Physical Sciences and Mathematics Commons^™

Ensemble Forecast Spread Induced By Soil Moisture Changes Over Mid-South And Neighbouring Midwestern Region Of The Usa, Arturo I. Quintanar, Rezaul Mahmood

School of Natural Resources: Faculty Publications

This study investigated the potential impact of soil moisture perturbations on the statistical spread of an ensemble forecast for three different synoptic events during the summer of 2006. Soil moisture was perturbed from a control simulation to generate a 12 member ensemble with six drier and six moister soils. The impacts on the near-surface atmospheric conditions and on precipitation were analysed. It was found, as previous studies have confirmed, that soil moisture can change the spatial and temporal distribution of precipitation and of the overlying circulation. It was found that regardless of the conditions in synoptic forcing, temperature, relative humidity …

Adaptive Management Of Bull Trout Populations In The Lemhi Basin, Andrew J. Tyre, James T. Peterson, Sarah J. Converse, Tiffany Bogich, Damien Miller, Max Post Van Der Burg, Carmen Thomas, Ralph Thompson, Jeri Wood, Donna C. Brewer, Michael C. Runge

School of Natural Resources: Faculty Publications

The bull trout Salvelinus confluentus, a stream-living salmonid distributed in drainages of the northwestern United States, is listed as threatened under the Endangered Species Act because of rangewide declines. One proposed recovery action is the reconnection of tributaries in the Lemhi Basin. Past water use policies in this core area disconnected headwater spawning sites from downstream habitat and have led to the loss of migratory life history forms. We developed an adaptive management framework to analyze which types of streams should be prioritized for reconnection under a proposed Habitat Conservation Plan. We developed a Stochastic Dynamic Program that identified optimal …

Characterizing The Performance Of Ecosystem Models Across Time Scales: A Spectral Analysis Of The North American Carbon Program Site-Level Synthesis, Michael C. Dietze, Rodrigo Vargas, Andrew D. Richardson, Paul C. Stoy, Alan G. Barr, Ryan S. Anderson, M. Altaf Arain, Ian T. Baker, T. Andrew Black, Jing M. Chen, Philippe Ciais, Lawrence B. Flanagan, Christopher M. Gough, Robert F. Grant, David Hollinger, R. Cesar Izaurralde, Christopher J. Kucharik, Peter Lafleur, Shugang Liu, Erandathie Lokupitiya, Yiqi Luo, J. William Munger, Changhui Peng, Benjamin Poulter, David T. Price, Daniel M. Ricciuto, William J. Riley, Alok Kumar Sahoo, Kevin Schaefer, Andrew E. Suyker, Hanqin Tian, Christina Tonitto, Hans Verbeeck, Shashi B. Verma, Weifeng Wang, Ensheng Weng

School of Natural Resources: Faculty Publications

Ecosystem models are important tools for diagnosing the carbon cycle and projecting its behavior across space and time. Despite the fact that ecosystems respond to drivers at multiple time scales, most assessments of model performance do not discriminate different time scales. Spectral methods, such as wavelet analyses, present an alternative approach that enables the identification of the dominant time scales contributing to model performance in the frequency domain. In this study we used wavelet analyses to synthesize the performance of 21 ecosystem models at 9 eddy covariance towers as part of the North American Carbon Program’s site-level intercomparison. This study …

Heritable Choice Of Colony Size In Cliff Swallows: Does Experience Trump Genetics In Older Birds?, Erin A. Roche, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

The variation in breeding colony size seen in populations of most colonial birds may reflect heritable choices made by individuals that are phenotypically specialized for particular social environments. Although a few studies have reported evidence for genetically based choice of group sizes in birds, we know relatively little about the extent to which animals potentially rely on experience versus innate preferences in deciding how many conspecifics to settle with at different times of their lives. We conducted a cross-fostering experiment in 1997–1998 on cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA, in which some individuals were reared in colonies …

Optimizing Spectral Indices And Chemometric Analysis Of Leaf Chemical Properties Using Radiative Transfer Modeling, Jean-Baptiste Féret, Christophe François, Anatoly A. Gitelson, Gregory P. Asner, Karen M. Barry, Cinzia Panigada, Stéphane Jacquemoud

