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Assessing The Climate Water Balance Model’S Ability To Predict Soil Moisture Variability And Species Distribution Of A Forested Watershed In The Northern Cumberland Plateau, Katherine J. Love Jan 2020

Assessing The Climate Water Balance Model’S Ability To Predict Soil Moisture Variability And Species Distribution Of A Forested Watershed In The Northern Cumberland Plateau, Katherine J. Love

Theses and Dissertations--Forestry and Natural Resources

Spatial patterns of moisture and tree species have been studied using environmental gradients, often represented by terrain attributes in GIS. With climate change, GIS terrain variables, which are static as long as the elevation remains unchanged, will not reflect alterations in temperature, water cycle, and atmospheric conditions. In this thesis, the commonly used terrain variables and climate water balance variables were evaluated and compared for their ability to explain soil moisture and tree species distributions in a forested watershed in the Northern Cumberland Plateau. The results suggest that GIS terrain variables generally perform better than climate water balance variables, however, …


Understanding The Mechanisms Controlling The Concentration-Discharge Relationships Of Streams In Northeastern And North Midwestern United States, Veronica Porter Jan 2020

Understanding The Mechanisms Controlling The Concentration-Discharge Relationships Of Streams In Northeastern And North Midwestern United States, Veronica Porter

Dissertations, Master's Theses and Master's Reports

Analysis of concentration-discharge (C-Q) power-law relationships (C=aQb) is a powerful diagnostic tool to unravel solute export processes. However, application to watersheds with less intensive data can be difficult due to unexplained variation in C-Q behavior. To tackle this problem, I started my study at a small but data-intensive watershed in Vermont and then applied the insights to 138 watersheds throughout the Great Lakes Basin (GLB). I found that an increase in solute concentrations from shallow to deep flowpaths results in chemodynamic dilution (negative b-coefficient), a decrease produces chemodynamic flushing (positive b-coefficient). When applied …


Geochemical Flux Analysis Of Glacial River Runoff For Sólheimajökull, Iceland, Jessica Garrison Jan 2020

Geochemical Flux Analysis Of Glacial River Runoff For Sólheimajökull, Iceland, Jessica Garrison

Mahurin Honors College Capstone Experience/Thesis Projects

Geochemical fluxes in aqueous studies are an essential component of research to understand weathering and changes in a hydrologic system. These data can indicate any discrepancies, outliers, or gradual changes in a water environment to gain information on pollutants, carbon cycles, biological input, etc. Glacial melt is the majority of the surface water present throughout the country. The melting amount is increasing with the temperatures, which can be monitored by the changes in geochemical flux during increased discharge in glacial rivers. A high-resolution data set of Sόlheimajökull Glacier in Iceland was used to determine how changing climatic conditions for the …


Earth News, V43, Winter 2020, University Of Northern Iowa. Department Of Earth And Environmental Sciences. Jan 2020

Earth News, V43, Winter 2020, University Of Northern Iowa. Department Of Earth And Environmental Sciences.

Earth News

Inside this issue:
--From the Department Head
--Faculty Updates
--Staff Updates
--SGE Chapter News
--Outreach-Global Visit
--Student Recognition
--Sunday at the Quarry
--Student Spotlights
--Student Research
--50th Anniversary
--Alumni Updates
--Homecoming 2019
--Gifts from Alumni & Friends
--Contribution Form


Ecosystem Health In Guánica Bay And La Parguera, Puerto Rico: Remote Sensing Of Ocean Color And Metal Analysis Of Coral Tissue And Surficial Sediments, Jahnelle Howe Jan 2020

Ecosystem Health In Guánica Bay And La Parguera, Puerto Rico: Remote Sensing Of Ocean Color And Metal Analysis Of Coral Tissue And Surficial Sediments, Jahnelle Howe

