different from the bare soil for nearly all studies. The only exception observed was for the forage radish cover crop which showed the potential to improve soil N mineralization in select three-year rotations. Findings of these studies show that most wide C:N ratio crop residues will immobilize soil N in a no-till system under ideal conditions (i.e. moisture, temperature, and residue particle size). These findings suggestion that a fertilizer N credits may require reevaluation and take into consideration soil moisture with validated data to support the fertilizer N credit.
Influences of Climate Variability and Landscape Modifications on Water Dynamics, Community Structure, and Amphipod Populations in Large Prairie Wetlands: Implications for Waterbird Conservation
(North Dakota State University, 2014) Wiltermuth, Mark Thomas
Northern prairie pothole wetlands provide crucial habitat for numerous waterbirds. However, wetland abundance and quality in the Prairie Pothole Region of North America has declined because of agricultural landscape modifications. Effective management of waterbird populations relies on understanding how landscape modifications alter wetland hydrology and biological communities in context of climate-driven wet-dry periods. A common modification involves consolidation of smaller more-temporary wetlands into larger more-permanent ones. I evaluated whether consolidation drainage has progressive-chronic effects on hydrology of remaining wetlands during 2003-2010 in the Prairie Pothole Region of North Dakota. For wetlands in topographic basins that were not already full, rate of water surface area change was positively correlated with consolidation drainage during a wetting phase, but negatively correlated during a drying phase. This unbalancing of water budgets through wetting and drying phases suggests that 1) consolidation drainage has a progressive-chronic effect on wetland hydrology; and 2) wetlands receiving water in extensively drained landscapes will continue to increase in volume through each climate fluctuation until they reach their spilling point, then stabilize. Proportion of wetlands covered by cattail was negatively correlated with increases in water depth, thus cattail coverage may increase as water levels stabilize as a result of consolidation drainage. Fish were present in 57% of wetlands and probability of fish occurrence was greater in wetlands that had greater water depth and wetland connectivity. Weak evidence suggests amphipod densities decreased where there was extensive drainage and increased in more full basins, probably due to improved overwinter survival. The alternative stable states hypothesis predicts clear versus turbid observable states that reflect differing trophic structures in wetlands. I conducted a landscape-scale evaluation of this hypothesis by examining the distribution of remotely-sensed chlorophyll a concentrations within 978 wetlands. My findings suggest that trophic structure in prairie wetlands is better understood within a continuum of trophic status rather than discrete states. My results provide an improved understanding of how land use and climate variability influence productivity in wetlands across the region and should help shape future research and conservation priorities focused on wetland services and waterbird populations.
Impact of Carbon Nanotubes on Bacterial Viability: Indicators, Mitigation, and Role of Phage Shock Proteins
(North Dakota State University, 2014) Le, Tu Thi Anh
The toxicity of single walled carbon nanotubes (SWCNTs) to a model bacterium, Escherichia coli ATCC 8739 was investigated. Estimates of E. coli viability following treatment with SWCNTs were similar using four viability methods: plate count, galactosidase enzyme assay, LIVE/DEAD® Baclight™ assay, and RNA quantificatio. Pristine SWCNTs, carboxylic functionalized SWCNTs (SWCNT-COOHs) and hydroxyl functionalized SWCNTs (SWCNTOHs) were used to assess toxicity. Regardless of the length of SWCNTs, the toxicity was in the following order: SWCNT-OHs < SWCNTs < SWCNT-COOHs. While there was no difference in the impact of short and long SWCNT-OHs, the long pristine SWCNTs and SWCNT-COOHs were more toxic than the corresponding short SWCNTs. The viability of cells exposed to all three types of SWCNTs was greater with increasing cell density. Alterations of cell morphology ware observed after the cells were exposed to SWCNTs. Entrapment of cells in alginate and polyvinyl alcohol (PVA) as a means to limit the antibacterial effect of SWCNTs was examined. The results showed that cell entrapment could reduce the bactericidal effects of SWCNTs. Calcium alginate and PVA provided equivalent cell protection against SWCNTs. The toxicity of SWCNTs for entrapped cells depended on the length and concentrations of SWCNTs, the presence of functional groups, and the initial cell density. Transcriptomic and proteomic analyses were used to study the molecular mechanisms by which SWCNTs induce bactericidal activity. Expression levels of genes and proteins, particularly phage shock proteins (Psp) that are known to react under membrane stress such as iv pspA, pspB, and pspC, changed following cell exposure to SWCNTs. Expression of the Psp operon was affected by the length, concentration, and functionalization of SWCNTs. Overall, this study provided multiple methods that can be used to quantify the toxicity of SWCNTs for bacterial cells. A way to mitigate the bactericidal effects of SWCNTs was identified and verified. Gene and protein expression, particularly expression of the Psp operon, were reported in cells stressed by exposure to SWCNTs.
