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Articles 1531 - 1560 of 4183

Full-Text Articles in Natural Resources and Conservation

Abundance Estimation From Multiple Data Types For Groupliving Animals: An Example Using Dhole (Cuon Alpinus), Dusit Ngoprasert, George A. Gale, Andrew J. Tyre Sep 2019

Abundance Estimation From Multiple Data Types For Groupliving Animals: An Example Using Dhole (Cuon Alpinus), Dusit Ngoprasert, George A. Gale, Andrew J. Tyre

School of Natural Resources: Faculty Publications

Large carnivores are declining globally and require baseline population estimates for management, however large-scale population estimation is problematic for species without unique natural marks. We used camera trap records of dhole Cuon alpinus, a group-living species, from three national parks in Thailand as a case study in which we develop integrated likelihood models to estimate abundance incorporating two different data sets, count data and detection/non-detection data. We further investigated relative biases of the models using different proportions of data with lower versus higher quality and assessed parameter identifiability. The simulations indicated that the relative bias on average across 24 tested …


Monitoring Drought Impact On Annual Forage Production In Semi-Arid Grasslands: A Case Study Of Nebraska Sandhills, Marketa Podebradska, Bruce K. Wylie, Michael J. Hayes, Brian D. Wardlow, Deborah J. Bathke, Norman B. Bliss, Devendra Dahal Sep 2019

Monitoring Drought Impact On Annual Forage Production In Semi-Arid Grasslands: A Case Study Of Nebraska Sandhills, Marketa Podebradska, Bruce K. Wylie, Michael J. Hayes, Brian D. Wardlow, Deborah J. Bathke, Norman B. Bliss, Devendra Dahal

School of Natural Resources: Faculty Publications

Land management practices and disturbances (e.g. overgrazing, fire) have substantial effects on grassland forage production. When using satellite remote sensing to monitor climate impacts, such as drought stress on annual forage production, minimizing land management practices and disturbance effects sends a clear climate signal to the productivity data. This study investigates the effect of this climate signal by: (1) providing spatial estimates of expected biomass under specific climate conditions, (2) determining which drought indices explain the majority of interannual variability in this biomass, and (3) developing a predictive model that estimates the annual biomass early in the growing season. To …


Ecological Correlates Of Group Integrity Among Dispersing Cliff Swallows, Stacey L. Hannebaum, Mary B. Brown, Charles R. Brown Sep 2019

Ecological Correlates Of Group Integrity Among Dispersing Cliff Swallows, Stacey L. Hannebaum, Mary B. Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Breeding colonies of birds represent groups of individuals that associate during one breeding season, at least partially dissociate for the non-breeding season, and may re-associate the next year through collective settlement at another breeding site. Little is known about the extent to which colonial birds maintain group integrity when occupying different sites in different years or the benefits of long-term associations among colonial individuals. For cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, USA, we examined ecological correlates and potential benefits associated with group integrity. Using a dataset of over 25,000 individuals, we found that associations between dispersing cliff swallows were …


Partitioning Spatial, Environmental, And Community Drivers Of Ecosystem Functioning, Amelie Truchy, Emma Gothe, David G. Angeler, Frauke Ecke, Ryan A. Sponseller, Mirco Bundschuh, Richard K. Johnson, Brendan G. Mckie Sep 2019

Partitioning Spatial, Environmental, And Community Drivers Of Ecosystem Functioning, Amelie Truchy, Emma Gothe, David G. Angeler, Frauke Ecke, Ryan A. Sponseller, Mirco Bundschuh, Richard K. Johnson, Brendan G. Mckie

School of Natural Resources: Faculty Publications

Context: Community composition, environmental variation, and spatial structuring can influence ecosystem functioning, and ecosystem service delivery. While the role of space in regulating ecosystem functioning is well recognised in theory, it is rarely considered explicitly in empirical studies.

Objectives: We evaluated the role of spatial structuring within and between regions in explaining the functioning of 36 reference and human-impacted streams.

