Natural Resources and Conservation Commons^™

Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin

Biological Sciences: Faculty Scholarship

The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought …

Soil Microbial Community Dynamics In Response To Prescribed Extreme Fires Following Juniperus Virginiana Invasion In The Loess Canyons Of Nebraska, Julie A. Fowler

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

In Nebraska and other regions of the Great Plains, the conifer Juniperus virginiana (eastern redcedar) is converting grasslands to dense woodlands. This is driven by the interacting drivers of fire suppression, altered grazing regimes, climate change and other anthropogenic factors, impacting the provisioning of ecosystem services. This vegetation state transition modifies water resource regulation and biogeochemical cycles leading to altered edaphic properties including soil microbial community composition. To restore these grasslands and control J. virginiana spread, prescribed extreme burns are implemented as a management tool through local prescribed burn associations. We hypothesized that the alternative state transition to dense J. …

Cover Crop Effects On Near-Surface Soil Aggregate Stability In The Southern Mississippi Valley Loess (Mlra 134), Chandler M. Arel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Intensive agricultural cultivation within major land resource area (MLRA) 134, the Southern Mississippi Valley Loess, has led to soil erosion, soil compaction, and the overall destabilization of near-surface soil aggregates. The use of cover crops during the agricultural offseason has been shown to help alleviate soil compaction and provide stabilizing effects against soil erosion, which are particularly important as the silty soils of MLRA 134 have a large erosion potential. This study evaluated the effects of cover crop and no-cover crop treatment on silt-loam soils within MLRA 134. Treatments were implemented during Fall 2018 and Fall 2019 and consisted of …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison K. Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

A 60- Year Record Of The Demotechnic Index Of States, 1960-2019, Gavin James Kellough

Graduate Theses and Dissertations

A country’s dependency on energy resources can be interpreted through the calculation of energy indices. The Demotechnic Index (DI) was used to determine the trajectory of energy efficiency of each state in the United States over the period 1960-2019. The DI serves as a measure of the energy intensity of states and a proxy for energy sustainability of each state.The DI is the ratio of total energy use to total metabolic energy demand of a population. Mathematically, DI = (E_T-E_M)/E_M E_T represents the total energy used (metabolic energy + technological energy in kilojoules annually, kJ/y), while EM represents the basic …

Longleaf Pine Restoration In The South Carolina Sandhills Wiregrass Gap, Jacob W. Murray

All Theses

Longleaf pine restoration has been a topic of great concern and intrigue in the southeast and has taken on new fervor in recent decades as restoration methods continue to develop. Many landowners and forest managers are now pursuing ecological forestry and restoration ecology in great numbers as a new form of land management. However, niche regions can often be overlooked, as is the case with the Carolina Sandhills Wiregrass Gap, an area devoid of wiregrass and one that is on the outskirt regions of the historical longleaf pine range. Field studies were conducted pre- and post-harvest during two growing seasons …

Low Impact Sampling Of Speleothems – Reconciling Scientific Study With Cave Conservation, Claire L.V. Macgregor, John C. Hellstrom, Jon D. Woodhead, Russell N. Drysdale, Rolan S. Eberhard

International Journal of Speleology

Speleothems are increasingly valued as important paleoclimate archives and yet the removal of samples from caves can come at a cost to natural heritage, impacting delicate environments with limited mechanisms for repair. Conservation of cave environments is a key responsibility for scientists and, with this in mind, we are working to develop and implement techniques that allow us to extract valuable scientific data, with minimal impact. In this study, we demonstrate the utility of low-impact reconnaissance dating surveys on caves in southern Tasmania and southwest Western Australia as a precursor to the removal of stalagmites for paleoclimate reconstruction. Small flakes …

Floodplain Forests Vegetation Dynamics Driven By Water Deficits Across Scales, Nga Thanh Nguyen

LSU Doctoral Dissertations

Restoration of floodplain ecosystems relies on identifying the most crucial hydrologic process which has been altered by human and climate. Flooding is a well-known dominant hydrologic process for floodplain ecosystems, but surprisingly little is known about drought's role in structuring ecosystems. In addition, several issues remained uncertain, such as the nature of drought within floodplains and the sensitivity of floodplain species-specific growth to climate. These gaps of understanding have in common in missing observations of mechanistic pathways of vegetation response to water deficits at multiple scales in time and space.Generally, this research contributed to floodplain management by expanding our understanding …

