Physical Sciences and Mathematics Commons^™

An Information Theory-Based Approach To Assessing Spatial Patterns In Complex Systems, Tarsha Eason, Wen Ching-Chuang, Shana Sundstrom, Heriberto Cabezas

School of Natural Resources: Faculty Publications

Given the intensity and frequency of environmental change, the linked and cross-scale nature of social-ecological systems, and the proliferation of big data, methods that can help synthesize complex system behavior over a geographical area are of great value. Fisher information evaluates order in data and has been established as a robust and effective tool for capturing changes in system dynamics, including the detection of regimes and regime shifts. The methods developed to compute Fisher information can accommodate multivariate data of various types and requires no a priori decisions about system drivers, making it a unique and powerful tool. However, the …

Variation In White-Tailed Deer Antler Size: The Effects Of Age, Landscape Composition, And Physiographic Province, Kathleen B. Quebedeaux, Andrew R. Little, Nathan P. Nibbelink, Gino J. D'Angelo, Charlie H. Killmaster, Karl V. Miller

School of Natural Resources: Faculty Publications

Spatial variation in landscape composition can influence phenotypic expression in wildlife species and can improve management efforts to express certain phenotypic traits. We evaluated the influence of age, landscape composition, and physiographic province on white-tailed deer (Odocoileus virginianus) antler characteristics using data from 16,622 male deer (age range: 1.5–3.5+ years old) harvested between 1997–2016 across five physiographic provinces in Georgia. Age and physiographic province influenced antler size index (ASI; P < 0.001). ASI of yearling males was greatest (- x = 53.37; SE = 0.39) in the Upper Coastal Plain and least (- x = 46.23; SE = 0.51) in the Lower Coastal Plain physiographic province. Given the differences in ASI among physiographic provinces, we evaluated how landscape composition within each physiographic province influenced ASI of 7,325 yearling (1.5-year-old) males. Yearling ASI was positively related to increasing coverage of cultivated crops and suburban-urban areas (e.g., parks, small housing developments). Conversely, evergreen and deciduous forested cover consistently had a negative effect on ASI, except in the Ridge and Valley physiographic province where evergreen was positively related to ASI. Wildlife managers and hunters should recognize the effects of age, landscape composition, and physiographic province when setting antler size expectations.

Variation In White-Tailed Deer Antler Size: The Effects Of Age, Landscape Composition, And Physiographic Province., K. B. Quebedeaux, Andrew R. Little, N. P. Nibbelink, G. J. D'Angelo, C. H. Killmaster, K. V. Miller

School of Natural Resources: Faculty Publications

Spatial variation in landscape composition can influence phenotypic expression in wildlife species and can improve management efforts to express certain phenotypic traits. We evaluated the influence of age, landscape composition, and physiographic province on white-tailed deer (Odocoileus virginianus) antler characteristics using data from 16,622 male deer (age range: 1.5–3.5+ years old) harvested between 1997–2016 across five physiographic provinces in Georgia. Age and physiographic province influenced antler size index (ASI; P < 0.001). ASI of yearling males was greatest (- x = 53.37; SE = 0.39) in the Upper Coastal Plain and least (- x = 46.23; SE = 0.51) in the Lower Coastal Plain physiographic province. Given the differences in ASI among physiographic provinces, we evaluated how landscape composition within each physiographic province influenced ASI of 7,325 yearling (1.5-year-old) males. Yearling ASI was positively related to increasing coverage of cultivated crops and suburban-urban areas (e.g., parks, small housing developments). Conversely, evergreen and deciduous forested cover consistently had a negative effect on ASI, except in the Ridge and Valley physiographic province where evergreen was positively related to ASI. Wildlife managers and hunters should recognize the effects of age, landscape composition, and physiographic province when setting antler size expectations.

Environmental Controls On The Seasonal Variation In Gas Exchange And Water Balance In A Near-Coastal Mediterranean Pinus Halepensis Forest, Mariangela N. Fotelli, Evangelia Korakaki, Spyridon A. Paparrizos, Kalliopi Radoglou, Tala Awada, Andreas Matzarakis

School of Natural Resources: Faculty Publications

No abstract provided.

Tree-Ring Stable Isotopes Show Different Ecophysiological Strategies In Native And Invasive Woody Species Of A Semi-Arid Riparian Ecosystem In The Great Plains Of The United States, Tala Awada, Kristen Skolaut, Giovanna Battipaglia, Matthias Saurer, Diego A. Riveros-Iregui, Adam Schapaugh, Julie Huddle, Xinhua Zhou, Derrell Martin, Paolo Cherubini

School of Natural Resources: Faculty Publications

No abstract provided.

