Environmental & Conservation Sciences

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Research from the Department of Environmental & Conservation Sciences. The department website may be found at https://www.ndsu.edu/ecs

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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.
Alluvial Fans in the McMurdo Dry Valleys: A Proxy for Melting Along Terrestrial Margins of the East Antarctic Ice Sheet
(North Dakota State University, 2013) Zamora, Felix
Surface melting along Antarctic ice sheet margins is the most poorly understood input in models of future sea level rise. Alluvial fans in the McMurdo Dry Valleys originate from meltwater produced from high-elevation glaciers and snowbanks along these margins but many show no evidence for recent melting. These fans could serve as a record of past melting along terrestrial ice sheet margins, which would help quantify inputs to sea-level rise.To describe how melting has taken place in the past, five representative fans were examined. Fans are composed of thin, planar-bedded gravelly sands deposited by sheetflooding. Geospatial analsysis suggests the distance of the meltwater source from the Ross Sea is the predominant control on fan activity, and that aggradation results when regional climatic gradients shift inland. Geomorphic observations suggest centuries to millennia pass between periods of aggradation. OSL dating indicates that fans are no older than Holocene in age.
Ammonia Oxidizing Archaea in Engineered Water and Wastewater Systems: Presence, Activity and Relationship to Heavy Metal Inhibition, and Disinfectants
(North Dakota State University, 2017) Roy, Dhritikshama
Ammonia oxidizing archaea (AOA) have been found as a key player in ammonia oxidation. Over the past decade, AOA have been shown in some cases to outnumber ammonia oxidizing bacteria (AOB) in marine, terrestrial and aquatic environments, and to participate in nitrification. In this dissertation research, AOA along with AOB were examined for their presence and activities in wastewater treatment plants (WWTPs), and water treatment plants (WTPs) employing different disinfectants and their distribution systems (DSs). Firstly, this research investigated the abundance and seasonal variation of AOA and AOB by quantitative polymerase chain reaction targeting the ammonia monooxygenase subunit A gene (amoA) in the biofilm from trickling filters (TFs) and a moving bed bioreactor (MBBR) employed separately at two WWTPs. AOA and AOB dominated nitrifying cultures from the same WWTPs were selected using specific inhibitors, and investigated for nitrification activity. Secondly, this research examined copper inhibition of nitrification by attached and suspended growth ammonia-oxidizing cultures containing different fractions of AOA. The third and final research part investigated AOA and AOB abundance and nitrification activity in different treatment steps of WTPs practicing chloramination and chlorination and distal and proximal zones of their DSs. A laboratory experiment simulating DS conditions with chorine and chloramine was conducted to understand the effects of disinfectant concentration and type, and water temperature on AOA and AOB populations and activity. AOA were dominant in the nitrifying TF (NTF) and MBBR, while AOB dominated in the biochemical oxygen demand TF. AOA and AOB were more abundant during warm months. In-situ nitrification activity showed the oxidation of ammonia to nitrite decreased when AOA populations from the NTF and MBBR were inhibited, demonstrating that AOA contributes to nitrification. Nitrification by the cultures heavily dominated by AOA were less inhibited by copper than the cultures with less AOA dominance. In WTP systems studied, more AOA were observed in chloraminated DS compared to chlorinated DSs. More AOA and AOB were detected in the distal zones than the proximal zones of DSs suggesting that AOA and AOB grew in the distribution systems. AOA had longer inactivation time under cold water temperature compared to AOB.
