Open Access. Powered by Scholars. Published by Universities.®

Life Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1171 - 1200 of 3791

Full-Text Articles in Natural Resources and Conservation

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault Feb 2020

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as …


Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren Jan 2020

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …


Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt Jan 2020

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …


Statistical Analysis Of Nutrient Loads From The Mississippi-Atchafalaya River Basin (Marb) To The Gulf Of Mexico, Phyllis Okwan, Yi Zhen, Huan Feng, Shinjae Yoo, Murty S. Kambhampati, Abreione Walker, Shayne Boykin, Joe Omojola, Noel Blackburn Jan 2020

Statistical Analysis Of Nutrient Loads From The Mississippi-Atchafalaya River Basin (Marb) To The Gulf Of Mexico, Phyllis Okwan, Yi Zhen, Huan Feng, Shinjae Yoo, Murty S. Kambhampati, Abreione Walker, Shayne Boykin, Joe Omojola, Noel Blackburn

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study investigated the annual and seasonal variations in nutrient loads (NO2− + NO3− and orthophosphate) delivered to the Gulf of Mexico from the Mississippi-Atchafalaya River Basin (MARB) and examined the water quality variations. The results indicate that (1) annually, the mean NO2− + NO3− and orthophosphate loads showed a steady increase during 1996–1999, a persistent level during 2000–2007, and a moderate increase during 2008–2016; (2) seasonally, NO2− + NO3− and orthophosphate in MARB in spring and summer were higher than those in autumn and winter. Analysis of …


Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight Jan 2020

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

United States Department of Agriculture Wildlife Services: Staff Publications

  1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
  2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …


Catfish Population Characteristics Among River Segments With Altered Fluvial Geomorphic Conditions In The Missouri River, Nebraska, Usa, Martin J. Hamel, Jonathan J. Spurgeon, Mark A. Pegg Jan 2020

Catfish Population Characteristics Among River Segments With Altered Fluvial Geomorphic Conditions In The Missouri River, Nebraska, Usa, Martin J. Hamel, Jonathan J. Spurgeon, Mark A. Pegg

School of Natural Resources: Faculty Publications

Alteration of river systems around the world has created novel environments that have been fragmented, homogenized, or transformed from their natural state, thus posing challenges for understanding how fish populations function. The Missouri River has undergone significant alteration through reservoir construction and channelization. Channel Catfish Ictalurus punctatus and Flathead Catfish Pylodictis olivaris both reside in various fragmented sections of the river, and there is a substantial gap in knowledge of how catfishes synchronously function in this modified system. From 2009 to 2018, we assessed catfishes with baited hoop nets and low-frequency electrofishing among four different areas: upper and lower unchannelized …


A Review Of Vegetation Phenological Metrics Extraction Using Time-Series, Multispectral Satellite Data, Linglin Zeng, Brian D. Wardlow, Daxiang Xiang, Shun Hu, Deren Li Jan 2020

A Review Of Vegetation Phenological Metrics Extraction Using Time-Series, Multispectral Satellite Data, Linglin Zeng, Brian D. Wardlow, Daxiang Xiang, Shun Hu, Deren Li

School of Natural Resources: Faculty Publications

Vegetation dynamics and phenology play an important role in inter-annual vegetation changes in terrestrial ecosystems and are key indicators of climate-vegetation interactions, land use/land cover changes, and variation in year-to-year vegetation productivity. Satellite remote sensing data have been widely used for vegetation phenology monitoring over large geographic domains using various types of observations and methods over the past several decades. The goal of this paper is to present a detailed review of existing methods for phenology detection and emerging new techniques based on the analysis of time-series, multispectral remote sensing imagery. This paper summarizes the objective and applications of detecting …


Gateways-Nd: Demonstrating Institutional Change In Stem Teaching And Learning Within North Dakota State University, J.M.D. Motsenbacher, E. A. Berg, J. Ladbury, R. Reichenbach, M. Hanson, P. Kelter, L. Montplaisir, J. Nyachwaya Jan 2020

Gateways-Nd: Demonstrating Institutional Change In Stem Teaching And Learning Within North Dakota State University, J.M.D. Motsenbacher, E. A. Berg, J. Ladbury, R. Reichenbach, M. Hanson, P. Kelter, L. Montplaisir, J. Nyachwaya

School of Natural Resources: Documents and Reviews

No abstract provided.


