Physical Sciences and Mathematics Commons^™

Applying Topographic Classification, Based On The Hydrological Process, To Design Habitat Linkages For Climate Change, Yongwon Mo, Dong Kun Lee, Keunyea Song, Ho Gul Kim, Soo Jin Park

School of Natural Resources: Faculty Publications

The use of biodiversity surrogates has been discussed in the context of designing habitat linkages to support the migration of species affected by climate change. Topography has been proposed as a useful surrogate in the coarse-filter approach, as the hydrological process caused by topography such as erosion and accumulation is the basis of ecological processes. However, some studies that have designed topographic linkages as habitat linkages, so far have focused much on the shape of the topography (morphometric topographic classification) with little emphasis on the hydrological processes (generic topographic classification) to find such topographic linkages. We aimed to understand whether …

Introductory Biology Students’ Use Of Enhanced Answer Keys And Reflection Questions To Engage In Metacognition And Enhance Understanding, Jaime L. Sabel, Joseph T. Dauer, Cory T. Forbes

School of Natural Resources: Faculty Publications

Providing feedback to students as they learn to integrate individual concepts into complex systems is an important way to help them to develop robust understanding, but it is challenging in large, undergraduate classes for instructors to provide feedback that is frequent and directed enough to help individual students. Various scaffolds can be used to help students engage in self-regulated learning and generate internal feedback to improve their learning. This study examined the use of enhanced answer keys with added reflection questions and instruction as scaffolds for engaging undergraduate students in self-regulated learning within an introductory biology course. Study findings show …

Geological Principles Illustrated In The Art Along The Antelope Valley Hiker/Biker Trail – The Big X (Salt Creek Roadway/Antelope Valley Parkway) South To Q Street, Robert Diffendal, Jr.

School of Natural Resources: Faculty Publications

When the weather is good (and even sometimes when it isn’t) I occasionally walk around the periphery of the UNL city campus, often over the lunch hour, now that the trails and the sidewalks allow one to walk a complete circuit. The walk along Antelope Creek from the Big X to Q Street is beautiful. The designers of the project made nice art works on the floor of the creek and on the retaining walls on the valley sides that add to the beauty of nature.

I am a geologist and wondered about some of the art and its meaning …

The Future Of Earth Observation In Hydrology, Matthew F. Mccabe, Matthew Rodell, Douglas E. Alsdorf, Remko Uijlenhoet, Wolfgang Wagner, Arko Lucieer, Rasmus Houborg, Niko E. C. Verhoest, Trenton E. Franz, Jiancheng Shi, Huilin Gao, Eric F. Wood

School of Natural Resources: Faculty Publications

In just the past 5 years, the field of Earth observation has progressed beyond the offerings of conventional space-agency-based platforms to include a plethora of sensing opportunities afforded by CubeSats, unmanned aerial vehicles (UAVs), and smartphone technologies that are being embraced by both for-profit companies and individual researchers. Over the previous decades, space agency efforts have brought forth well-known and immensely useful satellites such as the Landsat series and the Gravity Research and Climate Experiment (GRACE) system, with costs typically of the order of 1 billion dollars per satellite and with concept-to-launch timelines of the order of 2 decades (for …

Scaling, Similarity, And The Fourth Paradigm For Hydrology, Chirsta D. Peters-Lidard, Martyn Clark, Luis Samaniego, Niko E. C. Verhoest, Tim Van Emmerik, Remko Uijlenhoet, Kevin Achieng, Trenton E. Franz, Ross Woods

School of Natural Resources: Faculty Publications

In this synthesis paper addressing hydrologic scaling and similarity, we posit that roadblocks in the search for universal laws of hydrology are hindered by our focus on computational simulation (the third paradigm) and assert that it is time for hydrology to embrace a fourth paradigm of data intensive science. Advances in information-based hydrologic science, coupled with an explosion of hydrologic data and advances in parameter estimation and modeling, have laid the foundation for a data-driven framework for scrutinizing hydrological scaling and similarity hypotheses. We summarize important scaling and similarity concepts (hypotheses) that require testing; describe a mutual information framework for …