School of Natural Resources: Faculty Publications

We used synthetic reflectance spectra generated by a radiative transfer model, PROSPECT-5, to develop statistical relationships between leaf optical and chemical properties, which were applied to experimental data without any readjustment. Four distinct synthetic datasets were tested: two unrealistic, uniform distributions and two normal distributions based on statistical properties drawn from a comprehensive experimental database. Two methods used in remote sensing to retrieve vegetation chemical composition, spectral indices and Partial Least Squares (PLS) regression, were trained both on the synthetic and experimental datasets, and validated against observations. Results are compared to a cross-validation process and model inversion applied to the …

Tracking Large Carnivore Dispersal Using Isotopic Clues In Claws: An Application To Cougars Across The Great Plains, Viviane Hénaux, Larkin A. Powell, Keith A. Hobson, Clayton Kent Nielsen, Michelle A. Larue

School of Natural Resources: Faculty Publications

1. Cougar (Puma concolor) populations, like other large carnivores, have increased during recent decades and may be recolonizing their former ranges in Midwestern North America. The dispersal routes taken by these animals from established populations are unknown and insight into these movements would facilitate their conservation and management.

2. We inferred the origin and migration route of four dispersing cougars using stable hydrogen (δD) and carbon (δ¹³C) isotope values along one of their claws. We compared isotopic variations within claws to regional and large-scale isoscapes of δD and δ¹³C values in prey species. Using …

Effect Of Passive Integrated Transponder Tag Implantation Site On Tag Retention, Growth, And Survival Of Two Sizes Of Juvenile Bluegills And Yellow Perch, Mark A. Kaemingk, Michael J. Weber, Paul R. Mckenna, Michael L. Brown

School of Natural Resources: Faculty Publications

Passive integrated transponder (PIT) tags are commonly used to monitor growth, habitat use, activity rates, and survival of individual fish. However, for successful completion of research objectives, the tags must be retained and must not affect fish growth or survival. We compared the effects of PIT tagging location on tag retention, growth, and survival of juvenile bluegills Lepomis macrochirus and yellowperch Perca flavescens. In total, 80 bluegills and 80 yellow perch from two size-classes (75–101 and 128–162 mm total length) were randomly assigned to a control or to one of three tagging location treatments: isthmus, body cavity, or dorsal musculature. …

Analysis Of The Community Based Planning Process In Holmes Lake Watershed, Lincoln, Nebraska, Courtney Quinn, Mark E. Burbach, Lois Wright Morton

School of Natural Resources: Faculty Publications

In 1998, the Nebraska Department of Environmental Quality (NDEQ) listed Holmes Lake, in Lincoln, NE on the Clean Water Act, Section 303(d) list of impaired and threatened waters. Holmes Lake was listed as impaired due to aquatic life use impairments.

Experts from various agencies worked together to form a Technical Advisory Committee to work closely with a Watershed Advisory Council of local citizens and stakeholders. Technical experts explained the water impairments and possible remedies to citizens. The Watershed Advisory Council then helped to prioritize actions. The lake was drained in 2003. In 2004, sediment was excavated, the shoreline was stabilized, …

Paleoamerican Diet, Migration And Morphology In Brazil: Archaeological Complexity Of The Earliest Americans, Sabine Eggers, Maria Parks, Gisela Grupe, Karl J. Reinhard

School of Natural Resources: Faculty Publications

During the early Holocene two main paleoamerican cultures thrived in Brazil: the Tradição Nordeste in the semi-desertic Sertão and the Tradição Itaparica in the high plains of the Planalto Central. Here we report on paleodietary singals of a Paleoamerican found in a third Brazilian ecological setting – a riverine shellmound, or sambaqui, located in the Atlantic forest. Most sambaquis are found along the coast. The peoples associated with them subsisted on marine resources. We are reporting a different situation from the oldest recorded riverine sambaqui, called Capelinha. Capelinha is a relatively small sambaqui established along a river 60 km from …

