Physical Sciences and Mathematics Commons^™

A Unifying Gravity Framework For Dispersal, E. Jongejans, O. Skarpaas, M. J. Ferrari Et Al.

School of Natural Resources: Faculty Publications

No abstract provided.

Evaluating An Unconfined Aquifer By Analysis Of Age-Dating Tracers In Stream Water, D. K. Solomon, T. E. Gilmore, B. Kimball, D. P. Genereux

School of Natural Resources: Faculty Publications

The mean transit time (MTT) is a fundamental property of a groundwater flow system that is strongly related to the ratio of recharge rate to storage volume. However, obtaining samples for estimating the MTT using environmental tracers is problematic as flow-weighted samples over the full spectrum of transit times are needed. Samples collected fromthe base flow of a gaining stream in the North Carolina Coastal Plain (West Bear Creek) that were corrected for exchange with the atmosphere yielded environmental tracer concentrations (SF₆ and CFC-11) very similar to flow-weighted values from nine or ten streambed piezometers that directly sampled groundwater …

Application Of Remote Sensing For Quantifying And Mapping Surface Energy Fluxes In South Central Nebraska: Analyses With Respect To Field Measurements, Vivek Sharma, Suat Irmak, Ayse Kilic, Denis Mutibwa

School of Natural Resources: Faculty Publications

Large-scale quantification of crop evapotranspiration (ETc) from various vegetation surfaces can aid in planning, managing, and allocating water resources. Field measurement of surface energy fluxes, including ETc, remains (and should remain) a crucial process for calibration and validation of satellite/remote sensing-based methods, which can provide important supporting information for water balance assessments and for analyzing the spatial distribution of energy fluxes on large scales. The Surface Energy Balance System (SEBS) was evaluated in estimating surface energy fluxes in south central Nebraska using Landsat imagery and meteorological data. SEBS-estimated surface energy fluxes were compared to Bowen Ratio Energy Balance System (BREBS) …

2015 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Lauren R. Dinan, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Abstract:

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2014–2015). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The lower Platte River and its major tributaries provide important nesting and migratory stopover habitat for two bird species of special conservation concern: the state and federally endangered Interior Least Tern (Sternula antillarum athalassos) and threatened Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University …

A Mixed-Methods Approach To Assessing Success In Transitioning Water Management Institutions: A Case Study Of The Platte River Basin, Nebraska, Christina Hoffman Babbitt, Mark E. Burbach, Lisa Pennisi

School of Natural Resources: Faculty Publications

To address increasing conflicts between surface water and groundwater users, the state of Nebraska has adopted a more localized and integrated approach in managing water resources. Integrated approaches offer promise in better managing connected water resources within the state; however, little review of the potential benefits and/or challenges of these actions has been conducted. This case study uses both qualitative and quantitative data collection efforts to take an in-depth look at how this new and innovative management system is working through the eyes of stakeholders living and working in the basin. Data collection reveals that overall the current water management …

Investigating Diurnal And Seasonal Climatic Response To Land Use And Land Cover Change Over Monsoon Asia With The Community Earth System Model, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

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

School of Natural Resources: Faculty Publications

No abstract provided.

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

School of Natural Resources: Faculty Publications

No abstract provided.

Twentieth Century Droughts And Agriculture: Examples From Impacts On Soybean Production In Kentucky, Usa, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Neural Network Analysis On The Effect Of Heat Fluxes On Greenhouse Gas Emissions From Anaerobic Swine Waste Treatment Lagoon, N. Lovanh, J. Loughrin, M. Rysz, A. I. Quintanar, B. T. Oh, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Enso Teleconnection Pattern Changes Over The Southeastern United States Under A Climate Change Scenario In Cmip5 Models, Ji-Hyun Oh, D.W. Shin, Steven D. Cocke, Guillermo A. Baigorria

School of Natural Resources: Faculty Publications

A strong teleconnection exists between the sea surface temperature (SST) over the tropical Pacific and the winter precipitation in the southeastern United States (SE US).This feature is adopted to validate the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in this study. In addition, the authors examine whether the teleconnection pattern persists in the future under a global warming scenario. Generally, most of the eight selected models show a positive correlation between November SST over Ni˜no 3 region and December–February (DJF) mean daily precipitation anomalies over the SE US, consistent with the observation. However, the models with poor realization …

Modeling The Snow Surface Temperature With A One-Layer Energy Balance Snowmelt Model, J. You, D. G. Tarboton, C. H. Luce

School of Natural Resources: Faculty Publications

Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort …

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller …

Translating Aboveground Cosmic-Ray Neutron Intensity To High-Frequency Soil Moisture Profiles At Sub-Kilometer Scale, R. Rosolem, T. Hoar, A. Arellano, J. L. Anderson, W. J. Shuttleworth, X. Zeng, Trenton E. Franz