Dissertations and Theses

Guánica Bay is an estuary located in southwest Puerto Rico, with a coral reef ecosystem at its periphery. This ecosystem is affected by sediments, nutrients, and contaminants from the watershed through the Bay and into the offshore water. This project evaluates Guánica Bay and La Parguera coastal areas through remote sensing and chemical analysis to assess coastal ecosystem health. The concentration of metals in two coral species and their associated surface sediments was were analyzed by X-ray fluorescence (XRF) and Direct Mercury Analyzer (DMA- 80). Ocean color remote sensing was used to estimate nutrient inputs and phytoplankton biomass through chlorophyll- …


Sampling The Local Fare: Fishes At The Sam Israel House Pit (45gr76), Soap Lake, Washington, Adam Fruge Jan 2020

Sampling The Local Fare: Fishes At The Sam Israel House Pit (45gr76), Soap Lake, Washington, Adam Fruge

All Master's Theses

The Sam Israel site is a precontact archaeological complex with numerous fish bones at the north end of Soap Lake, Washington. Excavated in 1976, the fish remains recovered from there were never fully analyzed prior to this research. Since this inland Columbia Plateau site had thousands of fish bones, it contained untapped potential for our understanding of ancient local fish procurement. As such, I conducted a detailed analysis of 2,862 fish bone specimens from the Sam Israel House Pit locus to: study a larger sample of fish bones in greater detail than was done before; compare the distribution of fishes …


Modeling Cle Elum Reservoir Shoreline Erosion: Gis Analysis To Support Cultural And Environmental Resource Management, Yakima Basin, Washington, Michael H. Horner Jan 2020

Modeling Cle Elum Reservoir Shoreline Erosion: Gis Analysis To Support Cultural And Environmental Resource Management, Yakima Basin, Washington, Michael H. Horner

All Master's Theses

In the Yakima Basin, managers are expanding reservoirs including Cle Elum Lake to increase the availability of water. The objective of this study was to examine areas prone to further shoreline erosion to inform resource management. This research included the use of airphotos and fieldwork to identify erosional shorelines. Erosion was verified in the field using a video survey as well as indicators such as shoreline slope, sediment size, and nearshore width. Near-term erosional segments were identified by more rapidly receding bluffs while long-term erosional segments included both bedrock cliffs and bluffs. Although most of the shoreline is depositional, near-term …


Distribution Of Invasive Plant Species On Debris Cones At Mount Rainier National Park, Shaun Morrison Jan 2020

Distribution Of Invasive Plant Species On Debris Cones At Mount Rainier National Park, Shaun Morrison

All Master's Theses

Invasive plant populations within Mount Rainier National Park are a biological and ecological threat to the unique mountain landscape. A better understanding of their distribution and transport within the landscape is needed to improve invasive species monitoring for National Park Service management. This study investigates how invasive plant populations in Stevens Canyon are utilizing the debris cone disturbances and associated geomorphic processes to facilitate movement within the park. Vegetation transects were performed along Stevens Canyon Road (to observe the roadside community composition) and on the debris cone features (to observe species movement from the roadside). These vegetation observations are presented …


Late Holocene Paleoflood Hydrology Of The Snake River In The Lower Hells Canyon, Idaho, Kent C. Allen Jan 2020

Late Holocene Paleoflood Hydrology Of The Snake River In The Lower Hells Canyon, Idaho, Kent C. Allen

All Master's Theses

The Snake River watershed spans a large geographic region from the Rocky Mountains to the inland Pacific Northwest, and a comprehensive paleoflood chronology on the mainstem of the river is key to identifying the frequency and magnitude of large prehistoric floods within the region. We examined and compared four sites of slackwater deposits along a 20-km reach of the Lower Hells Canyon on the Snake River, Idaho. The sites contain evidence of up to 34 paleofloods within the last 1700 years. Stratigraphic breaks, soils, and in-situ plant or archaeological materials demarcate distinct layers that represent discrete paleoflood events. Radiocarbon dates …


