Graduate Degree in Natural Resource Sciences

Student Sampling at Cedar Point

The School of Natural Resources combines interdisciplinary approaches and disciplinary excellence to foster an integrated, systems approach to address complex natural resource, environmental, and human issues. We provide quality academic experiences for students to develop innovative approaches toward fundamental research in natural resource systems. Further, we promote a comprehensive conservation ethic for the effective and appropriate management of natural resources.

Degree Summary

Fact Sheet

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Optional Specializations

Many students focus their studies in one of our numerous specializations. These specializations are optional, well-defined areas of study that have been approved by the Graduate Council and appear on transcripts alongside degrees and majors. Each specialization has an unique set of requirements that must be met for a program to be considered completed.

Advising Faculty

Choosing an advisor whose interests match your research goals is critical for the success of your work. SNR emphasizes the cooperative exchange between students and advisors in research programs while still giving advisors the overall responsibility for the direction and course of the student's research.

Locate faculty who can advise:


Master of Science in Natural Resource Sciences

Credit Hours:

  • 30 total graduate credit hours
  • 15 in major credit hours (including thesis)
  • 20-24 total course work
  • 6-10 hours of thesis work (a maximum of 10 hours can be listed on the Memorandum of Courses)
  • 8 hours of Grad-only courses (without 400 or lower counterpart)
  • Optional minor
  • Once admitted to Candidacy by filing a Memorandum of Courses, you may not change options

Oral Presentations:

Graduate students are required to present two seminars:

  • A research prospectus seminar (presented either late in your first semester or early in your second semester of residency)
  • A final results seminar (before your final oral exam)


The School holds regular departmental and special seminars to which all graduate students are expected to attend. These seminars are presented by students and faculty in the School, by faculty in other departments, and by visiting scholars from other universities or agencies.

Scholastic Grade Requirements:

Scholastic Grade Requirements are set by UNL Graduate Studies and are described here.


Comprehensive Examination

  • Optional
  • Covers the student's approved program of study
  • Taken approximately 10 months before graduation, typically during the semester prior to graduation
  • Administered by the advisor, as directed by the student's committee

Final oral examination (Final Defense) of the Thesis

  • Conducted in the semester of graduation
  • Consists of two parts, generally held on the same day:
    • a seminar on the thesis topic (described above)
    • a formal oral examination
  • Thesis examinations are open to all Graduate Faculty; active participation in the examination process (other than at the seminar) is at the discretion of the advisor and the student's advisory committee.
Doctorate of Philosophy in Natural Resource Sciences

PhD candidates in Natural Resource Sciences must:

  • Complete 90 semester hours of graduate credit (including a dissertation); previous credit earned during the completion of a master’s degree may be counted towards this total if approved by your graduate advisor. Scholastic Grade Requirements are set by UNL Graduate Studies and are described here.
  • At least half of the graduate work (45 hours), including the dissertation, will be completed in the student's major.
  • Write a dissertation
  • Pass written and oral comprehensive exams
  • Demonstrate proficiency in one research tool
  • Present two formal seminar presentations – one generally covering the topic of your research prospectus, the other discussing your final research results.

Completing a program for the PhD degree normally requires a minimum of three full years of graduate study. The time limit for finishing the PhD degree is eight years from the time of filing your program of studies in the graduate studies office.

For more information about UNL’s PhD requirements, please see the University’s bulletin.

Minor Option in Natural Resource Sciences

A minor in Natural Resource Sciences consists of at least 9 graduate credit hours for the Master of Science program and 15 hours for the Doctorate of Philosophy program.


Graduates can find work at a wide range of positions in both the public and private sectors that are engaged in natural resource management. Alumni of the program have secured positions in a wide array of government agencies as well as non-government organizations and private businesses that range in scope and location from local to international scales.

Come join us. Follow your passion, and change the world!

How to Apply

Follow the steps at our "How to Apply" webpage.