Anthropogenic stressors on freshwater wetlands: a microbial perspective
(North Dakota State University, 2024) Cornish, Christine
Benthic microbial communities play fundamental roles in wetland ecosystems including nutrient and energy cycling, and the degradation and assimilation of pollutants. Because of these crucial roles, along with their short-life cycles and high diversity, microorganisms can also play an important role as indicators of environmental change, which is particularly relevant in the current climate of increasing anthropogenic stressors, including factors such as emerging pollutants and climate change. Consequently, understanding the responses of microbes to environmental change is critical. To assess the effects of anthropogenic stressors on microbial communities in wetland ecosystems, I examined the response of sediment microorganisms from North Dakota wetlands in both microcosm and field-scale studies. First, I used 16S rRNA gene sequencing to analyze wetland microbial community responses to glyphosate treatments using an experimental microcosm approach. I found no significant differences in microbial communities among concentrations or treatments compared to controls, suggesting microorganisms in this region may have evolved glyphosate tolerance. Second, also taking an experimental approach, I measured methane, carbon dioxide, and nitrous oxide flux and porewater concentrations in microcosms to analyze net microbial production and consumption of greenhouse gases following glyphosate and/or 2,4-D treatment. I found high glyphosate concentrations significantly increased carbon dioxide emissions potentially due to increased microbial activity from the use of glyphosate as a substrate, or due to increased respiration as a stress response. Lastly, I used 16S rRNA gene sequencing to compare microbial communities in natural and restored wetlands across the North Dakota Prairie Pothole Region to assess the effects of a physical stressor, hydrologic restoration. I found no significant differences in microbial communities across wetlands, which may be due to the lack of direct sediment disturbance from restoration, or due to the ability of microorganisms to rapidly recover, thus showing no assemblage differences 25 years after restoration. Overall, I demonstrated that integrating microbial ecology with ecotoxicology and restoration ecology can be a beneficial and applicable research approach to understanding the impact of anthropogenic-induced environmental change on wetlands and show that the use of microbial metrics and mechanisms can provide valuable insight on pertinent issues of global concern.
Antipredator Behavior and Morphology in Isolated Cyprinodont Fishes
(North Dakota State University, 2018) Snider, Madison R.
For desert fishes in the American Southwest, predation by invasive species has triggered massive population declines for decades, leaving researchers speculating on the underlying cause. It has been shown that Post-Pleistocene isolation of desert fishes in small habitats with limited predation pressure has led to loss of antipredator traits. Determining the status of antipredator behavioral and morphological traits could identify the most vulnerable desert fishes. In aquatic ecosystems, detection and response to chemical alarm cues derived from epithelial tissue increases the probability of predation survival. In chapter two, I evaluate alarm cue responses of two desert cyprinodontids: endangered Pahrump poolfish and Amargosa pupfish. In chapter three, I assess the prevalence and densities of epithelial club cells, the source of chemical alarm cues, for several desert fishes: Pahrump poolfish, Amargosa pupfish, White Sands pupfish, White River Springfish, and Hot Creek Valley tui chub.
The Applicability of Physiology for Conservation and Management Purposes: A Case-Study Using the Breeding Season of the Red-winged Blackbird (Agelaius Phoeniceus)
(North Dakota State University, 2017) Mahoney, Jessica
Physiology has the potential to play a unique and important role in conservation and management practices by helping identify the mechanistic responses of populations to environmental changes, and providing physiological tools and knowledge that can be applied to help solve conservation and environmental problems. It has previously been unclear, however, if the increase of physiology in conservation and management literature has translated into the application of physiological tools and knowledge into conservation and management plans. There were two purposes of this disquisition: 1) analyze how physiological tools have been integrated into applied conservation by reviewing USFWS endangered species recovery plans, and provide suggestions to help conservation scientists and physiologists work synergistically to solve conservation and management problems, and; 2) provide an example of how studying the physiology of a species can provide useful information for making management decisions, using the study of stress physiology in the red-winged blackbird (Agelaius phoeniceus) during their breeding season as our case study. Our results suggest that physiology is being underutilized in USFWS endangered species recovery plans. We hypothesize this absence of physiological tools and knowledge in conservation planning is primarily due to a deficit of physiological knowledge passing between physiologists and the cohort of federal agency recovery plan writers. We suggest the need for increased training of federal agency employees, the inclusion of authors with academic affiliations, increased integration of physiology and conservation research, and enhanced communication between all concerned parties. To illustrate how physiology can be useful, we exposed female red-winged blackbirds to predator and nest parasitism effigies, thus causing additional stress, during the breeding season. We were able to examine how females respond behaviorally and physiologically to stress, and how these responses alter their reproductive decisions. We found that females are responding both behaviorally and physiologically to the increased threat of predation and nest parasitism. There is potential to exploit these responses to manage the species, such as causing females to forgo breeding. We also determined that an individual’s stress physiology can be changed when held in captivity. We suggest using caution when trying to extrapolate captive data to wild populations.