Crystalline Architecture And Stratigraphy Of Coral Skeletal Density Banding: A Geobiological Record Of Changing Coral Reef Ecology, Kyle Fouke Jan 2020

Crystalline Architecture And Stratigraphy Of Coral Skeletal Density Banding: A Geobiological Record Of Changing Coral Reef Ecology, Kyle Fouke

Honors Theses

Coral skeletal density banding (CSDB), composed of alternating high density band (HDB) and low density band (LDB) layers that comprise the CaCO3 (aragonite) skeleton of scleractinian corals, are used as chronometers for global paleoclimatic reconstructions of sea surface temperature (SST). Scleractinian coral skeletons have been intensively studied for centuries with detail analysis of the macro- and microscale skeletal structure to establish taxonomic and evolutionary relationships of coral species, mechanisms of biomineralization, and seafloor physical, chemical and biological alteration (diagenesis) of the skeleton. This study is the first to determine the crystalline architecture of HDBs and CSDB stratigraphic …


Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman Jan 2020

Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman

Turkish Journal of Earth Sciences

Estimating the shear wave velocity and thickness of geologic units in a sedimentary structure is important for quantifying the local site effect caused by an earthquake. Inversion of the Rayleigh wave dispersion alone is sensitive to the absolute average shear wave velocity, while the H/V spectral ratio is sensitive to velocity contrasts. The solution of these models in a joint system using conventional inversion techniques suffers from difficulties while evaluating partial derivatives, dependencies to the initial model that is sometimes difficult to estimate, and trapping at a local minimum. Herein, a joint model using the Pareto optimality technique with multiobjective …


Evaluation Of The Relationship Between Land Use And Water Quality In Kittitas County, Wa, Lindsay Schulz Jan 2020

Evaluation Of The Relationship Between Land Use And Water Quality In Kittitas County, Wa, Lindsay Schulz

All Master's Theses

Water in Kittitas County is extremely valuable since it supports farming, recreation, and cultural activities, as well as environmental processes and a diversity of biological life while providing many ecosystem services. However, land conversions required by agricultural and urban land uses can negatively impact water quality and the biological function of the stream. I studied how forested, agricultural, and urban land use affect six streams. Fourteen sites were sampled, once each in July, August, and September 2019. Land use was calculated as a percentage of forested, agricultural, and urban land use within a 100-m buffer of the stream, upstream of …


The Limits Of Lead (Pb) Phytoextraction And Possibilities Of Phytostabilization In Contaminated Soil: A Critical Review, Sara Perl Egendorf, Peter M. Groffman, Gerry Moore, Zhongqi Cheng Jan 2020

The Limits Of Lead (Pb) Phytoextraction And Possibilities Of Phytostabilization In Contaminated Soil: A Critical Review, Sara Perl Egendorf, Peter M. Groffman, Gerry Moore, Zhongqi Cheng

Advanced Science Research Center

This review article focuses on lead (Pb), one of the most ubiquitous and harmful toxicants found in soil. Our objective is to address misconceptions regarding the ability of plants to uptake Pb through their roots and translocate it to above-ground tissues, and their ability to act as hyperaccumulators and thereby phytoextract Pb. In accordance with a number of cited definitions, we suggest that species capable of Pb phytoextraction can be rated with the following three criteria: (1) root uptake above a nominal threshold of 1,000 mg Pb/kg, (2) bioconcentration factor (BCF or shoot/soil concentration) >1, and (3) translocation factor (TF …


A Machine Learning And Data-Driven Prediction And Inversion Of Reservoir Brittleness From Geophysical Logs And Seismic Signals: A Case Study In Southwest Pennsylvania, Central Appalachian Basin, Tobi Micheal Ore Jan 2020

A Machine Learning And Data-Driven Prediction And Inversion Of Reservoir Brittleness From Geophysical Logs And Seismic Signals: A Case Study In Southwest Pennsylvania, Central Appalachian Basin, Tobi Micheal Ore

Graduate Theses, Dissertations, and Problem Reports (ETD)

In unconventional reservoir sweet-spot identification, brittleness is an important parameter that is used as an easiness measure of production from low permeability reservoirs. In shaly reservoirs, production is realized from hydraulic fracturing, which depends on how brittle the rock is–as it opens natural fractures and also creates new fractures. A measure of brittleness, brittleness index, is obtained through elastic properties of the rock. In practice, problems arise using this method to predict brittleness because of the limited availability of elastic logs.

