Physical Sciences and Mathematics Commons^™

The Risk Of Flawed Inference In Evolutionary Studies When Detectability Is Less Than One, Olivier Gimenez, Anne Viallefont, Anne Charmantier, Roger Pradel, Emmanuelle Cam, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown, Rita Covas, Jean-Michel Gaillard2

School of Natural Resources: Faculty Publications

Addressing evolutionary questions in the wild remains a challenge. It is best done by monitoring organisms from birth to death, which is very difficult in part because individuals may or may not be resighted or recaptured. Although the issue of uncertain detection has long been acknowledged in ecology and conservation biology, in evolutionary studies of wild populations it is often assumed that detectability is perfect. We argue that this assumption may lead to flawed inference. We demonstrate that the form of natural selection acting on body mass of sociable weavers is altered and that the rate of senescence of roe …

Fish Distributions And Nutrient Cycling In Streams: Can Fish Create Biogeochemical Hotspots?, Peter B. Mcintyre, Alexander S. Flecker, Michael J. Vanni, James M. Hood, Brad W. Taylor, Steven A. Thomas

School of Natural Resources: Faculty Publications

Rates of biogeochemical processes often vary widely in space and time, and characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots of nutrient transformations are generally attributed to physical and microbial processes. Here we examine the potential for heterogeneous distributions of fish to generate hotspots of nutrient recycling. We measured nitrogen (N) and phosphorus (P) excretion rates of 47 species of fish in an N-limited Neotropical stream, and we combined these data with population densities in each of 49 stream channel units to estimate unit- and reach-scale nutrient recycling. Species varied widely in rates of N …

2008 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months. The report was prepared to inform our partners and funding agencies of our activities and to provide a preliminary summary of results. These data analyses are not final and should be treated as such when citing information, data, or analyses found in this document.

The Interior Least Tern (Sternula antillarum athallassos) is a state and federal endangered species; it was first listed in 1985. The Piping Plover (Charadrius melodus) is a state and federal threatened species; it was also first …

Terrapene Ornata (Ornate Box Turtle) Predation On Cliff Swallows, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

During a 25-year study of Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, we observed Terrapene ornata prey, or attempt to prey, on swallows. On one occasion as large numbers of birds flushed and hit the net, the weight of the birds pulled the net down to ground level. One T. ornata, which was seen regularly at the colony, approached one adult Cliff Swallow that was very low in the net and killed it by biting and eating its head. After killing the bird, the turtle walked away carrying the head.

Experimental Inoculation Of House Sparrows (Passer Domesticus) With Buggy Creek Virus, Kathryn P. Huyvaert, Amy T. Moore, Nicholas A. Panella, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in …

Estimation Of Net Ecosystem Carbon Exchange For The Conterminous United States By Combining Modis And Ameriflux Data, Jingfeng Xiao, Qianlai Zhuang, Dennis D. Baldocchi, Beverly E. Law, Andrew D. Richardson, Jiquan Chen, Ram Oren, Gregory Starr, Asko Noormets, Siyan Ma, Shashi Verma, Sonia Wharton, Steven C. Wofsy, Paul V. Bolstad, Sean P. Burns, David R. Cook, Peter S. Curtis, Bert G. Drake, Matthias Falk, Marc L. Fischer, David R. Foster, Lianhong Gu, Julian L. Hadley, David Y. Hollinger, Gabriel G. Katul, Marcy Litvak, Timothy A. Martin, Roser Matamala, Steve Mcnulty, Tilden P. Meyers, Russell K. Monson, J. William Munger, Walter C. Oechel, Kyaw Tha Paw U, Hans Peter Schmid, Russell L. Scott, Ge Sun, Andrew E. Suyker, Margaret S. Torn

School of Natural Resources: Faculty Publications

Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board the National Aeronautics and Space Administration’s (NASA) Terra satellite to scale up AmeriFlux NEE measurements to the …

New Findings About The Complementary Relationship-Based Evaporation Estimation Methods, Jozsef Szilagyi, Janos Jozsa

School of Natural Resources: Faculty Publications

No abstract provided.

