Physical Sciences and Mathematics 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.

Papers in Natural Resources

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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

Papers in Natural Resources

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

Papers in Natural Resources

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

Papers in Natural Resources

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

Papers in Natural Resources

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

Papers in Natural Resources

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

Papers in Natural Resources

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 …

Workshop Examines Warming Of Lakes Worldwide, John D. Lenters, Simon J. Hook, Peter B. Mcintyre

Papers in Natural Resources

It is widely recognized that climate change is affecting terrestrial and aquatic ecosystems. Recent studies have revealed significant warming of lakes throughout the world, and this rate of warming is often larger than that of the ambient air temperature (up to 2–3 times more rapid). Although hypotheses have been proposed to explain these high rates of lake warming (e.g., ice albedo feedbacks or changes in cloud cover), the fundamental drivers remain poorly understood. Furthermore, these rapid warming rates have profound implications for lake hydrodynamics, productivity, and biotic communities. It is essential therefore that global data sets of water temperature be …

Estimating Seasonal Evapotranspiration From Temporal Satellite Images, Ramesh K. Singh, Shuguang Liu, Larry L. Tieszen, Andrew E. Suyker, Shashi B. Verma

Papers in Natural Resources

Estimating seasonal evapotranspiration (ET) has many applications in water resources planning and management, including hydrological and ecological modeling. Availability of satellite remote sensing images is limited due to repeat cycle of satellite or cloud cover. This study was conducted to determine the suitability of different methods namely cubic spline, fixed, and linear for estimating seasonal ET from temporal remotely sensed images. Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) model in conjunction with the wet METRIC (wMETRIC), a modified version of the METRIC model, was used to estimate ET on the days of satellite overpass using eight Landsat images …

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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, …

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

Papers in Natural Resources

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

Papers in Natural Resources

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 …

Attendance Patterns And Survival Of Western Meadowlark Nests, Larkin A. Powell, Matthew D. Giovanni, Scott R. Groepper, Mitchell Reineke, Walter H. Schacht

Papers in Natural Resources

Biologists have linked nest attendance and nestling feeding rates to nest predation risk. Patterns of nest attendance also influence the success of methods designed to find nests for research use, such as rope drags. Very little has been published with regard to variation of attendance during the nesting period, but advances in video nest monitoring allow continuous data collection to provide this information. Our objectives were to (1) document attendance patterns at Western Meadowlark (Stumella neglecta) nests, (2) identify predator species of meadowlark nests, and (3) assess the effects of our camera system on nest survival. We used a solar-powered, …

Using Slow-Release Permanganate Candles To Remediate Pah-Contaminated Water, Lindy Rauscher, Chainarong Sakulthaew, Steve D. Comfort

Papers in Natural Resources

Surface waters impacted by urban runoff in metropolitan areas are becoming increasingly contaminated with polycyclic aromatic hydrocarbons (PAHs). Slow-release oxidant candles (paraffin–KMnO₄) are a relatively new technology being used to treat contaminated groundwater and could potentially be used to treat urban runoff. Given that these candles only release permanganate when submerged, the ephemeral nature of runoff events would influence when the permanganate is released for treating PAHs. Our objective was to determine if slow-release permanganate candles could be used to degrade and mineralize PAHs. Batch experiments quantified PAH degradation rates in the presence of the oxidant candles. Results …

An Alternative Method Using Digital Cameras For Continuous Monitoring Of Crop Status, Toshihiro Sakamoto, Anatoly A. Gitelson, Anthony L. Nguy-Robertson, Timothy J. Arkebauer, Brian D. Wardlow, Andrew E. Suyker, Shashi B. Verma, Michio Shibayama

Papers in Natural Resources

Crop physiological and phenological status is an important factor that characterizes crop yield as well as carbon exchange between the atmosphere and the terrestrial biosphere in agroecosystems. It is difficult to establish high frequency observations of crop status in multiple locations using conventional approaches such as agronomical sampling and also remote sensing techniques that use spectral radiometers because of the labor intensive work required for field surveys and the high cost of radiometers designed for scientific use. This study explored the potential utility of an inexpensive camera observation system called crop phenology recording system (CPRS) as an alternative approach for …

On Evapotranspiration And Shallow Groundwater Fluctuations: A Fourier-Based Improvement To The White Method, Mehmet Evren Soylu, John D. Lenters, Erkan Istanbulluoglu, Steven P. Loheide Ii

Papers in Natural Resources

Evapotranspiration (ET) is a significant component of the water and energy balance in wetlands and riparian zones, yet it is also one of the most challenging components to estimate. Diurnal water table fluctuations can be used to directly measure groundwater consumption by phreatophytes, which are often important contributors to the total ET in riparian systems. Although such methods are cost effective, significant uncertainties usually exist, and more accurate techniques continue to be developed. In this study we present a new ‘‘Fourier method’’ for calculating daily (and longer) groundwater ET consumption using a moving, multiday sine function to capture robust, diurnal …

Sharing A Vision For Biodiversity Conservation And Agriculture, John E. Quinn

Papers in Natural Resources

Conservation biology and agriculture share a common landscape and a future that demands novel research and practice. Inevitably, limited resources create conflict in the absence of a shared vision forward. Therefore, given the similarities in proximate and even ultimate goals, we must envision a joint path toward renewable and resilient agroecosystems. In this commentary, I highlight the root of past conflicts and share a vision of progress forward that encompasses mutually beneficial outcomes. I include six areas of anticipatory research and inquiry at the intersection of conservation biology and agriculture to better identify shared goals and facilitate more frequent communication …

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

Papers in Natural Resources

No abstract provided.

Factors Affecting Global Climate, Alison N.P. Stevens

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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 …

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

Papers in Natural Resources

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 …

Estimating The Abundance Of Long-Billed Curlews In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen

Papers in Natural Resources

Long-billed Curlews (Numenius americanus) are shorebirds of high conservation concern in North America. Populations have de­clined in the last 150 yr primarily due to habitat loss and conversion. We conducted a 2-yr study to estimate the density and state­wide abundance of breeding Long-billed Curlews in Nebraska during 2008 and 2009. Surveys were conducted during the prenest­ing period in April when Long-billed Curlews were likely to be detected. We used a simple random sample of roadside survey routes (N = 39), each consisting of 40 5-min point-counts at 800-m intervals. We modeled detection probability and found that wind …

2012 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan

Papers in Natural Resources

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2012). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The Lower Platte River and its major tributaries provide important nesting habitat for two state and federally protected bird species, the Interior Least Tern (Sternula antillarum athalassos) and Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University of Nebraska-School of Natural Resources, and the Nongame Bird …