School of Natural Resources: Faculty Publications

Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the subkilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a “nearly-identical twin” experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance …

Connections Between Student Explanations And Arguments From Evidence About Plant Growth, Jenny Dauer, Jennifer H. Doherty, Allison L. Freed, Charles W. Anderson

School of Natural Resources: Faculty Publications

We investigate how students connect explanations and arguments from evidence about plant growth and metabolism—two key practices described by the Next Generation Science Standards. This study reports analyses of interviews with 22 middle and high school students postinstruction, focusing on how their sense-making strategies led them to interpret—or misinterpret—scientific explanations and arguments from evidence. The principles of conservation of matter and energy can provide a framework for making sense of phenomena, but our results show that some students reasoned about plant growth as an action enabled by water, air, sunlight, and soil rather than a process of matter and energy …

Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian D. Healy, Jonathan Spurgeon

School of Natural Resources: Faculty Publications

Nonnative fishes have been linked to the decline of native fishes and may affect aquatic food webs through direct and indirect pathways. These concerns have led to efforts to remove nonnative Brown and Rainbow Trout, which are abundant in tributaries of the Colorado River, to enhance native fish communities. We sampled fish, benthic, and drifting macroinvertebrates in November 2010, January 2011, June 2011, and September 2011 to assess resource availability and to evaluate the effects of nonnative Brown and Rainbow Trout in a tributary of the Colorado River in the Grand Canyon. We evaluated trout diets from stomach samples collected …

A Geospatial Approach For Prioritizing Wind Farm Development In Northeast Nebraska, Usa, Adam Miller, Ruopu Li

School of Natural Resources: Faculty Publications

Being cleaner and climate friendly, wind energy has been increasingly utilized to meet the ever-growing global energy demands. In the State of Nebraska, USA, a wide gap exists between wind resource and actual energy production, and it is imperative to expand the wind energy development. Because of the formidable costs associated with wind energy development, the locations for new wind turbines need to be carefully selected to provide the greatest benefit for a given investment. Geographic Information Systems (GIS) have been widely used to identify the suitable wind farm locations. In this study, a GIS-based multi-criteria approach was developed to …

Juvenile Green Sturgeon (Acipenser Medirostris) And White Sturgeon (Acipenser Transmontanus) Behavior Near Water-Diversion Fish Screens: Experiments In A Laboratory Swimming Fume, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue

School of Natural Resources: Faculty Publications

Water diversions that extract fresh water for urban, industrial, and agricultural uses, as well as export to southern California, are prevalent throughout the Sacramento–San Joaquin watershed. Many water diversions are fitted with fish-exclusion screens designed to prevent fish from entrainment (i.e., being drawn in). The impact of fish screens on the behavior of migrating juvenile fishes remains largely unknown, especially for threatened species such as sturgeon. We placed individual juvenile green (Acipenser medirostris) or white (Acipenser transmontanus) sturgeon in a laboratory swimming flume in the presence of standard fish screens (2 mm bar spacing) at two …

A Combined Chemical And Biological Approach To Transforming And Mineralizing Pahs In Runoff Water, Chainarong Sakulthaew, Steve D. Comfort, Chanat Chokejaroenrat, Clifford Harris, Xu Li

School of Natural Resources: Faculty Publications

The water quality of lakes, rivers and streams associated with metropolitan areas is declining from increased inputs of urban runoff that contain polycyclic aromatic hydrocarbons (PAHs). Our objective was to transform and mineralize PAHs in runoff using a combined chemical and biological approach. Using ¹⁴C-labeled phenanthrene, ¹⁴C-benzo(a)pyrene and a mixture of 16 PAHs, we found that ozone transformed all PAHs in a H₂O matrix within minutes but complete mineralization to CO₂ took several weeks. When urban runoff water (7.6 mg C L−1) replaced H₂O as the background matrix, some delays in degradation rates …

Patch-Burn Grazing Effects On Cattle Performance: Research Conducted In A Working Landscape, Stephen L. Winter, Samuel D. Fuhlendorf, Mark Goes

School of Natural Resources: Faculty Publications

• Patch-burn grazing is a range management strategy that might be able to simultaneously optimize livestock production objectives and wildlife habitat objectives.

• We compared patch-burn grazing to a traditional range management strategy in multiple pastures, representing a variety of land ownership and management histories, dispersed across a relatively large geographic area. Our results likely represent what land managers could expect if they adopted patch-burn grazing in similar situations.