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.
Attenuation of Nitrate from Simulated Agricultural Wastewater Using an Immobilized Anaerobic Biofilm
(North Dakota State University, 2012) Anar, Mohammad Jahidul
A number of methods are currently in use for attenuating nitrates from wastewater with varying degrees of efficiency. Bioremediation using bacteria may be an efficient and cost effective method. In an anaerobic bioremediation system, nitrate can replace carbon dioxide as an electron acceptor and aids in nitrate attenuation by assimilatory reduction. The purpose of this study was to investigate nitrate attenuation in a hyperfiltration system using a pure culture of strictly anaerobic, facultative Methanobrevibacter ruminantium bacteria. Filtration experiments were conducted using amalgamated Na- montmorillonite clay-glass beads compacted at 500 psi differential hydraulic pressure with or without a biofilm. A simulated agricultural wastewater of 3.105×10-4 moles/L of NO3- was bioremediated. The use of bacteria in attenuating nitrates offers promising results on a bench-scale.
Bat Population Monitoring in National Parks of The Great Lakes Region and Evaluation of Bat Acoustic Analysis Software
(North Dakota State University, 2019) Goodwin, Katy Rebecca
North American bats face multiple threats, prompting an increase in bat research and conservation efforts in recent decades. Researchers often use acoustic monitoring, which entails recording bats’ echolocation calls and subsequently identifying them to species, typically using automated software. Chapter 1 describes an acoustic monitoring program at eight U.S. national parks that aims to assess changes in bat populations over time. Data collected in 2016-2017 showed that activity levels of the little brown bat (Myotis lucifigus) decreased significantly while other species remained stable. Little brown bats have undergone similar population declines elsewhere due to the disease white-nose syndrome. Chapter 2 investigates whether different versions of bat call identification software are comparable to each other and how accurate they are. For the two software programs tested, agreement among versions was variable and species-dependent. Furthermore, newer versions were more conservative in assigning identifications, though not, on average, more accurate.
Biogeochemistry of Wet Ecosystems from Root Zone to Landscape
(North Dakota State University, 2012) Kissoon, La Toya Tricia
The biogeochemistry of wetland ecosystems varies, causing them to act as sources, sinks, filters or transformers of nutrients and pollutants. Wetland plants play important roles in the cycling of elements in wet ecosystems. The structural and physiological adaptations that allow these plants to colonize wetland habitats as emergent or submerged species contribute to biogeochemical processes in wetland substrates. Rhizosphere (root zone) oxidation, iron and manganese oxide precipitation, acidification of the rhizosphere, root exudation, and microbial activity influence the mobility of elements in wetland substrates. Both emergent and submerged wetland plants can alter conditions in the rhizosphere that influence the mobility of elements. These plants are also capable of removing elements such as Cd, Cu, Fe, Mn, N, P and Zn from solution and accumulating them in their tissues. Root zone studies were carried out in the greenhouse using the wetland plants Typha angustifolia (cattail) and Rumex crispus (curly dock) and in the field using Triglochin maritima (seaside arrowgrass) to determine differences in element concentrations in the root and bulk zone under different soil moisture conditions. Studies involving shallow lakes of Minnesota were carried out to determine relationships among (1) landscape variables (e.g. lake watershed size, percent agriculture, percent woodland), water and sediment characteristics (turbidity, chlorophyll-a, organic content, particle size), (3) element concentrations in waters and sediments, and (3) plant abundance and community composition. The studies reported here showed that different factors influenced the distribution of multiple elements in the root zone of emergent wetland plants and in waters and sediments of shallow lakes. First, the root zone studies indicated that pH, redox and moisture content of wetland soils influenced the distribution of elements in the rhizosphere and subsequent uptake of these elements by wetland plants. Second, the shallow lake study showed that land cover uses (agriculture and woodland), lake watershed size, and sediment physical characteristics (organic content and particle size) influenced the distribution of elements in waters and sediments of shallow lakes. Concentrations of these elements, land cover uses, open water area, turbidity, chlorophyll-a concentrations and sediment physical characteristics influenced abundance and distribution of submerged and floating plants.