Effects Of Habitat Disturbance On Survival Rates Of Softshell Turtles (Apalone Spinifera) In An Urban Stream, Michael Plummer, David G. Krementz, Larkin A. Powell, Nathan Mills

School of Natural Resources: Faculty Publications

We monitored Spiny Softshell Turtles (Apalone spinifera) using mark-recapture during 1994– 2005 in Gin Creek, Searcy, Arkansas. In 1997–2000 the creek bed and riparian zone were bulldozed in an effort to remove debris and improve water flow. This disturbance appeared to reduce the quantity and quality of turtle habitat. We tested for the potential effect of this habitat disturbance on the survival rates of marked turtles. We estimated annual survival rates for the population using models that allowed for variation in survival by state of maturation, year, and effects of the disturbance; we evaluated two different models of …

Variability In Soil Respiration Across Riparian-Hillslope Transitions, Vincent J. Pacific, Brian L. Mcglynn, Diego Andrés Riveros-Iregui, Daniel L. Welsch, Howard E. Epstein

School of Natural Resources: Faculty Publications

The spatial and temporal controls on soil CO₂ production and surface CO₂ efflux have been identified as outstanding gaps in our understanding of carbon cycling. We investigated both across two riparian-hillslope transitions in a subalpine catchment, northern Rocky Mountains, Montana. Riparian-hillslope transitions provide ideal locations for investigating the controls on soil CO₂ dynamics due to strong, natural gradients in the factors driving respiration, including soil water content (SWC) and soil temperature. We measured soil air CO₂ concentrations (20 and 50 cm), surface CO₂ efflux, soil temperature, and SWC at eight locations. We investigated (1) how …

Nondestructive Estimation Of Leaf Chlorophyll Content In Grapes, Mark Steele, Anatoly A. Gitelson, Donald Rundquist

School of Natural Resources: Faculty Publications

Leaf chlorophyll content provides valuable information about the physiological status of plants, and there is a need for accurate, efficient, practical methodologies to estimate this biophysical parameter. Reflectance measurement is a means of quickly and nondestructively assessing, in situ, the chlorophyll content in leaves. The objective of this study was to develop a precise, efficient, nondestructive technique to estimate leaf total chlorophyll (Chl) content in grapes. A relationship was established between Chl content and the red-edge chlorophyll index, based on reflectances in the red-edge (710–720 nm) and near-infrared (755–765 nm) spectral ranges, and the algorithm for Chl retrieval was calibrated. …

Remediating Explosive-Contaminated Groundwater By In Situ Redox Manipulation (Isrm) Of Aquifer Sediments, H.K. Boparai, Steven Comfort, Patrick J. Shea, J.E. Szecsody

School of Natural Resources: Faculty Publications

In situ chemical reduction of clays and iron oxides in subsurface environments is an emerging technology for treatment of contaminated groundwater. Our objective was to determine the efficacy of dithionite-reduced sediments from the perched Pantex Aquifer (Amarillo, TX) to abiotically degrade the explosives RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine), and TNT (2,4,6-trinitrotoluene). The effects of dithionite/buffer concentrations, sediments-solution ratios, and the contribution of Fe(II) were evaluated in batch experiments. Results showed that reduced Pantex sediments were highly effective in degrading all three high explosives. Degradation rates increased with increasing dithionite/buffer concentrations and soil to solution ratios (1:80–1:10 w/v). When Fe(II) was …

Rationale For A Permanent Seismic Network In The U.S. Central Plains Utilizing U.S. Array, Stephen S. Gao, Tina M. Niemi, Ross A. Black, Kelly H. Liu, Raymond R. Anderson, Robert M. Joeckel, Robert W. Busby, John Taber

School of Natural Resources: Faculty Publications

No abstract provided.

Geologic Map Of The O'Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert Diffendal, Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins

School of Natural Resources: Faculty Publications

SCALE 1:250,000

CONTOUR INTERVAL 200 FEET

Geology mapped principally from 1991-2000 by RFD, M.RV, E.JV, H. LG , and C.LT

Editing and layout by R.F. Diffendal, Jr. and D. Ebbeka

Map production by J. Nothwehr and L. Howard

Revised slightly 6 January 2009, 20 July 2010, 5 October 2010, 10 September 2012.

Chinese Liver Flukes In Latrine Sediments From Wong Nim’S Property, San Bernardino, California: Archaeoparasitology Of The Caltrans District Headquarters (Galley Proofs), Karl J. Reinhard, Adauto Araújo, Luciana Sianto, Julia G. Costello, Karen Swope

School of Natural Resources: Faculty Publications

Parasitological analysis of 5 sediment samples from latrine deposits spanning the time period from about 1880 to the 1930s are presented. Two sediment samples are from a latrine used by European-Americans. Three sediment samples are from latrines used by Chinese-Americans on the property of Wong Nim, an important member of the Chinese community. Two of the Chinese latrines were positive for human parasites. The human parasites encountered include the human whipworm (Trichuris trichiura), the giant intestinal roundworm (Ascaris lumbricoides, c.f.), and the Chinese liver fluke (Clonorchis sinensis). Evidence of the liver fluke is especially …

Power Laws, Discontinuities And Regional City Size Distributions, Ahjond S. Garmestan, Craig R. Allen, Colin M. Gallagher

School of Natural Resources: Faculty Publications

Urban systems are manifestations of human adaptation to the natural environment. City size distributions are the expression of hierarchical processes acting upon urban systems. In this paper, we test the entire city size distributions for the southeastern and southwestern United States (1990), as well as the size classes in these regions for power law behavior. We interpret the differences in the size of the regional city size distributions as the manifestation of variable growth dynamics dependent upon city size. Size classics in the city size distributions are snapshots of stable states within urban systems in flux.

