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Physical Sciences and Mathematics

2019

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Articles 1 - 30 of 97

Full-Text Articles in Public Affairs, Public Policy and Public Administration

Direct And Indirect Effects Of Temperature And Prey Abundance On Bald Eagle Reproductive Dynamics, Joshua H. Schmidt, Judy Putera, Tammy L. Wilson Dec 2019

Direct And Indirect Effects Of Temperature And Prey Abundance On Bald Eagle Reproductive Dynamics, Joshua H. Schmidt, Judy Putera, Tammy L. Wilson

United States National Park Service: Publications

Understanding the mechanisms by which populations are regulated is critical for predicting the effects of large-scale perturbations. While discrete mortality events provide clear evidence of direct impacts, indirect pathways are more difficult to assess but may play important roles in population and ecosystem dynamics. Here, we use multi-state occupancy models to analyze a long-term dataset on nesting bald eagles in south-central Alaska with the goal of identifying both direct and indirect mechanisms influencing reproductive output in this apex predator. We found that the probabilities of both nest occupancy and success were higher in the portion of the study area where …


Dronescape:Distributed Rapid On-Site Network Self-Deploying Cellular Advanced Phone Environment, Daryl Johnson, Bill Stackpole Dec 2019

Dronescape:Distributed Rapid On-Site Network Self-Deploying Cellular Advanced Phone Environment, Daryl Johnson, Bill Stackpole

Presentations and other scholarship

When disasters happen, the speed with which first responders and emergency personnel can contact and be contacted by the people affected by the disaster during the first minutes or hours is critical. Early communications can make the difference between life and death. During a disaster communications infrastructure of the affected area is likely to be compromised. This project proposes an inexpensive, rapidly deployable cloud of autonomous drones, each coupled with a micro-cellular base station that deploys from a transportable deployment module. The goal is to temporarily restore communications for both first responders to communicate amongst themselves as well as for …


Natural Resource Condition Assessment, Homestead National Monument Of America, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer Dec 2019

Natural Resource Condition Assessment, Homestead National Monument Of America, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer

United States National Park Service: Publications

Executive Summary

The National Park Service (NPS) Natural Resource Condition Assessment (NRCA) Program administered by the NPS Water Resources Division evaluates current conditions for important natural resources and resource indicators using primarily existing information and data. NRCAs also report on trends in resource condition when possible, identify critical data gaps, and characterize a general level of confidence for study findings. This NRCA complements historic resource assessments, is multi-disciplinary in scope, employs a hierarchical indicator framework, identifies and develops reference conditions/values for comparison against current conditions, and emphasizes spatial evaluation of conditions and GIS (map) products.

Congress established the Homestead National …


Plant Community Composition And Structure Monitoring At Wind Cave National Park, 2019 Data Report, Theresa L. Schaffner, Daniel J. Swanson, Stephanie L. Rockwood Dec 2019

Plant Community Composition And Structure Monitoring At Wind Cave National Park, 2019 Data Report, Theresa L. Schaffner, Daniel J. Swanson, Stephanie L. Rockwood

United States National Park Service: Publications

Abstract

This report presents the results of the Northern Great Plains Inventory and Monitoring Network (NGPN) and Northern Great Plains Fire Ecology Program (NGPFire) vegetation monitoring at Wind Cave National Park (WICA) in 2019. This was the ninth year of combined monitoring efforts.

Crew members from NGPN visited 18 long-term monitoring plots to collect data representing the plant communities at WICA. The NGPFire program collected pre- and post-burn data from an additional 37 plant community and forest structure monitoring plots. This work is part of a long-term monitoring effort designed to evaluate the condition of the vegetation community and understand …


Plant Community Composition And Structure Monitoring At Agate Fossil Beds National Monument, 2019 Data Report, Molly B. Davis Dec 2019

Plant Community Composition And Structure Monitoring At Agate Fossil Beds National Monument, 2019 Data Report, Molly B. Davis

United States National Park Service: Publications

Abstract

This report presents the results of vegetation monitoring efforts in 2019 at Agate Fossil Beds National Monument (AGFO) by the Northern Great Plains Inventory and Monitoring Network (NGPN) and the Northern Great Plains Fire Ecology Program (NGPFire). This was the ninth year of combined monitoring efforts.