To address this issue, machine learning techniques are adopted to predict brittleness at well locations from readily available geophysical …


The Impact Of Ryegrass On A Fragipan Soil, Keegan Patrick Smith Jan 2020

The Impact Of Ryegrass On A Fragipan Soil, Keegan Patrick Smith

Theses and Dissertations--Plant and Soil Sciences

Fragipans are soil horizons which negatively impact row crop yields due to their cemented nature. Annual ryegrass has been proposed as a cover crop to help remediate these dense horizons. The objectives of this study were to (1) evaluate potential ryegrass root exudates and their ability to solubilize proposed fragipan cementing agents, aluminum (Al), iron (Fe), and silica (Si) in stirred-batch reactor studies; and (2) evaluate annual ryegrass’ ability to remediate the fragipan through an 8-week greenhouse growth study using non-destructive, mini-rhizon samplers installed on soil cores for in situ pore water sampling, and non-invasive soil porosity calculations using X-ray …


Facies Distribution, Paleoenvironment And Sequence Stratigraphy Model Of The Oligo-Miocene Asmari Formation (Fars Province, South Of Iran), Fereshteh Kamalifar, Mohsen Aleali, Vahid Ahamadi, Akram Mirzaiee Jan 2020

Facies Distribution, Paleoenvironment And Sequence Stratigraphy Model Of The Oligo-Miocene Asmari Formation (Fars Province, South Of Iran), Fereshteh Kamalifar, Mohsen Aleali, Vahid Ahamadi, Akram Mirzaiee

Turkish Journal of Earth Sciences

The Oligocene (Rupelian-Chattian) to Miocene (Aquitanian)-aged Asmari Formation is considered one of the most significant petroliferous reservoirs in the Middle East. The Oligocene-Miocene Asmari Formation represents diverse facies patterns in different parts of Zagros, so analysis of its facies in different provinces of the Zagros Basin is necessary. In this study, the sedimentary depositional sequences of Asmari Formation in the Firuzabad (south of Shiraz) and Bastak (west of Bandar-Abbas) sections in the Zagros Basin (Fras Platform) have been analyzed for distinguishing facies characteristics, interpreting the paleoenvironment and determining dominant depositional sequences. Based on field investigations and laboratory studies, 13 microfacies …


Development Of A Synthesis Method For O2-Releasing Compound For Microbiological Experiments, Danae Greco Jan 2020

Development Of A Synthesis Method For O2-Releasing Compound For Microbiological Experiments, Danae Greco

Williams Honors College, Honors Research Projects

Many celestial bodies within our solar system may have habitable environments due to the presence of liquid water. Europa, one of Jupiter’s moons, may be habitable because of its liquid ocean and other potentially biologically favorable conditions. The ocean on Europa is hypothesized to contain large amounts of oxidants and low pH due to the radiolytically processed icy ocean shell. This suspected environment on Europa is similar to the composition of acid mine drainage on Earth, which can house microbial communities in environments of extreme acidity. Similar chemical reactions in Europa’s ocean may occur to produce the appropriate reduction-oxidation gradients …


