Physical Sciences and Mathematics Commons^™

Assessing Responses Of Betula Papyrifera To Climate Variability In A Remnant Population Along The Niobrara River Valley In Nebraska U.S. Through Dendroecological And Remote Sensing Techniques, Evan Bumann, Tala Awada, Brian Wardlow, Michael Hayes, Jane A. Okalebo, C. Helzer, Anastasios Mazis, J. Hiller, Paolo Cherubini

School of Natural Resources: Faculty Publications

Remnant populations of Betula papyrifera have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, and has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014), and satellite imagery [Landsat 5 TM (1985-2011) and MODIS (2000-2014)] derived NDVI as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth while increasing …

Climate Change Implications For Irrigation And Groundwater In The Republican River Basin, Usa, Gengxin Ou, Francisco Munoz-Arriola, Daniel R. Uden, Derrel Martin, Craig R. Allen, Nancy Shank

School of Natural Resources: Faculty Publications

This study investigates the influence of climate change on groundwater availability, and thereby, irrigation across political boundaries within the US High Plains aquifer. A regression model is developed to predict changes in irrigation according to predicted changes in precipitation and temperature from a downscaled dataset of 32 general circulation models (GCMs). Precipitation recharge changes are calculated with precipitation recharge curves developed for prognostic representations of precipitation across the Nebraska-Colorado-Kansas area and within the Republican River Basin focal landscape. Irrigation-recharge changes are scaled with changes in irrigation. The groundwater responses to climate forcings are then simulated under new pumping and recharge …

Early Warnings For State Transitions, Caleb P. Roberts, Dirac Twidwell, Jessica L. Burnett, Victoria M. Donovan, Carissa L. Wonkka, Christine L. Bielski, Ahjond S. Garmestani, David G. Angeler, Tarsha Eason, Brady W. Allred, Matthew O. Jones, David E. Naugle, Shana M. Sundstrom, Craig R. Allen

School of Natural Resources: Faculty Publications

New concepts have emerged in theoretical ecology with the intent to quantify complexities in ecological change that are unaccounted for in state-and-transition models and to provide applied ecologists with statistical early warning metrics able to predict and prevent state transitions. With its rich history of furthering ecological theory and its robust and broad-scale monitoring frameworks, the rangeland discipline is poised to empirically assess these newly proposed ideas while also serving as early adopters of novel statistical metrics that provide advanced warning of a pending shift to an alternative ecological regime. We review multivariate early warning and regime shift detection metrics, …

The Nebraska Mesonet: Technical Overview Of An Automated State Weather Network, Martha Shulski, Stonie Cooper, Glen Roebke, Allen L. Dutcher

School of Natural Resources: Faculty Publications

The Nebraska Mesonet was established in 1981 as one of the nation’s first automated state weather networks. ‘‘Automated’’ is defined by the nature of the observations being made and recorded by machine, as opposed to observations made and recorded manually. At the time of inception, the five observing locations were geared toward servicing agricultural production applications. The Nebraska Mesonet has grown to 69 stations (as of 2018) and is now a multipurpose environmental observing network under the Nebraska State Climate Office (NSCO). The network is composed of environmental observation stations, sited using best practices for mesoscale and microscale environment situations. …

Tracking Drought Perspectives: A Rural Case Study Of Transformations Following An Invisible Hazard, Theresa Jedd, Deborah J. Bathke, Duane Gill, Bimal Paul, Nicole Wall, Tonya K. Bernadt, Jacob Petr, Anthony James Mucia, Milan Wall

School of Natural Resources: Faculty Publications

Rural towns are especially susceptible to the effects of drought because their economies are dependent on natural resources.However, they are also resilient in many ways to natural hazards because they are rich in civic engagement and social capital. Because of the diverse nature of drought’s impacts, understanding its complex dynamics and its effects requires a multidisciplinary approach. To study these dynamics, this research combines appreciative inquiry, the Community Capitals Framework, and a range of climatological monitoring data to assess the 2012–14 Great Plains drought’s effect on McCook, Nebraska. Community coping measures, such as water-use reduction and public health programs, were …

Eddy Covariance Flux Errors Due To Random And Systematic Timing Errors During Data Acquisition, Gerardo Fratini, Simone Sabbatini, Kevin Ediger, Brad Riensche, George Burba, Giacomo Nicolini, Domenico Vitale, Dario Papale

School of Natural Resources: Faculty Publications

Modern eddy covariance (EC) systems collect high-frequency data (10–20 Hz) via digital outputs of instruments. This is an important evolution with respect to the traditional and widely used mixed analog/digital systems, as fully digital systems help overcome the traditional limitations of transmission reliability, data quality, and completeness of the datasets.

However, fully digital acquisition introduces a new problem for guaranteeing data synchronicity when the clocks of the involved devices themselves cannot be synchronized, which is often the case with instruments providing data via serial or Ethernet connectivity in a streaming mode. In this paper, we suggest that, when assembling EC …

Occupancy And Habitat Use By Six Species Of Forest Ungulates On Tiwai Island, Sierra Leone, Kathryn R. Mccollum, Emily Belinfante, April L. Conway, John P. Carroll

School of Natural Resources: Faculty Publications

Forest ungulates in West Africa are common bushmeat species and are subject to habitat degradation through deforestation. Based on historical data, there are possibly 12 species of forest Bovidae and Tragulidae found in eastern Sierra Leone. We used camera trapping to assess occupancy by forest ungulates on and around a small protected area, Tiwai Island, Sierra Leone. We then assessed habitat over two field seasons during 2008–2011 for those species where we had sufficient numbers of detections. We detected 6 of 12 potential species and obtained enough data to further assess the habitat of two species. Species detected included the …

Cosmic Ray Neutrons Provide An Innovative Technique For Estimating Intermediate Scale Soil Moisture, Thigesh Vather, Colin Everson, Michael Mengistu, Trenton E. Franz

School of Natural Resources: Faculty Publications

Soil moisture is an important hydrological parameter, which is essential for a variety of applications, thereby extending to numerous disciplines. Currently, there are three methods of estimating soil moisture: ground-based (in-situ) measurements; remote sensing based methods and land surface models. In recent years, the cosmic ray probe (CRP), which is an in-situ technique, has been implemented in several countries across the globe. The CRP provides area-averaged soil moisture at an intermediate scale and thus bridges the gap between in-situ point measurements and global satellite-based soil moisture estimates. The aim of this study was to test the suitability of the CRP …

Drought And Land-Cover Conditions In The Great Plains, Heather Tollerud, Jesslyn Brown, Tom Loveland, Rezaul Mamood, Norman Bliss

School of Natural Resources: Faculty Publications

Land–atmosphere interactions play a critical role in the Earth system, and a better understanding of these interactions could improve weather and climate models. The interaction among drought, vegetation productivity, and land cover is of particular significance. In a semiarid environment, such as the U.S. Great Plains, droughts can have a large influence on the productivity of agriculture and grasslands, with serious environmental and economic impacts. Here, we used the vegetation drought response index (VegDRI) drought indicator to investigate the response of vegetation to weather and climate for landcover types in the Great Plains in the United States from 1989 to …

The Fingerprint Of Climate Change And Urbanization In South Korea, Won-Ho Nam, Guillermo A. Baigorria, Eun-Mi Hong, Taegon Kim, Yong-Sang Choi, Song Feng

School of Natural Resources: Faculty Publications

Understanding long-term changes in precipitation and temperature patterns is important in the detection and characterization of climate change, as is understanding the implications of climate change when performing impact assessments. This study uses a statistically robust methodology to quantify long-, medium- and short-term changes for evaluating the degree to which climate change and urbanization have caused temporal changes in precipitation and temperature in South Korea. We sought to identify a fingerprint of changes in precipitation and temperature based on statistically significant differences at multiple-timescales. This study evaluates historical weather data during a 40-year period (1973–2012) and from 54 weather stations. …

Effects Of Roadside Edge On Nest Predators And Nest Survival Of Asian Tropical Forest Birds, Daphawan Khamcha, Larkin A. Powell, George A. Gale

School of Natural Resources: Faculty Publications

Creation of roadside forest edges can have indirect effects on forest bird communities, as edges can promote species detrimental to forest-nesting birds such as nest predators. We assessed species-specific rates of nest survival of understory birds, relative abundances of specific nest predators and predator-specific rates of nest predation relative to the distance from roadside forest edge in a dry evergreen forest in northeastern Thailand. During the breeding seasons (FebruaryeAugust) of 2014e2016 we searched for nests along two, 1-km transects which ran perpendicular from the edge of a five-lane highway into the forest interior. To assess nest predator species, video cameras …

Annual, Seasonal, And Diel Surface Energy Partitioning In The Semiarid Sand Hills Of Nebraska, Usa, Nathan C. Healey, Timothy J. Arkebauer, David P. Billesbach, John D. Lenters

School of Natural Resources: Faculty Publications

Study Region: The Nebraska Sand Hills consisting of four major land cover types: (1) lakes and wetlands (∼5% for both), (2) subirrigated meadows (∼10%), (3) dry valleys (∼20%), and (4) upland dunes (∼65%).

Study Focus: Examination of surface energy and water balances on multiple temporal scales with primary focus on latent heat flux (λE), and evapotranspiration (ET), to gain a better understanding of the annual, seasonal, and diel properties of surface energy partitioning among different Sand Hills ecosystems to improve regional water resource management. New Hydrological Insights for the Region: Based on surface energy and water balance measurements using Bowen …

Improving The Calibration Of Silicon Photodiode Pyranometers, Elizabeth Walter-Shea, Kenneth Hubbard, Mark A. Mesarch, Glen Roebke

School of Natural Resources: Faculty Publications

Reliable measurements of global irradiance are essential for research and practical applications. Silicon photodiode pyranometers (SiPs) offer low-cost sensors to measure direct and diffuse irradiance despite their non-uniform spectral response over the 300–1000 nm spectral range. In this study, non-adjusted linear and adjusted calibrations were applied at different times of the year to determine sources of estimated errors in global irradiance due to the two calibration approaches, calibration time, and sensor age. 16 SiPs, along with two standards, measured incident global irradiance over a 5-year period under a range of sky conditions. Sensors performed best in the months in which …

Recognition Of Regional Water Table Patterns For Estimating Recharge Rates In Shallow Aquifers, Troy E. Gilmore, Vitaly A. Zlotnik, Mason Johnson

School of Natural Resources: Faculty Publications

We propose a new method for groundwater recharge rate estimation in regions with stream-aquifer interactions, at a linear scale on the order of 10 km and more. The method is based on visual identification and quantification of classically recognized water table contour patterns. Simple quantitative analysis of these patterns can be done manually from measurements on a map, or from more complex GIS data extraction and curve fitting. Recharge rate is then estimated from the groundwater table contour parameters, streambed gradients, and aquifer transmissivity using an analytical model for groundwater flow between parallel perennial streams. Recharge estimates were obtained in …

Hydro-Stochastic Interpolation Coupling With The Budyko Approach For Prediction Of Mean Annual Runoff, Ning Qiu, Xi Chen, Qi Hu, Jintao Liu, Richao Huang, Man Gao

School of Natural Resources: Faculty Publications

The hydro-stochastic interpolation method based on traditional block Kriging has often been used to predict mean annual runoff in river basins. A caveat in such a method is that the statistic technique provides little physical insight into relationships between the runoff and its external forcing, such as the climate and land cover. In this study, the spatial runoff is decomposed into a deterministic trend and deviations from it caused by stochastic fluctuations. The former is described by the Budyko method (Fu’s equation) and the latter by stochastic interpolation. This coupled method is applied to spatially interpolate runoff in the Huaihe …

Using Art And Story To Explore How Primary School Students In Rural Tanzania Understand Planetary Health: A Qualitative Analysis, Elizabeth Vanwormer, Jesca Mlawa, Elizabeth Komba, Christopher Gustafson, Hilda Mrema, Jenny M. Dauer

School of Natural Resources: Faculty Publications

Background The global planetary health community increasingly recognises the need to prepare students to investigate and address connections between environmental change and human health. As we strive to support education on planetary health themes for students of all ages, understanding students’ concepts of linkages between the health of people and animals, and their shared environments might advance educational approaches. Children living in villages bordering Ruaha National Park in Iringa Region, Tanzania, have direct experience of these connections as they share a water-stressed but biodiverse environment with domestic animals and wildlife. Livelihoods in these villages depend predominantly on crop and livestock …

Mensurative Approach To Examine Potential Interactions Between Age-0 Yellow Perch (Perca Flavescens) And Bluegill (Lepomis Macrochirus), Mark A. Kaemingk, David W. Willis

School of Natural Resources: Faculty Publications

Bluegill (Lepomis macrochirus) andyellow perch (Perca flavescens) populations are often sympatric in the Great Plains region of the U.S.A. and portions of Canada; however, very little attention has been given to potential interactions between these species for available resources, especially during the early life stages. Relationships between age-0 bluegill and yellow perch growth and relative abundance were explored across multiple lakes and years within the Nebraska Sandhill region, USA. In addition, four habitat patch types (open water, Phragmites spp., Typha spp., Scirpus spp.) were sampled for age-0 bluegill and yellow perch, and food habits were examined for each species during …

Effects Of Simulated Cold Fronts On The Survival And Behavior Of Yellow Perch Perca Flavescens Yolk-Sac Fry, Mark A. Kaemingk

School of Natural Resources: Faculty Publications

No abstract provided.

Factors Associated With Bluegill Nest Site Selection Within A Shallow, Natural Lake, Mark A. Kaemingk

School of Natural Resources: Faculty Publications

No abstract provided.

Insights For Undergraduates Seeking An Advanced Degree In Wildlife And Fisheries Sciences, Mark A. Kaemingk

School of Natural Resources: Faculty Publications

No abstract provided.

A Survey Of Aquatic Invertebrate Communities In Nebraska Sandhill Lakes Reveals Potential Alternative Ecosystem States, Mark A. Kaemingk

School of Natural Resources: Faculty Publications

No abstract provided.

Adult Bobcat (Lynx Rufus) Habitat Selection In A Longleaf Pine Savanna, Andrew R. Little, L. Mike Conner, Michael J. Chamberlain, Nathan P. Nibbelink, Robert J. Warren

School of Natural Resources: Faculty Publications

Background: Pine savannas are primarily managed with frequent prescribed fire (≤ 3 years) to promote diversity of flora and fauna, and to maintain open, park-like conditions needed by species such as the endangered red-cockaded woodpecker (Picoides borealis). However, a knowledge gap exists in our understanding of bobcat (Lynx rufus) habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions.

Methods: We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales (i.e., study area boundary [hereafter, landscape scale]) and annual area of use [95% …

Comparing Crop Growth And Carbon Budgets Simulated Across Ameriflux Agricultural Sites Using The Community Land Model (Clm), Ming Chen, Timothy J. Griffis, John M. Baker, Jeffrey D. Wood, Tilden Meyers, Andrew E. Suyker

School of Natural Resources: Faculty Publications

Improvement of process-based crop models is needed to achieve high fidelity forecasts of regional energy, water, and carbon exchanges. However, most state-of-the-art Land Surface Models (LSMs) assessed in the fifth phase of the Coupled Model Inter-comparison project (CMIP5) simulated crops as unmanaged C3 or C4 grasses. This study evaluated the crop-enabled version of one of the most widely used LSMs, the Community Land Model (CLM4- Crop), for simulating corn and soybean agro-ecosystems at relatively long-time scales (up to 11 years) using 54 site-years of data. We found that CLM4-Crop had a biased phenology during the early growing season and that …

Guidelines For Ecotourism Operations In The Great Plains, Larkin A. Powell, Kelly Powell, Katie Nieland

School of Natural Resources: Faculty Publications

The International Union for the Conservation of Nature defines ecotourism as: Environmentally responsible travel to natural areas, in order to enjoy and appreciate nature (and accompanying cultural features, both past and present) that promote conservation, have a low visitor impact and provide for beneficially active socioeconomic involvement of local peoples.

Ecotourism has the potential to support communities and conservation efforts from revenue streams to parks and reserves in the Great Plains, while also contributing to a culture shift towards a conservation ethic. Recent surges in ecotourism have contributed to growth in the tourism sectors in Great Plains states, because these …

Modular Oxidant Delivery System, Mark Christenson, Steven Douglas Comfort

School of Natural Resources: Faculty Publications

In one implementation, a direct - push oxidant candle apparatus for the treatment of contaminated groundwater through direct - push installation methods includes : a drive tip positioned at a bottom end of the apparatus , the drive tip having one or more front surfaces that are shaped to create a bore as force is applied to an opposite base surface of the drive tip ; a structural pathway that is connected to and extend upwardly from the base surface of the drive tip ; one or more oxidant delivery devices that are enclosed within the structural pathway ; and …

Present And Future Thermal Environments Available To Sharp-Tailed Grouse In An Intact Grassland, Edward J. Raynor, Larkin Powell, Walter H. Schacht

School of Natural Resources: Faculty Publications

Better understanding animal ecology in terms of thermal habitat use has become a focus of ecological studies, in large part due to the predicted temperature increases associated with global climate change. To further our knowledge on how ground-nesting endotherms respond to thermal landscapes, we examined the thermal ecology of Sharp-tailed Grouse (Tympanuchus phasianellus) during the nesting period. We measured site-specific iButton temperatures (TiB) and vegetation characteristics at nest sites, nearby random sites, and landscape sites to assess thermal patterns at scales relevant to nesting birds. We asked if microhabitat vegetation characteristics at nest sites matched the characteristics that directed macrohabitat …

Evaluation Of Acoustic Telemetry Grids For Determining Aquatic Animal Movement And Survival, Richard T. Kraus, Christopher M. Holbrook, Christopher S. Vandergoot, Taylor R, Stewart, Matthew D. Faust, Douglas A. Watkinson, Colin Charles, Mark A. Pegg, Eva C. Enders, Charles C. Krueger

School of Natural Resources: Faculty Publications

1. Acoustic telemetry studies have frequently prioritized linear configurations of hydrophone receivers, such as perpendicular from shorelines or across rivers, to detect the presence of tagged aquatic animals. This approach introduces unknown bias when receivers are stationed for convenience at geographic bottlenecks (e.g. at the mouth of an embayment or between islands) as opposed to deployments following a statistical sampling design.

2. We evaluated two-dimensional acoustic receiver arrays (grids: receivers spread uniformly across space) as an alternative approach to provide estimates of survival, movement and habitat use. Performance of variably spaced receiver grids (5–25 km spacing) was evaluated by simulating …

Variability Of Rainfall Erosivity And Erosivity Density In The Ganjiang River Catchment, China: Characteristics And Influences Of Climate Change, Xianghu Li, Xuchun Ye

School of Natural Resources: Faculty Publications

Soil erosion is one of the most critical environmental hazards in the world. Understanding the changes in rainfall erosivity (RE) and erosivity density (ED), as well as their affecting factors, at local and catchment scales in the context of climate warming is an important prerequisite of soil erosion prevention and soil loss risk assessment. The present study identified the variability and trends of RE and ED in terms of both time and space in the Ganjiang River catchment over the period of 1960–2012, and also analyzed and discussed the impact of climate change. The results show that RE and ED …

Can Genomic Variation Explain The Extinction Of The Passenger Pigeon?, Chih-Ming Hung, R. M. Zink, Shou-Hsien Li

School of Natural Resources: Faculty Publications

No abstract provided.

Hybrid Speciation In Birds, With Special Reference To Darwin's Finches, G. E. Hill, R. M. Zink

School of Natural Resources: Faculty Publications

No abstract provided.