Methods: We gathered information on regional and local environmental variables, communities (taxonomy and traits), and used variance partitioning analysis to explain seven indicators of ecosystem functioning.

Results: Variation in functional indicators was explained not only by environmental variables and community …


Comparison Of Methods For Modeling Fractional Cover Using Simulated Satellite Hyperspectral Imager Spectra, Philip E. Dennison, Yi Qi, Susan K. Meerdink, Raymond F. Kokaly, David R. Thompson, Craig S.T. Daughtry, Miguel Quemada, Dar A. Roberts, Paul D. Gader, Erin B. Wetherley, Izaya Numata, Keely L. Roth Sep 2019

Comparison Of Methods For Modeling Fractional Cover Using Simulated Satellite Hyperspectral Imager Spectra, Philip E. Dennison, Yi Qi, Susan K. Meerdink, Raymond F. Kokaly, David R. Thompson, Craig S.T. Daughtry, Miguel Quemada, Dar A. Roberts, Paul D. Gader, Erin B. Wetherley, Izaya Numata, Keely L. Roth

School of Natural Resources: Faculty Publications

Remotely sensed data can be used to model the fractional cover of green vegetation (GV), non-photosynthetic vegetation (NPV), and soil in natural and agricultural ecosystems. NPV and soil cover are difficult to estimate accurately since absorption by lignin, cellulose, and other organic molecules cannot be resolved by broadband multispectral data. A new generation of satellite hyperspectral imagers will provide contiguous narrowband coverage, enabling new, more accurate, and potentially global fractional cover products. We used six field spectroscopy datasets collected in prior experiments from sites with partial crop, grass, shrub, and low-stature resprouting tree cover to simulate satellite hyperspectral data, including …


Bourbon Virus In Wild And Domestic Animals, Missouri, Usa, 2012–2013, Katelin C. Jackson, Thomas Gidlewski, J. Jeffrey Root, Angela M. Bosco-Lauth, R. Ryan Lash, Jessica R. Harmon, Aaron C. Brault, Nicholas A. Panella, William L. Nicholson, Nicholas Komar Sep 2019

Bourbon Virus In Wild And Domestic Animals, Missouri, Usa, 2012–2013, Katelin C. Jackson, Thomas Gidlewski, J. Jeffrey Root, Angela M. Bosco-Lauth, R. Ryan Lash, Jessica R. Harmon, Aaron C. Brault, Nicholas A. Panella, William L. Nicholson, Nicholas Komar

United States Department of Agriculture Wildlife Services: Staff Publications

Bourbon virus (BRBV) was first isolated from a febrile patient with a history of tick bites in Bourbon County, Kansas, USA; the patient later died from severe illness in 2014 (1). Several additional human BRBV infections were reported subsequently from the midwestern and southern United States (2). BRBV belongs to the family Orthomyxoviridae, genus Thogotovirus, which is distributed worldwide and includes Araguari, Aransas Bay, Dhori, Jos, Thogoto, and Upolu viruses (1,3). Thogoto and Dhori viruses have been associated with human disease (4–6). Viruses within the genus Thogotovirus have been associated with hard or soft ticks (7). Recent studies suggest that …


Public Access For Pheasant Hunters: Understanding An Emerging Need, Lyndsie S. Wszola, Anastasia E. Madsen, Erica F. Stuber, Christopher J. Chizinski, Jeffrey J. Lusk, J. Scott Taylor, Kevin L. Pope, Joseph J. Fontaine Sep 2019

Public Access For Pheasant Hunters: Understanding An Emerging Need, Lyndsie S. Wszola, Anastasia E. Madsen, Erica F. Stuber, Christopher J. Chizinski, Jeffrey J. Lusk, J. Scott Taylor, Kevin L. Pope, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Ring‐necked pheasant (Phasianus colchicus; i.e., pheasant) hunting participation is declining across North America, reflecting a larger downward trend in American hunting participation and threatening benefits to grassland conservation and rural economies. To stabilize and expand the pheasant hunting population, we must first identify factors that influence pheasant hunter participation. We used an extensive in‐person hunter survey to test the hypothesis that hunter demographics interact with social‐ecological traits of hunting locations to affect hunter decisions, outcomes, and perceptions. We built a series of Bayesian mixed effects models to parse variation in demographics, perceptions, and hunt outcomes of pheasant hunters interviewed at …


