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Articles 2821 - 2850 of 4183

Full-Text Articles in Natural Resources and Conservation

Northern Harrier Hatches Mallard Nest, Jeffery W. Stackhouse, Benjamin A. Geaumont Dec 2011

Northern Harrier Hatches Mallard Nest, Jeffery W. Stackhouse, Benjamin A. Geaumont

The Prairie Naturalist

The northern harrier (Circus cyaneus) is a widespread raptor commonly found nesting throughout the Northern Great Plains. Northern harriers forage primarily on small mammals and passerines with the males providing the majority of prey to nestlings until 14–28 days of age (Redpath et al. 2006, Vukovich and Ritchison 2006). Although the genus Circus is known to predate eggs from nest of many nesting birds (Hiraldo et al. 1975, Donaszar et al. 1996, Opermanis et al. 2000), few have been recorded commandeering nests of different species (Laine 1928, Fleskes 1992). In June 2010, we observed a northern harrier that …


Late Seasonal Captures Of The Plains Pocket Mouse (Perognathus Flavescens) In Iowa, Hans W. Otto, Jeremy A. White Dec 2011

Late Seasonal Captures Of The Plains Pocket Mouse (Perognathus Flavescens) In Iowa, Hans W. Otto, Jeremy A. White

The Prairie Naturalist

The plains pocket mouse, Perognathus flavescens, is a nocturnal granivore that inhabits friable soils in sparsely vegetated areas (Monk and Jones 1996). In the United States, the distribution of the plains pocket mouse extends from Arizona, New Mexico, and Texas through the Great Plains to North Dakota and Minnesota (Hall 1981). This species reaches its easternmost limits in Iowa, where it has been documented from a limited number of grassland sites in eastern, central, and western parts of the state (Bowles 1975, Wilson et al. 1996). Due to loss of grassland habitat, the plains pocket mouse is currently listed …


Herpetofaunal Diversity At Yankee Hill State Lake And Wildlife Management Area, Lancaster County, Nebraska, Shelby Klima Dec 2011

Herpetofaunal Diversity At Yankee Hill State Lake And Wildlife Management Area, Lancaster County, Nebraska, Shelby Klima

Department of Environmental Studies: Undergraduate Student Theses

A survey for amphibians and reptiles was conducted in March through October 2011 at Yankee Hill Wildlife Management Area in Lancaster County, Nebraska. The survey was conducted using several different techniques including: visual and auditory encounters, artificial and natural cover objects, aquatic trappings and road surveys. A total of 145 individuals representing 12 species were identified including seven reptiles and five amphibians. A total of 48% of the species that may potentially occur on the site were encountered, all of which are common, widely distributed generalist species. Neither Graham’s Crayfish Snake nor the Massasauga, both target species for this survey, …


Climatic Controls On The Summertime Energy Balance Of A Thermokarst Lake In Northern Alaska: Short-Term, Seasonal, And Interannual Variability, Brittany L. Potter Dec 2011

Climatic Controls On The Summertime Energy Balance Of A Thermokarst Lake In Northern Alaska: Short-Term, Seasonal, And Interannual Variability, Brittany L. Potter

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

Shallow, thermokarst lakes that develop atop permafrost are a prominent landscape feature on the Arctic Coastal Plain (ACP) of northern Alaska. The ACP is vulnerable to ongoing climate change and landscape modification, as thousands of thaw lakes and ponds are impacted by changes in temperature, precipitation, thawing permafrost, and human activity. Although summer in the Arctic is short, incoming solar radiation and lake evaporation are relatively high, and both factors play a significant role in the landscape water balance. Furthermore, lake evaporation is anticipated to increase as the ice-free season lengthens and water temperatures become warmer. To improve our understanding …


Abiotic Stress Responses In Photosynthetic Organisms, Joseph Msanne Dec 2011

Abiotic Stress Responses In Photosynthetic Organisms, Joseph Msanne

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

Cellular and molecular aspects of abiotic stress responses in Arabidopsis thaliana subjected to cold, drought, and high salinity and in two photosynthetic green alga, Chlamydomonas reinhardtii and Coccomyxa sp. C-169, subjected to nitrogen deprivation were investigated. Cold, drought, and high salinity can negatively affect plant growth and crop production. The first research aimed at determining the physiological functions of the stress-responsive Arabidopsis thaliana RD29A and RD29B genes. Cold, drought, and salt induced both genes; the promoter of RD29Awas found to be more responsive to drought and cold stresses, whereas the promoter of RD29B was highly responsive to salt stress. …