In 2019, crew members from NGPN visited 6 long-term plant community monitoring (PCM) plots to collect data on the upland mixed-grass prairie plant communities at AGFO. This work is part of a long-term monitoring program established to better understand the condition of the vegetation community and how it changes over time. NGPN staff …


Vegetation Classification And Mapping, Missouri National Recreational River, Tom Baldvins, Matt Ley, David Jones, Joe Stevens, Hannah Pilkington Dec 2019

Vegetation Classification And Mapping, Missouri National Recreational River, Tom Baldvins, Matt Ley, David Jones, Joe Stevens, Hannah Pilkington

United States National Park Service: Publications

Executive Summary

The vegetation inventory project at Missouri National Recreational River (MNRR) classified and mapped vegetation within the park administrative boundary and estimated thematic map accuracy quantitatively. The project was conducted over a four year period from the summer of 2015 to the winter of 2019.

The project follows guidance provided by the National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program. The overall process includes initial planning and scoping, imagery procurement, field data collection, data analysis, imagery interpretation and classification, and accuracy assessment. The initial planning and scoping meetings to support study plan development took place in December, 2009, …


A Mathematical Programming Model For The Green Mixed Fleet Vehicle Routing Problem With Realistic Energy Consumption And Partial Recharges, Vincent F. Yu, Panca Jodiwan, Aldy Gunawan, Audrey Tedja Widjaja Dec 2019

A Mathematical Programming Model For The Green Mixed Fleet Vehicle Routing Problem With Realistic Energy Consumption And Partial Recharges, Vincent F. Yu, Panca Jodiwan, Aldy Gunawan, Audrey Tedja Widjaja

Research Collection School Of Computing and Information Systems

A green mixed fleet vehicle routing with realistic energy consumption and partial recharges problem (GMFVRP-REC-PR) is addressed in this paper. This problem involves a fixed number of electric vehicles and internal combustion vehicles to serve a set of customers. The realistic energy consumption which depends on several variables is utilized to calculate the electricity consumption of an electric vehicle and fuel consumption of an internal combustion vehicle. Partial recharging policy is included into the problem to represent the real life scenario. The objective of this problem is to minimize the total travelled distance and the total emission produced by internal …


Study Group Travel Behaviour Patterns From Large-Scale Smart Card Data, Xiancai Tian, Baihua Zheng Dec 2019

Study Group Travel Behaviour Patterns From Large-Scale Smart Card Data, Xiancai Tian, Baihua Zheng

Research Collection School Of Computing and Information Systems

In this paper, we aim at studying the group travel behaviour (GTB) patterns from large-scale auto fare collection (AFC) data. GTB is defined as two or more commuters intentionally and regularly traveling together from an origin to a destination. We propose a method to identify GTB accurately and efficiently and apply our method to the Singapore AFC dataset to reveal the GTB patterns of Singapore commuters. The case study proves that our method is able to identify GTB patterns more accurately and efficiently than the state-of-the-art.


Material And Seismic Assessment Of The Great House At Casa Grande Ruins National Monument, Arizona, Douglas W. Porter, Anjali Mehrotra, Matthew J. Dejong, Angelyn Bass, Matthew Guebard, John Ochsendorf Nov 2019

Material And Seismic Assessment Of The Great House At Casa Grande Ruins National Monument, Arizona, Douglas W. Porter, Anjali Mehrotra, Matthew J. Dejong, Angelyn Bass, Matthew Guebard, John Ochsendorf

United States National Park Service: Publications

The authors characterized earthen wall materials and plasters in a mid-fourteenth-century Hohokam great house at Casa Grande Ruins National Monument (Arizona) and assessed the seismic susceptibility of its puddled earth walls. Characterization included determining the microstructure, microcomposition, porosity, aggregate mineralogy, and identification of phases in the binding matrix for each of 36 samples and reconstructing plaster technologies, including material selection, preparation, and application sequences. Findings support the ideas that earthen materials were manipulated to optimize their performance to suit the unique site conditions and needs of the ancient people using the structure and included finishes that were unusual in southwestern …