On The Spatial Heterogeneity Of Net Ecosystem Productivity In Complex Landscapes, Ryan E. Emanuel, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Howard E. Epstein

School of Natural Resources: Faculty Publications

Micrometeorological flux towers provide spatially integrated estimates of net ecosystem production (NEP) of carbon over areas ranging from several hectares to several square kilometers, but they do so at the expense of spatially explicit information within the footprint of the tower. This finer-scale information is crucial for understanding how physical and biological factors interact and give rise to towermeasured fluxes in complex landscapes. We present a simple approach for quantifying and evaluating the spatial heterogeneity of cumulative growing season NEP for complex landscapes. Our method is based on spatially distributed information about physical and biological landscape variables and knowledge of …

Long-Term Groundwater Monitoring Results At Large, Sudden Denatured Ethanol Releases, Roy F. Spalding, Mark A. Toso, Mary Exner Spalding, Gregory Hattan, Tom M. Higgins, Adam C. Sekely, Shane D. Jensen

School of Natural Resources: Faculty Publications

Hundreds of groundwater samples were collected at E95 (95% ethanol, 5% gasoline) train derailment spills in Balaton and Cambria, Minnesota and South Hutchinson, Kansas. Most samples were analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX), ethanol, methane, acetate, terminal electron acceptors, and field parameters. At each site, maximum groundwater ethanol concentrations at percent levels were restricted to the release area and downgradient ethanol transport was not detected. A shallow, anaerobic groundwater zone characterized by the absence of dissolved oxygen, low nitrate (less than 1 mg N/L), high Fe+2, and high dissolved methane (more than 10,000 μg/L) and BTEX formed and …

Cedar Infestation Impacts Avian Communities Along The Niobrara River Valley, Nebraska, January S. Frost, Larkin A. Powell

School of Natural Resources: Faculty Publications

Habitat modification has the potential to cause changes in structure and composition of bird communities. Our goal was to determine the response of Songbird community composition to eastern red cedar (Juniperus virginiana) removal in The Nature Conservancy’s Niobrara Valley Preserve, Nebraska. We used point counts to survey birds in the riparian matrix of grassland and forest habitats. More than 60 species were recorded on surveys during 2004–2005. We also use the program PRESENCE to determine the response of five species to various habitat components, including cedar density: House Wren (Troglodytes aedon), Spotted Towhee (Pipilo maculates …

Turning Students Into Problem Solvers, Larkin A. Powell, Andrew J. Tyre, Michael J. Conroy, James T. Peterson, B. Ken Williams

School of Natural Resources: Faculty Publications

In the popular movie Apollo 13, based on the actual NASA mission, three astronauts are stranded in space, their craft’s electrical system broken, their oxygen quickly running out. To help them fix the problem and return home safely, mission controllers summon a group of engineers, dump a pile of equipment onto a desk—the tools available to the astronauts—and tell them to find a solution, or more specifically, “a way to put a square peg in a round hole. Rapidly.” Eventually, the engineers’ plan saves the day, and the astronauts make it home.

State and federal agency biologists generally do …

Detecting Spatiotemporal Changes Of Corn Developmental Stages In The U.S. Corn Belt Using Modis Wdrvi Data, Toshihiro Sakamoto, Brian D. Wardlow, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

The dates of crop developmental stages are important variables for many applications including assessment of the impact of abnormal weather on crop yield. Time-series 250-m vegetation-index (VI) data acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) provide valuable information for monitoring the spatiotemporal changes of corn growth across large geographic areas. The goal of this study is to evaluate the performance of a new crop phenology detection method, namely, two-step filtering (TSF), for revealing the spatiotemporal pattern of specific corn developmental stages (early vegetative: V2.5; silking: R1; dent: R5; mature: R6) over an eight-year period (2001–2008) across Iowa, Illinois, and …

Sensitivity To Foliar Anthocyanin Content Of Vegetation Indices Using Green Reflectance, Andrés Viña, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