Ires Track I: Usa-China: International Research Experience For Native American Students In Iot-Enabled Environmental Monitoring Technologies., J. Wang, J.M.D. Motschenbacher Jan 2020

Ires Track I: Usa-China: International Research Experience For Native American Students In Iot-Enabled Environmental Monitoring Technologies., J. Wang, J.M.D. Motschenbacher

School of Natural Resources: Documents and Reviews

No abstract provided.


Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler Jan 2020

Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler

United States Department of Agriculture Wildlife Services: Staff Publications

In 2015, the mcr-1 gene was discovered in Escherichia coli in domestic swine in China that conferred resistance to colistin, an antibiotic of last resort used in treating multi-drug resistant bacterial infections in humans. Since then, mcr-1 was found in other human and animal populations, including wild gulls. Because gulls could disseminate the mcr-1 gene, we conducted an experiment to assess whether gulls are readily colonized with mcr-1 positive E. coli, their shedding patterns, transmission among conspecifics, and environmental deposition. Shedding of mcr-1 E. coli by small gull flocks followed a lognormal curve and gulls shed one strain >101 …


Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr Jan 2020

Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to

their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these …


Control Or Eradication: Problems In The Management Of Invasive Birds, Michael L. Avery, Chris J. Feare Jan 2020

Control Or Eradication: Problems In The Management Of Invasive Birds, Michael L. Avery, Chris J. Feare

United States Department of Agriculture Wildlife Services: Staff Publications

Humans have captured, transported and intentionally released wild birds for centuries (Blackburn et al., 2009). Motivations for such purposeful introductions include food (West and Zhou, 2007), religion (Agoramoorthy and Hsu, 2007), sport (McDowall, 1994), biocontrol (Bennett and Hughes, 1959; Kurdila, 1995) and aesthetics (Ryan, 1906; Thomson, 1922). Many purposeful bird introductions were the work of acclimatization societies, particularly in North America, New Zealand and Australia. These societies were formed in the 19th century by European settlers to transport bird species from their homelands in efforts to establish them in the newly settled regions (Thomson, 1922; Dunlap, 1997). As a result …


Biotic And Abiotic Factors Influencing Arsenic Biogeochemistry And Toxicity In Fluvial Ecosystems: A Review, Laura Barral-Fraga, María Teresa Barral, Keeley L. Macneill, Diego Martiñá-Prieto, Soizic Morin, María Carolina Rodríguez-Castro, Baigal-Amar Tuulaikhuu, Helena Guasch Jan 2020

Biotic And Abiotic Factors Influencing Arsenic Biogeochemistry And Toxicity In Fluvial Ecosystems: A Review, Laura Barral-Fraga, María Teresa Barral, Keeley L. Macneill, Diego Martiñá-Prieto, Soizic Morin, María Carolina Rodríguez-Castro, Baigal-Amar Tuulaikhuu, Helena Guasch

School of Natural Resources: Faculty Publications

This review is focused on the biogeochemistry of arsenic in freshwaters and, especially, on the key role that benthic microalgae and prokaryotic communities from biofilms play together in through speciation, distribution, and cycling. These microorganisms incorporate the dominant iAs (inorganic arsenic) form and may transform it to other arsenic forms through metabolic or detoxifying processes. These transformations have a big impact on the environmental behavior of arsenic because different chemical forms exhibit differences in mobility and toxicity. Moreover, exposure to toxicants may alter the physiology and structure of biofilms, leading to changes in ecosystem function and trophic relations. In this …


Use Of Otolith Chemistry To Assess Recruitment And Habitat Use Of A White Bass Fishery In A Nebraska Reservoir, Matthew A. Perrion, Mark A. Kaemingk, Keith D. Koupal, Casey W. Schoenebeck, Nate A. Bickford Jan 2020

Use Of Otolith Chemistry To Assess Recruitment And Habitat Use Of A White Bass Fishery In A Nebraska Reservoir, Matthew A. Perrion, Mark A. Kaemingk, Keith D. Koupal, Casey W. Schoenebeck, Nate A. Bickford