• We found that cattle performance in pastures managed with patch-burn grazing did not differ from that found in pastures managed with a traditional range management strategy. This suggests that land …

Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian Healy, Jonathan Spurgeon

School of Natural Resources: Faculty Publications

Nonnative fishes have been linked to the decline of native fishes and may affect aquatic food webs through direct and indirect pathways. These concerns have led to efforts to remove nonnative Brown and Rainbow Trout, which are abundant in tributaries of the Colorado River, to enhance native fish communities. We sampled fish, benthic, and drifting macroinvertebrates in November 2010, January 2011, June 2011, and Septem- ber 2011 to assess resource availability and to evaluate the effects of nonnative Brown and Rainbow Trout in a tributary of the Colorado River in the Grand Canyon. We evaluated trout diets from stomach samples …

Land Management And Land-Cover Change Have Impacts Of Similar Magnitude On Surface Temperature, Sebastiaan Luyssaert, Mathilde Jammet, Paul C. Stoy, Stephen Estel, Julia Pongratz, Eric Ceschia, Galina Churkina, Axel Don, Karl Heinz Erb, Morgan Ferlicoq, Bert Gielen, Thomas Grünwald, Richard A. Houghton, Katja Klumpp, Alexander Knohl, Thomas Kolb, Tobias Kuemmerle, Tuomas Laurila, Annalea Lohila, Denis Loustau, Matthew J. Mcgrath, Patrick Meyfroidt, Eddy J. Moors, Kim Naudts, Kim Novick, Juliane Otto, Kim Pilegaard, Casimiro A. Pio, Serge Rambal, Corinna Rebmann, James Ryder, Andrew E. Suyker, Andrej Varlagin, Martin Wattenbach, A. Johannes Dolman

School of Natural Resources: Faculty Publications

Anthropogenic changes to land cover (LCC) remain common, but continuing land scarcity promotes the widespread intensification of land management changes (LMC) to better satisfy societal demand for food, fibre, fuel and shelter. The biophysical effects of LCC on surface climate are largely understood, particularly for the boreal and tropical zones, but fewer studies have investigated the biophysical consequences of LMC; that is, anthropogenic modification without a change in land cover type. Harmonized analysis of ground measurements and remote sensing observations of both LCC and LMC revealed that, in the temperate zone, potential surface cooling from increased albedo is typically offset …

An Evaluation Of Two Traps And Sets For Trapping The Plains Pocket Gopher, Stephen M. Vantassel, Andrew J. Tyre, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

We investigated the efficiency of DK-1 and Macabee® pocket gopher (Geomys bursarius) traps placed in lateral tunnels in both open and closed tunnel sets in rangeland and nonirrigated alfalfa fields in Nebraska. We observed no statistical difference between the traps in capture efficiency when used in open, versus closed, tunnel sets. Trapping of pocket gophers was more effective in rangeland (probability of capture in a single tunnel system using 3 traps; 63%) than nonirrigated alfalfa fields (26%). We did not determine whether this variance was due to behavioral differences between Geomys bursarius and Geomys lutescens. We found that trapping pocket …

Productivity And Carbon Dioxide Exchange Of Leguminous Crops: Estimates From Flux Tower Measurements, Tagir Gilmanov, John M. Baker, Carl J. Bernacchi, David P. Billesbach, George G. Burba, Saulo Castro, Jiquan Chen, Werner Eugster, Marc L. Fischer, John A. Gamon, Maheteme T. Gebremedhin, Aaron J. Glenn, Timothy J. Griffis, Jerry L. Hatfield, Mark W. Heuer, Daniel M. Howard, Monique Y. Leclerc, Henry W. Loescher, Oliver Marloie, Tilden P. Meyers, Albert Olioso, Rebecca L. Phillips, John H. Prueger, R. Howard Skinner, Andrew E. Suyker, Mario Tenuta, Bruce K. Wylie

School of Natural Resources: Faculty Publications

Net CO₂ exchange data of legume crops at 17 flux tower sites in North America and three sites in Europe representing 29 site-years of measurements were partitioned into gross photosynthesis and ecosystem respiration by using the nonrectangular hyperbolic lightresponse function method. The analyses produced net CO₂ exchange data and new ecosystem-scale ecophysiological parameter estimates for legume crops determined at diurnal and weekly time steps. Dynamics and annual totals of gross photosynthesis, ecosystem respiration, and net ecosystem production were calculated by gap filling with multivariate nonlinear regression. Comparison with the data from grain crops obtained with the same method …

Stochastic Models To Generate Geospatial-, Temporal-, And Cross-Correlated Daily Maximum And Minimum Temperatures, Guillermo A. Baigorria