Selected Dissertations and Theses

Measurement and Prediction of Stage and Discharge with Ground-Based Imager - Ken Chapman
  • Dissertation Defense
  • 06/08/2023
Research, management, and modeling for water quality and resources, ecological processes, agricultural and urban planning, wildlife habitat, and much more depend on accurate water level and discharge measurement. Greater and more complex water resource needs for parties with competing interests demand more detailed models and effective science communication than are possible with the traditional scalar measurements. The scientific community recognizes the need for new methods that provide context for manual and programmatic extraction of a broader range information to make measurements and predictions, drive insights and facilitate communication between stakeholders and the public. Methods have been developed to accurately measure water level in ground-based imagery, but it is critical to improve those methods and create standardized tools, workflows, and software for use by the scientific community, academia, and industry. The purpose of this research was to find ways to develop and analyze tools and methods to measure and/or predict water level and streamflow in images with less artificial conditioning of the water scene than was previously possible. Three research studies were identified to accomplish this: 1) A site study to determine whether it is possible to predict water level and streamflow accurately to fill data gaps in United States Geological Survey historical data from a time-series of images with no artificial calibration or waterline target in the scene, 2) creation of a free, open-source software suitable for use by hydrologists and ecologiststo measure water level in images with a pixel to world coordinate calibration and waterline search target installed in a stream or river, and 3) creation of a new calibration target that improved the bow-tie calibration target and measurement surface used in #2 by allowing for calibration in every image and that occluded less of the scene allowing for improved contextual analysis.
Salt Valley Greenways: Nature’s Network - Carlee Moates
  • Oral Presentation
  • 04/26/2023
Greenways are nature’s infrastructure– offering transportation of plants, animals and insects, as well as places of study, survival and solace for people. The Salt Valley Greenways weave through and around the city of Lincoln, connecting the natural and rural world into the bustle of urban life. This storytelling project explores the diversity of resources that greenspaces provide and reveals those through conversation with scientists, artists, and folks who call Lincoln home.
Applications of screening in rangeland monitoring: Quantifying early warning signals of state transitions in Nebraska - Daniel Bauloye
  • Thesis Defense
  • 04/19/2023
Rangelands are important ecologically, economically, historically, and socially. Rangelands are also threatened by regime shifts (state transitions) like woody encroachment, desertification, and exotic annual grass invasion. Management of rangelands to prevent, contain, and reverse regime shifts relies on rangeland monitoring. Innovations in rangeland monitoring—such as the generation of new landcover datasets with field data, remote sensing, and geospatial cloud computing—allow for earlier detection (screening) of regime shifts in support of proactive rangeland management. In this thesis, I screened Nebraska landscapes for woody encroachment, desertification, and exotic annual grass invasion, according to three characteristics of regime shift signals: presence, persistence, and non-stationarity. In addition to informing management, results can help advance approaches to regime shift screening in rangelands.
The North Platte River Valley: the intersectionality of surface water quality and people - Anni Poetzl
  • Thesis Defense
  • 11/21/2022
The North Platte River (NPR) Valley of western Nebraska is a semi-arid watershed with row crop production, livestock production, and urban land use activity and has a population of diverse stakeholders. These land use activities contribute to the enrichment of surface waters, such as streams, which can affect human and ecosystem health, as well as economic development and recreational activities. The project objectives are to: (1) quantify the movement of dissolved inorganic nutrients from the land within the NPR Valley to the NPR via tributaries and canals, (2) identify spatiotemporal variability of nutrient limitation of periphyton growth within the NPR, and (3) explore the factors that are associated with the adoption of a web-based water quality monitoring tool. To address the first two objectives, I collected water samples and discharge measurements from canals, tributaries (streams leading back into the NPR), and the NPR from the Wyoming–Nebraska border every three weeks from June–September 2021; and I performed repeated nutrient limitation bioassays every three weeks at nine sites. I found that land use within the NPR Valley contributes to nutrient enrichment of the NPR and the subsequent export of nutrients downstream. Based on the lack of response of periphyton to the nutrient bioassays, it is likely that the nutrients coming from the watershed meet periphyton growth demands, except during the end of the growing season when some nutrient limitation of growth was detected. To meet the third objective, I created a survey tool to understand how attitudes, norms, and beliefs affect the use of a web-based water quality monitoring tool. Performance expectancy was the only significant predictor of behavioral intention for water users to use a web-based water quality monitoring tool. From a management perspective, these studies emphasize the need for better management of nutrient exports from the NPR Valley, but the incorporation of functional goals into the deployment of potential water quality tools to ensure high behavioral intention to use the tool.