Body Shape Divergence Among Wild and Experimental Populations of White Sands Pupfish (Cyprinodon Tularosa)
(North Dakota State University, 2011) Kowalski, Brandon Michael
Reports of contemporary evolution have become ubiquitous, but replicated studies of phenotypic divergence for wild populations are exceptionally rare. In 2001, a series of experimental populations were established to replicate a historic translocation event that led to a case of contemporary body shape evolution in the White Sands pupfish. Using landmark-based geometric morphometric techniques I examined phenotypic variation for seven of these populations, and two wild populations over a 5 year period (5-10 generations) in the field. Significant body shape divergence was observed, but divergence patterns were not parallel, suggesting that the ponds were ecologically dissimilar. Considerable body shape variation found among populations suggests that the observed divergence maybe governed by temporal environmental variance. In this study, body shape variation was correlated with population density. These data suggest that habitat intrinsic factors or unmeasured habitat features may have strong affects on body shape, warranting continuous monitoring of recently translocated fishes.
Cell Entrapment for Mitigating Fouling in Membrane Bioreactors Treating Domestic Wastewater
(North Dakota State University, 2018) Juntawang, Chaipon
Membrane bioreactors (MBRs) have been a process of choice for wastewater treatment and reuse because of several advantages over conventional process (activated sludge) including superior quality effluent, less biomass yields and more compact design. However, membrane fouling is a major drawback that hampers widespread and full-scale applications of MBRs. Cell entrapment is a relatively new wastewater treatment process. It involves cells artificially entrapped in a porous polymer matrix. In this dissertation research, three versions of entrapped cells-based MBR processes, aerobic MBR, anaerobic MBR and anaerobic forward osmosis (FO) MBR, were developed by using polyvinyl alcohol as a cell entrapment matrix. Their domestic wastewater treatment performances and fouling characteristics were tested and compared with their suspended cells-based MBR counterparts. For aerobic and anaerobic MBRs, entrapped cells-based processes provided similar organic removal but experienced delayed fouling compared to suspended cells-based processes. The entrapment diminished bound extracellular polymeric substances (bEPS) and soluble microbial products (SMP), which are a main culprit of irreversible fouling through pore blocking. Entrapped cells-based aerobic and anaerobic processes had 5 and 8 times lower pore blocking resistance than corresponding suspended cells-based processes. For anaerobic FOMBR, the entrapment protected cells from reverse salt flux leading to slightly higher organic removal. Lower bEPS and SMP in entrapped cells-based FOMBR led to higher permeate flux compared to suspended cells-based FOMBR. The delayed membrane fouling in entrapped cells-based MBRs means lower costs associated with membrane cleaning processes and longer membrane lifespan. Another contribution of this study is novel knowledge on fouling conditions and mitigation for FOMBR, an emerging wastewater treatment process.
Characterization of Road Dust in Western North Dakota
(North Dakota State University, 2015) Ljepoja, Danijela
Samples were collected during summer 2014, at three locations: along 15th St. SW near agricultural test plots, along an access road leading to a newly built oil drilling pad, and adjacent to the pad. MiniVol™ TAS Samplers (Air metrics, Springfield, OR) were used for sampling. Total Suspended Particles (TSP), and particulates less than 10 or 5 microns (PM10 and PM2.5, respectively) were collected using quartz fiber filters. Samples were collected both pre and post access road and pad construction. The mass concentration of TSP at 15th St. ranged from 365 - 911 µg/m3 (mean 507 µg/m3). Concentrations at the access road ranged from 8 – 68 µg/m3 and near the pad from 9 – 42 µg/m3. SEM/EDS analyses show most particulates are silicate or carbonate mineral fragments or biogenetic particles. The most common particle size is between 2.5µm and 10µm. The main sources of airborne particulate matter observed were from road dust re-suspension, and biological sources.