Anthocyanins are nonphotosynthetic water-soluble pigments associated with the resistance of plants to environmental stresses such as drought, low soil nutrients, high radiation, herbivores, and pathogens. Information on the absolute and relative amounts of anthocyanins allows evaluating the physiological conditions of plants and their responses to stress and has the potential for evaluating plant species diversity across broad geographic regions. As anthocyanins absorb radiation in the green region of the electromagnetic spectrum (with a peak of absorption at around 540–560 nm), broadband vegetation indices that use this spectral region in their formulation will exhibit sensitivity to their presence. In this letter, …

A Watershed-Scale Assessment Of A Process Soil Co2 Production And Efflux Model, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Lucy A. Marshall, Daniel L. Welsch, Ryan E. Emmanuel, Howard E. Epstein

School of Natural Resources: Faculty Publications

Growing season soil CO₂ efflux is known to vary laterally by as much as seven fold within small subalpine watersheds (<5 >km²), and such degree of variability has been strongly related to the landscape-imposed redistribution of soil water. Current empirical or process models offer low potential to simulate this variability or to simulate watershed-scale dynamics of soil CO₂ efflux. We modified an existing process soil CO₂ production and efflux model to include spatially variable soil moisture, and applied it to a well-studied and moderately complex watershed of the northern Rocky Mountains. We started at the …

Vadose Zone Mapping Using Geographic Information Systems And Geostatistics, Ruopu Li, Lin Zhao

School of Natural Resources: Faculty Publications

Characteristics of the vadose zone media are important for assessing contamination potentials for projects such as landfill siting and planning. However, accurate vadose zone maps at the regional scale are often not available. This study successfully mapped low-permeable components of the vadose zone across the Elkhorn River Basin, Nebraska, using geographic information systems (GIS), groundwater level data, and a test hole database. The map has the potential to land use planners for searching and planning landfill sites.

The North American Drought Monitor: A Continental Approach, Mark Svoboda

School of Natural Resources: Faculty Publications

The U.S. Drought Monitor

Since 1999, NOAA (CPC and NCDC), USDA, and the NDMC have produced a weekly composite drought map -- the U.S. Drought Monitor -- with input from numerous federal and non-federal partners.

History of the North American Drought Monitor (NADM)

• The concept for the NADM was developed and discussed in 2002
• The first NADM map was released in March 2003
• The first NADM map in all three languages (English, Spanish, and French)was released in October 2003

History of the NADM

• The United States started off as the only country to author and organize the map
• Canada …

Estimation Of Land Surface Evapotranspiration With A Satellite Remote Sensing Procedure, Ayse Kilic, Ian Ratcliffe, Pariskhit Ranade, Kenneth Hubbard, Ramesh K. Singh, Babuarao Kamble, Jeppe Kjaersgaard

School of Natural Resources: Faculty Publications

There are various methods available for estimating magnitude and trends of evapotranspiration. Bowen ratio energy balance system and eddy correlation techniques offer powerful alternatives for measuring land surface evapotranspiration. In spite of the elegance, high accuracy, and theoretical attractions of these techniques for measuring evapotranspiration, their practical use over large areas can be limited due to the number of sites needed and the related expense. Application of evapotranspiration mapping from satellite measurements can overcome the limitations. The objective of this study was to utilize the METRIC^TM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model in Great Plains environmental …

Do Invasive Riparian Woody Plants Affect Hydrology And Ecosystem Processes?, Julie A. Huddle, Tala Awada, Derrel L. Martin, Xinhua Zhou, Sue Ellen Pegg, Scott J. Josiah

School of Natural Resources: Faculty Publications

Political and socioeconomic pressures on riparian areas in semiarid regions of the Great Plains are growing as water resources become more limited. Management along waterways has altered stream ecology and hydrology in ways that encourage the invasion and expansion of native (e.g., Juniperus virginiana) and non-native (e.g., Tamarix sp. and Elaeagnus angustifolia) woody species. One management tool currently implemented to restore the hydrology or increase water yields along waterways in semiarid areas is the removal of vegetation or invasive species. How managers should respond to invasive woody plants to optimize hydrological functions without compromising other riparian ecosystem functions …