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Managing fisheries that exhibit variable annual recruitment is challenging, and maintenance stockings are often prescribed to minimize interannual population variation. Maintenance stockings are costly and may not be necessary if sufficient natural recruitment is occurring. Therefore, developing tools and techniques that can collectively assess hatching origin and subsequent habitat use of individuals would be valuable. Herein, we aimed to assess the efficacy of otolith chemistry techniques to (1) determine whether there was evidence of natural recruitment within an annually stocked white bass population and (2) examine the potential to describe spatial reservoir use of these age-0 fish. A sample of …


Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea Jan 2020

Using Northern Pike And Yellow Perch To Attempt A Trophic Cascade, Bryan Sea

Journal of Earth and Life Science

In the midwestern USA, water clarity has decreased in shallow lakes as a result of large populations of Fathead Minnow Pimephales promelas and agriculture that impact the life that depend on shallow habitats, such as waterfowl, fish, and aquatic plants. Northern Pike Esox lucius and Yellow Perch Perca flavescens were stocked in a few lakes in attempt to create a tropic cascade and reduce populations of nuisance Fathead Minnows. Northern Pike were stocked as fry and Yellow Perch were stocked as adults either pre-spawn or post-spawn. Lake managers hypothesized adult Yellow Perch would spawn and the age-0 Perch would feed …


Factors Associated With Larval Freshwater Drum Annual Peak Density In A Nebraska Irrigation Reservoir, Brett T. Miller, Brian C. Peterson, Keith D. Koupal, Casey W. Schoenebeck Jan 2020

Factors Associated With Larval Freshwater Drum Annual Peak Density In A Nebraska Irrigation Reservoir, Brett T. Miller, Brian C. Peterson, Keith D. Koupal, Casey W. Schoenebeck

The Prairie Naturalist

Freshwater drum (Aplodinotus grunniens) represent one of the most widely distributed fish species in North America. Identifying biotic and abiotic factors that influence larval freshwater drum densities can improve understanding of early life history. Our objective was to investigate correlations between annual peak density of larval freshwater drum and combinations of five variables (chlorophyll a, growing degree days [GDD], reservoir discharge, turbidity, and cladoceran density) from a longterm (2003–2017) monitoring program in a Nebraska irrigation reservoir. Twenty-eight a priori candidate models were assessed to determine the relative support of explanatory variables associated with annual peak density of larval freshwater drum …


Captive Ring-Necked Pheasant Response To Very High Experimental Doses Of Lead, Travis J. Runia, Alex J. Solem Jan 2020

Captive Ring-Necked Pheasant Response To Very High Experimental Doses Of Lead, Travis J. Runia, Alex J. Solem

The Prairie Naturalist

Ingestion of spent lead pellets is a well-documented source of lead exposure in free-ranging birds, although the consequence of lead ingestion varies widely among avian guilds. Ring-necked pheasants (Phasianus colchicus) appear to be less susceptible to lead poisoning than other game birds. Our objectives were to determine survival, liver lead accumulation, and body mass change of 129 captive-raised pheasants in response to being gavage-fed 5, 10, 20, or 40 lead pellets. All pheasants survived the 21-day experiment. Liver-lead levels were positively correlated with the number of lead pellets retained and negatively correlated with beginning body mass. Change in percent body …


Evaluation Of Four Larval Fish Sampling Methods In A Large Midwestern River, Nathan J. Lederman, Anthony R. Sindt, Douglas J. Dieterman, John D. Krenz, Shannon J. Fisher Jan 2020

Evaluation Of Four Larval Fish Sampling Methods In A Large Midwestern River, Nathan J. Lederman, Anthony R. Sindt, Douglas J. Dieterman, John D. Krenz, Shannon J. Fisher

The Prairie Naturalist

Understanding limitations of larval fish capture gears is critical for developing appropriate sampling protocols and interpreting catch data. We evaluated genera richness, genera diversity, assemblage similarities, abundance indices (i.e., density or catch per unit effort [CPUE]), and sample size requirements between a surface slednet and glow-stick light traps used in 2014 and 2015 and a benthic slednet and light-emitting diode light (LED) traps used in 2015 in the Minnesota River. The surface slednet captured the greatest number of larval fish genera (15) while the LED light trap captured the fewest (1). Similarities of assemblages sampled was highest between surface and …