Internet Of Things For Sustainable Forestry, Abdul Salam Jan 2020

Internet Of Things For Sustainable Forestry, Abdul Salam

Faculty Publications

Forests and grasslands play an important role in water and air purification, prevention of the soil erosion, and in provision of habitat to wildlife. Internet of Things has a tremendous potential to play a vital role in the forest ecosystem management and stability. The conservation of species and habitats, timber production, prevention of forest soil degradation, forest fire prediction, mitigation, and control can be attained through forest management using Internet of Things. The use and adoption of IoT in forest ecosystem management is challenging due to many factors. Vast geographical areas and limited resources in terms of budget and equipment …


Bacterial Community Dissimilarity In Soils Is Driven By Long-Termland-Use Practices, Aditi Sengupta, Janani Hariharan, Parwinder Grewal, Warren A. Dick Jan 2020

Bacterial Community Dissimilarity In Soils Is Driven By Long-Termland-Use Practices, Aditi Sengupta, Janani Hariharan, Parwinder Grewal, Warren A. Dick

School of Earth, Environmental, & Marine Sciences Faculty Publications

Land‐use practices impact soil microbial functionality and biodiversity, with reports suggesting that anthropogenic activities potentially result in reduced microbial functions and loss of species. The objective of this study was to assess the effect of long‐term (>50 yr) land use (natural forest and grassland, and agricultural land) on soil bacterial community structure. A high‐throughput sequencing‐by‐synthesis approach of the 16S rRNA gene was used to study bacterial community and predicted functional profiles of Alfisols, as affected by variables including land‐use (forest, grass, agricultural) and soil/crop management (rotation and tillage) in long‐term experimental plots in Hoytville, OH. The distribution of the …


Modeling Hydrologic Impacts Of Tribal Water Rights Quantification And Settlement On The Flathead Indian Irrigation Project, Jordan Andrew Jimmie Jan 2020

Modeling Hydrologic Impacts Of Tribal Water Rights Quantification And Settlement On The Flathead Indian Irrigation Project, Jordan Andrew Jimmie

Graduate Student Theses, Dissertations, & Professional Papers

The Confederated Salish and Kootenai Tribes (CSKT) of the Flathead Reservation are a federally-recognized group of tribes (Kootenai, Salish, and Pend d’Oreille) located in western Montana. On the reservation lies the expansive Flathead Indian Irrigation Project (FIIP), which supplies irrigation water to approximately 127,000 acres of tribal and non-tribal agricultural land. The 1904 Flathead Allotment Act opened “surplus” land to non-native homesteaders without tribal consent, initiating the land ownership fragmentation observed on the reservation today. This legacy, combined with historically unquantified tribal reserved water rights and the antiquated state of the FIIP infrastructure, including water losses from unlined earthen canals, …


A Spatially Distributed Investigation Of Stream Water Temperature In A Contemporary Mixed-Land-Use Watershed, Jason P. Horne Jan 2020

A Spatially Distributed Investigation Of Stream Water Temperature In A Contemporary Mixed-Land-Use Watershed, Jason P. Horne

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stream water temperature is an important physical variable that influences many biological and abiotic water quality processes. The land-use/land-cover (LULC) types and corresponding variability in stream water temperature (Tw) processes in contemporary mixed-land-use watersheds necessitate research to advance management and policy decisions. Water temperature was analyzed from 21 gauging sites using a nested-scale experimental watershed study design. Results showed that forested land use was significantly negatively correlated (α = 0.05) with mean and maximum Tw. Agricultural land use was significantly positively correlated (α = 0.05) with maximum Tw except during the spring season. Mixed development and Tw were significantly correlated …


Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis Jan 2020

Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis

Williams Honors College, Honors Research Projects

Previous research investigating the speleogenesis of iron-ore caves (IOC) in the Quadrilátero Ferrífero, or “Iron Quadrangle,” of Brazil suggests that microbial iron reduction and subsequent dissolution of the surrounding Fe(III) rich rocks is responsible for cave formation. A soft intra-wall substance (sub muros) containing iron-reducing bacteria (FeRB) was discovered underneath the durable crusts of cave walls. The goal of the study was to determine if reduction rates were comparable between sub muros samples, while additionally observing how different electron donors affect microbial iron reduction. To do this, I compared Fe(III) reduction rates between sub muros samples collected from …