Chemical Repellents for Reducing Blackbird Damage on Mature Sunflowers: The Importance of Plant Structure and Avian Behavior in Field Applications
(North Dakota State University, 2019) Kaiser, Brandon Amberg
Across North America, blackbirds (Icteridae) depredate high-energy crops, such as sunflower (Helianthus annuus), placing an economic burden on producers. Chemically-defended crops, in the form of human-applied repellents, may induce birds to forage elsewhere if a learned aversion can be established. However, repellent deployment must be feasible for producers at the scale of commercial agriculture. Thus, my main objective was to evaluate the efficacy of anthraquinone-based repellents applied to ripening sunflower for reducing blackbird damage. I conducted concentration response (no-choice) and preference tests (two-choice) to evaluate repellent efficacy on captive blackbirds using application strategies practical for agricultural producers. I evaluated field application strategies to assess the potential for broad-scale application using new drop-nozzle technology. Additionally, I describe behavior of captive blackbirds as they interact with ripening sunflower to further inform repellent application. Our results support the conclusion that application of anthraquinone-based repellents is not currently a feasible option for ripening sunflower.
Chironomids Then and Now: Climate Change Effects on a Tundra Food Web in the Alaskan Arctic
(North Dakota State University, 2019) Lackmann, Alec Ray
Although climate change is a global phenomenon, the Arctic is warming faster than any other region on earth. These climatic changes have driven rapid regional changes over the past half-century in both the physical landscape and the ecosystems therein. One such ecological interaction is between migratory shorebird survival and local insect emergence. Annually, tens of millions of migratory shorebirds travel to the Arctic to rear their young in the relative absence of predators, but in a relative abundance of food (insects). Over evolutionary time, these trophic levels have coupled: shorebird chicks tend to hatch during the period of highest terrestrial insect availability. However, climate change is currently uncoupling this food-web synchrony, creating potential for trophic mismatch. In the High Arctic near Utqiaġvik (formerly Barrow), Alaska, trophic mismatch between nesting shorebirds and their insect food base is already detectable. In this ecosystem, flies in the Family Chironomidae (non-biting midges) dominate the prey trophic level in the avian food web. We have found that the pre-emergence development of one particular midge, Trichotanypus alaskensis, defies conventional wisdom of the Family, as this species molts to an additional fifth larval instar prior to pupation and emergence (all other chironomids are known to have four larval instars). We discovered an Utqiaġvik midge that reproduces asexually, a species that was not documented in the 1970s. Utilizing controlled temperature rearings of Utqiaġvik midge larvae, we discovered that as temperatures rise, emerging chironomid adults are generally smaller in size. We have found that chironomid pre-emergence developmental rates follow a positive exponential relationship as temperatures increase, can vary by taxon, yet are consistent across field and lab settings for a given taxon. At Utqiaġvik in the 2010s, chironomid emergence occurs 8-12 days earlier than it did in the 1970s. These findings shape our understanding of trophic mismatch in this arctic food web.
Cosmogenic 10Be Surface Exposure Dating and Numerical Modeling of Late Pleistocene Glaciers and Lakes in Northwestern Nevada
(North Dakota State University, 2019) Fleming, Kaitlyn Chelsea
This thesis focuses on the glacial record in the Pine Forest and Santa Rosa Ranges located in the northwestern Great Basin. Seventeen cosmogenic exposure ages in the two ranges are consistent with observations elsewhere in the Great Basin where glacier maxima and lake highstands in the northwestern Great Basin occurred at ~18-17 ka. Developing chronologies of moraines in the Santa Rosa and Pine Forest Ranges has helped to precisely limit the relative timing of glacier and lake maxima. Model results are consistent with previous studies of the LGM (21-20 ka) interval and early Heinrich Stadial 1 (18-17 ka) intervals, such that the northern Great Basin was colder with near-modern precipitation during the LGM and likely greater than modern precipitation during the subsequent interval 18-17 ka. Overall, the chronology of glacial deposits in the northwestern Great Basin and inferred climate during the last glaciation show consistency across the northern Great Basin.
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.