Predicting Functional Responses In Agro-Ecosystems From Animal Movement Data To Improve Management Of Invasive Pests, Mark Q. Wilber, Sarah M. Chinn, James C. Beasley, Raoul K. Bourghton, Ryan K. Brooks, Stephen S. Ditchkoff, Justin W. Fischer, Steve B. Hartley, Lindsey K. Holmstrom, John C. Kilgo, Jesse S. Lewis, Ryan S. Miller, Nathan P. Snow, Kurt C. Vercauteren, Samantha M. Wisely, Colleen T. Webb, Kim M. Peen Sep 2019

Predicting Functional Responses In Agro-Ecosystems From Animal Movement Data To Improve Management Of Invasive Pests, Mark Q. Wilber, Sarah M. Chinn, James C. Beasley, Raoul K. Bourghton, Ryan K. Brooks, Stephen S. Ditchkoff, Justin W. Fischer, Steve B. Hartley, Lindsey K. Holmstrom, John C. Kilgo, Jesse S. Lewis, Ryan S. Miller, Nathan P. Snow, Kurt C. Vercauteren, Samantha M. Wisely, Colleen T. Webb, Kim M. Peen

United States Department of Agriculture Wildlife Services: Staff Publications

Functional responses describe how changing resource availability affects consumer resource use, thus providing a mechanistic approach to prediction of the invasibility and potential damage of invasive alien species (IAS). However, functional responses can be context dependent, varying with resource characteristics and availability, consumer attributes, and environmental variables. Identifying context dependencies can allow invasion and damage risk to be predicted across different ecoregions. Understanding how ecological factors shape the functional response in agro-ecosystems can improve predictions of hotspots of highest impact and inform strategies to mitigate damage across locations with varying crop types and availability. We linked heterogeneous movement data across …


Landscape Factors That Influence European Starling (Sturnus Vulgaris) Nest Box Occupancy At Nasa Plum Brook Station (Pbs), Erie County, Ohio, Usa, Morgan Pfeiffer, Thomas W. Seamans, Bruce N. Buckingham, Bradley F. Blackwell Sep 2019

Landscape Factors That Influence European Starling (Sturnus Vulgaris) Nest Box Occupancy At Nasa Plum Brook Station (Pbs), Erie County, Ohio, Usa, Morgan Pfeiffer, Thomas W. Seamans, Bruce N. Buckingham, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

During the last decade at NASA Plum Brook Station (PBS), Erie County, Ohio, United States, there has been a nearly 50% decrease in European Starling (Sturnus vulgaris) occupancy (nests with ≥1 egg) of nest boxes designed to be used by starlings. Increased availability of natural cavities, from invertebrate pests, might have altered nest box occupation rates. It was hypothesized that starling nest box occupation rates would be a function of an index of potentially suitable tree cavities for nesting starlings, the semi-colonial nature of breeding starlings, and access to foraging areas (e.g., mowed lawns near buildings). Specifically, it was predicted …


Paleoclimate Of The Subtropical Andes During The Latest Miocene, Lauca T Basin, Chile, Melina Feitl, Andrea K. Kern, Amanda Jones, Sherilyn C. Fritz, P. A. Baker, R.M. Joeckel, Wout Salenbien, Debra A. Willard Aug 2019

Paleoclimate Of The Subtropical Andes During The Latest Miocene, Lauca T Basin, Chile, Melina Feitl, Andrea K. Kern, Amanda Jones, Sherilyn C. Fritz, P. A. Baker, R.M. Joeckel, Wout Salenbien, Debra A. Willard