Mod$$At: A Hydro-Economic Modeling Framework For Aquifer Management In Irrigated Agricultural Regions, Mani Rouhi Rad, Erin M.K. Haacker, Vaishali Sharda, Soheil Nozari, Zaichen Xiang, A. Araya, Venkatesh Uddameri, Jordan Suter, Prasanna Gowda Jan 2020

Mod$$At: A Hydro-Economic Modeling Framework For Aquifer Management In Irrigated Agricultural Regions, Mani Rouhi Rad, Erin M.K. Haacker, Vaishali Sharda, Soheil Nozari, Zaichen Xiang, A. Araya, Venkatesh Uddameri, Jordan Suter, Prasanna Gowda

Department of Earth and Atmospheric Sciences: Faculty Publications

In this paper, we introduce a hydro-economic modeling framework for the management of groundwater re- sources that are used for irrigated agricultural production. The model, MOD$$AT, can be used to study the costs of aquifer depletion and the net benefits of specific aquifer management policies. MOD$$AT is composed of three components, namely, an economic component, a hydrologic component and an agronomic component. A main goal of this paper is to introduce the hydro-economic model and describe how it can be transferable to different contexts. With this objective in mind, we describe model components step-by-step so that the process of integration …


The Impacts Of Accessibility On Vulnerability Of Place In Comfort Castle, Jamaica, Heather Thole Jan 2020

The Impacts Of Accessibility On Vulnerability Of Place In Comfort Castle, Jamaica, Heather Thole

Dissertations, Master's Theses and Master's Reports

Jamaica experiences meteorological, hydrological, and geological natural hazards that can produce island-wide impacts. The island’s exposure to multiple hazard types requires effective and sustainable mitigation and disaster risk management to lessen potential impacts, especially for vulnerable populations and communities. Comfort Castle, a small rural farming community, sits in the upper Rio Grande Valley of Portland parish and experiences earthquakes, landslides, hurricanes, heavy rainfall, and floods. Steep terrain and remoteness due to geographic location affect the community’s geophysical vulnerability. Their social vulnerability results from a lack of employment, health, educational, and livelihood resources within the community. Together, geophysical, and social factors …


Soil Carbon Dynamics And Greenhouse Gas Emissions In Conservation Tillage Systems At Multiple Scales, Yawen Huang Jan 2020

Soil Carbon Dynamics And Greenhouse Gas Emissions In Conservation Tillage Systems At Multiple Scales, Yawen Huang

Theses and Dissertations--Plant and Soil Sciences

Conservation tillage practices like no-tillage and reduced tillage have been widely implemented worldwide, with expectations they would provide multiple benefits (e.g., yield enhancement and soil carbon sequestration) for food security and climate adaptation and mitigation. However, the adoption of conservation tillage faces both opportunities and challenges. A knowledge gap still exists regarding the effects of conservation tillage on the carbon cycle in agroecosystems. This dissertation reflects a comprehensive evaluation of conservation tillage at multiple scales using an integrated systems approach, a combination of data synthesis, the agriculture ecosystem model, and field observations and measurements. I first conducted a meta-analysis to …


Assessing The Hierarchy Of Long-Term Environmental Controls On Diatom Communities Of Yellowstone National Park Using Lacustrine Sediment Records, Victoria Chraibi, Sherilyn C. Fritz Jan 2020

Assessing The Hierarchy Of Long-Term Environmental Controls On Diatom Communities Of Yellowstone National Park Using Lacustrine Sediment Records, Victoria Chraibi, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

An ecosystem’s ability to maintain structure and function following disturbance, defined as resilience, is influenced by a hierarchy of environmental controls, including climate, surface cover, and ecological relationships that shape biological community composition and productivity. This study examined lacustrine sediment records of naturally fishless lakes in Yellowstone National Park to reconstruct the response of aquatic communities to climate and trophic cascades from fish stocking. Sediment records of diatom algae did not exhibit a distinct response to fish stocking in terms of assemblage or algal productivity. Instead, 3 of 4 lakes underwent a shift to dominance by benthic diatom species from …