An Evaluation Of Emergent Macrophytes And Use Among Groups Of Aquatic Taxa, Kristopher J. Stahr, Mark A. Kaemingk

School of Natural Resources: Faculty Publications

Aquatic vegetation serves an important ecological role. Previous research on the interactions of macrophytes and aquatic organisms has focused primarily on submersed macrophytes due to their structural complexity and associated ecological impacts. However, the role of emergent vegetation is far less understood and often overlooked because they lack structural complexity. We evaluated 3 common emergent macrophytes and an open water habitat, and determined use among multiple aquatic taxa. Pelican Lake, Nebraska, USA, served as our study system because it is dominated by 3 emergent macrophytes: common cattail (Typha latifolia), softstem bulrush (Schoenoplectus tabernaemontani), and common reed …

Transcriptomic Effects Of Dispersed Oil In A Non-Model Decapod Crustacean, Hernan Vázquez-Miranda, Brent P. Thoma, Juliet M. Wong, Darryl L. Felder, Keith A. Crandall, Heather D. Bracken-Grissom

School of Natural Resources: Faculty Publications

Background. Oil spills are major environmental disasters. Dispersants help control spills, as they emulsify oil into droplets to speed bioremediation. Although dispersant toxicity is controversial, the genetic consequences and damages of dispersed oil exposure are poorly understood. We used RNA-seq to measure gene expression of flatback mudcrabs (Eurypanopeus depressus, Decapoda, Brachyura, Panopeidae) exposed to dispersed oil. Methods. Our experimental design included two control types, oil-only, and oil-dispersant treatments with three replicates each. We prepared 100 base pair-ended libraries from total RNA and sequenced them in one Illumina HiSeq2000 lane. We assembled a reference transcriptome with all replicates per treatment, …

Predation Risk: A Potential Mechanism For Effects Of A Wind Energy Facility On Greater Prairie-Chicken Survival, Jennifer A. Smith, Mary B. Brown, J.O. Harrison, Larkin A. Powell

School of Natural Resources: Faculty Publications

Recent expansion of the wind energy industry has raised concerns about the potential effects of wind energy facilities on prairie grouse. For example, efforts have been made to evaluate indirect effects on prairie grouse survival, but it is also critical to investigate the underlying mechanisms to direct conservation strategies. The objective of this study was to investigate the indirect effects of a wind energy facility on the survival of female Greater Prairie-Chickens (Tympanuchus cupido pinnatus) and on the occupancy of avian and mammalian predators. Between March and July of 2013 and 2014, we investigated spatial variation in predation risk by …

Nest Site Selection And Nest Survival Of Eastern Wild Turkeys In A Pyric Landscape, Nathan A. Yeldell, Bradley S. Cohen, Andrew R. Little, Bret A. Collier, Michael J. Chamberlain

School of Natural Resources: Faculty Publications

Pine (Pinus spp.)-dominated forests are commonly managed with prescribed fire in the southeastern United States to reduce fuel loads, maintain diverse plant communities, and increase habitat quality for wildlife. Prescribed fire alters understory vegetation, which is a key component of nesting habitat for ground-nesting birds. We assessed the influences of vegetation, prescribed fire, and landscape features (e.g., roads, edge) on nest site selection and nest survival of eastern wild turkeys (Meleagris gallopavo silvestris) in a pine-dominated ecosystem in west-central Louisiana. We radio-marked 55 female wild turkeys and evaluated vegetation and landscape characteristics associated with 69 nests during the …

Hydraulics Near Unscreened Diversion Pipes In Open Channels: Large Flume Experiments, Ali Ercan, M. Levent Kavvas, Kara Carr, Zachary Hockett, Houssein Bandeh, Timothy D. Mussen, Dennis E. Cocherell, Jamilynn B. Poletto, Joseph J. Cech Jr., Nann A. Fangue

