Digital Commons Network^™

How Good Is Good Enough? Data Requirements For Reliable Crop Yield Simulations And Yield-Gap Analysis, Patricio Grassini, Lenny G.J. Van Bussel, Justin Van Wart, Joost Wolf, Lieven Claessens, Haishun Yang, Hendrik Boogaard, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Numerous studies have been published during the past two decades that use simulation models to assess crop yield gaps (quantified as the difference between potential and actual farm yields), impact of climate change on future crop yields, and land-use change. However, there is a wide range in quality and spatial and temporal scale and resolution of climate and soil data underpinning these studies, as well as widely differing assumptions about cropping-system context and crop model calibration. Here we present an explicit rationale and methodology for selecting data sources for simulating crop yields and estimating yield gaps at specific locations that …

Using Swat To Simulate Crop Yields And Salinity Levels In The North Fork River Basin, Usa, Aaron R. Mittelstet, Daniel E. Storm, Art L. Stoecker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop yields and salinity levels in the North Fork of the Red River (North Fork River) basin, located in southwestern Oklahoma and the Texas Panhandle, were analyzed based on the diverse climate in the region. Saline irrigation water is a major problem in the basin. The Elm Fork Creek flows through salt deposits, making the creek and its receiving stream, the North Fork River, too saline to use for irrigation. This greatly reduces the number of hectares that can be utilized for agricultural crops within the basin. A baseline SWAT model was setup, calibrated and validated to simulate streamflow and …

In The Eye Of The Cyclops: The Classic Case Of Cospeciation And Why Paradigms Are Important, Daniel R. Brooks, Eric P. Hoberg, Walter A. Boeger

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Scientific disagreements due to empirical problems—not enough data, not enough of the critical type of data, problems in analyzing the data—are generally short-lived and resolved in the next cycle of data production. Such disagreements are thus transitory in nature. Persistent scientific conflicts, on the other hand, do not necessarily mean some facts are correct and some are wrong, nor do they mean that we do not have enough information. More often, such persistent conflicts mean that the conceptual frameworks used by different groups of researchers are insufficient to resolve apparent conflicts in the data. The latter seems to be the …

Evolution In Action: Climate Change, Biodiversity Dynamics And Emerging Infectious Disease, Eric P. Hoberg, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host–parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly …

Hymenolepis Folkertsi N. Sp. (Eucestoda: Hymenolepididae) In The Oldfield Mouse Peromyscus Polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) From The Southeastern Nearctic With Comments On Tapeworm Faunal Diversity Among Deer Mice, Arseny A. Makarikov, Todd N. Nims, Kurt E. Galbreath, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia, United States, near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from those attributed to most other species in the genus by having testes arranged in a triangle and a scolex with a prominent rostrum-like protrusion. The newly recognized species is further distinguished by the relative position and length of the cirrus sac, shape of seminal receptacle, and relative size of external seminal vesicle and seminal receptacle. Hymenolepidid cestodes have sporadically …

Land Use/Land Cover Changes And Regional Climate Over The Loess Plateau During 2001-2009 – Part I. Observed Evidences, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Lidar Scanning With Supplementary Uav Captured Images For Structural Inspections, Richard L. Wood, Mohammad Ebrahim Mohammadi

Department of Civil and Environmental Engineering: Faculty Publications

Structural assessment using remote sensing technologies can be performed efficiently and effectively using such technologies as LiDAR (light detection and ranging). LiDAR can be employed for various structural assessments, such as as-built conditions for a newly constructed facility, routine inspection during its service life, or structural collapse evaluation after a natural hazard or extreme event. However, the main disadvantage of LiDAR is that it is a line-of-sight technology that can result in significant occlusions. Architectural or structural components can be partially or fully occluded by another object with respect to the location of the laser scanner. Supplemental photogrammetry techniques, such …

Terrestrial Orchids In A Tropical Forest: Best Sites For Abundance Differ From Those For Reproduction, Melissa Whitman, James D. Ackerman

School of Biological Sciences: Faculty Publications

Suitable habitat for a species is often modeled by linking its distribution patterns with landscape characteristics. However, modeling the relationship between fitness and landscape characteristics is less common. In this study we take a novel approach towards species distribution modeling (SDM) by investigating factors important not only for species occurrence, but also abundance and physical size, as well as fitness measures. We used the Neotropical terrestrial orchid Prescottia stachyodes as our focal species, and compiled geospatial information on habitat and neighboring plants for use in a two-part conditional SDM that accounted for zero inflation and reduced spatial autocorrelation bias. First, …