Ecophysiological Responses Of Herbaceous Plants To The Presence Or Absence Of Amorpha Canescens In A Nebraska Sandhills Grassland, Jessica L. Milby Dec 2011

Ecophysiological Responses Of Herbaceous Plants To The Presence Or Absence Of Amorpha Canescens In A Nebraska Sandhills Grassland, Jessica L. Milby

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

Deeply-rooted shrubs are a common component of grasslands. This study investigated the ecophysiological role of Amorpha canescens, a common leguminous shrub, in Sandhills grassland, and response of herbaceous plants to the presence or absence of A. canescens. Two sites were selected for the study at the Gudmundsen Sandhills Laboratory near Whitman, Nebraska – one with A. canescens (G-L) and one without (G-NL) A. canescens. Plant canopy cover and aboveground biomass were characterized on both sites in June and August 2010. Seasonal trends in net photosynthesis (A), stomatal conductance (gs), transpiration (E), water use efficiency (WUE), and predawn …


Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands By Paul Johnsgard, Jane E. Austin Dec 2011

Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands By Paul Johnsgard, Jane E. Austin

The Prairie Naturalist

Paul Johnsgard has long been captivated by wild cranes and their unique vocalizations, courtship dances, and wide-ranging migrations. As a scientist and an admirer, Johnsgard has watched their migrations and behaviors for decades as hundreds of thousands of cranes staged each spring by the central Platte River, not far from his home in Lincoln, Nebraska. As an artist, he has skillfully captured their courtship dances and other behaviors in his exceptional line drawings. And, as an author, he has written extensively on their ecology in three earlier books: Cranes of the World (1983), Those of the Gray Wind: The Sandhill …


Depth And Littoral Habitat Association Of Age-0 Yellow Perch In Two South Dakota Glacial Lakes, Daniel J. Dembkowski, Melissa R. Wuellner, David W. Willis Dec 2011

Depth And Littoral Habitat Association Of Age-0 Yellow Perch In Two South Dakota Glacial Lakes, Daniel J. Dembkowski, Melissa R. Wuellner, David W. Willis

The Prairie Naturalist

Yellow perch (Perca flavescens) are a recreationally important species and represent a key ecological component of glacial lake littoral fish assemblages (Stone 1996, Blackwell et al. 1999). Research has shown a generalized pattern of juvenile (age-0) yellow perch spatial distribution wherein larvae hatch in near-shore areas, migrate to limnetic areas where they remain for approximately 40 d, and then return to demersal behaviors and within near-shore littoral habitats (Noble 1975, Whiteside et al. 1985). However, anomalous distribution and habitat use by age-0 yellow perch has been observed in South Dakota glacial lakes (Fisher and Willis 1997) and the …


Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen Dec 2011

Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen

The Prairie Naturalist

Book review of Effects of Climate Change on Birds, edited by Anders Pape Meller, Wolfgang Fiedler, and Peter Berthold.

Climate scientists from across the globe predict vast changes during the next century in the planet's temperatures, precipitation, storm intensities, fire regimes, hydrologic cycles, and atmospheric, water, and soil chemistries. The changes will be global, but their effects will be felt locally everywhere. To find a scientifically and socially engaging bellwether of these events, we need to look only through the lens of avian biology. Birds are found from pole to pole; their movements connect continents. They are loud, colorful …


Modeling Parental Provisioning By Red-Winged Blackbirds In North Dakota, George M. Linz, Richard S. Sawin, Mark W. Lutman, William J. Bleier Dec 2011

Modeling Parental Provisioning By Red-Winged Blackbirds In North Dakota, George M. Linz, Richard S. Sawin, Mark W. Lutman, William J. Bleier

The Prairie Naturalist

Male red-winged blackbirds (Agelaius phoeniceus) exhibit a difference in nest provisioning rates along an east-west gradient in North America. North Dakota is located in the center of North America and harbors a large population of breeding red-winged blackbirds (RWBL). This location provided an opportunity to compare provisioning rates in the central U.S. with those reported for the eastern and western populations. We placed video cameras at RWBL nests to record male and female feeding trips. Thirty-four nests were located on territories with original males and 30 were on territories where a replacement (floater) male had taken over a …