Determination Of Sustainable Zones For Groundwater Abstraction From The Multi-Layered Aquifer System In The Bengal Basin, Bangladesh, Anwar Zahid, Muhammad Qumrul Hassan, Nazrul I. Khandaker

Publications and Research

The use of deep groundwater (±300 m deep) is becoming an important issue in the Bengal Basin, due to both water quality problems and an acute shortage of available water in upper aquifers. In southeastern Bangladesh, multi-layered aquifer conditions exist with arsenic contamination at shallow depths, and high iron and brackish groundwater occurring mainly in the deeper layers. Many previous studies have offered explanations for the high concentrations of dissolved arsenic in groundwater - most of which proposed that the arsenic is derived from geo-genic sources and its release in groundwater is through natural processes, not the result of anthropogenic …

Droughtscape, Fall 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Fall 2021

The Relative Importance Of Wind-Driven And Chimney Effect Cave Ventilation: Observations In Postojna Cave (Slovenia), Lovel Kukuljan, Franci Gabrovsek, Matthew Covington

International Journal of Speleology

Density-driven chimney effect airflow is the most common form of cave ventilation, allowing gas exchange between the outside and the karst subsurface. However, cave ventilation can also be driven by other mechanisms, such as barometric changes or pressure differences induced by the outside winds. We discuss the mechanism and dynamics of wind-driven ventilation using observations in Postojna Cave, Slovenia. We show how seasonal airflow patterns driven by the chimney effect are substantially modified by outside winds. Wind flow over irregular topography forms near-surface air pressure variations and thus pressure differences between cave entrances at different locations. These pressure differences depend …

Underground Burning Of Jharia Coal Mine (India) And Associated Surface Deformation Using Insar Data, Jungrack Kim, Shih-Yuan Lin, Ramesh P. Singh, Chen-Wei Lan, Hye-Won Yun

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The underground burning in the Jharia coal mine (JCM) in India is a highly devastating environmental hazard inducing various adverse consequences. In the present study, we carried out time series analyses based on Interferometric Synthetic Aperture Radar (InSAR) and land surface temperature (LST) to study the environmental risk. First, a permanent scatterer (PS) time series analysis using Sentinel-1 images over three years was performed to detect the spatio-temporal distribution of ground deformation. Comparison of ground thermal anomaly clearly delineated the subsidence spots associated with the oxygen supply to combustion areas. On the contrary, few deformations were mapped showing pronounced uplift …

The Variability Of Seawater Carbonate Chemistry In Two Florida Urban Mangrove Ecosystems, Alexandrina R. Rangel

All HCAS Student Capstones, Theses, and Dissertations

Anthropogenic carbon dioxide (CO₂) emissions into the atmosphere are yielding serious impacts across the world’s ocean, including ocean acidification, sea level rise, and increasing seawater temperature. However, these changes are not occurring uniformly across all marine ecosystems. Coastal ecosystems, such as mangroves, already experience extreme and variable environmental conditions due to natural biogeochemical and physical processes. The goal of this study was to document small-scale variability in two urban mangrove ecosystems to gain insight into how ocean acidification will manifest within these systems. Using a stand-up paddleboard, a suite of sensors, and traditional bottle sampling techniques, we measured …

Right Side Up: Payment For Ecosystem Services On Privately Owned Grasslands In Nebraska, Kyle Martens

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

Grasslands are an important ecological and economic resource in the United States. As part of a natural system, these landscapes can provide income for ranching operations and employment in rural communities; habitat for grassland plants, animals, and migratory species; and offer other services not always readily observed such as improved soil health, clean water, and carbon sequestration. Despite the overarching benefits, the conversion of grasslands to other uses remains widespread throughout much of the remaining Great Plains ecosystem.

Shifting from livestock ranching to another land use often reflects a tipping point. This occurs when the alternative land use is perceived …

Fractured Rock Groundwater Wa Wheatbelt: Data And Methodology Review, Louise Hopgood, Richard Nixon

Natural resources commissioned reports

The Department of Primary Industries and Regional Development (DPIRD) in partnership with Water Corporation, working with Murdoch and Curtin universities, are looking at new options to improve farm water security in the wheatbelt of Western Australia.