Exposure And Potential Effects Of Pesticides And Pharmaceuticals In Protected Streams Of The Us National Park Service Southeast Region, Paul M. Bradley, Kristin M. Romanok, Jeffrey R. Duncan, William A. Battaglin, Jimmy M. Clark, Michelle L. Hladik, Bradley J. Huffman, Luke R. Iwanowicz, Celeste A. Journey, Kelly L. Smalling Nov 2019

Exposure And Potential Effects Of Pesticides And Pharmaceuticals In Protected Streams Of The Us National Park Service Southeast Region, Paul M. Bradley, Kristin M. Romanok, Jeffrey R. Duncan, William A. Battaglin, Jimmy M. Clark, Michelle L. Hladik, Bradley J. Huffman, Luke R. Iwanowicz, Celeste A. Journey, Kelly L. Smalling

United States National Park Service: Publications

Globally, protected areas offer refugia for a broad range of taxa including threatened and endangered species. In the United States (US), the National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected-stream ecosystems within the highly urbanized southeast region (SER) from bioactive contaminants was assessed in five systems based on 334 pesticide and pharmaceutical analytes in water and 119 pesticides in sediment. Contaminant mixtures were common across all sampled systems, with approximately 24% of the …


Satellite-Based Decadal Change Assessments Of Pan-Arctic Environments, Liza K. Jenkins, Tom Barry, Karl R. Bosse, William S. Currie, Tom Christensen, Sara Longan, Robert A. Shuchman, Danielle Tanzer, Jason J. Taylor Nov 2019

Satellite-Based Decadal Change Assessments Of Pan-Arctic Environments, Liza K. Jenkins, Tom Barry, Karl R. Bosse, William S. Currie, Tom Christensen, Sara Longan, Robert A. Shuchman, Danielle Tanzer, Jason J. Taylor

United States National Park Service: Publications

Remote sensing can advance the work of the Circumpolar Biodiversity Monitoring Program through monitoring of satellite-derived terrestrial and marine physical and ecological variables. Standardized data facilitate an unbiased comparison across variables and environments. Using MODIS standard products of land surface temperature, percent snow-covered area, NDVI, EVI, phenology, burned area, marine chlorophyll, CDOM, sea surface temperature, and marine primary productivity, significant trends were observed in almost all variables between 2000 and 2017. Analysis of seasonal data revealed significant breakpoints in temporal trends. Within the terrestrial environment, data showed significant increasing trends in land surface temperature and NDVI. In the marine environment, …


Can The Us And Europe Contain Russian Power In The European Energy Market? A Game Theoretic Approach, Jesse Richman, Nurullah Ayyilmaz Nov 2019

Can The Us And Europe Contain Russian Power In The European Energy Market? A Game Theoretic Approach, Jesse Richman, Nurullah Ayyilmaz

Political Science & Geography Faculty Publications

The Russian history of politicization of natural gas supplies led Europe to seek alternatives. US LNG is considered to be a viable alternative for Europe, which positioned the US as a strong competitor against Russia. In a game theoretic approach, we model this strategic decision-making process in simultaneous-move and sequential games. Our findings indicate a mixed strategy equilibrium: Europe cannot commit to diversify in the face of Russian advantages, and Russia cannot fully resist the temptation to politicize its supplies to Europe. The US might attempt to intervene in the European commitment problem through implementing sanctions on Russian gas sales. …


Vegetation Classification And Mapping, Niobrara National Scenic River, Tom Baldvins, Matt Ley, Joe Stevens, David Jones, Hannah Pilkington Nov 2019

Vegetation Classification And Mapping, Niobrara National Scenic River, Tom Baldvins, Matt Ley, Joe Stevens, David Jones, Hannah Pilkington

United States National Park Service: Publications

Executive Summary

The vegetation inventory project at Niobrara National Scenic River (NIOB) classified and mapped vegetation within the park administrative boundary and estimated thematic map accuracy quantitatively. The project was conducted over a four year period from the summer of 2015 to the winter of 2019. Located in north-central Nebraska, approximately 76 miles of the park is designated as a wild and scenic river. The vast majority of land within the NIOB administrative boundary is private or state-owned.