Manuscript Content: Where Does It Belong?, Christopher N. Jacques Dec 2011

Manuscript Content: Where Does It Belong?, Christopher N. Jacques

The Prairie Naturalist

One of the most common issues we address during content editing of papers for The Prairie Naturalist (journal) is the appropriate placement of content in the text body. Based on my experience with the editorial process, content placement also is one of the issues that authors are most resistant to suggestions or do not fully understand why we are so persistent about it (Thompson 2010). One of the primary objectives of scientific writing is to concisely and accurately disseminate information. Scientific papers are structured to help both the author and reader accomplish this objective. The material that belongs in each …


Mapping Potential Crp Land And Determining Crp Profitability In Lancaster County, Jamie Pesek Dec 2011

Mapping Potential Crp Land And Determining Crp Profitability In Lancaster County, Jamie Pesek

Department of Environmental Studies: Undergraduate Student Theses

Annually 17 tons of soil is lost due to the erosion of agriculture land. A majority of the soil lost is fertile topsoil, which can render the land unproductive. The Conservation Reserve Program (CRP) was enacted to reduce the high erosion rates on agriculture land by giving landowners a monetary incentive to let their land lay idle and allow the soil to regenerate. Although there is awareness of the benefits of CRP, little effort has been put toward delineating CRP eligible land. In this project, Geographical Information Systems were used to map CRP eligible land in Lancaster County, Nebraska based …


Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley Nov 2011

Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley

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

The Central Platte River Valley (CPRV) in Nebraska is an important spring stopover area for the midcontinent population of sandhill cranes. Alterations to crop rotation and loss habitat in the CPRV pose a risk to the population. Personnel drove designated routes in the CPRV from 2003–2010 to record the presence of cranes in agricultural fields and estimate abundance. I developed and evaluated models to predict habitat use and flock sizes. Alfalfa was predicted to receive the highest use followed by corn, soybeans, winter wheat, grassland, and shrubland. Use of all habitats and flock size increased as field area increased. Flock …


Optimizing Spectral Indices And Chemometric Analysis Of Leaf Chemical Properties Using Radiative Transfer Modeling, Jean-Baptiste Féret, Christophe François, Anatoly A. Gitelson, Gregory P. Asner, Karen M. Barry, Cinzia Panigada, Stéphane Jacquemoud Oct 2011

Optimizing Spectral Indices And Chemometric Analysis Of Leaf Chemical Properties Using Radiative Transfer Modeling, Jean-Baptiste Féret, Christophe François, Anatoly A. Gitelson, Gregory P. Asner, Karen M. Barry, Cinzia Panigada, Stéphane Jacquemoud

School of Natural Resources: Faculty Publications

We used synthetic reflectance spectra generated by a radiative transfer model, PROSPECT-5, to develop statistical relationships between leaf optical and chemical properties, which were applied to experimental data without any readjustment. Four distinct synthetic datasets were tested: two unrealistic, uniform distributions and two normal distributions based on statistical properties drawn from a comprehensive experimental database. Two methods used in remote sensing to retrieve vegetation chemical composition, spectral indices and Partial Least Squares (PLS) regression, were trained both on the synthetic and experimental datasets, and validated against observations. Results are compared to a cross-validation process and model inversion applied to the …


Tracking Large Carnivore Dispersal Using Isotopic Clues In Claws: An Application To Cougars Across The Great Plains, Viviane Hénaux, Larkin A. Powell, Keith A. Hobson, Clayton Kent Nielsen, Michelle A. Larue Oct 2011

Tracking Large Carnivore Dispersal Using Isotopic Clues In Claws: An Application To Cougars Across The Great Plains, Viviane Hénaux, Larkin A. Powell, Keith A. Hobson, Clayton Kent Nielsen, Michelle A. Larue

School of Natural Resources: Faculty Publications

1. Cougar (Puma concolor) populations, like other large carnivores, have increased during recent decades and may be recolonizing their former ranges in Midwestern North America. The dispersal routes taken by these animals from established populations are unknown and insight into these movements would facilitate their conservation and management.