School of Natural Resources: Faculty Publications

Uplift of the Andean Cordillera during the Miocene and Pliocene produced large-scale changes in regional atmospheric circulation that impacted local ecosystems. The Lauca Basin (northern Chilean Altiplano) contains variably fluvial and lacustrine sedimentary sequences spanning the interval from 8.7 to 2.3 Ma. Field samples were collected from paleo-lacustrine sediments in the basin. Sediments were dated using detrital zircon geochronology on volcanic tuffs, yielding an age range between ~5.57 and 5.44 Ma. These new age constraints provided an opportunity to evaluate changes in the Lauca Basin ecosystem across this dynamic Miocene-Pliocene transition. We employed multiple proxies (lithofacies analysis, diatoms, pollen, and …


Globe-Lfmc, A Global Plant Water Status Database For Vegetation Ecophysiology And Wildfire Applications, Marta Yebra, Gianluca Scortechini, Abdulbaset Badi, Maria Eugenia Beget, Matthias M. Boer, Ross Bradstock, Emilio Chuvieco, F. Mark Danson, Philip Dennison, Victor Resco De Dios, Carlos M. Di Bella, Greg Forsyth, Philip Frost, Mariano Garcia, Abdelaziz Hamdi, Binbin He, Matt Jolly, Tineke Kraaij, M. Pilar Martín, Florent Mouillot, Glenn Newnham, Rachael H. Nolan, Grazia Pellizzaro, Yi Qi, Xingwen Quan, David Riaño, Dar Roberts, Momadou Sow, Susan Ustin Aug 2019

Globe-Lfmc, A Global Plant Water Status Database For Vegetation Ecophysiology And Wildfire Applications, Marta Yebra, Gianluca Scortechini, Abdulbaset Badi, Maria Eugenia Beget, Matthias M. Boer, Ross Bradstock, Emilio Chuvieco, F. Mark Danson, Philip Dennison, Victor Resco De Dios, Carlos M. Di Bella, Greg Forsyth, Philip Frost, Mariano Garcia, Abdelaziz Hamdi, Binbin He, Matt Jolly, Tineke Kraaij, M. Pilar Martín, Florent Mouillot, Glenn Newnham, Rachael H. Nolan, Grazia Pellizzaro, Yi Qi, Xingwen Quan, David Riaño, Dar Roberts, Momadou Sow, Susan Ustin

School of Natural Resources: Faculty Publications

Globe-LFMC is an extensive global database of live fuel moisture content (LFMC) measured from 1,383 sampling sites in 11 countries: Argentina, Australia, China, France, Italy, Senegal, Spain, South Africa, Tunisia, United Kingdom and the United States of America. The database contains 161,717 individual records based on in situ destructive samples used to measure LFMC, representing the amount of water in plant leaves per unit of dry matter. The primary goal of the database is to calibrate and validate remote sensing algorithms used to predict LFMC. However, this database is also relevant for the calibration and validation of dynamic global vegetation …


Evolutionary History Predicts High‐Impact Invasions By Herbivorous Insects, Angela M. Mech, Kathryn A. Thomas, Travis D. Marsico, Daniel A. Herms, Craig R. Allen, Matthew P. Ayres, Kamal J.K. Gandhi, Jessica Gurevitch, Nathan P. Havill, Ruth A. Hufbauer, Andrew M. Liebhold, Kenneth F. Raffa, Ashley N. Schulz, Daniel R. Uden, Patrick C. Tobin Aug 2019

Evolutionary History Predicts High‐Impact Invasions By Herbivorous Insects, Angela M. Mech, Kathryn A. Thomas, Travis D. Marsico, Daniel A. Herms, Craig R. Allen, Matthew P. Ayres, Kamal J.K. Gandhi, Jessica Gurevitch, Nathan P. Havill, Ruth A. Hufbauer, Andrew M. Liebhold, Kenneth F. Raffa, Ashley N. Schulz, Daniel R. Uden, Patrick C. Tobin

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. A long‐standing goal of invasion biology is to identify factors driving highly variable impacts of non‐native species. Although hypotheses exist that emphasize the role of evolutionary history (e.g., enemy release hypothesis & defense‐free space hypothesis), predicting the impact of non‐native herbivorous insects has eluded scientists for over a century.