The project follows guidance provided by the National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program. The overall process includes initial planning …


Natural Resource Condition Assessment, Tallgrass Prairie National Preserve, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer, Rob Schorr Nov 2019

Natural Resource Condition Assessment, Tallgrass Prairie National Preserve, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer, Rob Schorr

United States National Park Service: Publications

Executive Summary

The National Park Service (NPS) Natural Resource Condition Assessment (NRCA) Program administered by the NPS Water Resources Division evaluates current conditions for important natural resources and resource indicators using primarily existing information and data. NRCAs also report on trends in resource condition when possible, identify critical data gaps, and characterize a general level of confidence for study findings. This NRCA complements historic resource assessments, is multi-disciplinary in scope, employs a hierarchical indicator framework, identifies and develops reference conditions/values for comparison against current conditions, and emphasizes spatial evaluation of conditions and GIS products.

Created in 1996, Tallgrass Prairie National …


Urban-Rural Surface Temperature Deviation And Intra-Urban Variations Contained By An Urban Growth Boundary, Kevan B. Moffett, Yasuyo Makido, Vivek Shandas Nov 2019

Urban-Rural Surface Temperature Deviation And Intra-Urban Variations Contained By An Urban Growth Boundary, Kevan B. Moffett, Yasuyo Makido, Vivek Shandas

Urban Studies and Planning Faculty Publications and Presentations

The urban heat island (UHI) concept describes heat trapping that elevates urban temperatures relative to rural temperatures, at least in temperate/humid regions. In drylands, urban irrigation can instead produce an urban cool island (UCI) effect. However, the UHI/UCI characterization suffers from uncertainty in choosing representative urban/rural endmembers, an artificial dichotomy between UHIs and UCIs, and lack of consistent terminology for other patterns of thermal variation at nested scales. We use the case of a historically well-enforced urban growth boundary (UGB) around Portland (Oregon, USA): to explore the representativeness of the surface temperature UHI (SUHI) as derived from Moderate Resolution Imaging …


Relationships Between Soil Macroinvertebrates And Nonnative Feral Pigs (Sus Scrofa) In Hawaiian Tropical Montane Wet Forests, Nathaniel H. Wehr, Creighton M. Litton, Noa K. Lincoln, Steven C. Hess Oct 2019

Relationships Between Soil Macroinvertebrates And Nonnative Feral Pigs (Sus Scrofa) In Hawaiian Tropical Montane Wet Forests, Nathaniel H. Wehr, Creighton M. Litton, Noa K. Lincoln, Steven C. Hess

United States National Park Service: Publications

Abstract Nonnative feral pigs (Sus scrofa) are recognized throughout the New World as a highly significant introduced species in terms of ecosystem alteration. Similarly, nonnative soil macroinvertebrates (e.g. earthworms, ground beetles) invade and alter the structure and function of native habitats globally. However, the relationship between feral pigs and soil macroinvertebrates remains largely unknown. This study analyzed relationships between these taxa using nine sites located inside and outside of feral pig management units representing a * 25 year chronosequence of removal in tropical montane wet forests in Hawai‘i. Soil macroinvertebrates were sampled from plots categorized as: actively trampled by feral …


Community Outreach For The Virginia Beach Comprehensive Flooding Response Plan (Sea-Level Wise), Michelle Covi, Wie Yusuf, Gail Nicula, Daniel Richards, Afi Anuar Oct 2019

Community Outreach For The Virginia Beach Comprehensive Flooding Response Plan (Sea-Level Wise), Michelle Covi, Wie Yusuf, Gail Nicula, Daniel Richards, Afi Anuar

Presentations, Lectures, Posters, Reports

[From Introduction]

In partnership with the City of Virginia Beach, the Old Dominion University research team of Drs. Michelle Covi, Wie Yusuf, Gail Nicula, Daniel Richards and Afi Anuar developed and executed a program for public engagement meetings using the ASERT (Action-oriented Stakeholder Engagement for a Resilient Tomorrow) framework to solicit resident engagement with and input into the City’s Comprehensive Sea Level Rise and Recurrent Flooding Response Plan, now known as Sea Level Wise.