School of Natural Resources: Faculty Publications

Most of the water diversions on the Sacramento and San Joaquin Rivers (California, United States) and their tributaries are currently unscreened. These unscreened diversions are commonly used for irrigation and are potentially harmful to migrating and resident fishes. A large flume (test section: 18.29 m long, 3.05 m wide and 3.20 m high) was used to investigate the hydraulic fields near an unscreened water diversion under ecologically and hydraulically relevant diversion rates and channel flow characteristics. We investigated all combinations of three diversion rates (0.28, 0.42, and 0.57 m³/s) and three sweeping velocities (0.15, 0.38, and 0.61 m/s), …

Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Teijun Wang, Justin Gibson, Ayse Kilie, Richard Allen, Andrew E. Suyker

School of Natural Resources: Faculty Publications

In this study, the feasibility of using inverse vadose zone modeling for estimating field-scale actual evapotranspiration (ETa/ was explored at a long-term agricultural monitoring site in eastern Nebraska. Data from both point-scale soil water content (SWC) sensors and the areaaverage technique of cosmic-ray neutron probes were evaluated against independent ETa estimates from a co-located eddy covariance tower. While this methodology has been successfully used for estimates of groundwater recharge, it was essential to assess the performance of other components of the water balance such as ETa. In light of recent evaluations of land surface models (LSMs), independent estimates of hydrologic …

Long-Term Analysis Of The Asynchronicity Between Temperature And Precipitation Maxima In The United States Great Plains, Paul Flanagan, Jeffrey B. Basara, Xiangming Xiao

School of Natural Resources: Faculty Publications

Agriculture is a critical industry to the economy of the Great Plains (GP) region of North America and sensitive to change in weather and climate. Thus, improved knowledge of meteorological and climatological conditions during the growing season and associated variability across spatial and temporal scales is important. A distinct climate feature in the GP is the asynchronicity (AS) between the timing of temperature and precipitation maxima. This study investigated a long-term observational data set to quantify the AS and to address the impacts of climate variability and change. Global Historical Climate Network Daily (GHCN-Daily) data were utilized for this study; …

Enhancing Dynamical Seasonal Predictions Through Objective Regionalization, Saleh Satti, Benjamin F. Zaitchik, Hamaba S. Babr, Tsegaye Tadesse

School of Natural Resources: Faculty Publications

Improving seasonal forecasts in East Africa has great implications for food security and water resources planning in the region. Dynamically based seasonal forecast systems have much to contribute to this effort, as they have demonstrated ability to represent and, to some extent, predict large-scale atmospheric dynamics that drive interannual rainfall variability in East Africa. However, these global models often exhibit spatial biases in their placement of rainfall and rainfall anomalies within the region, which limits their direct applicability to forecast-based decision-making. This paper introduces a method that uses objective climate regionalization to improve the utility of dynamically based forecast-system predictions …

Complex Variation In Habitat Selection Strategies Among Individuals Driven By Extrinsic Factors, Edward J. Raynor, Hawthorne L. Beyer, John M. Briggs, Anthony Joern

School of Natural Resources: Faculty Publications

Understanding behavioral strategies employed by animals to maximize fitness in the face of environmental heterogeneity, variability, and uncertainty is a central aim of animal ecology. Flexibility in behavior may be key to how animals respond to climate and environmental change. Using a mechanistic modeling framework for simultaneously quantifying the effects of habitat preference and intrinsic movement on space use at the landscape scale, we investigate how movement and habitat selection vary among individuals and years in response to forage quality–quantity tradeoffs, environmental conditions, and variable annual climate. We evaluated the association of dynamic, biotic forage resources and static, abiotic landscape …

Carbon Flux Phenology From The Sky: Evaluation For Maize And Soybean, Alexandria G. Mccombs, Cuizhen Wang, Ankur Desai, Andrew E. Suyker, Sebastien C. Bird