Winter rainfall has declined since 2000 and dams, traditionally used for farm water supply, no longer provide sufficient or reliable water, especially after 1 to 2 below average years. Increasingly, groundwater supplies are being considered to supply farm needs, including those from fractured rock aquifers, with opportunities to desalinate to improve water quality.

This project undertook to review groundwater availability in fractured rock aquifers …

Droughtscape, Summer 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Summer 2021

Soil Morphology And Carbon Stocks Of Deflation Basin Wetlands In Eastern Nebraska, Usa, Aubrey Grace Kemper

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

Wetlands contribute important ecosystem services such as water filtration and storage, wildlife habitat, and carbon sequestration. The objective of this study is to compare the soil 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 deflation basin wetlands in the Todd Valley, a loess-mantled, former course of the Platte River, in eastern Nebraska. Soil morphological descriptions were evaluated to two meters’ depth using cores collected along three transects from the upland to the basin floor in three basins, carbon and nitrogen stocks …

Incorporating Life Into Living Shorelines: Can Gulf Ribbed Mussels Reduce Shoreline Erosion And Enhance Restoration Practices?, Jordan Logarbo

LSU Master's Theses

The gulf ribbed mussel (Geukensia granosissima) exists throughout the Gulf of Mexico and influences biotic and abiotic environmental attributes as an ecosystem engineer. Ribbed mussels are an important component of marsh ecosystems providing services including filtering particulate matter, depositing and transforming nutrients in the system, increasing soil strength via byssal threads and providing structure via their shells.

The spatial distribution of mussels along the marsh edge of Sister Lake, LA was investigated via a broad survey of 150 sites, in relation to elevation, exposure and vegetation percent cover. This survey was followed by a second survey at a …

Bioaccumulation And Partitioning Of Heavy Metals In Cicindelidia Haemorrhagica In Yellowstone National Park, Monica Gotschall

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

The tiger beetle Cicindelidia haemorrhagica (Coleoptera: Cicindelidae) are widely distributed in Yellowstone National Park (YNP) and exclusively living on thermal areas. Heavy metals including arsenic, copper, lead, and selenium are present in these thermal springs, presenting an unique environment for C. haemorrhagica. Therefore, from 2018 – 2020 I sampled adult C. haemorrhagica from YNP and adult C. haemorrhagica from a known population in a salt flat in Idaho not associated with a hot spring and measured heavy metal concentrations. All populations of C. haemorrhagica bioaccumulated heavy metals. Cuticular waxes showed small concentrations of metals indicating that those metals are …

A Foray Into Laboratory Scale Soil Incubations With Corn Stover And High Lignin Fermentation Byproduct, Michelle Wang

ENGS 88 Honors Thesis (AB Students)

As the production of biofuels increases to meet the demands of a growing low carbon economy, questions of sustainability surrounding its feedstock and waste streams have become increasingly relevant. In the biofuel production process, crop residues like corn stover are harvested from the field and converted to biofuels leaving generating a residue called high lignin fermentation byproduct (HLFB). From extensive process modelling in the literature, it is suggested that HLFB should be either combusted to fuel auxiliary conversion processes or returned to the soil in place of the crop residues that were harvested. Currently, there is little literature testing the …

Droughtscape, Spring 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Spring 2021

Occurrence And Potential Transformation Pathways Of Nitrogen Species In The Intermediate Vadose Zone, Jordan Shields

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

Nebraska is a large agricultural producing state with a heavy reliance on groundwater resources and nitrogen fertilizer application to maintain output. Poor management, such as excessive fertilizer application, improper timing, and over irrigation can lead to contamination of groundwater. Nitrate is the leading groundwater contaminant in Nebraska and chronic consumption at medium to high concentrations leads to adverse health effects. Nitrate, a highly soluble anion, is present in the root zone in numerous forms and undergoes biogeochemical transformations before being leached through the profile. In order to predict the timing and quantity of nitrate contamination in groundwater, researchers study the …

