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Earth Sciences

2023

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Full-Text Articles in Natural Resources Management and Policy

Population Demography Of A Glacial-Relict Stream Fish Mediated Via Anthropogenic Alteration, Joseph M. Spooner Dec 2023

Population Demography Of A Glacial-Relict Stream Fish Mediated Via Anthropogenic Alteration, Joseph M. Spooner

School of Natural Resources: Dissertations, Theses, and Student Research

Northern Pearl Dace Margariscus nachtriebi are a small-bodied glacial-relict fish species of greatest conservation need (SGCN) found throughout Canada and the northern United Sates. Their distribution within the Nebraska Sandhills Ecoregion is isolated from the northern core distribution of the species following the last glaciation period approximately 18,000 years ago. Headwater streams within the Nebraska Sandhills Ecoregion are predominately groundwater fed and provide the cool water temperatures needed to support Northern Pearl Dace and other glacial-relict SGCN. Headwater streams within the Nebraska Sandhills Ecoregion have been geomorphically altered through anthropogenic processes such as channelization whereby habitat homogenization has occurred. Evidence …


Habitat Heterogeneity In Nebraska Streams And Distribution Prediction For Tier-1 Cyprinids Using Multi-Scale Modeling Of Fluvial And Landscape Features, Connor P. Hart Dec 2023

Habitat Heterogeneity In Nebraska Streams And Distribution Prediction For Tier-1 Cyprinids Using Multi-Scale Modeling Of Fluvial And Landscape Features, Connor P. Hart

School of Natural Resources: Dissertations, Theses, and Student Research

Multiscale environmental processes determine in-stream habitat conditions which drive species distributions. Habitat constitutes the physical template upon which ecological processes occur and species conduct life stage activities. Habitat heterogeneity promotes biodiversity of aquatic systems. Stream classification informs freshwater conservation by providing a useful framework to account for habitat heterogeneity, often based on landscape regions of similar environmental processes. A greater understanding of landscape-based classification frameworks as means to classify stream systems may improve understanding of drivers of biodiversity. Using Nebraska as a case study, on a statewide scale, objectives were 1) to characterize habitat availability for several at-risk fish species, …


Ecological Impacts Of Restoring Fire-Grazing Interaction In Sandhills Prairie Through Patch-Burn Grazing, Nolan P. Sipe Dec 2023

Ecological Impacts Of Restoring Fire-Grazing Interaction In Sandhills Prairie Through Patch-Burn Grazing, Nolan P. Sipe

School of Natural Resources: Dissertations, Theses, and Student Research

A Collaborative Adaptive Management (CAM) Project was started at the University of Nebraska in 2020 to address some of the key uncertainties related to the management of grasslands in the Nebraska Sandhills through stakeholder driven experiments and the adaptive management cycle. Patch-burn grazing was selected by CAM as a management tool to generate heterogeneity across the landscape and promote biodiversity while balancing economic and ecological trade-offs. The patch-burn grazing system was implemented with controlled burns in May of 2022 and March of 2023. Other parties in CAM will be examining the impact that patch-burn grazing has on forage and livestock …


Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo Dec 2023

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

<strong> Theses and Dissertations </strong>

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …


Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger Dec 2023

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …


Connecting The Nebraska Water Quality Index To The Aquatic Microbial Community Of The North Platte River Basin, Nebraska, Paula R. Guastello Nov 2023

Connecting The Nebraska Water Quality Index To The Aquatic Microbial Community Of The North Platte River Basin, Nebraska, Paula R. Guastello

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Water Quality Index, under development by the Nebraska Department of Environment and Energy, summarizes in a single value eight environmental parameters that have been monitored in Nebraska for nearly 20 years. Water quality parameters including those used in the Nebraska Water Quality Index have been shown in previous studies to impact bacterial growth. As such, this index has the potential to correlate with the freshwater microbial community. Here, I relate the Nebraska Water Quality Index to microbial community composition and structure using 16S rRNA gene amplicon sequence data collected from the North Platte River Basin, Nebraska. This index …


Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy Oct 2023

Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are indispensable tools that facilitate studies to assess climate impacts and adaptation responses, but have not been adequately tested in terms of accurately predicting crop growth and water stress responses to high carbon dioxide concentrations [CO2]. The soybean model, GLYCIM, previously modified with a coupled leaf-level gas exchange – energy balance model, was integrated with a two-dimensional convectivediffusive root growth module which linked soil and leaf water potentials with the regulation of stomatal conductance. We evaluated the accuracy of this modified GLYCIM using experimental data from a Free-Air CO2 Enrichment (FACE) site, SoyFACE, and …


Prioritization Of Scientific Sources Of Water Information: The Effect Knowledge, Beliefs, And Political Identity, Sadie Hundemer Sep 2023

Prioritization Of Scientific Sources Of Water Information: The Effect Knowledge, Beliefs, And Political Identity, Sadie Hundemer

Journal of Applied Communications

Scientists are reported to be more trusted than other information sources; yet, on essential water facts, people sometimes reject what they perceive water scientists to believe in favor of other belief determinants. This study examines the factors that affect the difference in people's stated willingness to reconsider their water beliefs in response to information provided by scientists relative to information provided by other sources. Regression analysis of responses provided by 806 Florida and Georgia residents found water science knowledge to be a consistently strong influencer of the gap in reliance on scientific information providers relative to other sources. This result …


Dual Activation Of Peroxymonosulfate Using Mnfe2O4/G‑C3N4 And Visible Light For The Efficient Degradation Of Steroid Hormones: Performance, Mechanisms, And Environmental Impacts, Kitipong Poomipuen, Chainarong Sakulthaew, Chanat Chokejaroenrat, Athaphon Angkaew, Kanidrawee Techauay, Thapanee Poompoung, Kanokwan Teingtham, Piyaporn Phansak, Piyangkun Lueangjaroenkit, Daniel D. Snow Sep 2023

Dual Activation Of Peroxymonosulfate Using Mnfe2O4/G‑C3N4 And Visible Light For The Efficient Degradation Of Steroid Hormones: Performance, Mechanisms, And Environmental Impacts, Kitipong Poomipuen, Chainarong Sakulthaew, Chanat Chokejaroenrat, Athaphon Angkaew, Kanidrawee Techauay, Thapanee Poompoung, Kanokwan Teingtham, Piyaporn Phansak, Piyangkun Lueangjaroenkit, Daniel D. Snow

Daugherty Water for Food Global Institute: Faculty Publications

Single activation of peroxymonosulfate (PMS) in a homogeneous system is sometimes insufficient for producing reactive oxygen species (ROS) for water treatment applications. In this work, manganese spinel ferrite and graphitic carbon nitride (MnFe2O4/g-C3N4; MnF) were successfully used as an activator for PMS under visible light irradiation to remove the four-mostdetected- hormone-contaminated water under different environmental conditions. The incorporation of g-C3N4 in the nanocomposites led to material enhancements, including increased crystallinity, reduced particle agglomeration, amplified magnetism, improved recyclability, and increased active surface area, thereby facilitating the PMS activation and electron …


Water-Energy-Food Linkages In Community Smallholder Irrigation Schemes: Center Pivot Irrigation In Rwanda, Ankit Chandra, Derek M. Heeren, Lameck O. Odhiambo, N. Brozovic Sep 2023

Water-Energy-Food Linkages In Community Smallholder Irrigation Schemes: Center Pivot Irrigation In Rwanda, Ankit Chandra, Derek M. Heeren, Lameck O. Odhiambo, N. Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Water, energy, and food are linked in intricate ways in irrigated agriculture and understanding the interplay of these components is crucial for sustainable and profitable crop production, particularly in smallholder setting such as in sub-Saharan Africa. This study evaluates water-energy-food linkages, engineering and economic performance, irrigation decision making, and challenges faced around water management in a community-based mechanized irrigation scheme in Rwanda. The research is the first to analyze such as scheme, which uses technology typically used by large farmers in a smallholder setting. The study investigates the variation in water requirements and the relationship and impacts of this variability …