Determining Greenhouse Gas Emissions and Nitrogen Dynamics of Solid Beef Manure Applied to Fargo-Clay Soil of the Red River Valley
(North Dakota State University, 2018) Niraula, Suresh
Land application of solid beef manure may prompt greenhouse gases (GHGs) - nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions. Nitrogen (N) in manure can also be lost through ammonia volatilization (NH3), leaching (NO3-), denitrification, and erosion. The objectives of this research were to assess the effects of (i) land application of solid beef manure (SM) on emission of GHGs, NH3 volatilization, and corn (Zea mays L.) yield, (ii) soil moisture [(30, 60, and 90% water-holding capacity (WHC)] on GHGs and NH3 emissions from urea and manure application, and (iii) soil temperature (5, 10, 15, and 25°C) on GHGs and NH3 emissions from urea and manure amended Fargo-Ryan silty clay soil of the RRV. The two-year growing season cumulative N2O emission (cN2O) ranged from 0.3 (non-fertilized, NF) to 1.2 (urea only, UO) kg N ha-1. The UO reduced cumulative carbon dioxide (cCO2) by 42% compared to manure N sources. The cumulative CH4 (cCH4) emission ranged from -0.03 to 0.23 kg CH4-C ha-1 CH4-C ha-1, with the highest emission from manure with straw bedding (BM). Manure reduced cNH3 by ~11% compared to UO. Cumulative soil N in 2017 were significantly greater by 11%, respectively, compared to 2016. Nitrogen source did not show any difference in grain yield and grain N uptake in field study. In the laboratory, across WHC levels, 1.01% of the total applied N was lost as N2O at 60% WHC from urea treated soil. Soil CO2 from manure was up to two times the emission from CF treated soils. The cumulative NH3 volatilization loss from soil ranged from 29.4 to 1250.5 µg NH3-N kg−1 soil, with the highest loss from CF amended soils at 30% WHC. In addition, laboratory study showed cumulative GHGs and NH3 emission generally increased with increase in temperature, with the highest emission observed at 25 °C. The results highlight the challenge of meeting crop nutrients demand while reducing GHG emissions by selection of an N source.
Development and Genetic Regulation of the Novel Abdominal Appendages in the Male Sepsid Fly, Themira Biloba
(North Dakota State University, 2013) Herath, Bodini Jeevanthika
Evolutionary novel structures are structures with no known homology. Novel structures often provide a novel function to the organism. Some species of sepsid flies (family Sepsidae) have evolved novel abdominal appendages on the fourth segment in males and are thought to be used during mating to stimulate the female abdomen. However, the necessity of these appendages for the sepsid flies has not been determined, and a little is known about the genetic basis of these structures. Controlled laboratory experiments were conducted to identify the necessity of these appendages in sepsid Themira biloba. Surgical manipulation of the bristle length of the appendages prevented successful mating, and this was observed when the longest bristles were manipulated; reducing the length of short bristles had no effect. These results indicate that bristle length is important for mating success and that the longer bristles are critical. The genetic regulation of the initial specification of the abdominal appendages in sepsids was also investigated. In situ hybridization was done to examine the expression of abdominal-A and Abdominal-B genes in sepsid T. biloba, to determine whether their expression has deviated in forming the appendages. However, the expression domains of these genes are conserved in T. biloba, and are not different from those observed in D. melanogaster. Overall my research emphasizes the necessity of the abdominal appendages, and provides insight into the genetic basis of these novel structures.
Development and Scale Up of Aqueous Surfactant-Assisted Extraction of Canola Oil for Use as Biodiesel Feedstock
(North Dakota State University, 2012) Tuntiwiwattanapun, Nattapong
In oilseed extraction, alternative extraction media have been studied to replace the traditional solvent, hexane, due to health, safety, and environmental concerns. In this work, aqueous surfactant-assisted extraction was developed and scaled up for hexane-free canola oil extraction. An inexpensive commercial surfactant system was formulated and used as an extraction medium based on the dynamic interfacial tension value. The extraction conditions were evaluated to achieve the maximum oil recovery. The highest oil detachment efficiency was 80% in the absence of hexane at room temperature. The extracted oil had acceptable content of free fatty acids, water and phospholipids for use as a biodiesel feedstock. The biodiesel product passed the ASTM D6751 biodiesel standard for water content, kinematic viscosity, acid value and oxidative stability.

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