Comparing Native Bee Communities On Reconstructed And Remnant Prairie In Missouri, Joseph Larose, Elisabeth B. Webb, Deborah Finke Jan 2020

Comparing Native Bee Communities On Reconstructed And Remnant Prairie In Missouri, Joseph Larose, Elisabeth B. Webb, Deborah Finke

The Prairie Naturalist

The tallgrass prairie of North America is an imperiled ecosystem that has been the subject of considerable restoration effort and research in the past two decades. While native prairie plant species are purposely introduced during restoration, prairie invertebrates, including native bees (Anthophila), are not and must colonize from surrounding remnants. Prairie restorations may not support the same bee communities as remnant prairies because of habitat differences and dispersal limitations. We sampled native bees on reconstructed and remnant prairies in Missouri in the summers of 2016 and 2017 and compared the communities by evaluating species richness, diversity, and community composition. We …


Greater Prairie-Chickens And Sharp-Tailed Grouse Have Similarly High Nest Survival In The Nebraska Sandhills, Larkin Powell, Walter Schacht, Julia P. Ewald, Kathryn R. Mccollum Jan 2020

Greater Prairie-Chickens And Sharp-Tailed Grouse Have Similarly High Nest Survival In The Nebraska Sandhills, Larkin Powell, Walter Schacht, Julia P. Ewald, Kathryn R. Mccollum

The Prairie Naturalist

The ranges of two native galliform species overlap in the Nebraska Sandhills, the largest contiguous grassland in North America. We monitored nests of greater prairie-chickens (Tympanuchus cupido) and sharp-tailed grouse (Tympanuchus phasianellus) in Cherry County, Nebraska, in 2015 and 2016. Our objectives were to 1) compare daily probability of nest survival between species, 2) evaluate vegetation structure at nests for potential effects on nest survival, 3) compare nest site topography between species, and 4) use a simple model of breeding season success to evaluate the potential for stable populations at our study sites. We captured and …


Influence Of Mink Predation On Brown Trout Survival And Size-Structure In Rapid Creek, South Dakota, Austin Galinat Jan 2020

Influence Of Mink Predation On Brown Trout Survival And Size-Structure In Rapid Creek, South Dakota, Austin Galinat

Electronic Theses and Dissertations

I compared movement, home range, habitat selection, and mortality among radio-tagged Brown Trout (Salmo trutta) at an American Mink (Neovison vison)-removal site, improved habitat site, and an undisturbed stream site in Rapid Creek, South Dakota. I observed high, post-surgery (> 26 days) survival rate (90%) of radio tagged Brown Trout. Average gross movement of Brown Trout was greater at the improved habitat site (127 m) compared to the mink removal (31 m) site, while average home range size (i.e., stream distance) among all three sites was not significantly different indicating strong site fidelity (125 to 200 m). Brown Trout movements …


Evaluation Of Fall-Seeded Cover Crops For Grassland Nesting Waterfowl In Eastern South Dakota, Charles W. Gallman Iii Jan 2020

Evaluation Of Fall-Seeded Cover Crops For Grassland Nesting Waterfowl In Eastern South Dakota, Charles W. Gallman Iii

Electronic Theses and Dissertations

The Prairie Pothole Region is the primary breeding ground for many species of North American waterfowl. This landscape was historically dominated by mixed and tallgrass prairies interspersed with wetlands, but >70% of native grassland area has been lost due to widespread conversion to croplands, which may threaten waterfowl production. Cover cropping is a re-emerging farming technique that may provide suitable nesting cover for grassland nesting waterfowl on active farmlands. My research objectives were to evaluate the utility of fall-seeded cover crops to breeding waterfowl compared to perennial cover, determine if cover crops in rotation with row crops can successfully support …


Remote Sensing Approaches To Predict Forest Characteristics In Northwest Montana, Ryan P. Rock Jan 2020

Remote Sensing Approaches To Predict Forest Characteristics In Northwest Montana, Ryan P. Rock