Fire Effects On Soil Organic Matter In The Creek Fire, Gracie E. Doolin Sep 2023

Fire Effects On Soil Organic Matter In The Creek Fire, Gracie E. Doolin

Master of Science in Environmental Sciences and Management Projects

Wildfires have increased in frequency and severity over the past few decades due to the increased concertation of CO2 emissions from anthropogenic influence. Soil carbon (C) sequestration has been identified as a climate change mitigation strategy; however, the influx of large-scale wildfires has accelerated landscape processes such as erosion, reducing soil aggradation, and soil C and nitrogen (N) protection. This trend is highlighted by the Creek Fire that occurred in September 2020 and burned 379,895 acres in the Sierra National Forest. This research is designed to close the knowledge gap regarding the impact of burn severity on soil organic matter …


Design Of Stormwater Bmps For Surface And Groundwater Protection Based On Site-Scale Soil Properties: Phase I, Kelly Kibler, Lisa Chambers, Melanie Beazley Aug 2023

Design Of Stormwater Bmps For Surface And Groundwater Protection Based On Site-Scale Soil Properties: Phase I, Kelly Kibler, Lisa Chambers, Melanie Beazley

Florida DOT

Much of Earth’s nutrient cycling takes place in soils. Characteristics of soils control physical, chemical, and biological processes that determine rates of nutrient fluxes, storage, or transformation. As remediation of excess nutrients in stormwater runoff is one function of stormwater Best Management Practices (BMPs), the soil profile constitutes one of the most important factors of BMP design. Variation observed in BMP effectiveness (e.g., why one BMP design works effectively in one place and not another) can often be explained by variations in the soil profile, either through direct means or by a soil’s influence on hydraulics of stormwater flow through …


Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter Aug 2023

Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter

School of Natural Resources: Dissertations, Theses, and Student Research

Advisors: Andrew Little, Christopher Chizinski

To gain insights into the challenges faced by Nebraska farmers and landowners when adopting precision agriculture technologies, I analyzed data collected from a 2022 survey involving 7,503 participants, consisting of producers and farmland owners from across the state of Nebraska. The primary objective was to provide valuable insights for agencies seeking to improve their precision agriculture and conservation outreach efforts for the benefit of conservation and Nebraskan farmers and landowners. This study aimed to understand key factors influencing adoption behaviors by evaluating the constraints to precision agriculture adoption, assessing the impact of producer and landowner …


Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora Jul 2023

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …


Critical Factors And Individual Decision Making In Earthquake And Tsunami Preparedness Among Coastal Communities Inoregon U.S.A., Shelley Olds Jul 2023

Critical Factors And Individual Decision Making In Earthquake And Tsunami Preparedness Among Coastal Communities Inoregon U.S.A., Shelley Olds

School of Natural Resources: Dissertations, Theses, and Student Research

Earthquakes and tsunamis are natural hazards that cause considerable loss of life, destruction of property and infrastructure, and economic damage. Preparedness is critical in regions of significant earthquake and tsunami risk. A key challenge for organizations that manage hazard preparedness and response is mobilizing earthquake preparedness among individuals and families. This dissertation provides an examination of individual earthquake and tsunami preparedness from both a global and regional perspective. It comprises two publications that explore various aspects of disaster preparedness.

Chapter One provides an overview of global seismic and tsunami hazards, along with potential impacts, and addresses the challenges in promoting …


Mentoring Experiences Of Undergraduate Students And Faculty Members In Science, Technology, Engineering, And Mathematics, Pamela Martínez Oquendo Jul 2023

Mentoring Experiences Of Undergraduate Students And Faculty Members In Science, Technology, Engineering, And Mathematics, Pamela Martínez Oquendo

School of Natural Resources: Dissertations, Theses, and Student Research

I present a comprehensive view of mentoring experiences of undergraduate students and faculty members in science, technology, engineering, and mathematics (STEM). In CHAPTER 1, I describe a brief outline of this dissertation. In CHAPTER 2, I present an interpretative phenomenological analysis of the lived experiences of former STEM undergraduate mentors of the Nebraska STEM For You (NE STEM 4U) afterschool mentoring program. In CHAPTER 3, I describe how the ramifications of faculty mentorship influence the science pipeline using a qualitative synthesis. In CHAPTER 4, I describe how the STEM faculty-student mentoring engagement involves a strong psychological support component using a …