Effects Of Marsh Management In Coastal Marsh Impoundments On Marsh Vertical Accretion In The Face Of Sea Level Rise., Scott P. Graham

LSU Master's Theses

Many coastal marshes are managed for wildlife through the use of levees and water control structures. Management techniques such as water manipulation, herbicide application, and controlled burns are used to set back succession and facilitate recruitment of annual plant species, which are highly sought after by many wildlife. These marsh impoundments alter or prevent natural tidal exchange, which might alter or prevent sediment and nutrient inputs to the marsh. Although these management techniques are effective in managing for wildlife, there are few studies comparing vertical accretion between managed and unmanaged marshes. Vertical accretion is important because it allows coastal wetlands …

Moving Beyond ‘More Crop Per Drop’: Insights From Two Decades Of Research On Agricultural Water Productivity, Meredith Giordano, Susanne M. Scheierling, David O. Tréguer, Hugh Turral, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

Concern over increasing water scarcity has led to the introduction of the concept of agricultural water productivity and an emphasis on interventions to achieve ‘more crop per drop’. Yet, a strong debate continues on how the concept is to be defined and used. Drawing largely from the irrigation literature, the origins of the concept and its methodological developments are reviewed, and its use in applied work over two decades is discussed. Based on this analysis of conceptual and applied research, key insights into the concept’s contributions and limitations are presented, as well as opportunities for further refinements.

Bed Particle Displacements And Morphological Development In A Wandering Gravel-Bed River, Ryan Mcqueen, Peter Ashmore, T Millard, N Goeller

Geography & Environment Publications

Bed particles were tracked using passive integrated transponder tags in a wandering reach of the San Juan River, British Columbia, Canada, to assess particle movement around three major bars in the river. In-channel topographic changes were monitored through repeat LiDAR surveys during this period and used in concert with the tracer data set to assess the relationship between particle displacements and changes in channel morphology, specifically, the development and re-working of bars. This has direct implications for virtual velocity and morphologic based estimates of bedload flux, which rely on accurate estimates of the variability and magnitude of particle path lengths …

Peralkaline Silicic Extrusive Rocks: Magma Genesis, Evolution, Plumbing Systems, And Eruption., Ray Macdonald, John C. White, Harvey E. Belkin

EKU Faculty and Staff Scholarship

Peralkaline silicic extrusive rocks are an important component of the volcanological record. Here we review several aspects of their formation and evolution, including the tectonic settings in which they occur, their main petrological and geochemical features, the magmatic lineages along which they evolve, and the parameters (T, P, fO₂, melt water contents) that control the lineages. Particular attention is paid to the composition of the extraordinary melts formed at the lowest temperatures. Various lines of evidence are presented to explain the silica-gaps in some lineages. The partial melting of continental crust and the role of crustal contamination …

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO₄ complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …

Droughtscape, Winter 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2021

The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey

School of Natural Resources: Faculty Publications

Groundwater age-dating is an important tool for quantifying and managing water resources. Groundwater age is the elapsed time between recharge (at the land surface or water table) and the time when groundwater is sampled. If groundwater is sampled at the point of discharge from an aquifer, then the age represents the groundwater transit time. Groundwater that has recharged in recent decades is considered young groundwater. In many areas, the quality and quantity of young groundwater has been impacted by human activities and groundwater age-dating is useful for quantifying current and historical water and contaminant fluxes into and through aquifers. This …

A Karst Feature Prediction Model For Prince Of Wales Island, Alaska Based On High Resolution Lidar Imagery, Alexander Lyles

Master's Theses or Doctor of Nursing Practice

Investigation into surface karst formation is significant to hazard prediction, hydrogeologic drainage, and land management. Southeast Alaska contains over 600,000 acres of mapped carbonate bedrock, and some of the fastest recorded karst dissolution in the world. The objectives of this study are to develop and compare multiple semi-automated models to map and delineate karst features from bare-earth LiDAR imagery using ArcGIS Desktop 10.7, and to apply a preliminary geostatistical analysis of sinkhole morphometric parameters to highlight potential spatial patterns of karst evolution on Prince of Wales Island, Alaska. A semi-automated approach of mapping karst features provides a dataset that minimizes …