Spatial And Temporal Ecological Uniqueness Of Andean Diatom Communities Are Correlated With Climate, Geodiversity And Long-Term Limnological Change, Xavier Benito, Annika Vilmi, Melina Luethje, Maria Laura Carrevedo, Marja Lindholm, Sherilyn C. Fritz Jan 2020

Spatial And Temporal Ecological Uniqueness Of Andean Diatom Communities Are Correlated With Climate, Geodiversity And Long-Term Limnological Change, Xavier Benito, Annika Vilmi, Melina Luethje, Maria Laura Carrevedo, Marja Lindholm, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

High-elevation tropical lakes are excellent sentinels of global change impacts, such as climate warming, land-use change, and atmospheric deposition. These effects are often correlated with temporal and spatial beta diversity patterns, with some local communities contributing more than others, a phenomenon known as local contribution to beta diversity (LCBD) or ecological uniqueness. Microorganisms, such as diatoms, are considered whole-ecosystem indicators, but little is known about their sensitivity and specificity in beta diversity studies mostly because of the lack of large spatial and temporal datasets. To fill this gap, we used a tropical South American diatom database comprising modern (144 lakes) …


The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew S. Van Den Broeke, Timothy J. Gunkel Jan 2020

The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew S. Van Den Broeke, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Faculty Publications

Seasonal bird migration occurs on large spatial scales and is influenced by many factors including weather conditions. Weather can include thunderstorms, which may force migrants to land or cause them to reroute a migration path. In this study, a sample of isolated thunderstorms was analyzed from the domains of three weather radars in the central United States to test hypotheses regarding the influence of thunderstorms on the distribution of migrants. Migrating bird density was often reduced in the wake of storms, and this wake reduction was typically more pronounced for larger, more intense and faster- moving storms, particularly in eastern …


The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew V.D. Broeke, Timothy J. Gunkel Jan 2020

The Influence Of Isolated Thunderstorms And The Low-Level Wind Field On Nocturnally Migrating Birds In Central North America, Matthew V.D. Broeke, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Faculty Publications

Seasonal bird migration occurs on large spatial scales and is influenced by many factors including weather conditions. Weather can include thunderstorms, which may force migrants to land or cause them to reroute a migration path. In this study, a sample of isolated thunderstorms was analyzed from the domains of three weather radars in the central United States to test hypotheses regarding the influence of thunderstorms on the distribution of migrants. Migrating bird density was often reduced in the wake of storms, and this wake reduction was typically more pronounced for larger, more intense and faster- moving storms, particularly in eastern …


Controls On Channel Deposits Of Highly Variable Rivers: Comparing Hydrology And Event Deposits In The Burdekin River, Australia, Jan Alexander, Christopher M. Herbert, Christopher R. Fielding, Kathryn J. Amos Jan 2020

Controls On Channel Deposits Of Highly Variable Rivers: Comparing Hydrology And Event Deposits In The Burdekin River, Australia, Jan Alexander, Christopher M. Herbert, Christopher R. Fielding, Kathryn J. Amos

Department of Earth and Atmospheric Sciences: Faculty Publications

Discharge event frequency, magnitude and duration all control river chan- nel morphology and sedimentary architecture. Uncertainty persists as to whether alluvial deposits in the rock record are a time-averaged amalgam from all discharge events, or a biased record of larger events. This paper investigates the controls on channel deposit character and subsurface strati- graphic architecture in a river with seasonal discharge and very high inter- annual variability, the Burdekin River of north-east Australia. In such rivers, most sediment movement is restricted to a few days each year and at other times little sediment moves. However, the maximum discharge magnitude does …