Quantifying the Relationship between Soil Organic Carbon and Soil Color in Nebraska - Aldi Airori
  • Thesis Defense
  • 11/15/2022
Soil color is easily measured in the field and holds potential to be used as an indirect measurement of soil organic carbon (SOC). Such a method would be a powerful tool, building on decades of Munsell soil color data recorded in soil surveys. The main limitation to this approach is knowledge about the specific color-SOC relationship in a region, which often vary in relation to parent material, soil texture, climate, and land use. A secondary limitation is the subjective nature of the Munsell color data. The objectives of this study are: 1) to develop and evaluate the accuracy of pedotransfer function (PTFs) for the prediction of SOC based on soil color and texture in the state of Nebraska and 2) to evaluate digital based color measurements methods as field predictors of soil organic carbon (SOC) in Nebraska. To address the first objective, data were obtained from National Soil Information System (NASIS) database, including all pedons sampled across 13 Major Land Resources Areas (MLRAs). The dataset was comprised of 1576 soil pedon description and included samples of varied soil textures, Munsell color, and SOC. The second objective was addressed using digital color measurements of 50 soil samples from Kellogg Soil Survey Laboratory archive. Methods used for digital color measurement included a portable color sensor (PCS) and smartphone camera (SPC). Regressions of moist Munsell value versus SOC using the NASIS data had R2 values ranging from 0.23 to 0.69 for individual MLRAs. In contrast regression developed using the PCS for three selected MLRAs had R2 values ranging from 0.49 to 0.81. Various PTFs based on the NASIS data resulted in RMSE of prediction ranging from 0.795 to 2.1. Digital color measurements using SPCs were found to be of low accuracy and were weakly related to SOC. The results indicate the potential of using soil color as a predictor for SOC, especially when PCS are used to measure soil color.
New Physical Foundations in Equivalent Water Thickness and Crop Water Stress Detection - Wenqi Ou
  • Dissertation Defense
  • 11/14/2022
Monitoring crop water stress is critical for developing strategies for improving crop productivity and mitigating water stress damage. The common approaches to monitoring crop water stress include field crop measurement (e.g., leaf water potential and relative water content), climate observation (e.g., soil moisture and precipitation), and remote sensing data (e.g., vegetation indices). Equivalent Water Thickness (EWT), defined as the ratio of water mass to leaf (leaf EWT) or ground area (canopy EWT), has been used as a direct field measurement of the vegetation water status indicator and has shown to be measurable by remote sensing data. Therefore, there is increasing interest in using EWT in important economic crops (e.g., corn and soybean) for water stress detection. However, the utilities of crop EWT and water stress detection lack the physical foundation on three domains: responsive characteristics to environmental changes and plant physiological processes, limitations of corn leaf EWT remote sensing estimation at multiple spatial scales, and variations of the standardized anomalies in different drought conditions and the associations between standardized anomalies of crop leaf EWT and vegetation indices. Therefore, the overreaching goal of this dissertation was to identify the potential role of canopy EWT in agriculture water management. Therefore, we conducted a long-term study of leaf and canopy EWT in the experimental sites near Mead, Nebraska. In this dissertation, we established the following research objectives: examine the relationships between canopy EWT with latent heat flux (LE), soil water content (SWC), vapor pressure deficiency (VPD), and leaf EWT with their associated leaf area index (LAI), gross primary productivity(GPP), and LE (Chapter II), identify the heterogeneity of corn leaf EWT vertical distribution and the accuracy of remote sensing estimations in field scales (Chapter III), and investigate the correspondences between canopy EWT standardized anomalies with other drought indicators and the associations between vegetation indices and leaf EWT standardized anomalies(Chapter IV). This dissertation provided new physical foundations in the EWT of corn and soybean and insight into crop water stress detection with remote sensing data.
Toward Usable Environmental Information: A Case Study with The Santee Sioux Nation - Alexis Chavez
  • Thesis Defense
  • 08/12/2022