School of Natural Resources: Faculty Publications

Carbon flux phenology is widely used to understand carbon flux dynamics and surface exchange processes. Vegetation phenology has been widely evaluated by remote sensors; however, very few studies have evaluated the use of vegetation phenology for identifying carbon flux phenology. Currently available techniques to derive net ecosystem exchange (NEE) from a satellite image use a single generic modeling subgroup for agricultural crops. But, carbon flux phenological processes vary highly with crop types and land management practices; this paper reexamines this assumption. Presented here are an evaluation of ground-truth remotely sensed vegetation indices with in situ NEE measurements and an identification …

The Roles Of Ecology, Behavior And Effective Population Size In The Evolution Of A Community., C.M. Hung, S. Drovetski, R. M. Zink

School of Natural Resources: Faculty Publications

No abstract provided.

Acoustic Characteristics Of Lekking Male Greater Prairie-Chicken (Tympanuchus Cupido Pinnatus) Vocalizations (Supplement), Cara E. Whalen, Mary Bomberger Brown, Joann Mcgee, Larkin A. Powell, Edward J. Walsh

School of Natural Resources: Faculty Publications

Boom

Cackle

Whine

Whoop

Reproductive Ecology Of Interior Least Tern And Piping Plover In Relation To Platte River Hydrology And Sandbar Dynamics, Jason M. Farnsworth, David M. Baasch, Chadwin B. Smith, Kevin L. Werbylo

School of Natural Resources: Faculty Publications

Investigations of breeding ecology of interior least tern (Sternula antillarum athalassos) and piping plover (Charadrius melodus) in the Platte River basin in Nebraska, USA, have embraced the idea that these species are physiologically adapted to begin nesting concurrent with the cessation of spring floods. Low use and productivity on contemporary Platte River sandbars have been attributed to anthropomorphically driven changes in basin hydrology and channel morphology or to unusually late annual runoff events. We examined distributions of least tern and piping plover nest initiation dates in relation to the hydrology of the historical central Platte River …

Temporal Migration Shifts In The Aransas-Wood Buffalo Population Of Whooping Cranes (Grus Americana) Across North America, Joel G. Jorgensen, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Birds are altering the phenology of critical life history events, including migration, in response to the effects of global climate change. Whooping Cranes (Grus americana) are one of the most critically endangered birds in the world. Their remnant population, referred to as the Aransas-Wood Buffalo Population, numbers between 300-400 individuals and migrates between the U.S. Gulf of Mexico coast and north-central Canada twice each year. Previous analyses suggested Whooping Crane migration was temporally constant in spring and fall. New analyses of observations spanning 1942-2016 show Whooping Crane migration is now occurring earlier in spring by approximately 22 days …

Ecophysiological Responses Of Native Invasive Woody Juniperus Virginiana L. To Resource Availability And Stand Characteristics In The Semiarid Grasslands Of The Nebraska Sandhills, Joseph Msanne, Tala Awada, N. M. Bryan, Walter H. Schacht, Rhae A. Drijber, Y. Li, X. Zhou, Jane A. Okalebo, David A. Wedin, James R. Brandle, J. Hiller

School of Natural Resources: Faculty Publications

Vegetation in grasslands is changing at an unprecedented rate. In the Nebraska Sandhills, this shift is attributed in part to encroachment of the woody species Juniperus virginiana. We investigated changes in resource availability and their feedback on seasonal trends in photosynthetic characteristics of J. virginiana trees scattered in open grasslands vs. a dense 57-year-old stand. Dense stand exhibited lower volumetric soil water content, NH₄ ⁺, NO₃ ^–, and δ¹³C, as well as foliage δ¹³C, δ¹⁵N, and N content, compared to grasslands. Water potential was higher in trees in grasslands …

Drivers Of Nitrogen Transfer In Stream Food Webs Across Continents, B. C. Norman, M. R. Whiles, S. M. Collins, A. S. Flecker, S. K. Hamilton, S. L. Johnson, E. J. Rosi-Marshall, L. R. Ashkenas, W. B. Bowden, C. L. Crenshaw, T. Crowl, W. K. Dodds, R. O. Hall, R. El-Sabaawi, N. A. Griffiths, E. Marti, W. H. Mcdowell, S. D. Peterson, H. M. Rantala, T. Riis, K. S. Simon, J. L. Tank, S. A. Thomas, D. Von Schiller, J. R. Webster