Nu-Spidercam: A Large-Scale, Cable-Driven, Integrated Sensing And Robotic System For Advanced Phenotyping, Remote Sensing, And Agronomic Research, Geng Bai, Yufeng Ge, David Scoby, Bryan Leavitt, Vincent Stoerger, Norbert Kirchgessner, Suat Irkmak, George Graef, James Schnable, Tala Awada

School of Natural Resources: Faculty Publications

No abstract provided.

Leveraging Image Analysis For High-Throughput Plant Phenotyping, Sruti Das Choudhury, Ashok Samal, Tala Awada

School of Natural Resources: Faculty Publications

No abstract provided.

Comment On "Derivation Of A Sigmoid Generalized Complementary Function For Evaporation With Physical Constraints" By S. Han And F. Tian, Jozsef Szilagyi, Richard D. Crago

School of Natural Resources: Faculty Publications

No abstract provided.

National Survey Of Geoscience Teaching Practices 2016: Current Trends In Geoscience Instruction Of Scientific Modeling And Systems Thinking, Diane Lally, Cory T. Forbes, Karen S. Mcneal, Nicholas A. Soltis

School of Natural Resources: Faculty Publications

No abstract provided.

Empirical Methods For Remote Sensing Of Nitrogen In Drylands May Lead To Unreliable Interpretation Of Ecosystem Function, Hamid Dashti, Nancy F. Glenn, Susan Ustin, Jessica J. Mitchell, Yi Qi, Nayani T. Ilangakoon, Alejandro N. Flores, Jose Luis Silvan-Cardenas, Kaiguang Zhao, Lucas P. Spaete, Marie-Anne De Graaff

School of Natural Resources: Faculty Publications

No abstract provided.

The Complementary Relationship (Cr) Of Evaporation: A Calibration-Free Diagnostic And Benchmarking Tool For Large-Scale Terrestrial Evapotranspiration Modeling, N. Ma, J. Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

The Adaptive Cycle: More Than A Metaphor, Shana M. Sundstrom, Craig R. Allen

School of Natural Resources: Faculty Publications

The adaptive cycle and its extension to panarchy (nested adaptive cycles) has been a useful metaphor and conceptual model for understanding long-term dynamics of change in ecological and social–ecological systems. We argue that adaptive cycles are ubiquitous in complex adaptive systems because they reflect endogenously generated dynamics as a result of processes of self-organization and evolution. We synthesize work from a wide array of fields to support this claim. If dynamics of growth, conservation, collapse and renewal are endogenous dynamics of complex adaptive systems, then there ought to be signals of system change over time that reflect this. We describe …

Chronology Of Dune Development In The White River Badlands, Northern Great Plains, Usa, P. E. Baldauf, P. A. Burkhart, Paul R. Hanson, M. Miles, Ashley Larsen

School of Natural Resources: Faculty Publications

Aeolian dune field chronologies provide important information on drought history on the Great Plains. The White River Badlands (WRB) dunes are located approximately 60 km north of the Nebraska Sand Hills (NSH), in the western section of the northern Great Plains. Clifftop dunes, sand sheets, and stabilized northwest-southeast trending parabolic dunes are found on upland mesas and buttes, locally called tables. The result of this study is a dune stabilization history determined from samples collected from stratigraphic exposures and dune crests. Thirty-seven OSL ages, from this and previous investigations, show three periods of dune activity: 1) ~21,000 years ago to …

Isotopic Composition Of Groundwater And Precipitation In Nebraska, Usa, Mikaela L. Cherry, Troy E. Gilmore, Aaron R. Mittelstet, Didier Gastmans, John Gates

School of Natural Resources: Faculty Publications

Groundwater is vital worldwide for water supply, agriculture and industry. Nearly 60% of all water use in Nebraska is from groundwater. Over 90% of groundwater is used for irrigation in Nebraska, which has the largest area of irrigated land in the United States. Many Nebraskans depend on groundwater for drinking water, both from private wells and municipal wells. The sustainability of groundwater resources is dependent on groundwater recharge. The recharge processes, as well as climatic patterns, influence the stable isotope signatures.

Based on weekly samples collected at two monitoring stations managed by the National Atmospheric Deposition Program (NADP), Harvey (2001) …

Variation In Reproductive Timing For The Northern Long-Eared Myotis (Myotis Septentrionalis) Across Nebraska, Keith Geluso, Cliff Lemen, Patricia Freeman, Brett R. Andersen, Jeremy A. White, Heather M. Johnson

School of Natural Resources: Faculty Publications

The northern long-eared myotis (Myotis septentrionalis), a federally threatened species, occurs in extreme northern, eastern, and southern Nebraska. These regions vary in climate due to geographic location, topography, and elevation. During a 1-week period in early July 2015, we surveyed bats across the state and observed striking variation in the reproductive status for M. septentrionalis. We examined whether or not growing degree days, an abiotic climatic factor used mainly for agricultural practices, was associated with this reproductive variation in a mammalian species. In early July, we captured only pregnant females in the Pine Ridge region of northwestern Nebraska, …

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 …