Environmental Sciences Commons^™

Insights From Characterizing Extinct Human Gut Microbiomes, Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis, Jr.

School of Natural Resources: Faculty Publications

In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (~8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to …

Evolutionary And Practical Implications Of Pseudo-Estrus Behavior In Florida Panthers (Puma Concolor Coryi), John F. Benson, Mark A. Lotz, E. Darrell Land, Dave P. Onorato

School of Natural Resources: Faculty Publications

Estrus behavior by females for reasons other than reproduction (pseudo-estrus) has been reported in species of primates and felids, and alternative hypotheses have been put forth to explain its evolution and function. We observed 3 separate cases of pseudo-estrus behavior by 2 Puma concolor coryi (Florida Panther) females while they were nursing young (old) kittens. We used VHF and GPS telemetry data, genetic pedigree analysis, and visual observations to provide insight into the evolutionary and practical implications of this behavior for Panthers. We suggest that female Panthers likely consort with males while nursing kittens to maintain amicable relations with these …

A Geospatial Modeling Framework For Assessing Biofuels-Related Land-Use And Land-Cover Change, Ruopu Li, Qingfeng (Gene) Guan, James W. Merchant

School of Natural Resources: Faculty Publications

With the increasing biofuel demands in recent years, the cultivated lands for biofuel crops, i.e., corn and soybeans, the major sources of ethanol and biodiesel, have been greatly expanding in the northern Great Plains states of the United States. Simulating the spatio-temporal dynamics of biofuel croplands can provide critical information required for assessing the impacts of land-use change on wildlife conservation and water quality. But, yearly agricultural practices such as crop rotations often complicate the spatially explicit modeling of specific crops’ expansion. Our research focused on developing a geospatial modeling framework that is able to distinguish long-term, regional changes in …

Using Slow-Release Permanganate Candles To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson, Ann Kambhu, Steve D. Comfort

School of Natural Resources: Faculty Publications

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L^-1) was identified in a low permeable silty-clay aquifer (K_h = 0.5 …

Comparative Transcriptome Analysis Of Two Olive Cultivars In Response To Nacl-Stress, Christos Bazakos, Maria E. Manioudaki, Ioannis Therios, Demetrios Voyiatzis, Dimitris Kafetzopoulos, Tala Awada, Panagiotis Kalaitzis

School of Natural Resources: Faculty Publications

Background: Olive (Olea europaea L.) cultivation is rapidly expanding and low quality saline water is often used for irrigation. The molecular basis of salt tolerance in olive, though, has not yet been investigated at a system level. In this study a comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt-tolerant and a salt-sensitive one.

Methodology/Principal Findings: A 135-day long …

Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas

School of Natural Resources: Faculty Publications

Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon biomass, chlorophyll a, and nutrient ratios in montane streams of Trinidad, West Indies. We sampled 4 focal tributaries of a single river, 2 of which had canopies experimentally thinned, every other month over a 2-y period to observe temporal dynamics and light effects on epilithon. We also sampled 18 sites across Trinidad’s Northern Range Mountains …

Evaluation Of The Effects Of September Hunting Seasons On Canada Geese In Nebraska, Scott R. Groepper, Mark P. Vrtiska, Larkin A. Powell, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

Populations of temperate-nesting Canada geese (Branta canadensis) have increased in Nebraska, USA, resulting in an increased number of nuisance and damage complaints. September hunting seasons were initiated in southeastern Nebraska in 2004 to reduce populations of Canada geese. We analyzed band recoveries from Canada geese banded in southeastern Nebraska during their hatch-year (HY) or after-hatch-year (AHY) to determine whether September hunting seasons affected survival, harvest, and recovery rates. Survival analyses revealed that HY geese had higher survival than AHY geese (SAHY = 0.696, 95% CI = 0.679–0.713; SHY = 0.896, 95% CI = 0.786–0.953) and September seasons did …

Understanding The Pathoecological Relationship Between Ancient Diet And Modern Diabetes Through Coprolite Analysis: A Case Example From Antelope Cave, Mojave County, Arizona, Karl J. Reinhard, Keith L. Johnson, Sara Leroy-Toren, Kyle Wieseman, Isabel Teixeira-Santos, Mônica Vieira

School of Natural Resources: Faculty Publications

The elevated prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in Native Americans of the Southwest has been explained by several authors in terms of a dietary change from preindustrial traditional foods to modern foods. Physiology adapted to traditional foods became deleterious during the process of modernization. Although several versions of this hypothesis exist, they all relate to the rise in modern NIDDM with change from prehistoric subsistence practices to modern dietary practices. This is especially true for the Southwestern desert tribes of Arizona and New Mexico. Coprolite analysts have been recovering the sort of data needed by diabetes researchers to explore …

Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon

School of Natural Resources: Faculty Publications

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO₃ ⁻) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (¹⁵NO₃ ⁻) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 ⁻ in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H₂S) gradient (2 to …

Remote Estimation Of Crop Gross Primary Production With Landsat Data, Anatoly Gitelson, Yi Peng, Jeffrey G. Masek, Donald Rundquist, Shashi Verma, Andrew E. Suyker, John M. Baker, Tilden Meyers

School of Natural Resources: Faculty Publications

An accurate and synoptic quantification of gross primary production (GPP) in crops is essential for studies of carbon budgets at regional and global scales. In this study, we tested a model, relating crop GPP to a product of total canopy chlorophyll (Chl) content and potential incident photosynthetically active radiation (PAR_potential). The approach is based on remotely sensed data; specifically, vegetation indices (VI) that are proxies for total Chl content and PARpotential, which is incident PAR under a condition of minimal atmospheric aerosol loading. Using VI retrieved from surface reflectance Landsat data, we found that the model is capable …

Complex Terrain Leads To Bidirectional Responses Of Soil Respiration To Inter-Annual Water Availability, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Ryan E. Emanuel, Howard E. Epstein

School of Natural Resources: Faculty Publications

Research on the terrestrial C balance focuses largely on measuring and predicting responses of ecosystem-scale production and respiration to changing temperatures and hydrologic regimes. However, landscape morphology can modify the availability of resources from year to year by imposing physical gradients that redistribute soil water and other biophysical variables within ecosystems. This article demonstrates that the well-established biophysical relationship between soil respiration and soil moisture interacts with topographic structure to create bidirectional (i.e., opposite) responses of soil respiration to inter-annual soil water availability within the landscape. Based on soil respiration measurements taken at a subalpine forest in central Montana, we …

The General Ensemble Biogeochemical Modeling System (Gems) And Its Applications To Agricultural Systems In The United States, Shuguang Liu, Zhengxi Tan, Mingshi Chen, Jinxun Liu, Anne Wein, Zhengpeng Li, Shengli Huang, Jennifer Oeding, Claudia Young, Shashi Verma, Andrew Suyker, Stephen Faulkner, Gregory W. Mccarty

School of Natural Resources: Faculty Publications

The General Ensemble Biogeochemical Modeling System (GEMS) (Liu, 2009; Liu et al., 2004c) was developed to integrate well-established ecosystem biogeochemical models with various spatial databases for the simulations of biogeochemical cycles over large areas. Figure 18.1 shows the overall structure of the GEMS. Some of the key components are described below.

General Ensemble Biogeochemical

Modeling System (GEMS) 310

Multiple Underlying Biogeochemical Models 310

Monte Carlo Simulations 311

Model Inputs: Management Practices and Others 311

Model Outputs 311

Data Assimilation 311

Simulation of Agricultural Practices: EDCM as an Example 312

Net Primary Production (NPP) and Improvements in Crop Genetics and Agronomics …

National Climate Assessment Technical Report On The Impacts Of Climate And Land Use And Land Cover Change, Thomas Loveland, Rezaul Mahmood, Toral Patel-Weynand, Krista Karstensen, Kari Beckendorf, Norman Bliss, Andrew Carlton

School of Natural Resources: Faculty Publications

This technical report responds to the recognition by the U.S. Global Change Research Program (USGCRP) and the National Climate Assessment (NCA) of the importance of understanding how land use and land cover (LULC) affects weather and climate variability and change and how that variability and change affects LULC. Current published, peer-reviewed, scientific literature and supporting data from both existing and original sources forms the basis for this report’s assessment of the current state of knowledge regarding land change and climate interactions. The synthesis presented herein documents how current and future land change may alter environment processes and in turn, how …

Interior Least Tern Powerline Collision On The Lower Platte River, Lauren R. Dinan, Joel G. Jorgensen, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Collisions with electrical powerlines are a well-known documented cause of avian mortality (Avian Power Line Interaction Committee [APLIC] 1994, Savereno et al. 1996). Mortality caused by collisions with powerlines can be an important concern for many bird species, but is a serious conservation problem for threatened and endangered species because any mortality can have biological and legal ramifications (Janss 2000). Loss of individuals, particularly breeding adults, from an already small population may impede a species’ recovery by reducing reproduction and recruitment into the breeding population. The death of an individual from a threatened or endangered species as a result of …

Fish Assemblage Shifts And Population Dynamics Of Smallmouth Bass (Micropterus Dolomieu) In The Beaver Archipelago, Northern Lake Michigan: A Comparison Between Historical And Recent Time Periods Amidst Ecosystem Changes., Mark A. Kaemingk, Tracy L. Galarowicz, John A. Clevenger, David F. Clapp, Herbert L. Lenon