School of Natural Resources: Faculty Publications

Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen ¹⁵N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in headwater streams with varying physical, chemical, and biological features. N transfer efficiencies from primary uptake compartments (PUCs; heterotrophic microorganisms and primary producers) to primary consumers was lower (mean: 11.5%, range:100%). Total N transferred (as a rate) was greater in streams …

Partitioning Assimilatory Nitrogen Uptake In Streams: An Analysis Of Stable Isotope Tracer Additions Across Continents, J. L. Tank, E. Martí, T. Riis, D. Von Schiller, A. J. Reisinger, W. K. Dodds, M. R. Whiles, L. R. Ashkenas, W. B. Bowden, S. M. Collins, C. L. Crenshaw, T. A. Crowl, N. A. Griffiths, N. B. Grimm, S. K. Hamilton, S. L. Johnson, W. H. Mcdowell, B. M. Norman, E. J. Rosi, K. S. Simon, S. A. Thomas, J. R. Webster

School of Natural Resources: Faculty Publications

Headwater streams remove, transform, and store inorganic nitrogen (N) delivered from surrounding watersheds, but excessive N inputs from human activity can saturate removal capacity. Most research has focused on quantifying N removal from the water column over short periods and in individual reaches, and these ecosystem-scale measurements suggest that assimilatory N uptake accounts for most N removal. However, cross-system comparisons addressing the relative role of particular biota responsible for incorporating inorganic N into biomass are lacking. Here we assess the importance of different primary uptake compartments on reach-scale ammonium (NH₄⁺-N) uptake and storage across a wide range …

Tolerance: The Forgotten Child Of Plant Resistance, Robert K. D. Peterson, Andrea C. Varella, Leon G. Higley

School of Natural Resources: Faculty Publications

Plant resistance against insect herbivory has greatly focused on antibiosis, whereby the plant has a deleterious effect on the herbivore, and antixenosis, whereby the plant is able to direct the herbivore away from it. Although these two types of resistance may reduce injury and yield loss, they can produce selection pressures on insect herbivores that lead to pest resistance. Tolerance, on the other hand, is a more sustainable pest management strategy because it involves only a plant response and therefore does not cause evolution of resistance in target pest populations. Despite its attractive attributes, tolerance has been poorly studied and …

Review Of Great Plains Geology By Robert F. Diffendal, Jon Trevelyan

School of Natural Resources: Faculty Publications

Professor Robert Diffendal Jr's little guidebook to the Great Plains of the USA makes for a fascinating read for an Englishman like me, who has never been there (but wants to). As he says in the article opposite, they rarely correspond to the impression most people have of them. For example, they are not just flat plains with cowboys herding longhorn cattle as you might imagine from the movies (in fact, they probably rarely were). Rather, it is clear from the guide that they can provide a visitor with an interesting mixture of geology, palaeontology, ecotourism and archaeology. In addition, …

Landscape Features Affecting Northern Bobwhite Predator-Specific Nest Failures In Southeastern Usa, Susan Ellis-Felege, Shannon E. Albeke, Nathan P. Nibbelink, Michael J. Conroy, D. Clay Sisson, William E. Palmer, John P. Carroll

School of Natural Resources: Faculty Publications

Nest predation is a critical component in avian productivity and typically is the leading cause of nest failure for most birds. Several landscape features are thought to drive the behavioral interaction between northern bobwhite (Colinus virginianus; e.g., nest placement) and their predators (e.g., search methods for food acquisition). In order to understand habitat characteristics influencing predation, we studied bobwhite nests using 24-hour near-infrared video cameras. We monitored 675 bobwhite nests with cameras on 3 properties in northern Florida and southern Georgia, USA, during 2000–2006. To test the association between nest failures and specific failure causes with landscape structure, we calculated …

Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon

School of Natural Resources: Faculty Publications

Tree species in the boreal forest cycle between periods of active growth and dormancy alter their photosynthetic processes in response to changing environmental conditions. For deciduous species, these changes are readily visible, while evergreen species have subtler foliar changes during seasonal transitions. In this study, we used remotely sensed optical indices to observe seasonal changes in photosynthetic activity, or photosynthetic phenology, of six boreal tree species. We evaluated the normalized difference vegetation index (NDVI), the photochemical reflectance index (PRI), the chlorophyll/carotenoid index (CCI), and steady-state chlorophyll fluorescence (F_S) as a measure of solar-induced fluorescence (SIF), and compared these …

Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon

School of Natural Resources: Faculty Publications

Tree species in the boreal forest cycle between periods of active growth and dormancy alter their photosynthetic processes in response to changing environmental conditions. For deciduous species, these changes are readily visible, while evergreen species have subtler foliar changes during seasonal transitions. In this study, we used remotely sensed optical indices to observe seasonal changes in photosynthetic activity, or photosynthetic phenology, of six boreal tree species. We evaluated the normalized difference vegetation index (NDVI), the photochemical reflectance index (PRI), the chlorophyll/carotenoid index (CCI), and steady-state chlorophyll fluorescence (F_S) as a measure of solar-induced fluorescence (SIF), and compared these …

Potential Of Windbreak Trees To Reduce Carbon Emissions By Agricultural Operations In The Us, William Ballesteros Possu, James R. Brandle, Michele Schoeneberger

School of Natural Resources: Faculty Publications

Along with sequestering C in forest, trees on farms are able to contribute to greenhouse mitigation through emission avoidance mechanisms. To evaluate the magnitude of these contributions, emission avoidance contributions for field and farmstead windbreak designs in regions across the United States were estimated, along with greenhouse gas (GHG) emission budgets for corn, soybean, winter wheat, and potato operations. We looked at farming scenarios with large (600 ha), mid (300 ha), and small-size (60 ha) farms containing farmsteads built before and after 2000, and growing different cropping systems. Windbreak scenarios were assumed to be up to 5% of the crop …

Common Carp Disrupt Ecosystem Structure And Function Through Middle-Out Effects, Mark A. Kaemingk, Jeffrey C. Jolley, Craig P. Paukert, David W. Willis, Kjetil Henderson, Richard S. Holland, Greg A. Wanner, Mark L. Lindvall

School of Natural Resources: Faculty Publications

Middle-out effects or a combination of top-down and bottom-up processes create many theoretical and empirical challenges in the realm of trophic ecology. We propose using specific autecology or species trait (i.e. behavioural) information to help explain and understand trophic dynamics that may involve complicated and nonunidirectional trophic interactions. The common carp (Cyprinus carpio) served as our model species for whole-lake observational and experimental studies; four trophic levels were measured to assess common carp-mediated middle-out effects across multiple lakes. We hypothesised that common carp could influence aquatic ecosystems through multiple pathways (i.e. abiotic and biotic foraging, early life feeding, nutrient). Both …

How Do Undergraduate Stem Mentors Reflect Upon Their Mentoring Experiences In An Outreach Program Engaging K-8 Youth?, Kari Nelson, Jaime Sabel, Cory Forbes, Neal Grandgenett, William Tapprich, Christine E. Cutucache

School of Natural Resources: Faculty Publications

Background: Many university students are becoming involved in mentoring programs, yet few studies describe the impact of mentoring on the mentor. Additionally, many studies report that students graduating from college are not prepared to enter the workforce in terms of key career skills and/or content knowledge. Herein, we examine the impact of our program, NE STEM 4U (Nebraska Science, Technology, Engineering and Math for You), in which undergraduate (UG) mentors engage K-8 youth in after-school STEM experiments. The UGs reflected upon their experiences using post-mentoring evaluations, 12- and 24-week interviews, and exit surveys. Many of the questions asked of the …