Nir-Red Reflectance-Based Algorithms For Chlorophyll-A Estimation In Mesotrophic Inland And Coastal Waters: Lake Kinneret Case Study, Yosef Z. Yacobi, Wesley Moses, Semion Kaganovsky, Benayahu Sulimani, Bryan Leavitt, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

A variety of models have been developed for estimating chlorophyll-a (Chl-a) concentration in turbid and productive waters. All are based on optical information in a few spectral bands in the red and near-infra-red regions of the electromagnetic spectrum. The wavelength locations in the models used were meticulously tuned to provide the highest sensitivity to the presence of Chl-a and minimal sensitivity to other constituents in water. But the caveat in these models is the need for recurrent parameterization and calibration due to changes in the biophysical characteristics of water based on the location and/or time of the year. In this …

Isolation By Distance Explains Genetic Structure Of Buggy Creek Virus, A Bird-Associated Arbovirus, Abinash Padhi, Amy T. Moore, Mary Bomberger Brown, Jerome E. Foster, Martin Pfeffer, Charles R. Brown

School of Natural Resources: Faculty Publications

Many of the arthropod-borne viruses (arboviruses) show extensive genetic variability and are widely distributed over large geographic areas. Understanding how virus genetic structure varies in space may yield insight into how these pathogens are adapted to and dispersed by different hosts or vectors, the relative importance of mutation, drift, or selection in generating genetic variability, and where and when epidemics or epizootics are most likely to occur. However, because most arboviruses tend to be sampled opportunistically and often cannot be isolated in large numbers at a given locale, surprisingly little is known about their spatial genetic structure on the local …

Evaluating Observed And Projected Future Climate Changes For The Arctic Using The Köppen-Trewartha Climate Classification, Song Feng, Chang-Hoi Ho, Qi Hu, Robert Oglesby, Su-Jong Jeong, Baek-Min Kim

School of Natural Resources: Faculty Publications

The ecosystems in the Arctic region are known to be very sensitive to climate changes. The accelerated warming for the past several decades has profoundly influenced the lives of the native populations and ecosystems in the Arc­tic. Given that the Köppen-Trewartha (K-T) climate classifi­cation is based on reliable variations of land-surface types (especially vegetation), this study used the K-T scheme to evaluate climate changes and their impact on vegetation for the Arctic (north of 50°N) by analyzing observations as well as model simulations for the period 1900–2099. The models include 16 fully coupled global climate mod­els from the Intergovernmental Panel …

River Geomorphology And Fish Barriers Affect On Spatial And Temporal Patterns Of Fish Assemblages In The Niobrara River, Nebraska, Greg A. Wanner, Mark A. Pegg, Steven Schainost, Robert A. Klumb, Dane A. Shuman

School of Natural Resources: Faculty Publications

The Niobrara River in northern Nebraska traverses the heart of the Great Plains with portions of the river protected under the National Wild and Scenic River system managed by the National Park Service. The Niobrara River changes from a narrow, entrenched stream to a wide, highly braided river with four fish barriers and 36 distinct geomorphic segments in the lower 531 river kilometers (rkm). Our objectives were to examine the spatial and temporal patterns of fish assemblages in the Niobrara River related to environmental variables, fish barriers, and river geomorphology. Tote-barge electrofishing occurred monthly from June to September in 2009 …

Stormwater Management: Terminology, Kathryn A. Pekarek, David P. Shelton, Kelly Feehan, Bobbi A. Holm

School of Natural Resources: Faculty Publications

Stormwater runoff is the result of precipitation that does not infiltrate into the soil. Rather, it flows over land areas or through storm drains to streams, rivers, and lakes. This water collects pollutants as it moves over streets, parking lots, driveways, and other surfaces. Typically, stormwater runoff is untreated before being discharged to surface water. The quantity and quality of stormwater runoff is directly related to land use; as more urban development occurs — especially impervious surfaces — greater amounts of water and contaminants are generated. According to the U.S. Environmental Protection Agency (EPA), highly urbanized areas generate over five …