School of Natural Resources: Faculty Publications

The ecological and economic importance of Great Lakes nearshore areas and the paucity of information on nearshore Lake Michigan fish assemblages prompted us to document changes that occurred from a historical time period (1969–1972, 1975, 1977, and 1984) to a recent period (2005–2008) in a nearshore northern Lake Michigan (Beaver Archipelago) fish assemblage, with an emphasis on smallmouth bass Micropterus dolomieu. From historical to recent periods, the Beaver Archipelago fish assemblage shifted from predominantly brown bullheads Ameiurus nebulosus to predominantly smallmouth bass. Relative abundance of brown bullheads and white suckers Catostomus commersonii declined from historical to recent time periods, as …

Priority Effects Among Young-Of-The-Year Fish: Reduced Growth Of Bluegill Sunfish (Lepomis Macrochirus) Caused By Yellow Perch (Perca Flavescens)?, Mark A. Kaemingk, Jeffrey C. Jolley, David W. Willis, Steven R. Chipps

School of Natural Resources: Faculty Publications

1. When available, Daphnia spp. are often preferred by age-0 yellow perch and bluegill sunfish because of energetic profitability. We hypothesised that predation by age-0 yellow perch could lead to a midsummer decline (MSD) of Daphnia spp. and that priority effects may favour yellow perch because they hatch before bluegill, allowing them to capitalise on Daphnia spp. prior to bluegill emergence.

2. Data were collected from 2004 to 2010 in Pelican Lake, Nebraska, U.S.A. The lake experienced a prolonged MSD in all but 1 year (2005), generally occurring within the first 2 weeks of June except in 2008 and 2010 …

Phosphorus In Phoenix: A Budget And Spatial Representation Of Phosphorus In An Urban Ecosystem, Genevieve S. Metson, Rebecca L. Hale, David M. Iwaniec, Elizabeth M. Cook, Jessica R. Corman, Christopher S. Galletti, Daniel L. Childers

School of Natural Resources: Faculty Publications

As urban environments dominate the landscape, we need to examine how limiting nutrients such as phosphorus (P) cycle in these novel ecosystems. Sustainable management of P resources is necessary to ensure global food security and to minimize freshwater pollution. We used a spatially explicit budget to quantify the pools and fluxes of P in the Greater Phoenix Area in Arizona, USA, using the boundaries of the Central Arizona– Phoenix Long-Term Ecological Research site. Inputs were dominated by direct imports of food and fertilizer for local agriculture, while most outputs were small, including water, crops, and material destined for recycling. Internally, …

Monitoring Live Fuel Moisture Using Soil Moisture And Remote Sensing Proxies, Yi Qi, Philip E. Dennison, Jessica Spencer, David Riano

School of Natural Resources: Faculty Publications

Live fuel moisture (LFM) is an important fuel property controlling fuel ignition and fire propagation. LFM varies seasonally, and is controlled by precipitation, soil moisture, evapotranspiration, and plant physiology. LFM is typically sampled manually in the field, which leads to sparse measurements in space and time. Use of LFM proxies could reduce the need for field sampling while potentially improving spatial and temporal sampling density. This study compares soil moisture and remote sensing data to field-sampled LFM for Gambel oak (Quercus gambelii Nutt) and big sagebrush (Artemisia tridentata Nutt) in northern Utah. Bivariate linear regression models were constructed …

Bats In And Around Structures, Dennis M. Ferraro, Lisa Pennisi, Scott E. Hygnstrom, Stephen M. Vantassel

School of Natural Resources: Faculty Publications

No abstract provided.

The Collaborative Forest Landscape Restoration Program: A History And Overview Of The First Projects, Courtney A. Schultz, Theresa Jedd

School of Natural Resources: Faculty Publications

No abstract provided.

Predation, Herbivory, And Parasitism, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.

Planet Protectors, A.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.

Dynamics Of Predation, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.

Factors Affecting Global Climate, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.

Estimation Of Chlorophyll-A Concentration In Turbid Productive Waters Using Airborne Hyperspectral Data, Wesley J. Moses, Anatoly Gitelson, Richard L. Perk, Daniela Gurlin, Donald C. Rundquist, Bryan C. Leavitt, Tadd M. Barrow, Paul Brakhage

School of Natural Resources: Faculty Publications

Algorithms based on red and near infra-red (NIR) reflectances measured using field spectrometers have been previously shown to yield accurate estimates of chlorophylla concentration in turbid productive waters, irrespective of variations in the bio-optical characteristics of water. The objective of this study was to investigate the performance of NIR-red models when applied to multi-temporal airborne reflectance data acquired by the hyperspectral sensor, Airborne Imaging Spectrometer for Applications (AISA), with non-uniform atmospheric effects across the dates of data acquisition. The results demonstrated the capability of the NIR-red models to capture the spatial distribution of chlorophyll-a in surface waters without the need …