2. We inferred the origin and migration route of four dispersing cougars using stable hydrogen (δD) and carbon (δ13C) isotope values along one of their claws. We compared isotopic variations within claws to regional and large-scale isoscapes of δD and δ13C values in prey species. Using …


Droughtscape, Fall 2011, Kelly Smith Oct 2011

Droughtscape, Fall 2011, Kelly Smith

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

Drought Preparedness Community Options

Drought Likely to Persist, Intensify Across South

Database Will Help Planners Find Options

Impacts: Ag Losses, Fire, Water Restrictions

NDMC Welcomes International Visitors

New Drought Impact Reporter Online

Sim-Drought, Available Now at Select Agencies


Future Participation In The Conservation Reserve Program In North Dakota, Lorilie M. Atkinson, Rebecca J. Romsdahl, Michael J. Hill Oct 2011

Future Participation In The Conservation Reserve Program In North Dakota, Lorilie M. Atkinson, Rebecca J. Romsdahl, Michael J. Hill

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The purpose of this study was to gauge the impact of agriculture and energy policies on conservation practices through a survey of conservation reserve program (CRP) contract holders in a selected Prairie Pothole Region of North Dakota-Burleigh, Kidder, and Stutsman Counties. The survey results showed that 48% of respondents are considering returning CRP acres to annual crop production once the contract expires. The largest influence on post-CRP land use was the market prices for production of annual crops. Respondents also identified lack of knowledge of conservation programs as a large hurdle to participation. This may indicate a need for improved …


Review Of Grass: In Search Of Human Habitat. By Joe C. Truett. Foreword By Harry W. Greene., Mary Ann Vinton Oct 2011

Review Of Grass: In Search Of Human Habitat. By Joe C. Truett. Foreword By Harry W. Greene., Mary Ann Vinton

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Much of the book is devoted to discussing the heavy human dependence on grasslands and whether this relationship can be maintained in company with grassland conservation. Can humans continue to use grasslands for food, fiber, and newer uses like biofuels and carbon banking while still sustaining the ecosystem? Many of us in academic ecology struggle with resolving perceived conflicts between conservation and human grassland use. In many cases, a "win-win" scenario exists in which, for example, the proper use of livestock grazing is perfectly compatible with a healthy grassland ecosystem. In other cases, such as conserving prairie dog populations, tensions …


Effect Of Passive Integrated Transponder Tag Implantation Site On Tag Retention, Growth, And Survival Of Two Sizes Of Juvenile Bluegills And Yellow Perch, Mark A. Kaemingk, Michael J. Weber, Paul R. Mckenna, Michael L. Brown Sep 2011

Effect Of Passive Integrated Transponder Tag Implantation Site On Tag Retention, Growth, And Survival Of Two Sizes Of Juvenile Bluegills And Yellow Perch, Mark A. Kaemingk, Michael J. Weber, Paul R. Mckenna, Michael L. Brown

School of Natural Resources: Faculty Publications

Passive integrated transponder (PIT) tags are commonly used to monitor growth, habitat use, activity rates, and survival of individual fish. However, for successful completion of research objectives, the tags must be retained and must not affect fish growth or survival. We compared the effects of PIT tagging location on tag retention, growth, and survival of juvenile bluegills Lepomis macrochirus and yellowperch Perca flavescens. In total, 80 bluegills and 80 yellow perch from two size-classes (75–101 and 128–162 mm total length) were randomly assigned to a control or to one of three tagging location treatments: isthmus, body cavity, or dorsal musculature. …


Analysis Of The Community Based Planning Process In Holmes Lake Watershed, Lincoln, Nebraska, Courtney Quinn, Mark E. Burbach, Lois Wright Morton Sep 2011

Analysis Of The Community Based Planning Process In Holmes Lake Watershed, Lincoln, Nebraska, Courtney Quinn, Mark E. Burbach, Lois Wright Morton

School of Natural Resources: Faculty Publications

In 1998, the Nebraska Department of Environmental Quality (NDEQ) listed Holmes Lake, in Lincoln, NE on the Clean Water Act, Section 303(d) list of impaired and threatened waters. Holmes Lake was listed as impaired due to aquatic life use impairments.