2. Using a census of all 58 non‐native conifer‐specialist insects in North America, we quantified the contribution of over 25 factors that could affect the impact they have on their novel hosts, including insect traits (fecundity, voltinism, native range, etc.), host traits (shade tolerance, growth rate, wood density, etc.), and …


Comparison Of The Efficacy Of Four Drug Combinations For Immobilization Of Wild Pigs, Christine K. Ellis, Morgan E. Wehtje, Lisa L. Wolfe, Peregrine L. Wolff, Clayton D. Hilton, Mark C. Fisher, Shari Green, Michael P. Glow, Joeseph M. Halseth, Michael J. Lavelle, Nathan P. Snow, Eric H. Vannatta, Jack C. Rhyan, Kurt C. Vercauteren, William R. Lance, Pauline Nol Aug 2019

Comparison Of The Efficacy Of Four Drug Combinations For Immobilization Of Wild Pigs, Christine K. Ellis, Morgan E. Wehtje, Lisa L. Wolfe, Peregrine L. Wolff, Clayton D. Hilton, Mark C. Fisher, Shari Green, Michael P. Glow, Joeseph M. Halseth, Michael J. Lavelle, Nathan P. Snow, Eric H. Vannatta, Jack C. Rhyan, Kurt C. Vercauteren, William R. Lance, Pauline Nol

United States Department of Agriculture Wildlife Services: Staff Publications

Field immobilization of native or invasive wild pigs (Sus scrofa) is challenging. Drug combinations commonly used often result in unsatisfactory immobilization, poor recovery, and adverse side effects, leading to unsafe handling conditions for both animals and humans. We compared four chemical immobilization combinations, medetomidine–midazolam–butorphanol (MMB), butorphanol–azaperone–medetomidine (BAM™), nalbuphine–medetomidine–azaperone (NalMed-A), and tiletamine– zolazepam–xylazine (TZX), to determine which drug combinations might provide better chemical immobilization of wild pigs. We achieved adequate immobilization with no post-recovery morbidity withMMB. Adequate immobilization was achieved with BAM™; however, we observed post-recovery morbidity. Both MMB and BAM™ produced more optimal results relative to body temperature, recovery, and …


Vision In An Abundant North American Bird: The Red-Winged Blackbird, Esteban Fernández-Juricic, Patrice E. Baumhardt, Luke P. Tyrrell, Amanda Elmore, Shelagh T. Deliberto, Scott J. Werner Aug 2019

Vision In An Abundant North American Bird: The Red-Winged Blackbird, Esteban Fernández-Juricic, Patrice E. Baumhardt, Luke P. Tyrrell, Amanda Elmore, Shelagh T. Deliberto, Scott J. Werner

United States Department of Agriculture Wildlife Services: Staff Publications

Avian vision is fundamentally different from human vision; however, even within birds there are substantial between species differences in visual perception in terms of visual acuity, visual coverage, and color vision. However, there are not many species that have all these visual traits described, which can constrain our ability to study the evolution of visual systems in birds. To start addressing this gap, we characterized multiple traits of the visual system (visual coverage, visual acuity, centers of acute vision, and color vision) of the Red-winged Blackbird (Agelaius phoeniceus), one of the most abundant and studied birds in North America. We …


Low Secondary Risks For Captive Coyotes From A Sodium Nitrite Toxic Bait For Invasive Wild Pigs, Nathan P. Snow, Katherine E. Horak, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren Aug 2019

Low Secondary Risks For Captive Coyotes From A Sodium Nitrite Toxic Bait For Invasive Wild Pigs, Nathan P. Snow, Katherine E. Horak, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

An acute toxic bait is being developed to deliver micro‐encapsulated sodium nitrite (SN) to stimulate severe methemoglobinemia and humane death for invasive wild pigs (Sus scrofa), thereby providing a new tool for reducing their populations. During April 2016, we evaluated sensitivity to SN and outcomes of secondary consumption in the ubiquitous mammalian scavenger, coyote (Canis latrans), to determine secondary risks of consuming carcasses of wild pigs that died from consuming the SN toxic bait. At the National Wildlife Research Center in Fort Collins, Colorado, USA, we first evaluated whether coyotes fed carcasses of domestic pigs killed by consumption of SN …