Across the country, Indigenous Peoples have developed and implemented adaptation plans to improve their resilience to climate and weather disturbances. An essential component of these plans is to use environmental information effectively. Institutions like universities and governmental agencies usually provide this environmental information. However, many studies have shown that much of this information is not usable for its intended users. Additionally, there has been little research into the issues that can affect Indigenous Peoples’ usage of environmental information in the U.S. Therefore, this case study aimed to assist the Santee Sioux Nations’ Office of Environmental Protection (OEP) capacity in using environmental information by investigating how to improve it. Moreover, the study also explored how others can improve their collaborative practices with the OEP since the environmental information’s usability depends not only on its quality but also on the relationships that establish its accessibility, validity, and ultimately, its usability.

Through a rigorous ethical process with employees from the OEP, a case study was developed that consisted of a focus group, document analysis, and observations. The results reveal that, unlike previous research on usable science that focuses on technical issues, the main obstacles to usability result from present-day structural issues that connect to past U.S. actions. A similarity with the previous research is that the relationship between the information producers and users is a critical factor in this study for increasing the usability of environmental information.

Non-breeding Season Survival and Habitat Selection of Northern Bobwhite in Northeast Colorado - Joe Wolske
  • Thesis Defense
  • 07/22/2022
Northern bobwhites (Colinus virginianus) have experienced range wide population declines and are listed as a Tier 2 species of conservation concern in Colorado. Recent harvest data from northeastern Colorado suggests fewer bobwhites and managers aim to identify the vital rates and habitat features by which population growth rate may be limited to guide management actions. Although many studies have suggested that bobwhite populations are most sensitive to changes in reproductive factors, recent work suggests that some populations can be sensitive to adult non-breeding season survival. Additionally, northeastern Colorado has habitat and weather dynamics unique to the northern periphery of the northern bobwhite range. We monitored bobwhites in northeastern Colorado for the 2019-2020 and 2020-2021 non-breeding seasons to estimate non-breeding season survival and habitat selection. This included constructing known-fate survival models for each study season to determine any variation in survival between the winter stages of early-winter, mid-winter, and late-winter, as well as sex, age class, and mass at the time of capture. The highest performing model for each season estimated weekly survival that varied between the winter stages. We also monitored bobwhite habitat selection by performing weekly covey habitat surveys. Predictor variables include vegetation cover percentages, micro-climate variables, vegetative structure variables, and species richness estimates at used and random sites. We then used step-wise backward selection modeling to determine if any variables were being selected disproportionate to their availability. Our final habitat selection model included visual obstruction, percent bare ground and percent litter cover. The coefficients for relative probability of use were positive for each variable in the model. Our research aims to provide demographic and habitat selection data to managers to assist them in management action decision making.
Coupling Dendrochronology and Remote Sensing Techniques to Assess the Biophysical Traits of Juniperus Virginiana and Pinus Ponderosa Within Grassland Communities in the Semi-Arid Grasslands of the Nebraska Sandhills - Reece Allen
  • Thesis Defense
  • 07/21/2022
Woody species encroachment is occurring within the sandhills region in Nebraska, primarily driven by Juniperus virginiana and Pinus ponderosa, altering ecosystems and the services they provide. Effective, low cost, and cross-scale monitoring of woody species growth and performance is necessary for integrated grassland and forest management in the face of climate variability and change, and anthropogenic management. In this study, we sought to establish a relationship between remote sensing-derived vegetation indices (VIs) and dendrochronological (raw and standardized tree ring width) measurements to assess the performance of encroaching woody J. virginiana and P. ponderosa located within the Nebraska National Forest in the sandhills. We hypothesized that environmental stresses that impact foliage growth and photosynthetic capacity also impact annual tree ring growth of woody species, including invasive J. virginiana and P. ponderosa, which can be detected using remote sensing techniques, and that abiotic stresses that affect tree performance would be decoupled from that of native grasslands due to differences in physiology, response to stress, and rooting depth. We evaluated relationships between the abiotic environment (precipitation, temperature, PDSI, and soil water content 0 – 3 m depth), tree ring growth, and VIs. Our results indicated that precipitation, temperature, and PDSI were significant (p < 0.05) predictors of J. virginiana and P. ponderosa growth based on dendrochronological and VI measurements (1984 – 2013), while soil water content from 40 – 300 cm was a significant predictor of J. virginiana performance (2005 – 2013). Out of six tested VIs, four (NDVI, GCI, GRVI, and LSWI) were significant predictors of tree ring growth for both species. R2 values between grassland VIs and growing season climate were greater than those of J. virginiana or P. ponderosa, while grassland performance was decoupled from soil water content. We determined via Least Absolute Shrinkage and Selection Operator (LASSO) regressions that previous year climate was an important determinant of current year growth of both tree species but did not affect current year grassland performance. This study provides evidence for the efficacy of VIs in monitoring interannual variations in the growth of woody species, while determining abiotic factors significantly impacting the growth of grasslands, J. virginiana, and P. ponderosa in the sandhills region.