Graduate Student Theses, Dissertations, & Professional Papers

Remote sensing can be utilized by land management organizations to save money and time. Mapping vegetation using either aerial photographs or satellite imagery and the applications for forest management are of particular interest to the Montana Department of Natural Resources. In 2018, the organization began a pilot program to test the incorporation of raster analysis of remotely sensed data into their inventory program and had limited success. This analysis identified two areas of improvement: the selection method of inventory plots and the imagery used for classification and metrics. This study found that selecting inventory plots using a generalized random tessellation …


Agri-Combs: Open-Path Dual-Comb Spectroscopy Of Livestock Emissions, D. I. Herman, L. C. Hutcherson, C. Weerasekara Et Al. Jan 2020

Agri-Combs: Open-Path Dual-Comb Spectroscopy Of Livestock Emissions, D. I. Herman, L. C. Hutcherson, C. Weerasekara Et Al.

School of Natural Resources: Documents and Reviews

No abstract provided.


Mitogenome Of Northern Long-Eared Bat, Sarah Gaughan, Kevin L. Pope, Jeremy A. White, Cliff Lemen, Patricia Freeman Jan 2020

Mitogenome Of Northern Long-Eared Bat, Sarah Gaughan, Kevin L. Pope, Jeremy A. White, Cliff Lemen, Patricia Freeman

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The complete mitogenome of the northern long-eared bat (Myotis septentrionalis) was determined to be 17,362 bp and contained 22 tRNA genes, 2 rRNA genes and one control region. The whole genome base composition was 33.8% GC. Phylogenetic analysis suggests that M. septentrionalis be positioned next to M. auriculus in the Nearctic subclade of the Myotis genus. This complete mitochondrial genome provides essential molecular markers for resolving phylogeny and future conservation efforts.


Use And Expenditures On Public Access Hunting Lands, Lyndsie S. Wszola, Lutz F. Gruber, Erica F. Stuber, Lindsey N. Messinger, Christopher J. Chizinski, Joseph J. Fontaine Jan 2020

Use And Expenditures On Public Access Hunting Lands, Lyndsie S. Wszola, Lutz F. Gruber, Erica F. Stuber, Lindsey N. Messinger, Christopher J. Chizinski, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The recreational and economic benefits of hunting on traditional permanent public lands are well-established. Increasingly popular “open fields” hunting access programs temporarily open private lands to public hunting through public-private partnerships. Open fields programs have the potential to create public hunting opportunities and economic development in rural communities, but the extent to which open fields programs compare to traditional public lands at providing benefits to hunters and rural communities has not yet been evaluated. We compared hunter use and expenditures on open fields lands and traditional public lands in Nebraska, USA. We used Convolution Likelihood Ecological Abundance Regression, a novel …


Exit Here: Strategies For Dealing With Aging Dams And Reservoirs, Henry H. Hansen, Emily Forzono, Alisha Grams, Lindsay Ohlman, Christine Ruskamp, Mark A. Pegg, Kevin L. Pope Jan 2020

Exit Here: Strategies For Dealing With Aging Dams And Reservoirs, Henry H. Hansen, Emily Forzono, Alisha Grams, Lindsay Ohlman, Christine Ruskamp, Mark A. Pegg, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Aging infrastructure is prevalent throughout the world, but water control management structures, specifically dams, are of growing concern. Dams and their corresponding reservoirs have inherent, but separate, lifespans. The proportion of dams around the world that continue operation beyond their intended lifespans is growing at an alarming rate. Society will not only have to navigate the tradeoffs associated with the deterioration of services provided by reservoirs and dams, but also impending structural failures. Society is nearing a critical pinch point where we will have to decide how to deal with dams and reservoirs at scales that range from a single …


Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye Jan 2020

Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4 · 6H2O) is an understudied material that can be created from P- and nitrogen (N)-containing wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple superphosphate (TSP) on corn (Zea mays) response in a greenhouse pot study. …


Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood Jan 2020

Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has recently been recognized as a candidate for monitoring chemical changes in the rhizosphere. The information it provides about nutrient diffusion may improve nitrogen use efficiency, leading to enhanced management and success of restoration projects. The objective of this study was to determine the efficacy of microdialysis sampling to quantify the relative recoveries (RR%) of nitrate-N and ammonium-N, the two inorganic nitrogen compounds typically found in soil. The effects of microdialysis flow rate, sample medium concentration, and the presence of both analytes in solution on the relative recoveries obtained from …


Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong Jan 2020

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …