Other Environmental Sciences Commons^™

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 …

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, …

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 …

Population Growth And Mortality Sources Of The Black Bear Population In Northern Georgia, Andrew R. Little, Adam Hammond, James A. Martin, Kristina L. Johannsen, Karl V. Miller

School of Natural Resources: Faculty Publications

An understanding of black bear (Ursus americanus) population trends and cause-specific mortality is needed to direct management decisions in northern Georgia given an increasing human population. Therefore, we evaluated black bear population trends and mortality sources across 26 counties and 18 Wildlife Management Areas in northern Georgia from 1979–2014. We collected harvest data from 6,433 individuals during the study period. Using age-at-harvest data, population reconstruction illustrated an increasing trend in the bear population for both males (λ = 1.113) and females (λ = 1.108). Bait station indices reflected a similar increase in the bear population based on increased …

Exploring Elementary Students’ Scientific Knowledge Of Agriculture Using Evidence-Centered Design, Molly Brandt, Cory Forbes, Jenny Keshwani

School of Natural Resources: Faculty Publications

The public is more disconnected from agriculture than ever. Americans are now two to four generations removed from the farm with a majority of Americans having no direct experience in agriculture. As a result, the public lacks the knowledge and appreciation of the food, fuel, and fiber it demands. The National Agricultural Learning Objectives (NALOs) were recently developed to describe students’ agricultural knowledge but have, as yet, not been used to guide research into students’ agricultural literacy. The purpose of this project is to further understand students’ agricultural literacy through NALO-based assessment of students’ knowledge. This study focused on the …

Assessment Of Irrigation Physics In A Land Surface Modeling Framework Using Non-Traditional And Human-Practice Datasets, Paticia M. Lawston, Joseph A. Santanello Jr., Trenton E. Franz, Matthew Rodell

School of Natural Resources: Faculty Publications

Irrigation increases soil moisture, which in turn controls water and energy fluxes from the land surface to the planetary boundary layer and determines plant stress and productivity. Therefore, developing a realistic representation of irrigation is critical to understanding land–atmosphere interactions in agricultural areas. Irrigation parameterizations are becoming more common in land surface models and are growing in sophistication, but there is difficulty in assessing the realism of these schemes, due to limited observations (e.g., soil moisture, evapotranspiration) and scant reporting of irrigation timing and quantity. This study uses the Noah land surface model run at high resolution within NASA’s Land …

Unusual Aerobic Performance At High Temperatures In Juvenile Chinook Salmon, Oncorhynchus Tshawytscha, Jamilynn B. Poletto, Dennis E. Cocherell, Sarah E. Baird, Trinh X. Nguyen, Valentina Cabrera-Stagno, Anthony P. Farrell, Nann A. Fangue

School of Natural Resources: Faculty Publications

Understanding how the current warming trends affect fish populations is crucial for effective conservation and management. To help define suitable thermal habitat for juvenile Chinook salmon, the thermal performance of juvenile Chinook salmon acclimated to either 15 or 19°C was tested across a range of environmentally relevant acute temperature changes (from 12 to 26°C). Swim tunnel respirometers were used to measure routine oxygen uptake as a measure of routine metabolic rate (RMR) and oxygen uptake when swimming maximally as a measure of maximal metabolic rate (MMR) at each test temperature. We estimated absolute aerobic scope (AAS = MMR − RMR), …

Nest Site Selection And Nest Survival Of Greater Prairie-Chickens Near A Wind Energy Facility, Jocelyn Olney Harrison, Mary B. Brown, Larkin A. Powell, Walter H. Schacht, Jennifer A. Smith

School of Natural Resources: Faculty Publications

Rapid development of wind energy facilities in the Great Plains of North America has raised concerns regarding their potential negative impact on the nesting ecology of Greater Prairie-Chickens (Tympanuchus cupido pinnatus). We investigated the effects of a pre-existing, 36-turbine wind energy facility on nest site selection and nest survival of Greater Prairie-Chickens in the unfragmented grasslands of the Nebraska Sandhills, USA. In 2013 and 2014, we monitored 91 nests along a 24-km disturbance gradient leading away from the wind energy facility. We found little evidence of an effect of the wind energy facility on Greater Prairie-Chicken nest site …

Defining Ecological Drought For The Twenty-First Century, Shelley D. Crausbay, Aaron R. Ramirez, Shawn L. Carter, Molly S. Cross, Kimberly R. Hall, Deborah J. Bathke, Julio L. Betancourt, Steve Colt, Amanda E. Cravens, Melinda S. Dalton, Jason B. Dunham, Lauren E. Hay, Michael J. Hayes, Jamie Mcevoy, Chad A. Mcnutt, Max A. Moritz, Keith H. Nislow, Nejem Raheem, Todd Sanford

School of Natural Resources: Faculty Publications

THE RISING RISK OF DROUGHT. Droughts of the twenty-first century are characterized by hotter temperatures, longer duration, and greater spatial extent, and are increasingly exacerbated by human demands for water. This situation increases the vulnerability of ecosystems to drought, including a rise in drought-driven tree mortality globally (Allen et al. 2015) and anticipated ecosystem transformations from one state to another—for example, forest to a shrubland (Jiang et al. 2013). When a drought drives changes within ecosystems, there can be a ripple effect through human communities that depend on those ecosystems for critical goods and services (Millar and Stephenson 2015). For …

Book Review: Ecology And Conservation Of Lesser Prairie-Chickens, Edited By David A. Haukos And Clint W. Boal. 2016., Larkin Powell

School of Natural Resources: Faculty Publications

Scholars, conservationists, policymakers, and students will find critical information and a detailed case study on an avian species of conservation concern in this edited volume. Haukos and Boal have gathered work by 29 contributing authors in a well-designed set of 18 chapters that showcases current information about the Lesser Prairie-Chicken (Tympanuchus pallidicinctus). The book is timely in covering this species, which has found itself in the throes of the court system recently, having been designated with federal protection as a threatened species in 2014, only to have the courts vacate the listing rule in 2015, just as this volume went …

Modeling With A Conceptual Representation: Is It Necessary? Does It Work?, Rebecca C. Jordan, Steven Gray, Amanda E. Sorensen, Samantha Pasewark, Suparna Sinha, Cindy E. Hmelo-Silver

School of Natural Resources: Faculty Publications

In response to recent educational imperatives in the United States, modeling and systems thinking have been identified as being critical for science learning. In this paper, we investigate models in the classroom from two important perspectives: (1) from the teacher perspective to understand how teachers perceive models and use models in the classroom and (2) from the students perspective to understand how student use model-based reasoning to represent their understanding in a classroom setting. Qualitative data collected from 19 teachers who attended a professional development workshop in the northeastern United States indicate that while teachers see the value in teaching …

Reframing Communication About Zika And Mosquitoes To Increase Disease Prevention Behavior, Amanda E. Sorensen, Rebecca C. Jordan, Shannon Ladeau

School of Natural Resources: Faculty Publications

Emergence of invasive vector species and the diseases they carry present a clear danger to the public as well as a challenge for scientists and experts to control effectively. Given the urgent need to address this phenomenon, we suggest that desired public action toward these invasive vectors can be motivated through intentional framing in science communication. In this paper, we sought to evaluate the effect of framing about ZIKV (Zika virus) on reported willingness to comply with mosquito prevention action. Post framing intervention, we found a significant increase (N = 26, p < 0.001) in individuals willing to take preventative action against mosquitoes. By methodically investigating best communication practices, this study and others can help practitioners mobilize communities to address large-scale ecological problems. Additionally, the principles outlined here may be transferrable to other communication efforts about ecological issues outside of ZIKV and mosquitoes.

Ecology And Conservation Of Lesser Prairie-Chickens, Larkin A. Powell

School of Natural Resources: Faculty Publications

Scholars, conservationists, policymakers, and students will find critical information and a detailed case study on an avian species of conservation concern in this edited volume. Haukos and Boal have gathered work by 29 contributing authors in a well-designed set of 18 chapters that showcases current information about the Lesser Prairie-Chicken (Tympanuchus pallidicinctus). The book is timely in covering this species, which has found itself in the throes of the court system recently, having been designated with federal protection as a threatened species in 2014, only to have the courts vacate the listing rule in 2015, just as this …

Culturally Induced Range Infilling Of Eastern Redcedar: A Problem In Ecology, An Ecological Problem, Or Both?, Aubrey Streit Krug, Daniel R. Uden, Craig R. Allen, Dirac L. Twidwell Jr

School of Natural Resources: Faculty Publications

The philosopher John Passmore distinguished between (1) “problems in ecology,” or what we might call problems in scientific understanding of ecological change, and (2) “ecological problems,” or what we might call problems faced by societies due to ecological change. The spread of eastern redcedar (Juniperus virginiana) and conversion of the central and southern Great Plains of North America to juniper woodland might be categorized as a problem in ecology, an ecological problem, or both. Here, we integrate and apply two interdisciplinary approaches to problem-solving—social-ecological systems thinking and ecocriticism—to understand the role of human culture in recognizing, driving, and …

Modeling With A Conceptual Representation: Is It Necessary? Does It Work?, Rebecca C. Jordan, Steven Gray, Amanda E. Sorensen, Samantha Pasewark, Suparna Sinha, Cindy E. Hmelo-Silver

School of Natural Resources: Faculty Publications

In response to recent educational imperatives in the United States, modeling and systems thinking have been identified as being critical for science learning. In this paper, we investigate models in the classroom from two important perspectives: (1) from the teacher perspective to understand how teachers perceive models and use models in the classroom and (2) from the students perspective to understand how student use model-based reasoning to represent their understanding in a classroom setting. Qualitative data collected from 19 teachers who attended a professional development workshop in the northeastern United States indicate that while teachers see the value in teaching …

Mesoscale Modeling Of The Meteorological Impacts Of Irrigation During The 2012 Central Plains Drought, Clint Aegerter, Jun Wang, Cui Ge, Suat Irmak, Robert Oglesby, Brian D. Wardlow, Haishun Yang, Jingshen You, Martha Shulski

School of Natural Resources: Faculty Publications

In the summer of 2012, the central plains of the United States experienced one of its most severe droughts on record. This study examines the meteorological impacts of irrigation during this drought through observations and model simulations using the Community Land Model coupled to the Weather Research and Forecasting (WRF) Model. A simple parameterization of irrigation processes is added into the WRF Model. In addition to keeping soil moisture in irrigated areas at a minimum of 50% of soil moisture hold capacity, this irrigation scheme has the following new features: 1) accurate representation of the spatial distribution of irrigation area …

A Quantitative Framework For Assessing Ecological Resilience, Didier L. Baho, Craig R. Allen, Ahjond Garmestani, Hannah Fried-Petersen, Sophia E. Renes, Lance Gunderson, David G. Angeler

School of Natural Resources: Faculty Publications

Quantitative approaches to measure and assess resilience are needed to bridge gaps between science, policy, and management. In this paper, we suggest a quantitative framework for assessing ecological resilience. Ecological resilience as an emergent ecosystem phenomenon can be decomposed into complementary attributes (scales, adaptive capacity, thresholds, and alternative regimes) that embrace the complexity inherent to ecosystems. Quantifying these attributes simultaneously provides opportunities to move from the assessment of specific resilience within an ecosystem toward a broader measurement of its general resilience. We provide a framework that is based on reiterative testing and recalibration of hypotheses that assess complementary attributes of …