Calibration And Validation Of The Cosmic Ray Neutron Rover For Soilwater Mapping Within Two South African Land Classes, Thigesh Vather, Colin Everson, Trenton E. Franz Aug 2019

Calibration And Validation Of The Cosmic Ray Neutron Rover For Soilwater Mapping Within Two South African Land Classes, Thigesh Vather, Colin Everson, Trenton E. Franz

School of Natural Resources: Faculty Publications

Knowledge of soil water at a range of spatial scales would further our understanding of the dynamic variable and its influence on numerous hydrological applications. Cosmic ray neutron technology currently consists of the Cosmic Ray Neutron Sensor (CRNS) and the Cosmic Ray Neutron Rover (CRNR). The CRNR is an innovative tool to map surface soil water across the land surface. This research assessed the calibration and validation of the CRNR at two survey sites (hygrophilous grassland and pine forest) within the Vasi area with an area of 72 and 56 ha, respectively. The assessment of the calibrations showed that consistent …


Modeling Irrigation Behavior In Groundwater Systems, Timothy Foster, Nicholas Brozovic, Adrian P. Butler Aug 2019

Modeling Irrigation Behavior In Groundwater Systems, Timothy Foster, Nicholas Brozovic, Adrian P. Butler

Daugherty Water for Food Global Institute: Faculty Publications

Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas …


Water Productivity In Meat And Milk Production In The Us From 1960 To 2016, Mesfin Mekonnen, C.M.U. Neale, Chittaranjan Ray, Galen E. Erickson, Arjen Y. Hoekstra Aug 2019

Water Productivity In Meat And Milk Production In The Us From 1960 To 2016, Mesfin Mekonnen, C.M.U. Neale, Chittaranjan Ray, Galen E. Erickson, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Global demand for livestock products is rising, resulting in a growing demand for feed and potentially burdening freshwater resources to produce this feed. To offset this increased pressure on water resources, the environmental performance of livestock sector should continue to improve. Over the last few decades, product output per animal and feedstuff yields in the US have improved, but before now it was unclear to what extent these improvements influenced the water productivity (WP) of the livestock products. In this research, we estimate changes in WP of animal products from 1960 to 2016. We consider feed conversion ratios (dry matter …


Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier Aug 2019

Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier

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

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, …


Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier Aug 2019

Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier

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

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, …


Drought Impacts Assessment In Brazil: A Remote Sensing Approach, Denis Mariano Aug 2019

Drought Impacts Assessment In Brazil: A Remote Sensing Approach, Denis Mariano

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

Climate extremes are becoming more frequent in Brazil; studies project an increase in drought occurrences in many regions of the country. In the south, drought events lead to crop yield losses affecting the value chain and, therefore, the local economy. In the northeast, extended periods of drought lead to potential land degradation, affecting the livelihood and hindering local development. In the southern Amazon, an area that experienced intense land use change (LUC) in the last, the impacts are even more complex, ranging from crop yield loss and forest resilience loss, affecting ecosystem health and putting a threat on the native …


Regime Detection Measures For The Practical Ecologist, Jessica L. Burnett Aug 2019

Regime Detection Measures For The Practical Ecologist, Jessica L. Burnett

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

Forecasting undesirable change is, arguably, the holy grail of ecology. Paired with an understanding of system interactions, a forecast is ideal if it provides reliable predictions in sufficient time to prevent or mitigate unwanted systemic change. Early warning systems (or early warning signals, early warning indicators) have been developed and tested for some ecological systems data, but have been mostly applied to marine fisheries time series and nutrient loadings in shallow lakes. Despite the numerous quantitative methods proposed for identifying or forecasting regime shifts in ecological data, few are used in practice. This dissertation contributes to our understanding of the …


Nitrate Removal And Placement Of Floating Treatment Wetlands In The Midwest, Mary G. Keilhauer Aug 2019