Monthly Land Cover-Specific Evapotranspiration Models Derived From Global Eddy Flux Measurements And Remote Sensing Data, Yuan Fang, Ge Sun, Peter Caldwell, Steven G. Mcnulty, Asko Noormets, Jean-Christophe Domec, John King, Zhiqiang Zhang, Xudong Zhang, Guanghui Lin, Guangsheng Zhou, Jingfeng Xiao, Jiquan Chen

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Evapotranspiration (ET) is arguably the most uncertain ecohydrologic variable for quantifying watershed water budgets. Although numerous ET and hydrological models exist, accurately predicting the effects of global change on water use and availability remains challenging because of model deficiency and/or a lack of input parameters. The objective of this study was to create a new set of monthly ET models that can better quantify landscape-level ET with readily available meteorological and biophysical information. We integrated eddy covariance flux measurements from over 200 sites, multiple year remote sensing products from the Moderate Resolution Imaging Spectroradiometer (MODIS), and statistical modelling. Through examining …

Wildland Fire Deficit And Surplus In The Western United States, 1984–2012, Sean A. Parks, Carol Miller, Marc-André Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Wildland fire is an important disturbance agent in the western US and globally. However, the natural role of fire has been disrupted in many regions due to the influence of human activities, which have the potential to either exclude or promote fire, resulting in a ‘‘fire deficit’’ or ‘‘fire surplus’’, respectively. In this study, we developed a model of expected area burned for the western US as a function of climate from 1984 to 2012.We then quantified departures from expected area burned to identify geographic regions with fire deficit or surplus. We developed our model of area burned as a …

Importance Of Succession, Harvest, And Climate Change In Determining Future Composition In U.S. Central Hardwood Forests, Wen J. Wang, Hong S. He, Frank R. Thompson Iii, Jacob S. Fraser, Brice B. Hanberry, William D. Dijak

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Most temperate forests in U.S. are recovering from heavy exploitation and are in intermediate successional stages where partial tree harvest is the primary disturbance. Changes in regional forest composition in response to climate change are often predicted for plant functional types using biophysical process models. These models usually simplify the simulation of succession and harvest and may not consider important species-specific demographic processes driving forests changes. We determined the relative importance of succession, harvest, and climate change to forest composition changes in a 125-million ha area of the Central Hardwood Forest Region of U.S. We used a forest landscape modeling …

An Individual-Based Model For Feral Hogs In Great Smoky Mountains National Park, Rene A. Salinas, William H. Stiver, Joseph L. Corn, Suzanne Lenhart, Charles Collins, Marguerite Madden, Kurt C. Vercauteren, Brandon S. Schmit, Ellen Kasari, Agricola Odoi, Graham Hickling, Hamish Mccallum

United States Department of Agriculture Wildlife Services: Staff Publications

The expansion of feral hog (Sus scrofa) populations in the United States has resulted in increased efforts to develop and implement control strategies designed to minimize the impacts done by this invasive species. We describe an individual-based model for feral hogs in Great Smoky Mountains National Park (GSMNP). The objectives of the model are to provide an understanding of the population dynamics of this feral hog population and to determine the efficacy of the annual harvest as a population control method. Results suggest that the dynamics of the population are driven by fall hard mast production and the …

Impacts Of Colonial Waterbirds On Vegetation And Potential Restoration Of Island Habitats, Christopher R. Ayers, Katie C. Hanson-Dorr, Sadie O'Dell, Charles D. Lovell, Michael L. Jones, Jason R. Suckow, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Colonial waterbirds have impacted forested island ecosystems throughout their breeding range, changing vegetation, and soil characteristics and bird communities. Our objectives were to (1) determine effects of three levels of colonial waterbird exclusion on overall vegetation diversity and growth, and survival of a candidate restoration species (black elderberry; Sambucus nigra canadensis); (2) investigate effects of different planting techniques on survival and growth of black elderberry; and (3) determine effects of waterbird colonization on soil chemistry. In 2012, we investigated effects of three levels of waterbird exclusion (none control plots [CON]; partial, which excluded waterbirds larger than gulls [PEX]; and …

Utility Of Mosquito Surveillance Data For Spatial Prioritization Of Vector Control Against Dengue Viruses In Three Brazilian Cities, Kim M. Pepin, Clint B. Leach, Cecilia Marques-Toledo, Karla H. Laass, Kelly S. Paixao, Angela D. Luis, David T.S. Hayman, Nels D. Johnson, Michael G. Buhnerkempe, Scott Carver, Daniel A. Grear, Kimberly Tsao, Alvaro E. Eiras, Colleen T. Webb