Secondary Science Teachers Use of Models in Teaching and Learning about Earth's Climate - Kimberly Carroll Steward
  • Dissertation Defense
  • 07/21/2022
Global climate change (GCC) presents a spectrum of unprecedented global issues. Increased em-phasis is being placed on empowering citizens through outreach and education in response to the urgency of the phenomenon. It is imperative to cultivate 'climate literacy,' particularly in stu-dents, to sufficiently prepare the next generation of scientists, policymakers, industry leaders, and other citizens. Opportunities for teaching and learning about Earth's climate system and GCC are decentralized across topics and grades, and Earth science is increasingly de-emphasized in the K-12 curriculum (Banilower et al., 2018). Furthermore, teachers feel under prepared in their science content knowledge for teaching about GCC, describe instruction in this area as a low priority, and report limited resources to support teaching and learning about GCC. This presentation will present findings from three related manuscripts, each investigating secondary science teachers' enactment of a curricular intervention using a cloud-based global climate model within different contexts and across time, building toward a greater understanding of teaching and learning about Earth's climate.
Integrated Study of Using Planning Tools and Remote Sensing Approaches to Monitor and Assess Wetland Conservation in Nebraska - Ligang Zhang
  • Dissertation Defense
  • 06/16/2022
Wetland is one of the most important natural resources which provide human society lots of ecosystem services. Human actions and disturbances have caused critical wetland degradation and losses on earth. The main impact factors, including pollution, biological resources use, natural system modification, agriculture, and aquaculture, are significant reasons for wetland degradation. This study focuses on the wetland conservation efforts in Nebraska. In general, this study assesses the wetland conservation in Nebraska from three aspects: 1) How wetland conservation was integrated into Nebraska’s local planning system; 2) What’s the contemporary status of public-owned saline wetlands in Nebraska; 3) What’s the inundation condition of private-owned conservation easements. The first aspect uses a planning evaluation approach to analyze the most current local comprehensive plans. Findings suggest that local governments need more direct and proactive inputs to improve wetland conservation. The second and third aspects adopt machine learning and Google Earth Engine to classify the Sentinel-2 imageries for Nebraska's public and private-owned wetlands. Different machine learning models are applied and compared in the study process. This study shows the possibility of an observation approach for long-term continuous monitoring of Nebraska’s eastern saline wetlands and conservation easements lands efficiently and cost-effectively. The research findings also provide solid scientific evidence for conservation decision-making in these saline wetland areas.
Drone and Al for precision conservation: a case study in playa wetlands of the Rainwater Basin in Nebraska - Qiao Hu
  • Dissertation Defense
  • 04/21/2022
Artificial Intelligence (AI) in computer vision is revolutionizing the geoscience and remote sensing domains. Convolutional neural network (CNN), as a typical Automated machine learning (AutoML), automatically represents image contexts (spatial-spectral correlation) from remote sensing imagery into spatially and spectrally relevant knowledge. The end-to-end design relieves researchers from tedious feature engineering and local tuning work. Considering the vital role of long-term frequent land cover monitoring in assessing the local ecosystem health cost-effective adaptations of AutoML, such as CNN, in local cases are vital to support in-time conservation and proactive ecological management. This study aims to explore the adaptation of these cutting-edge AutoML techniques in wetland monitoring and delineation, which can improve traditional wetland mapping pipelines by facilitating cost savings. Three publicly managed playa wetlands in the Rainwater Basin, Nebraska, USA, were selected as the study areas. By implementing AutoML techniques, I want to address three critical aspects in wetland ecosystem monitoring: 1) automatic waterfowl censusing using thermal sensors, 2) automatic wetland inundation delineation during the spring season using multi-spectral sensors, 3) and automatic aquatic vegetation segmentation under dynamic environments (during the fall season) using optical sensors. The remote sensing data in this study mainly relies on high spatial resolution UAV imagery. Different levels of computer vision techniques, including image processing, machine learning, and deep learning approaches, were developed and tested. The results indicate that CNN with proper designs and configurations can facilitate significant cost-savings on wetland mapping.
Effects of Instructors’ Beliefs on Incorporation of Sustainability Curriculum at a Midwestern University - Anna Oetting
  • Thesis Defense
  • 04/14/2022

The degree to which sustainability is taught is often varied and inconsistent across colleges, departments, and higher education institutions. However, educating students and future generations regarding the different pillars of sustainability, including economic, social, and environmental topics, is increasing in importance and urgency.