Bat Use Of Afforested And Encroached Patches And Their Role In Extending Bat Habitat Into The Nebraska Sandhills, Jacob L. Wagner Jun 2023

Bat Use Of Afforested And Encroached Patches And Their Role In Extending Bat Habitat Into The Nebraska Sandhills, Jacob L. Wagner

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sandhills are currently undergoing a state shift to a redcedar dominated woodland due to anthropologic planting of eastern redcedar (Juniperus virginiana) and woody encroachment from the periphery of the Sandhills. To better understand this novel ecosystem and how bats are utilizing it I collected data at Barta Brothers Ranch with acoustic sensor grids consisting of 24 100m spaced acoustic sensors placed adjacent to planted windbreaks. Supplemental data from the Nebraska North American Bat Monitoring Program was used for data analysis at larger spatial scales. I used linear regressions and kriging interpolation maps to see how bats used windbreaks …


The Flow Of Power: Addressing Asymmetric Flood Risk In The Upper Valley, Eric Vr Hryniewicz Jun 2023

The Flow Of Power: Addressing Asymmetric Flood Risk In The Upper Valley, Eric Vr Hryniewicz

Geography Undergraduate Senior Theses

Floods are the most damaging natural disasters in America. Land use change in upland watersheds can increase the probability and severity of floods (Bronstert, Niehoff, & Burger, 2002). When watersheds are divided by political and private property boundaries it leads to a misalignment of incentives in which downstream users lack recourse for upstream land use decisions contributing to flood risk. In this thesis, researchers interrogate the attributes of town officials and towns that determine what motivates town governments to act on flooding and what motivates and enables town officials to collaborate on planning and how do they collaborate in practice. …


The Association Between Drought Exposure And Respiratory-Related Mortality In The United States From 2000 To 2018, Yeongjin Gwon, Yuanyuan Ji, Jesse E. Bell, Azar M. Abadi, Jesse D. Berman, Austin Rau, Ronald D. Leeper, Jared Rennie Jun 2023

The Association Between Drought Exposure And Respiratory-Related Mortality In The United States From 2000 To 2018, Yeongjin Gwon, Yuanyuan Ji, Jesse E. Bell, Azar M. Abadi, Jesse D. Berman, Austin Rau, Ronald D. Leeper, Jared Rennie

Daugherty Water for Food Global Institute: Faculty Publications

Climate change has brought increasing attention to the assessment of health risks associated with climate and extreme events. Drought is a complex climate phenomenon that has been increasing in frequency and severity both locally and globally due to climate change. However, the health risks of drought are often overlooked, especially in places such as the United States, as the pathways to health impacts are complex and indirect. This study aims to conduct a comprehensive assessment of the effects of monthly drought exposure on respiratory mortality for NOAA climate regions in the United States from 2000 to 2018. A two-stage model …


Report On And Recommendations Arising From The Visit Of Dr Michael Warne (University Of Queensland) And Robert Sluggett To Kununurra, Michael Warne Dr, Rob Sluggett Jun 2023

Report On And Recommendations Arising From The Visit Of Dr Michael Warne (University Of Queensland) And Robert Sluggett To Kununurra, Michael Warne Dr, Rob Sluggett

Natural resources commissioned reports

Dr Michael Warne of the Reef Catchments Science Partnership and Robert Sluggett of Farmacist Pty Ltd were invited by Richard George of Department of Primary Industries and Regional Development (DPIRD) to visit Kununurra, Western Australia.