Nitrate Removal And Placement Of Floating Treatment Wetlands In The Midwest, Mary G. Keilhauer

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

The Midwestern United States is vulnerable to eutrophic conditions from high nutrient concentrations. Recommendations for nonpoint source pollution management include runoff treatment (i.e., filter strips, riparian buffers) and in-situ lake treatment practices (i.e., aluminum sulfate (alum) treatments, aeration, up/downdraft pumping, floating treatment wetlands). Floating treatment wetlands (FTWs) are an innovative wetland design for nutrient removal from nonpoint sources and provide a unique in-situ treatment. Best management practice studies have commonly focused on adjacent to water practices, which have resulted in a gap for guidance for in-situ treatment placement and design. Therefore, the objectives of this project were to (1) Quantify …


Evaluation Of The Metric Model For Mapping Energy Balance Components And Actual Evapotranspiration For A Super-Intensive Drip-Irrigated Olive Orchard, Samuel Ortega Aug 2019

Evaluation Of The Metric Model For Mapping Energy Balance Components And Actual Evapotranspiration For A Super-Intensive Drip-Irrigated Olive Orchard, Samuel Ortega

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

A field experiment was carried out to evaluate the METRIC (Mapping EvapoTranspiration at high Resolution Internalized with Calibration) model for mapping net radiation (Rni), soil heat flux (Gi), sensible heat flux (Hi), latent heat flux (LEi), actual evapotranspiration (ETa) and crop coefficient (Kc) of a superintensive drip-irrigated olive (Olea europeae L. cv Arbequina) orchard located in Pencahue Valley, Region del Maule, Chile (35 23’ LS; 71 44’ LW; 96 m above sea level). The study was conducted in an experimental plot of 21.1 hectares using 9 satellite images (Landsat 7 ETM+) acquired on clear sky days during 2011/2012 and 2012/2013 …


Developing A Framework To Link Multi-Sector Drought Impacts To Drought Severity At The State Level, Mary Noel Aug 2019

Developing A Framework To Link Multi-Sector Drought Impacts To Drought Severity At The State Level, Mary Noel

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

The United States Drought Monitor, a weekly map depicting severity and spatial extent of drought, is a key indicator for federal and state policy decisions including the annual distribution of hundreds of millions of dollars for agricultural financial relief in the United States. However, the current table describing potential drought impacts for the map’s severity levels fails to adequately represent a state’s unique environmental, economic, and social values affected by drought. One approach to improve this broad, national-scale assessment is to transition from the former platform to a more detailed characterization of drought impacts at the state level. To accomplish …


Validation Of A Death Assay For Angiostrongylus Cantonensis Larvae (L3) Using Propidium Iodide In A Rat Model (Rattus Norvegicus), Susan I. Jarvi, John Jacob, Robert T. Sugihara, Israel L. Leinbach, Ina H. Klasner, Lisa M. Kaluna, Kirsten A. Snook, M. Kathleen Howe, Steven H. Jacquier, Ingo Lange, Abigail L. Atkinson, Ashley R. Deane, Chris N. Niebuhr, Shane R. Siers Jul 2019

Validation Of A Death Assay For Angiostrongylus Cantonensis Larvae (L3) Using Propidium Iodide In A Rat Model (Rattus Norvegicus), Susan I. Jarvi, John Jacob, Robert T. Sugihara, Israel L. Leinbach, Ina H. Klasner, Lisa M. Kaluna, Kirsten A. Snook, M. Kathleen Howe, Steven H. Jacquier, Ingo Lange, Abigail L. Atkinson, Ashley R. Deane, Chris N. Niebuhr, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

Angiostrongylus cantonensis is a pathogenic nematode and the cause of neuroangiostrongyliasis, an eosinophilic meningitis more commonly known as rat lungworm disease. Transmission is thought to be primarily due to ingestion of infective third stage larvae (L3) in gastropods, on produce, or in contaminated water. The gold standard to determine the effects of physical and chemical treatments on the infectivity of A. cantonensis L3 larvae is to infect rodents with treated L3 larvae and monitor for infection, but animal studies are laborious and expensive and also raise ethical concerns. This study demonstrates propidium iodide (PI) to be a reliable marker of …