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Vector control remains the primary defense against dengue fever. Its success relies on the assumption that vector density is related to disease transmission. Two operational issues include the amount by which mosquito density should be reduced to minimize transmission and the spatio-temporal allotment of resources needed to reduce mosquito density in a cost-effective manner. Recently, a novel technology, MI-Dengue, was implemented city-wide in several Brazilian cities to provide real-time mosquito surveillance data for spatial prioritization of vector control resources. We sought to understand the role of city-wide mosquito density data in predicting disease incidence in order to provide …

Rabies Surveillance Among Bats In Tennessee, Usa, 1996–2010, Amy T. Gilbert, Gary F. Mccracken, Lorinda L. Sheeler, Lisa I. Muller, Dorcas O'Rourke, William J. Kelch, John C. New Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Rabies virus (RABV) infects multiple bat species in the Americas, and enzootic foci perpetuate in bats principally via intraspecific transmission. In recent years, bats have been implicated in over 90% of human rabies cases in the US. In Tennessee, two human cases of rabies have occurred since 1960: one case in 1994 associated with a tricolored bat (Perimyotis subflavus) RABV variant and another in 2002 associated with the tricolored/silver-haired bat (P. subflavus/ Lasionycteris noctivagans) RABV variant. From 1996 to 2010, 2,039 bats were submitted for rabies testing in Tennessee. Among 1,943 bats in satisfactory condition for testing and with a …

Modeling And Mapping The Probability Of Occurrence Of Invasive Wild Pigs Across The Contiguous United States, Meredith L. Mcclure, Christopher L. Burdett, Matthew L. Farnsworth, Mark W. Lutman, David M. Theobald, Philip D. Riggs, Daniel A. Grear, Ryan S. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa), also known as wild swine, feral pigs, or feral hogs, are one of the most widespread and successful invasive species around the world. Wild pigs have been linked to extensive and costly agricultural damage and present a serious threat to plant and animal communities due to their rooting behavior and omnivorous diet. We modeled the current distribution of wild pigs in the United States to better understand the physiological and ecological factors that may determine their invasive potential and to guide future study and eradication efforts. Using national-scale wild pig occurrence data reported between 1982 and …

Possible Tsunami Deposits On The Caribbean Coast Of The Yucatán Peninsula, Charles Shaw, Larry Benson

United States Geological Survey: Staff Publications

The western Caribbean Basin is notable for its tectonic stability. It has experienced no historical earthquakes or the tsunami that sometimes accompany them. This paper describes a single, wedge-shaped, boulder-covered, coastal berm on the Yucatán coast of México that stretches unbroken for 50 km across a coastal segment characterized by rocky headlands that alternate with crescent beaches. The remainder of the 350 km of Yucatán coast consists mostly of mangrove that extends 1 to 30 km inland, often behind long, sandy beaches. On the headlands, the surface of the berm is densely paved with boulders—large boulders on its seaward face …

Seasonal Shifts In Diet And Gut Microbiota Of The American Bison (Bison Bison), Gaddy T. Bergmann, Joseph Craine, Michael S. Robeson, Noah Fierer

United States Department of Agriculture Wildlife Services: Staff Publications

North American bison (Bison bison) are becoming increasingly important to both grassland management and commercial ranching. However, a lack of quantitative data on their diet constrains conservation efforts and the ability to predict bison effects on grasslands. In particular, we know little about the seasonality of the bison diet, the degree to which bison supplement their diet with eudicots, and how changes in diet influence gut microbial communities, all of which play important roles in ungulate performance. To address these knowledge gaps, we quantified seasonal patterns in bison diet and gut microbial community composition for a bison herd in …

Radiocarbon Dating Of Late Quaternary Sediments Using Fossil Gastropod Shells, Jeffrey S. Pigati, John P. Mcgeehin, Daniel R. Muhs