The project was financially supported by the National Water Grid Authority project “Managing water quality to enable future irrigation development in the Kimberley Region”. The aim of the visit was for Dr Warne and Rob Sluggett to engage with farmers, key stakeholders and staff from DPIRD in order to understand the agriculture and water quality in the Ord and Keep river region; and to share …


Review Of Toxicity Of Agricultural Chemicals And Implications For Aquatic Fauna Of The Keep River, Samanatha Reynolds, David Morgan Jun 2023

Review Of Toxicity Of Agricultural Chemicals And Implications For Aquatic Fauna Of The Keep River, Samanatha Reynolds, David Morgan

Natural resources commissioned reports

This report was compiled for the Western Australian Department of Primary Industries and Regional Development (DPIRD) as part of the National Water Grid Authority (NWGA) project entitled “Managing water quality to enable future irrigation development in the Kimberley Region, WA”. The purpose of this report is to review the toxicity of farm chemicals (herbicides and insecticides) used by farm operators in the Keep River catchment and their potential impacts on the aquatic species in the river, in particular those species that are listed under the Environment Protection and Biodiversity Conservation Act 1999. It is designed to complement the report entitled …


Downstream Hydrochemistry And Irrigation Water Quality Of The Syr Darya, Aral Sea Basin, South Kazakhstan, Bagdat Satybaldiyev, Baimurat Ismailov, Nurbek Nurpeisov, Kairat Kenges, Daniel D. Snow, Arindam Malakar, Omirzhan Taukebayev, Bolat Uralbekov May 2023

Downstream Hydrochemistry And Irrigation Water Quality Of The Syr Darya, Aral Sea Basin, South Kazakhstan, Bagdat Satybaldiyev, Baimurat Ismailov, Nurbek Nurpeisov, Kairat Kenges, Daniel D. Snow, Arindam Malakar, Omirzhan Taukebayev, Bolat Uralbekov

Daugherty Water for Food Global Institute: Faculty Publications

New hydrochemical measurements from the Syr Darya provide insights into factors affecting the composition and quality of a major freshwater source replenishing the Aral Sea. This river is heavily used for power and irrigation and crosses territories of four Central Asia republics. It is intensely managed, draining several major tributaries, many reservoirs, and numerous irrigation distribution systems and canals. Analysis of seasonal changes in dissolved ion concentrations using geochemical diagrams, elemental ratios, statistical correlation, and equilibrium modeling allowed the characterization of mineral formation processes that control the dissolved chemical composition. Measured water hydrochemistry and composition type differs substantially from previous …


The Last Drought Frontier: Building A Drought Index For The State Of Alaska, Olivia Campbell May 2023

The Last Drought Frontier: Building A Drought Index For The State Of Alaska, Olivia Campbell

School of Natural Resources: Dissertations, Theses, and Student Research

Drought is characterized by periods of below average precipitation. There are five major types of drought recognized in the literature: meteorological, hydrological, agricultural, socioeconomic, and ecological. A relatively new concept in the drought literature is “snow drought.” A key part of the definition of drought is that it is not always accompanied by extreme heat. This means drought can occur even in cold climates, cold seasons, and higher latitudes and altitudes, like Alaska. Drought is a natural part of climate variability, but Alaska’s climate is changing faster than any other state in the United States. Alaska is no stranger to …


Evaluation Of Hydrogeochemical Characteristics Of San Joaquin, Tulare, And Mojave Aquifers, Southern California, Maedeh Hassanvand May 2023

Evaluation Of Hydrogeochemical Characteristics Of San Joaquin, Tulare, And Mojave Aquifers, Southern California, Maedeh Hassanvand

Graduate Theses and Dissertations

Before making attempts to enhance and manage the quality of water, a thorough understanding of these processes is necessary since the chemical quality of groundwater is impacted by a number of linked processes. This would be more important in arid and semiarid regions like the southern part of California where more rely on groundwater for agriculture and drinking water uses than the other states. As a result, fundamental knowledge of the governing processes of groundwater chemistry is required for effective water resource management. Thus, this study is primarily concerned with three aspects in Mojave, Tulare, and San Joaquin aquifers: The …


Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek Apr 2023

Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek

Masters Theses

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume …


Pan-Arctic Soil Moisture Control On Tundra Carbon Sequestration And Plant Productivity, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Beniamino Gioli, Barbara Bailey, George Burba, Eugénie S. Euskirchen, Jennifer D. Watts, Kyle A. Arndt, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Albertus J. Dolman, Roisin Commane, Charles E. Miller, Josh Hashemi, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Elyn R. Humphreys, Oliver Sonnentag, Gesa Meyer, Gabriel H. Gosselin, Philip Marsh, Walter C. Oechel Mar 2023

Pan-Arctic Soil Moisture Control On Tundra Carbon Sequestration And Plant Productivity, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Beniamino Gioli, Barbara Bailey, George Burba, Eugénie S. Euskirchen, Jennifer D. Watts, Kyle A. Arndt, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Albertus J. Dolman, Roisin Commane, Charles E. Miller, Josh Hashemi, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Elyn R. Humphreys, Oliver Sonnentag, Gesa Meyer, Gabriel H. Gosselin, Philip Marsh, Walter C. Oechel

Daugherty Water for Food Global Institute: Faculty Publications

Long-term atmospheric CO2 concentration records have suggested a reduction in the positive effect of warming on high-latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long-term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site-years of eddy covariance …


Assessing Ecosystem Health Through Contaminants In The Tijuana River National Estuarine Research Reserve, Nancy Torres Jan 2023

Assessing Ecosystem Health Through Contaminants In The Tijuana River National Estuarine Research Reserve, Nancy Torres

Theses

Although the Tijuana River Estuary (TRE) remains the largest, most-intact coastal wetland in Southern California, it has a history of major changes, much of this related to its location immediately north of the US / Mexico Border. One of the primary challenges is cross-border flows from the rapidly growing city of Tijuana, Baja California, Mexico, and the delivery of wastewater, debris, and sediment to sensitive coastal wetland ecosystems. There is a need to more fully investigate these environmental changes to assess the ecosystem health of the Tijuana River Estuary over time, especially related to pollution impacts. This can inform an …


Bibliography, Leslie North Jan 2023

Bibliography, Leslie North

Faculty/Staff Personal Papers

Bibliography of publications by Leslie North.


Evaluating Benthic Macroinvertebrate Populations In Response To Scouring Events In The Trinity River, Ca, Liam Hay, Michael W. O'Neil, Chloe Pieper-Wasem Jan 2023

Evaluating Benthic Macroinvertebrate Populations In Response To Scouring Events In The Trinity River, Ca, Liam Hay, Michael W. O'Neil, Chloe Pieper-Wasem

Environmental Science & Management Senior Capstones

River systems across California have been impacted by appurtenant structures such as dams and diversions. These structures have had an adverse impact on Benthic invertebrate (BMI) communities by regulating river systems and changing the natural hydraulic pulses that follow seasonal precipitation. Benthic invertebrates are a critical food resource for salmonids and serve as an indicator of ecosystem health. Our study was interested in seeing the effects of scouring events on BMI in the Trinity River of Trinity County, C.A. Following a large precipitation event that occurred in the region in December 2022, an influx of water entered the river through …


Labile Carbon And Soil Texture Control Nitrogen Transformation In Deep Vadose Zone, Lidong Li, Jordan Shields, Daniel D. Snow, Michael Kaiser, Arindam Malakar Jan 2023

Labile Carbon And Soil Texture Control Nitrogen Transformation In Deep Vadose Zone, Lidong Li, Jordan Shields, Daniel D. Snow, Michael Kaiser, Arindam Malakar

Daugherty Water for Food Global Institute: Faculty Publications

Understanding transient nitrogen (N) storage and transformation in the deep vadose zone is critical for controlling groundwater contamination by nitrate. The occurrence of organic and inorganic forms of carbon (C) and nitrogen and their importance in the deep vadose zone is not well characterized due to difficulty in sampling and the limited number of studies. We sampled and characterized these pools beneath 27 croplands with different vadose zone thicknesses (6–45 m).We measured nitrate and ammonium in different depths for the 27 sites to evaluate inorganic N storage. We measured total Kjeldahl nitrogen (TKN), hot-water extractable organic carbon (EOC), soil organic …