Experts from various agencies worked together to form a Technical Advisory Committee to work closely with a Watershed Advisory Council of local citizens and stakeholders. Technical experts explained the water impairments and possible remedies to citizens. The Watershed Advisory Council then helped to prioritize actions. The lake was drained in 2003. In 2004, sediment was excavated, the shoreline was stabilized, …


Paleoamerican Diet, Migration And Morphology In Brazil: Archaeological Complexity Of The Earliest Americans, Sabine Eggers, Maria Parks, Gisela Grupe, Karl J. Reinhard Sep 2011

Paleoamerican Diet, Migration And Morphology In Brazil: Archaeological Complexity Of The Earliest Americans, Sabine Eggers, Maria Parks, Gisela Grupe, Karl J. Reinhard

School of Natural Resources: Faculty Publications

During the early Holocene two main paleoamerican cultures thrived in Brazil: the Tradição Nordeste in the semi-desertic Sertão and the Tradição Itaparica in the high plains of the Planalto Central. Here we report on paleodietary singals of a Paleoamerican found in a third Brazilian ecological setting – a riverine shellmound, or sambaqui, located in the Atlantic forest. Most sambaquis are found along the coast. The peoples associated with them subsisted on marine resources. We are reporting a different situation from the oldest recorded riverine sambaqui, called Capelinha. Capelinha is a relatively small sambaqui established along a river 60 km from …


Breeding Fidelity And Landscape Effects On Distribution Of Mallards And Duck Broods In The Nebraska Sandhills, Zachary J. Cunningham Aug 2011

Breeding Fidelity And Landscape Effects On Distribution Of Mallards And Duck Broods In The Nebraska Sandhills, Zachary J. Cunningham

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

I investigated aspects of mallard (Anas platyrhnchos) breeding ecology in the Nebraska Sandhills during 2007-2008. Previous work in this region suggests that nest success is low for a large area of intact grassland such as the Sandhills. My goal was to conduct a local-scale examination of age distribution and return rates of mallards, and a large-scale examination of brood distribution in the Sandhills region as a whole. This information will help explain factors contributing to the low nest success previously observed, determine relationships between landscape composition and spatial distribution of waterfowl in the Sandhills, and predict productivity and …


Avian Influenza In Migratory Birds In The United States, 2007–2009, And Effects Of September Hunting Seasons On Survival, Harvest, And Recovery Rates Of Canada Geese Banded In Southeast Nebraska, Scott R. Groepper Aug 2011

Avian Influenza In Migratory Birds In The United States, 2007–2009, And Effects Of September Hunting Seasons On Survival, Harvest, And Recovery Rates Of Canada Geese Banded In Southeast Nebraska, Scott R. Groepper

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

Highly-pathogenic avian influenza virus (HPAIV H5N1) poses risks to wild birds, poultry, and humans. Personnel with the United States Department of Agriculture-Animal Plant Health Inspection Service-Wildlife Services, state, and tribal wildlife agencies collected 168,940 samples from migratory birds from 2007 to 2009 to test for presence of HPAIV H5N1. No HPAIV was found, but other subtypes were discovered, including H5 and H7. I estimated prevalence of avian influenza virus by flyway and found prevalence was lowest each year in the Atlantic Flyway (6.7%–8.3%), highest in the Pacific Flyway in 2007 (13.3%) and 2008 (13.4%), and highest in the Mississippi Flyway …


Using Slow-Release Permanganate To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson Aug 2011

Using Slow-Release Permanganate To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson

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

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L-1) was identified in a low permeable silty-clay aquifer (Kh = 0.5 m …


Impact Of Alternative Range Management Systems On Grasslands In The Central Platte River Valley, Nebraska, Luis E. Ramirez Jul 2011

Impact Of Alternative Range Management Systems On Grasslands In The Central Platte River Valley, Nebraska, Luis E. Ramirez

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

Land management strategies can directly and indirectly affect plant assemblages and their behavior. Little research has been performed in south central Nebraska to quantify the effect of fire and grazing interactions on species composition, vegetation structure, forage quality, and potential cost associated with land management.