Juvenile Hawksbill Residency And Habitat Use Within A Caribbean Marine Protected Area, Thomas H. Selby, Kristen M. Hart, Brian J. Smith, Clayton G. Pollock, Zandy Hillis-Starr, Madan K. Oli Oct 2019

Juvenile Hawksbill Residency And Habitat Use Within A Caribbean Marine Protected Area, Thomas H. Selby, Kristen M. Hart, Brian J. Smith, Clayton G. Pollock, Zandy Hillis-Starr, Madan K. Oli

United States National Park Service: Publications

Understanding the spatial ecology of highly mobile marine vertebrates is necessary for informing conservation and management strategies aimed at protecting such species. Buck Island Reef National Monument (BIRNM), off the coast of St. Croix, US Virgin Islands, harbors critical foraging habitat for Critically Endangered juvenile hawksbills Eretmochelys imbricata that exhibit high site fidelity until sexual maturation. Using an array of fixed passive acoustic receivers that covered over 20.2 km2 at its largest configuration and in-water biannual sampling, we analyzed residency patterns and habitat use of 29 hawksbills. High recapture rates allowed for long- term data collection for some individuals, with …


Eureka, Ca Fishing Community Sustainability Plan, Lisa Wise Consulting, Inc., Humboldt State University Oct 2019

Eureka, Ca Fishing Community Sustainability Plan, Lisa Wise Consulting, Inc., Humboldt State University

Local Reports and Publications

The Eureka Fishing Community Sustainability Plan (FCSP) is the product of years of planning, hard work, and collaboration among a wide range of interests, led by local commercial and charter fishermen, processors, representatives from the mariculture industry, fishing-related businesses, fishing families, civic leaders, elected officials, City of Eureka staff, academia, business owners and operators, and funding from the federal government.

An FCSP is a document outlined in the federal Magnuson-Stevens Fishery Conservation and Management Act (MSA) to address “the social development needs of coastal communities.” The word “Fishing” has been added at the community’s discretion to better represent the focus …


Inferring Accurate Bus Trajectories From Noisy Estimated Arrival Time Records, Lakmal Meegahapola, Noel Athaide, Kasthuri Jayarajah, Shili Xiang, Archan Misra Oct 2019

Inferring Accurate Bus Trajectories From Noisy Estimated Arrival Time Records, Lakmal Meegahapola, Noel Athaide, Kasthuri Jayarajah, Shili Xiang, Archan Misra

Research Collection School Of Computing and Information Systems

Urban commuting data has long been a vital source of understanding population mobility behaviour and has been widely adopted for various applications such as transport infrastructure planning and urban anomaly detection. While individual-specific transaction records (such as smart card (tap-in, tap-out) data or taxi trip records) hold a wealth of information, these are often private data available only to the service provider (e.g., taxicab operator). In this work, we explore the utility in harnessing publicly available, albeit noisy, transportation datasets, such as noisy “Estimated Time of Arrival" (ETA) records (commonly available to commuters through transit Apps or electronic signages). We …


Water And War: The Potential For Perpetuation Of Conflict Due To Climate Change, Kaufman Butler Oct 2019

Water And War: The Potential For Perpetuation Of Conflict Due To Climate Change, Kaufman Butler

Independent Study Project (ISP) Collection

Climate change has had a dramatic impact on the world’s weather for years, scientists can only make predictions about how global climate will continue to change going forward; but in all scenarios the circumstances are quite dire. The Middle East and North Africa (MENA) will see some of the most severe effects of climate change, which will permanently alter the lives of millions of people in the region. In the MENA region, climate change is projected to result in extreme drought and temperatures which will lead to increased water scarcity, in what is already the most water poor region in …


Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo Oct 2019

Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo

Independent Study Project (ISP) Collection

As climate change continues to threaten the future state of our world, we are searching for measures to take for mitigation. Among these measures, the most talked about method is the development of renewable energies. Great amounts of attention is paid to solar and wind power, but relatively little effort is given to researching the possibilities of ocean energy, particularly tidal barrage energy. This study assesses the possibility of a tidal barrage plant in Hvalfjörður, Iceland. This hypothetical power plant in Hvalfjörður would have an installed capacity of 840MWh and could produce 613GWh per year. This is less than 0.01% …


Barriers And Opportunities To Electric Vehicle Development In Nepal, Allyson Krupa Oct 2019

Barriers And Opportunities To Electric Vehicle Development In Nepal, Allyson Krupa

Independent Study Project (ISP) Collection

As the global carbon dioxide level reaches its highest point in human history (407.4 parts per million), energy systems must transition from fossil fuel to renewable-powered sources. Since the transportation sector contributes nearly one-third of global greenhouse gas (GHG) emissions, electric mobility offers a significant opportunity to reduce GHG emissions. Globally, there has been a rise in demand for electric vehicles. In Nepal, a clean energy transition within the context of rising urbanization and air pollution is imperative for quality of life, socio-economic development, and broadly climate change mitigation/adaptation. Furthermore, Nepal’s vast hydropower potential may increase energy independence and provide …


E-Waste Shouldn’T Be Waste: A Study On The Practices, Perceptions, And Policies On E-Waste In Urban Arusha, Tanzania, Melanie Mckenzie Oct 2019

E-Waste Shouldn’T Be Waste: A Study On The Practices, Perceptions, And Policies On E-Waste In Urban Arusha, Tanzania, Melanie Mckenzie

Independent Study Project (ISP) Collection

This study examines the e-waste stream in urban Arusha, answer the questions of where electronics go, how people usually dispose of them, if people are aware of the impacts of e-waste, and what next steps are necessary. The study took place in November 2019 in urban Arusha, Tanzania. Through snowball and convenience sampling in 4 quotas (community members, electricians, business members, and a policy maker), the study finds that there is no place for the proper disposal of e-waste in Arusha. Many electronics are disposed of improperly by being put into the landfill or burned. Most participants were unaware of …


An Analysis Of The Rajasthan Public Health System’S Response To The 2019 Dengue Insurgence, Luke Bryan Oct 2019

An Analysis Of The Rajasthan Public Health System’S Response To The 2019 Dengue Insurgence, Luke Bryan

Independent Study Project (ISP) Collection

Dengue virus is in a pandemic status and is a major public health issue in the modern world. The mosquito-borne disease is largely prevalent in Asia and specifically India, where more than half of the states are considered to have complete presence of the dengue virus. The intricate infrastructure of the Indian public health system looks for dengue cases at all levels and reports to the integrated disease surveillance programme (IDSP).

Analyses of the IDSP and trends of dengue cases was done in response to dengue outbreaks throughout the state. Geographic information system (GIS) maps were created to evaluate a …


What About The Environment?: Exploring The Neglected Third Dimension Of Antimicrobial Resistance, Paige E. Montfort Oct 2019

What About The Environment?: Exploring The Neglected Third Dimension Of Antimicrobial Resistance, Paige E. Montfort

Independent Study Project (ISP) Collection

Antimicrobial resistance (AMR) is one of the most urgent and complex health risks of our time, with links to human health, animal health, and the environment. The majority of research and policy related to AMR, however, has been dedicated to human and animal health. The third dimension — the environment — has been relatively neglected. Conversations about this problem have begun, but gaps in understanding remain. This study explores the key barriers that have hindered developments related to the environmental aspect of AMR and some of the solutions that have begun to or could be utilized to overcome these barriers. …