Nest Survival Of Long-Billed Curlew In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Long-billed Curlew Numenius americanus is an imperiled shorebird of western North America. Populations have declined dramatically in the last 150 years from the conversion of prairie to agriculture and it is now listed as a “Tier I at-risk” species in Nebraska. We undertook a 3-year project (2008–2010) to study the nest survival of Long-billed Curlews in Nebraska. We measured vegetation characteristics at each nest site (n = 14 nests) on two different spatial scales and used program MARK to model nest survival as a function of multiple covariates. Apparent nest survival was 29% (n = 4 successful nests) and our …

Nebraska's Tern And Plover Conservation Partnership -- A Model For Sustainable Conservation Of Threatened And Endangered Species, Mary Bomberger Brown, Mark E. Burbach, John Dinan, Renae J. Held, Ron J. Johnson, Joel G. Jorgensen, Jeanine Lackey, Jeffrey F. Marcus, Gina S. Matkin, Christine M. Thody

School of Natural Resources: Faculty Publications

Implementing successful conservation programs is critical if we are to protect the earth's most imperiled species. These programs must respect state and federal legal concerns as well as local economic and social interests, Here we describe a sustainable partnership approach to Piping Plover and Interior Least Tern conservation in Nebraska, USA. Partners include industry groups, federal, state, and local agencies, and non-governmental organizations. The factor that unifies all partners is a desire to accomplish cooperative threatened and endangered species conservation. We believe that implementing this sort of partnership model could be useful in addressing the protection of other species of …

The Influence Of Habitat And Environment On Smallmouth Bass (Micropterus Dolomieu) Nest Sites And Nest Success In Northern Lake Michigan, Mark A. Kaemingk, Alexander Clem, Tracy L. Galarowicz

School of Natural Resources: Faculty Publications

Information on smallmouth bass nesting ecology is lacking in northern Lake Michigan, despite available information for other Great Lakes ecosystems. Our objectives were to identify factors that influenced nesting sites and nest success in a smallmouth bass population in northern Lake Michigan. Temperature, substrate firmness, and lake bottom rugosity were measured and related to the number of smallmouth bass nests in four bays. We also investigated the role of temperature, effective fetch, and storms to explain nest success. Temperature appeared to be most important in explaining the number of nests and nest success; transects that experienced the greatest number of …

Movement Of Smallmouth Bass Within The Beaver Island Archipelago, Northern Lake Michigan., Mark A. Kaemingk, Tracy L. Galarowicz, John A. Clevenger, David F. Clapp

School of Natural Resources: Faculty Publications

Fish movement may vary across a wide array of aquatic ecosystems and may be related to the overall size of the system inhabited. We investigated movement of smallmouth bass in Lake Michigan because this information is lacking for larger systems. A total of 16 smallmouth bass were surgically implanted with ultrasonic transmitters within the Beaver Archipelago, northern Lake Michigan. During 2007–2008, a maximum of one location per individual was recorded daily during three specific tracking periods – pre-spawn, spawning, and post-spawn – to determine diurnal movement patterns. Movement was evaluated as site fidelity, minimum displacement rate,maximumexcursion rate, and distance from …

Exploring Spatial Distributions Of Larval Yellow Perch Perca Flavescens, Bluegill Lepomis Macrochirus, And Their Prey In Relation To Wind., Mark A. Kaemingk, Jeffrey C. Jolley, David W. Willis, Brian Ds Graeb

School of Natural Resources: Faculty Publications

The objectives of the present study were to determine if spatial differences existed between zooplankton, larval yellow perch Perca flavescens and bluegill Lepomis macrochirus (length, LT) in Pelican Lake (332 ha), NE, U.S.A. It was hypothesized that wind could act as a transport mechanism for larval fishes in this shallow lake, because strong winds are common at this geographic location. Potential spatial differences were explored, relating to zooplankton densities, size structure and densities of larval P. flavescens and L. macrochirus. Density differences (east v. west side of the lake) were detected for small- (two occasions), medium- (two occasions) and large-sized …