I evaluate the effect of season-long continuous, patch-burning, and rotational grazing approaches on vegetation and ranching costs to determine their value as conservation tools. This study includes data collected between 2007 and 2009 from grasslands in south central Nebraska. I found that land management influence plant assemblages by shifting communities when grazing and/or fire are …


Discontinuities: Predicting Invasions And Extinctions, Aaron Lotz Jul 2011

Discontinuities: Predicting Invasions And Extinctions, Aaron Lotz

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

In this dissertation, I explore multiple tenets of the textural discontinuity hypothesis, which states that hierarchical landscape structures with scale-specific pattern entrain attributes of animals inhabiting the landscape. Landscapes form hierarchies that are structured by vegetative, geomorphological and contagious disturbance processes. The spatial and temporal patterns inherent in landscapes reflect numerous processes, interacting on distinct scales, which shape the assembly of animal communities. Analysis of body mass patterns and functional group distributions has been suggested as methods to provide insight about these underlying hierarchical processes. Scientists have posited that species at the edges of body mass aggregations may be exposed …


On The Spatial Heterogeneity Of Net Ecosystem Productivity In Complex Landscapes, Ryan E. Emanuel, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Howard E. Epstein Jul 2011

On The Spatial Heterogeneity Of Net Ecosystem Productivity In Complex Landscapes, Ryan E. Emanuel, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Howard E. Epstein

School of Natural Resources: Faculty Publications

Micrometeorological flux towers provide spatially integrated estimates of net ecosystem production (NEP) of carbon over areas ranging from several hectares to several square kilometers, but they do so at the expense of spatially explicit information within the footprint of the tower. This finer-scale information is crucial for understanding how physical and biological factors interact and give rise to towermeasured fluxes in complex landscapes. We present a simple approach for quantifying and evaluating the spatial heterogeneity of cumulative growing season NEP for complex landscapes. Our method is based on spatially distributed information about physical and biological landscape variables and knowledge of …


Long-Term Groundwater Monitoring Results At Large, Sudden Denatured Ethanol Releases, Roy F. Spalding, Mark A. Toso, Mary Exner Spalding, Gregory Hattan, Tom M. Higgins, Adam C. Sekely, Shane D. Jensen Jul 2011

Long-Term Groundwater Monitoring Results At Large, Sudden Denatured Ethanol Releases, Roy F. Spalding, Mark A. Toso, Mary Exner Spalding, Gregory Hattan, Tom M. Higgins, Adam C. Sekely, Shane D. Jensen

School of Natural Resources: Faculty Publications

Hundreds of groundwater samples were collected at E95 (95% ethanol, 5% gasoline) train derailment spills in Balaton and Cambria, Minnesota and South Hutchinson, Kansas. Most samples were analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX), ethanol, methane, acetate, terminal electron acceptors, and field parameters. At each site, maximum groundwater ethanol concentrations at percent levels were restricted to the release area and downgradient ethanol transport was not detected. A shallow, anaerobic groundwater zone characterized by the absence of dissolved oxygen, low nitrate (less than 1 mg N/L), high Fe+2, and high dissolved methane (more than 10,000 μg/L) and BTEX formed and …


Turning Students Into Problem Solvers, Larkin A. Powell, Andrew J. Tyre, Michael J. Conroy, James T. Peterson, B. Ken Williams Jul 2011

Turning Students Into Problem Solvers, Larkin A. Powell, Andrew J. Tyre, Michael J. Conroy, James T. Peterson, B. Ken Williams

School of Natural Resources: Faculty Publications

In the popular movie Apollo 13, based on the actual NASA mission, three astronauts are stranded in space, their craft’s electrical system broken, their oxygen quickly running out. To help them fix the problem and return home safely, mission controllers summon a group of engineers, dump a pile of equipment onto a desk—the tools available to the astronauts—and tell them to find a solution, or more specifically, “a way to put a square peg in a round hole. Rapidly.” Eventually, the engineers’ plan saves the day, and the astronauts make it home.

State and federal agency biologists generally do …


Cedar Infestation Impacts Avian Communities Along The Niobrara River Valley, Nebraska, January S. Frost, Larkin A. Powell Jul 2011

Cedar Infestation Impacts Avian Communities Along The Niobrara River Valley, Nebraska, January S. Frost, Larkin A. Powell

School of Natural Resources: Faculty Publications

Habitat modification has the potential to cause changes in structure and composition of bird communities. Our goal was to determine the response of Songbird community composition to eastern red cedar (Juniperus virginiana) removal in The Nature Conservancy’s Niobrara Valley Preserve, Nebraska. We used point counts to survey birds in the riparian matrix of grassland and forest habitats. More than 60 species were recorded on surveys during 2004–2005. We also use the program PRESENCE to determine the response of five species to various habitat components, including cedar density: House Wren (Troglodytes aedon), Spotted Towhee (Pipilo maculates …