A mixed methods case study utilizing surveys and interviews investigates why instructors incorporate sustainability, what impacts course incorporation of sustainability, and barriers that instructors face.

The study found that instructors’ beliefs regarding the importance of sustainability transfers to the level of incorporation in their curriculum. Topics of sustainability incorporated are determined by instructors’ industry and college versus instructors' specific beliefs. Instructors are more intrinsically versus extrinsically motivated to teach the topic and face a variety of external barriers, such as lack of resources, time, and opportunities. By investigating instructors’ beliefs regarding sustainability from multiple fields, this research fills a void in the published literature and provides general recommendations for how to support faculty and university change.

Multi-Criteria Evaluation Model for Classifying Marginal Cropland In Nebraska Using Historical Crop Yield and Biophysical Characteristics - Andrew Laws
  • Thesis Defense
  • 04/13/2022

Marginal cropland is cropland that is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). A multi-criteria evaluation model was conducted using Google Earth Engine to identify and classify marginal cropland in Nebraska. Eight criteria, including crop yield, slope, climate and soils criteria, were individually thresholded then aggregated to create crop-specific marginal classifications. A new method for classifying long-term crop rotations was devised to examine differences in marginality classification between rotation classes. The results show statewide spatial trends in, as well as the net positive benefits of crop rotation on, marginality classification. The identification of marginal land will also provide evidence to facilitate discussion on biofuels production using perennial biomass crops, targeted land for conservation practices and solar energy capture, both of which have potential to be integrated into current cropping systems. Future work will involve connecting the results of this study with researchers and outreach professionals to aid in ensuring the long-term viability of agriculture in Nebraska.

Analysis of Soil Change in Four Nebraska Major Land Resource Areas - Trinity Baker
  • Dissertation Defense
  • 04/05/2022

The world’s population is growing and an increasing populace requires more resources. These requirements place increasing pressure on the environment and the soil. Soils serve many important functions throughout the world. These functions range from offering a media for food production, providing a sink for organic carbon, nutrient cycling, and improving water quality. It is important to focus on the human impact on soils and their change over time.

For my research I examined how soils across Nebraska have changed over a time period of roughly 65 years. I sampled and analyzed 39 pedonsfrom four Major Land Resource Areas (MLRAs) across the state of Nebraska. These sites were selected because they each represent a distinctive combination of climate, geology, and land use within Nebraska. At the time of original sampling (1951-1961), nearly all the sites were under row-crop production. I created a correlation for estimating soil organic carbon for four MLRAs using loss-on-ignition organic matter values. Next, I examined how the soils in MLRAs 67 and 71 have changed over 65 years of continued irrigation and agricultural production. Lastly, I assessed how the soils MLRAs 102 and 106have changed after 65 years of non-irrigated agricultural production.

Comparison of Vadose Zone Nitrate-N to 50-Year Record of Nitrogen Fertilizer Inputs on Nebraska Cropland - Kobi Benao
  • Thesis Defense
  • 11/29/2021
Nitrogen (N) fertilizer is an essential nutrient for agricultural production worldwide, especially in Nebraska where corn requires a large amount. Historical N fertilizer input and poor environmental management practices resulted in unintended consequences in the ecosystem and environment. Lack of spatially complete N fertilizer application time series data in the US, in particular, the state of Nebraska makes N fertilizer quantification in the vadose zone challenging. The state of Nebraska needs spatial time series fertilizer maps to better address its N fertilizer input and potential nitrate-N (NO3--N) migration and storage in the vadose zone (VZ). This thesis assesses 50 years of Nebraska's spatial N fertilizer inputs on cropland, cropping patterns, timings of application, and soil type impact to NO3--N leaching and compares it with the estimated VZ NO3--N mass stored in the Bazile area and the Lower Platte South Natural Resources Districts (LPSNRD).
Extraction and Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Wastewater Matrices to Determine Environmental Loading in the Midwest - Justin Caniglia
  • Thesis Defense
  • 11/22/2021
Per- and polyfluoroalkyl substances (PFAS) are a recalcitrant suite of chemicals that are environmentally persistent and have been detected worldwide in numerous human and environmental matrices. Human exposure to PFAS has been associated with a myriad of human health impacts due to their carcinogenic nature. A better understanding of various transportation routes that instigate human and environmental exposure in the Midwest will assist communities in making management decisions regarding PFAS usage and treatment. However, current PFAS research is limited due to existing analytical constraints and limitations. This thesis focuses on assessing current extraction methodologies for PFAS for four environmental matrices (POCIS, non-potable water, solids, plant tissue) and a study looking at the transportation of PFAS within a wastewater treatment plant, adjacent surface waters, and agricultural ecosystem land applied with municipal biosolids for a better assessment of PFAS within the Midwest.
Understanding and Contextualizing Foraging among Recreational Opportunities in the North Central United States - Iris McFarlin
  • Thesis Defense
  • 07/14/2021

Over the past few decades, there has been a resurgence in the popularity of foraging for wild products and foods. Despite the cultural importance and ubiquity of foraging, there have been relatively few scientific investigations of social factors influencing foraging behavior, landscape preferences, and the types of materials foraged in the United States. As such, there is a fundamental need to better understand more about those who participate and their foraging behaviors. Two surveys were conducted to gather information on foragers’ motivations and characteristics and to contextualize foraging within the larger recreation landscape. The first survey used snowball sampling to reach foragers throughout the United States and collected information on motivations, types of land foraged, and the type of taxa foraged. Results indicated that respondents were motivated to relax and escape, to feel self-empowered and know about food sourcing, and for the social benefits of participation. We grouped respondents into four clusters based on motivations: 1) self-empowered foragers, 2) multimotivation foragers, 3) casual foragers, and 4) social foragers. While there were differences in in the reasons why individuals forage, there was little difference among the socio-demographic variables as well as where and what they forage.

A second survey was used to estimate the recreational demand among 16 recreational activities among the general population of Nebraska. The results indicated that approximately 13% of the Nebraska population engaged in at least one day of foraging. While activities such as recreational sports, spectator sports, culture and arts were more preferred than foraging, other outdoor activities such as hunting & shooting sports, fishing, and wildlife viewing were less preferred than foraging. Older Nebraskans gained more utility from foraging than their younger counterparts, but there was little difference in utility gained among other sociodemographic factors. Further, there was indication that foraging by Nebraskans was already at satiation, whereas other activities like the arts and culture were still not at satiation. By understanding the behaviors and motivations of foragers and how foraging fits into the recreation landscape, we gained further insight into the importance of foraging and the behaviors of those participating, which has important implications in the formulation of appropriate policies and management of recreational opportunities.

Soils Morphology and Carbon Stocks of Playa Wetlands in Eastern Nebraska, USA - Aubrey Kemper
  • Thesis Defense
  • 07/12/2021

Wetlands contribute important ecosystem services such as water filtration and storage, wildlife habitat, and carbon sequestration. The objective of this study was to compare both the morphology and the carbon and nitrogen stocks between the upland, basin edge, and basin floor in playa wetlands of eastern Nebraska. This work was conducted in three playa wetlands in the Todd Valley. Morphological descriptions were evaluated to two meters’ depth using cores collected along three transects from the upland to the playa floor in three playas, carbon and nitrogen stocks were evaluated in two of those playas. Results show evidence of erosion, deposition, and both leaching and accumulation of clay in all three playas, and presence of calcium carbonate in one playa. In one playa, both carbon and nitrogen stocks were lower at the basin edge compared to the surrounding uplands and in the other, there was no significant difference in carbon and nitrogen stocks between the upland, basin edge, and playa floor. Morphological features of the soils show colluvium deposition and clay accumulation in two basins and calcium carbonate accumulation in one basin. Profile distributions of carbon suggest that the limited carbon storage in these playa wetlands is, at least in part, due to leaching losses of dissolved organic carbon. The playas of eastern Nebraska show evidence of colluvium deposition caused by human-accelerated erosion and, compared to other depressional wetlands in the region, a limited capacity to accumulate organic matter and store carbon.

Describing How Students Make Decisions About Complex Issues - Citlally Jimenez
  • Dissertation Defense
  • 04/13/2021

Through a mixed methods approach, my work explored students’ decision-making practices as they worked through a structured decision-making tool to reason about socioscientific issues (e.g., how do we manage water?). The resulting tools can help researchers explore how students:

  • Provide reasoning using interdisciplinary evidence
  • Engage with tradeoffs in their decision-making process

Questions ?

Emma Hazel

Emma Hazel

SNR Graduate Admissions Coordinator (Interim)

School of Natural Resources
911 South Hardin Hall
3310 Holdredge Street

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