United States Geological Survey: Staff Publications

Terrestrial gastropods are one of the most successful groups of organisms on Earth. Their distribution includes all continents except Antarctica, and they occupy exceptionally diverse habitats, from marshes and wet meadows to alpine forests and Arctic tundra. Their shells are also commonly preserved in Quaternary deposits and potentially could be used for ¹⁴C dating. However, terrestrial gastropods are known to ingest limestone and incorporate the old carbon in their shells, resulting in apparent ages that are often too old. Recent studies have shown that many small (<1 cm diameter) terrestrial gastropods avoid this “limestone problem” even when living in areas in which carbonate rocks are readily available. However, the shells must also behave as closed systems with respect to carbon if their ages are to be considered reliable. Our latest work has been aimed at testing if small gastropod shells do, in fact, remain closed systems in late Quaternary deposits over a wide array of climate conditions across North America. Our results demonstrate that ages derived from Succineidae shells are identical to wood and charcoal ages in loess in Alaska, glacial deposits in the upper Midwest, loess in the Great Plains, and paleowetlands in the desert southwest. Moreover, Succineidae shell ages routinely fall within permitted limits set by stratigraphic boundaries, require less interpretation than humic acid ages that are commonly used in loess studies, can provide additional stratigraphic coverage to previous dating efforts, and maintain stratigraphic order more often than luminescence ages from the same stratigraphic intervals. Thus, we conclude that fossil Succineidae shells, and shells of a few other small gastropods, can be used for ¹⁴C dating regardless of the local lithology, past climate, or environmental …

Sea Level, Paleogeography, And Archeology On California's Northern Channel Islands, Leslie Reeder- Myers, Jon Erlandson, Daniel R. Muhs, Torben Rick

United States Geological Survey: Staff Publications

Sea-level rise during the late Pleistocene and early Holocene inundated nearshore areas in many parts of the world, producing drastic changes in local ecosystems and obscuring significant portions of the archeological record. Although global forces are at play, the effects of sea-level rise are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Interpretations of coastal paleoecology and archeology require reliable estimates of ancient shorelines that account for GIA effects. Here we build on previous models for California's Northern Channel Islands, producing more accurate late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability. This region has …

Nutri One-On-One: The Assessment And Evaluation Of A Brief One-On-One Nutritional Coaching In Patients Affected By Metabolic Syndrome, Jennifer King, Jeffrey E. Harris, David Kuo, Farzaneh Daghigh

PCOM Scholarly Works

Nutri One-on-One was a program with the aim to positively modify medical clinic patients’ nutritional habits and lifestyles through a brief one-on-one health coaching session. Each session was conducted by utilizing motivational interviewing techniques to allow for tailored nutrition education and goal setting. These sessions were followed by a phone call to participants at 1 month following the session. The outcomes assessed were participant perception of achieving personal nutrition and lifestyle goals, retention of knowledge, and participants’ satisfaction with the program. Physicians working in the clinic were assessed for satisfaction with the program. Most of the physicians were generally satisfied …

Escaping Cascadia, Todd Albertson

University Honors Theses

The preface, "Dualism and Narrative Mode," details the development of realist techniques and then looks to current research to address the question, "In what other ways can realism be maximized within fiction?" It proposes a style combining second-person imperative narration for the viewpoint character’s actions and third-person free indirect discourse for description and internalization.

The introduction, "The Geography of the Future," explores prediction within select literary works, explains mitigation reactions to such predictions, and details current geographical projections to build a picture of what the future will look like and how humans will interact with their environment.

Escaping Cascadia is …

Refugial Isolation And Range Expansions Drive The Genetic Structure Of Oxyria Sinensis (Polygonaceae) In The Himalaya-Hengduan Mountains, Lihua Meng, Gang Chen, Zhonghu Li, Yongping Yang, Zhengkun Wang, Liuyang Wang

Graduate School of Oceanography Faculty Publications

The formation of the Mekong-Salween Divide and climatic oscillations in Pleistocene were the main drivers for the contemporary diversity and genetic structure of plants in the Himalaya-Hengduan Mountains (HHM). To identify the relative roles of the two historical events in shaping population history of plants in HHM, we investigated the phylogeographic pattern of Oxyria sinensis, a perennial plant endemic to the HHM. Sixteen chloroplast haplotypes were identified and were clustered into three phylogenetic clades. The age of the major clades was estimated to be in the Pleistocene, falling into several Pleistocene glacial stages and postdating the formation of the …

‘Water Is Life’: Exploring The Relationship Between Place Identity, Water And Adaptive Capacity In Fort Resolution, Northwest Territories, Canada, Jennifer A. Fresque-Baxter

Theses and Dissertations (Comprehensive)