Application Of Day And Night Digital Photographs For Estimating Maize Biophysical Characteristics, Toshihiro Sakamoto, Anatoly Gitelson, Brian D. Wardlow, Timothy J. Arkebauer, Shashi Verma, Andrew E. Suyker, Michio Shibayama

School of Natural Resources: Faculty Publications

In this study, an inexpensive camera-observation system called the Crop Phenology Recording System (CPRS), which consists of a standard digital color camera (RGB cam) and a modified near-infrared (NIR) digital camera (NIR cam), was applied to estimate green leaf area index (LAI), total LAI, green leaf biomass and total dry biomass of stalks and leaves of maize. The CPRS was installed for the 2009 growing season over a rainfed maize field at the University of Nebraska-Lincoln Agricultural Research and Development Center near Mead, NE, USA. The vegetation indices called Visible Atmospherically Resistant Index (VARI) and two green–red–blue (2g–r–b) were calculated …

Groundwater Beneath A Phase Iii Management Area In The Central Platte Natural Resources District, Nebraska: National Institute Of Food And Agriculture–Conservation Effects Assessment Project, Donald W. Meals, Roy F. Spalding, Mary Exner Spalding, Richard B. Ferguson, Mark L. Mcfarland, Deanna L. Osmond, Jean Spooner

School of Natural Resources: Faculty Publications

The goal of the Nebraska National Institute of Food and Agriculture–Conservation Effects Assessment Project (NIFA–CEAP), Phase III, Central Platte Natural Resources District Project, Effectiveness of Irrigated Crop Management Practices in Reducing Groundwater Nitrate Concentrations, was to evaluate the effectiveness of documented farm management practices in lowering groundwater nitrate concentrations in a predominantly irrigated-corn watershed. The specific objectives included the following:

1. Analyze the trends in groundwater nitrate concentrations for the period of 1988 to 2006

2. Evaluate the effect of irrigation and nitrogen (N) inputs on groundwater nitrate concentrations using statistical approaches, including ArcGIS and cokriging and Bayesian Maximum Entropy …

Developing Slow-Release Persulfate Candles To Treat Btex Contaminated Groundwater, Ann Kambhu, Steve D. Comfort, Chanat Chokejaroenrat, Chainarong Sakulthaew

School of Natural Resources: Faculty Publications

The development of slow-release chemical oxidants for sub-surface remediation is a relatively new technol­ogy. Our objective was to develop slow-release persulfate-paraffin candles to treat BTEX-contaminated ground­water. Laboratory-scale candles were prepared by heating and mixing Na₂S₂O₈ with paraffin in a 2.25 to 1 ra­tio (w/w), and then pouring the heated mixture into circular molds that were 2.38 cm long and either 0.71 or 1.27 cm in diameter. Activator candles were prepared with FeSO₄ or zero-valent iron (ZVI) and wax. By treat­ing benzoic acid and BTEX compounds with slow-release persulfate and ZVI candles, we observed rapid …

Population Size Of Hatchery-Reared And Wild Pallid Sturgeon In The Lower Missouri River, Kirk D. Steffensen, Larkin A. Powell, Mark A. Pegg

School of Natural Resources: Faculty Publications

The population size of pallid sturgeon Scaphirhynchus albus is currently unknown throughout much of the Missouri River. Listed as federally endangered in 1990, the pallid sturgeon remains one of the rarest fishes in the Missouri and Mississippi River basins, and little to no natural recruitment occurs. Artificial population supplementation via a hatchery propagation program was initiated, necessitating the collection of sexually mature pallid sturgeon. Therefore, the Nebraska Game and Parks Commission maintained an intensive broodstock collection and mark– recapture effort from 2008 to 2010 to capture reproductively ready adults for the propagation program. Coordinated crews fished baited trotlines from the …

Operational Meris-Based Nir-Red Algorithms For Estimating Chlorophyll-A Concentrations In Coastal Waters — The Azov Sea Case Study, Wesley J. Moses, Anatoly A. Gitelson, Sergey Berdnikov, Vladislav Saprygin, Vasily Povazhnyi

School of Natural Resources: Faculty Publications

We present here results that strongly support the use of MERIS-based NIR-red algorithms as standard tools for estimating chlorophyll-a (chl-a) concentration in turbid productive waters. The study was carried out as one of the steps in testing the potential of the universal applicability of previously developed NIR-red algorithms, which were earlier calibrated using a limited set of MERIS imagery and in situ data from the Azov Sea and the Taganrog Bay, Russia, and data that were synthetically generated using a radiative transfer model. We used an extensive set of MERIS imagery and in situ data collected over …