Nonlinear Reaction–Diffusion Process Models Improve Inference For Population Dynamics, Xinyi Lu, Perry J. Williams, Mevin B. Hooten, James A. Powell, Jamie N. Womble, Michael R. Bower Sep 2019

Nonlinear Reaction–Diffusion Process Models Improve Inference For Population Dynamics, Xinyi Lu, Perry J. Williams, Mevin B. Hooten, James A. Powell, Jamie N. Womble, Michael R. Bower

United States National Park Service: Publications

Partial differential equations (PDEs) are a useful tool for modeling spatiotemporal dynamics of ecological processes. However, as an ecological process evolves, we need statistical models that can adapt to changing dynamics as new data are collected. We developed a model that combines an ecological diffusion equation and logistic growth to characterize colonization processes of a population that establishes long-term equilibrium over a heterogeneous environment. We also developed a homogenization strategy to statistically upscale the PDE for faster computation and adopted a hierarchical framework to accommodate multiple data sources collected at different spatial scales. We highlighted the advantages of using a …


Permafrost Hydrology Drives The Assimilation Of Old Carbon By Stream Food Webs In The Arctic, Jonathan A. O’Donnell, Michael P. Carey, Joshua C. Koch, Xiaomei Xu, Brett A. Poulin, Jennifer Walker, Christian E. Zimmerman Sep 2019

Permafrost Hydrology Drives The Assimilation Of Old Carbon By Stream Food Webs In The Arctic, Jonathan A. O’Donnell, Michael P. Carey, Joshua C. Koch, Xiaomei Xu, Brett A. Poulin, Jennifer Walker, Christian E. Zimmerman

United States National Park Service: Publications

Permafrost thaw in the Arctic is mobilizing old carbon (C) from soils to aquatic ecosystems and the atmosphere. Little is known, however, about the assimilation of old C by aquatic food webs in Arctic watersheds. Here, we used C isotopes (d13C, D14C) to quantify C assimilation by biota across 12 streams in arctic Alaska. Streams spanned watersheds with varying permafrost hydrology, from ice-poor bedrock to ice-rich loess (that is, yedoma). We measured isotopic content of (1) C sources including dissolved organic C (DOC), dissolved inorganic C (DIC), and soil C, and (2) stream biota, including benthic biofilm and macroinvertebrates, and …


Living Shorelines: Barriers And Promotion: Accomack County, Va, Amy Belcher, Rhiannon Bezore, Michelle Covi, Wie Yusuf Sep 2019

Living Shorelines: Barriers And Promotion: Accomack County, Va, Amy Belcher, Rhiannon Bezore, Michelle Covi, Wie Yusuf

Presentations, Lectures, Posters, Reports

Living shorelines can offer shoreline protection for low energy shorelines as well as providing ecoservices such as purifying water, buffering against floods, and attracting wildlife. This report highlights key benefits, possible barriers and solutions, and ideas for their promotion. Recommendations for implementing living shorelines are included for Accomack County, Virginia to aid in increasing awareness and utilization of living shorelines.


Social Interactions Do Not Drive Territory Aggregation In A Grassland Songbird, S.K. Winnicki, S.M. Munguia, E.J. Williams, W.A. Boyle Aug 2019

Social Interactions Do Not Drive Territory Aggregation In A Grassland Songbird, S.K. Winnicki, S.M. Munguia, E.J. Williams, W.A. Boyle

United States National Park Service: Publications

Understanding the drivers of animal distributions is a fundamental goal of ecology and informs habitat management. The costs and benefits of colonial aggregations in animals are well established, but the factors leading to aggregation in territorial animals remain unclear. Territorial animals might aggregate to facilitate social behavior such as (1) group defense from predators and/or parasites, (2) cooperative care of offspring, (3) extra-pair mating, and/or (4) mitigating costs of extra-pair mating through kin selection. Using experimental and observational methods, we tested predictions of all four hypotheses in a tallgrass prairie in northeast Kansas, United States. Grasshopper Sparrow (Ammodramus savannarum) males …