Water is recognised as a fundamental human right in Canada’s Northwest Territories (NWT). However, the current and potential effects of climate change coupled with resource development pressures are leading to concerns about maintaining the health and viability of freshwater in the NWT. These intersecting multiple exposures can have far-reaching impacts for NWT residents who rely on water for cultural, spiritual, economic and social purposes. Ongoing changes (e.g., to water quantity, water quality, weather, precipitation and ice dynamics, for example) will increasingly require NWT residents to adapt, seek ways to plan for the future, identify opportunities, and moderate the effects of …

The Christian Farmers Federation Of Ontario: Integrating Christian Principles With The Practicality Of Farming, Suzanne M. Armstrong

Theses and Dissertations (Comprehensive)

This thesis examines the Christian identity and characteristics of the Christian Farmers Federation of Ontario (CFFO), a general farm organization active in the diverse agricultural sector of Ontario, Canada. It highlights the intersection of religion and farming that emerged from interviews and participant observation within this group. The thesis probes what it means for them to be responsible Christian farmers in contemporary agriculture. Christian and secular scholars from three key areas of scholarship—Dutch immigration to Canada, agriculture of the middle or family farming, and Christian stewardship—help to contextualize their responses.

The CFFO was founded as a Dutch neo-Calvinist organization within …

Maps Of Marginalization: Exploring The Healthcare Experiences Of Men And Women With Fibromyalgia, Michelle J. Skop

Theses and Dissertations (Comprehensive)

This qualitative study explored the retrospective and ongoing healthcare experiences of men and women who have a diagnosis of fibromyalgia (FM), a contested, chronic, and gendered condition of unknown origin. The research question was: "How do men and women who have a diagnosis of FM experience interactions with healthcare providers?" The study, which was epistemologically rooted in the critical theories of feminist poststructuralism and intersectionality, blended constructivist grounded theory with a participatory component, an arts-based research methodology called body-map storytelling. Thirty-five participants were recruited from the Greater Toronto Area and Kitchener-Waterloo. Ten participants completed in-depth interviews while 25 participants completed …

An Analysis Of Quality For Volunteered Geographic Information, Joel C H Meier

Theses and Dissertations (Comprehensive)

In recent years there has been a growing number of online user communities engaged in the creation, visualization, and use of volunteered geographic information (VGI). These data may represent an untapped resource for researchers analyzing large-area geographic phenomena such as species distributions patterns or land and resource management issues. However very few studies have used VGI for analytic research questions as little is known about the quality of these data. An understanding of the validity of VGI is a prerequisite for further exploitation of these novel data sources in research contexts. This paper looks to identify key issues related to …

Dune And Coastal Evolution In Isla Salamanca National Park, Colombia, Juan Felipe Gómez

Theses and Dissertations (Comprehensive)

This project analyzes natural variables influencing the coastal and dune evolution in Isla Salamanca National Park (ISNP), a biosphere reserve and Ramsar site located in Colombia, on the Caribbean coast. Since at least the early 1950s, the park has been affected by eroding trends along most of the shoreline. Particularly, most modern dunes are located close to the coastline, forming scarped dunes regularly affected by storm wave-action.

The trends through time of rain, bathymetry and coastline changes during the last six decades were studied through statistical analysis, mapping of landscape features, and satellite images and historical aerial photograph …

Parent Engagement Pedagogy And Practice In New Preservice Teacher Education Programs In Ontario, Tracy E. Bachellier

Theses and Dissertations (Comprehensive)

Parent engagement that focuses on building relationships and increasing social capital has a positive impact on student outcomes. However, one of the greatest challenges new teachers face is working with parents in support of children’s learning. The need to better prepare teachers points to an enhanced curriculum of parent engagement during preservice teacher education.

Ontario faculties of education were surveyed regarding planned implementation of new accreditation guidelines for parent engagement. Document reviews of existing and modified teacher education programs were conducted. Participants reported parent engagement pedagogy in modified programs had somewhat increased and believed teacher candidates would be ‘somewhat’ to …

Affective Migration: The Role Of Food Preparation And Visceral Experience For Egyptian Migrant Women Settling In The Region Of Waterloo, Mary Neil

Theses and Dissertations (Comprehensive)

This study examining Egyptian migrants settling in Canada is exploratory in nature and is intended to initiate a conversation about the personal experience of transnationalism and the value of the body as an instrument of research. A semi-structured interview approach was designed to prompt the evocation of deep personal thoughts, experiences, and sensations in response to questions surrounding migration to Canada through the shared performative act of cooking and the visceral experience of eating in the private space of the migrant kitchen. Using a grounded theory approach, several adaptive mechanisms were identified such as the creation of manageable daily routines, …