Processing Trade-offs in a Cellulosic Biorefinery
(North Dakota State University, 2017) Nahar, Nurun
Commercial scale cellulosic biorefineries face significant challenges to produce low-cost fermentable sugar from biomass. Biorefinery processing steps are interrelated and trade-offs between process parameters impact the cost and efficiency of the overall system. Although densified biomass as a biorefinery feedstock would improve biomass supply logistics, it has not been considered viable due to high energy and emissions associated with the densification process. However, the potential synergies of biomass densification with downstream processing steps are critical. An energy-efficient system with improved supply logistics, reduced severity pretreatment, and improved hydrolysis efficiency will lower the cost of sugar production from cellulosic biomass. The objective of this research was to increase overall process efficiency of biorefineries by understanding how different process parameters affect the hydrolysis efficiency. Processing trade-offs in pretreatment and enzymatic hydrolysis for densified and non-densified biomass for economical sugar production were evaluated. A life cycle perspective was taken to compare fossil energy and greenhouse gas (GHG) emissions from pelleted and non-pelleted corn stover during transportation and soaking in aqueous ammonia (SAA) pretreatment. A model developed to demonstrate the interaction of enzymatic hydrolysis factors to improve hydrolysis efficiency showed that enzyme loadings had a more significant effect on hydrolysis rates than pH or temperature. Economical optimal enzyme loadings were lower than loadings to maximize yield, loadings can be adjusted to maximize profit based on enzyme costs, ethanol price, and process temperature. Pelleted corn stover allowed reduction in SAA-pretreatment severity with different combinations of temperature, time, and ammonia concentration to produce 90% or higher glucose yields. This suggests possible economic and environmental benefits of using pelleted biomass as a biorefinery feedstock. Use of pelleted biomass reduced transportation fossil energy and GHG emissions by 25%. A significant reduction of energy (89%) for SAA-pretreatment was achieved with pelleted biomass due to lower pretreatment time and higher solid loadings. Use of pelleted biomass allowed doubling of pretreatment solid loadings, which lowered pretreatment reactors from 59 to 9, in addition to associated water and chemical savings. This study demonstrated that SAA pretreatment is not feasible for non-pelleted biomass, but process synergies make SAA pretreatment possible for pelleted biomass.
Examination of the Period of Preparation for Breeding in Male and Female Songbirds
(North Dakota State University, 2017) Needham, Katie Beth
In virtually all species, reproduction must be precisely timed to coordinate breeding and rearing of offspring with favorable conditions. It is imperative for individuals to time the highest energetic cost to themselves or highest needs by offspring with greatest food availability in either abundance or nutrient make-up. To accomplish this, individuals must integrate signals conveying both internal and external status and accordingly alter the activity of the reproductive axis. To date most efforts to identify variation in control mechanisms for reproduction in seasonally breeding animals have focused on the brain as the initiator for reproduction. However, recent studies have re-directed attention to two other potential tissues, the pituitary and ovary, where variation in brake sensitivity may be important. To this end, a series of experiments were performed in two songbird species to elucidate the hormonal role in timing of breeding and the interaction of an energetic trade-off on the decision to breed in both males and females. I used two species, the wild dark-eyed junco (Junco hyemalis) and the wild-caught captive house sparrow (Passer domesticus) as model systems to address the following questions: 1) What physiological mechanisms explain individual variation in onset of gametogenesis? And 2) How are mechanisms of energy integrated with the reproductive axis’ control of reproduction and timing of breeding to regulate energetic trade-offs? Specifically, we focused the role of testosterone in males (Chapter 2), and mechanisms downstream of the hypothalamus in females (Chapter 3). Next, in Chapter 4, the question of whether an energetic demand would reduce sperm quality was addressed. Lastly, in Chapter 5, we asked if an energetically costly immune challenge would result in the delay of clutch initiation. The results of these studies demonstrate the significant differences between sexes in the signals conveying an individual’s internal and external status in order to alter activity of the reproductive axis, and therefore timing of breeding. Collectively, these findings provide further evidence that females are ‘in the driver’s seat’ for onset of breeding and should be the focus of future research.

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