Contact Rates With Nesting Birds Before And After Invasive Snake Removal: Estimating The Effects Of Trap-Based Control, Amy A. Yackel Adams, Melia G. Nafus, Page E. Klug, Björn Lardner, M.J. Mazurek, Julie A. Savidge, Robert N. Reed Jul 2019

Contact Rates With Nesting Birds Before And After Invasive Snake Removal: Estimating The Effects Of Trap-Based Control, Amy A. Yackel Adams, Melia G. Nafus, Page E. Klug, Björn Lardner, M.J. Mazurek, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive predators are responsible for almost 60% of all vertebrate extinctions worldwide with the most vulnerable faunas occurring on islands. The brown treesnake (Boiga irregularis) is a notorious invasive predator that caused the extirpation or extinction of most native forest birds on Guam. The success of avian reintroduction efforts on Guam will depend on whether snake-control techniques sufficiently reduce contact rates between brown treesnakes and reintroduced birds. Mouse-lure traps can successfully reduce brown treesnake populations at local scales. Over a 22-week period both with and without active snake removal, we evaluated snake-trap contact rates for mouse- and bird-lure traps. Bird-lure …


An Evaluation Of The Registration And Use Prospects For Four Candidate Toxicants For Controlling Invasive Mongooses (Herpestes Javanicus Auropunctatus), Emily W. Ruell, Chris N. Niebuhr, Robert T. Sugihara, Shane R. Siers Jul 2019

An Evaluation Of The Registration And Use Prospects For Four Candidate Toxicants For Controlling Invasive Mongooses (Herpestes Javanicus Auropunctatus), Emily W. Ruell, Chris N. Niebuhr, Robert T. Sugihara, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The eradication or control of invasive small Indian mongooses from islands likely requires toxic baiting when removal by trapping proves insufficient. The one toxic bait currently registered for mongooses in the United States has relatively low palatability and efficacy for mongooses. Developing and registering a new pesticide can be very expensive, while funding for developing toxicants for mongooses is limited. Once registered, use of a toxic bait may be hindered by other factors, such as public opposition to an inhumane toxicant, poorer efficacy than expected, or if the toxic bait is difficult for applicators to apply or store. Therefore, we …


How Characteristic Is The Species Characteristic Selection Scale?, Erica F. Stuber, Joseph J. Fontaine Jul 2019

How Characteristic Is The Species Characteristic Selection Scale?, Erica F. Stuber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Aim: The importance of framing investigations of organism–environment relationships to interpret patterns at relevant spatial scales is increasingly recognized. However, most research related to environmental relationships is single‐scaled, implicitly or explicitly assuming that a “species characteristic selection scale” exists. We tested the premise that a single characteristic scale exists to understand species– environment relationships within species by asking (a) what are the characteristic scales of species’ relationships with environmental predictors, and (b) is within species, cross‐predictor consistency in characteristic scales a general phenomenon.

Location: Nebraska, USA.

Time period: 2016.

Major taxa studied: Birds.

Methods: We used data from 86 species …


Operationalizing Ecological Resilience Concepts For Managing Species And Ecosystems At Risk, Jeanne C. Chambers, Craig R. Allen, Samuel A. Cushman Jul 2019

Operationalizing Ecological Resilience Concepts For Managing Species And Ecosystems At Risk, Jeanne C. Chambers, Craig R. Allen, Samuel A. Cushman

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

This review provides an overview and integration of the use of resilience concepts to guide natural resources management actions. We emphasize ecosystems and landscapes and provide examples of the use of these concepts from empirical research in applied ecology. We begin with a discussion of definitions and concepts of ecological resilience and related terms that are applicable to management. We suggest that a resilience-based framework for management facilitates regional planning by providing the ability to locate management actions where they will have the greatest benefits and determine effective management strategies. We review the six key components of a resilience-based framework, …