School of Natural Resources: Faculty Publications

Weather generators are tools used to downscale monthly to seasonal climate forecasts, from numerical climate models to daily values for use as inputs for crop and other environmental models. One main limitation of most of weather generators is that they do not incorporate neither the spatial/temporal correlations between/within sites nor the cross-correlations between variables, characteristics specially important when aggregating, for example, simulated crop yields, freeze events, or heat waves in a watershed or region.Three models were developed to generate realization of daily maximum and minimum temperatures for multiple sites. The first model incorporates only spatial correlation, whereas temporal correlation using …

Estimating Temperature Fields From Modis Land Surface Temperature And Air Temperature Observations In A Sub-Arctic Alpine Environment, Scott N. Williamson, David S. Hik, John A. Gamon, Jeffrey L. Kavanaugh, Gwenn E. Flowers

School of Natural Resources: Faculty Publications

Spatially continuous satellite infrared temperature measurements are essential for understanding the consequences and drivers of change, at local and regional scales, especially in northern and alpine environments dominated by a complex cryosphere where in situ observations are scarce. We describe two methods for producing daily temperature fields using MODIS ―clear-sky‖ day-time Land Surface Temperatures (LST). The Interpolated Curve Mean Daily Surface Temperature (ICM) method, interpolates single daytime Terra LST values to daily means using the coincident diurnal air temperature curves. The second method calculates daily mean LST from daily maximum and minimum LST (MMM) values from MODIS Aqua and Terra. …

Summer Soil Moisture Spatiotemporal Variability In Southeastern Arizona, Susan Stillman, Jason Ninneman, Xubin Zeng, Trenton E. Franz, Russell L. Scott, William J. Shuttleworth, Ken Cummins

School of Natural Resources: Faculty Publications

Soil moisture is important for many applications, but its measurements are lacking globally and even regionally. The Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona has measured near surface 5-cm soil moisture with 19 in situ probes since 2002 within its 150km2 area. Using various criteria to identify erroneous data, it is found that in any given period from 1 July to 30 September from 2002 to 2011, 13– 17 of these probes were producing reasonable data, and this is sufficient to estimate area-averaged seasonal soil moisture. A soil water balance model is then developed using rainfall as its only …

Local Awareness Of And Attitudes Toward Pygmy Hippopotamus Conservation In The Moa River Island Complex, Sierra Leone., April L. Conway, Sonia M. Hernandez, John P. Carroll, Gary T. Green, Lincoln Larson

School of Natural Resources: Faculty Publications

Abstract The pygmy hippopotamus Choeropsis liberiensis is an Endangered species found only in the Upper Guinea rainforests of West Africa. Using a two-phase approach, with initial semi-structured interviews followed by more extensive questionnaires, we examined local residents’ awareness of and attitudes towards the pygmy hippopotamus along the Moa River near Tiwai Island Wildlife Sanctuary in Sierra Leone. The interviews and questionnaires addressed human–hippopotamus interactions, local knowledge and awareness of pygmy hippopotamus ecology and behaviour, and public attitudes towards hippopotamus conservation. Overall, 22% of questionnaire respondents acknowledged benefits related to hippopotamus conservation; factors affecting the perception of benefits included age, livestock …

Using Art To Assess Environmental Education Outcomes, Ami G. Flowers, John P. Carroll, Gary T. Green, Lincoln R. Larson

School of Natural Resources: Faculty Publications

Construction of developmentally appropriate tools for assessing the environmental attitudes and awareness of young learners has proven to be challenging. Art-based assessments that encourage creativity and accommodate different modes of expression may be a particularly useful complement to conventional tools (e.g. surveys), but their efficacy and feasibility across diverse contexts has not been adequately explored. To examine the potential utility of integrating art into evaluations of environmental education outcomes, we adapted an existing drawing prompt and corresponding grading rubric to assess the environmental attitudes and awareness of children (ages 6–12) at summer camps in Athens, GA, USA (n = …

Evidence For Bluegill Spawning Plasticity Obtained By Disentangling Complex Factors Related To Recruitment, Mark A. Kaemingk, Kristopher J. Stahr, Jeffrey C. Jolley, Richard S. Holland, David W. Willis

School of Natural Resources: Faculty Publications

Fishes can exhibit many forms of plasticity to maximize fitness. However, limited information exists on the ability of freshwater fish to adjust spawning behavior and characteristics (e.g., timing, duration, magnitude of spawning events) to minimize mortality of recruits and ultimately maximize fitness.Wewanted to test the life history hypothesis for bluegill (Lepomis macrochirus) (i.e., opportunistic strategy) utilizing existing literature and results from our study to further evaluate the potential for spawning plasticity in this species. Our objective was to identify bluegill recruitment bottlenecks (i.e., periods of high mortality) and factors associated with these events in a single lake during …