Meso-Scale Weather And Climate Observations In Kentucky For Societal Benefit, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

A Coupled Mm5-Noah And Surface Model-Based Assessment Of Sensitivity Of Planetary Boundary Layer Variables To Anomalous Soil Moisture Conditions, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Equilibrium Sampling Used To Monitor Malodors In A Swine Waste Lagoon, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Unresolved Issues With The Assessment Of Multidecadal Global Land Surface Temperature Trends, Roger A. Pielke Sr., Christopher A. Davey, Dev Niyogi, Souleymane Fall, Jesse Steinweg-Woods, Ken Hubbard, Xiaomao Lin, Ming Cai, Young-Kwon Lim, Hong Li, John Nielsen-Gammon, Kevin Gallo, Robert Hale, Rezaul Mahmood, Stuart Foster, Richard T. Mcnider, Peter Blanken

School of Natural Resources: Faculty Publications

This paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data, …

Reinterpreting The Pollen Data From Dos Cabezas, Karl J. Reinhard, Vaughn M. Bryant, Sheila D. Vinton

School of Natural Resources: Faculty Publications

The published pollen analysis of the Dos Cabezas giants, Geyer et al. (2003), lists variety of purported dietary pollen types. The paper also hypothesises that the giants were poisoned with plant toxins. We have severe reservations about the pollen evidence of diet and poisoning. We suggest that the analysts made several errors in their interpretation. Firstly, some of the discovered pollen types are not prehistoric endemics to the Dos Cabezas region of coastal Peru. These include the pollen of fava beans (cultivated in the Old World), and specified species of agave and sage. We believe that some or all of …

If Larvae Were Smart: A Simple Model For Optimal Settlement Behavior Of Competent Larvae, Robert J. Toonen, Andrew J. Tyre

School of Natural Resources: Faculty Publications

Much research has been done on larval settlement cues. Rather than having simple fixed responses to constant environmental stimuli, it seems likely that settlement decisions made by individual larvae should vary depending on the individual and the conditions under which it encounters that cue. Here, we present a simple stochastic dynamic programming model that explores the conditions under which larvae may maximize their lifetime fitness by accepting lower quality habitat rather than continuing to search for superior habitat. Our model predicts that there is a relatively narrow range of parameter values over which larval selectivity among habitat types changes dramatically …

Interactions Across Spatial Scales Among Forest Dieback, Fire, And Erosion In Northern New Mexico Landscapes, Craig D. Allen

School of Natural Resources: Faculty Publications

Ecosystem patterns and disturbance processes at one spatial scale often interact with processes at another scale, and the result of such cross-scale interactions can be nonlinear dynamics with thresholds. Examples of cross-scale pattern-process relationships and interactions among forest dieback, fire, and erosion are illustrated from northern New Mexico (USA) landscapes, where long-term studies have recently documented all of these disturbance processes. For example, environmental stress, operating on individual trees, can cause tree death that is amplified by insect mortality agents to propagate to patch and then landscape or even regional-scale forest dieback. Severe drought and unusual warmth in the southwestern …

Ground Water Dependence Of Endangered Ecosystems: Nebraska’S Eastern Saline Wetlands, F. Edwin Harvey, Jerry F. Ayers, David C. Gosselin

School of Natural Resources: Faculty Publications

Many endangered or threatened ecosystems depend on ground water for their survival. Nebraska’s saline wetlands, home to a number of endangered species, are ecosystems whose development, sustenance, and survival depend on saline ground water discharge at the surface. This study demonstrates that the saline conditions present within the eastern Nebraska saline wetlands result from the upwelling of saline ground water from within the underlying Dakota Aquifer and deeper underlying formations of Pennsylvanian age. Over thousands to tens of thousands of years, saline ground water has migrated over regional scale flowpaths from recharge zones in the west to the present-day discharge …

Soil Carbon And Tree Litter Dynamics In A Red Cedar–Scotch Pine Shelterbelt, Thomas J. Sauer, Cynthia A. Cambardella, James R. Brandle

School of Natural Resources: Faculty Publications

Carbon sequestration in the woody biomass of shelterbelts has been investigated but there have been no measurements of the C stocks in soil and tree litter under this agroforestry practice. The objective of this study was to quantify C stored in surface soil layers and tree litter within and adjacent to a 35-year-old shelterbelt in eastern Nebraska, USA. The 2-row shelterbelt was composed of eastern red cedar (Juniperus virginiana) and scotch pine (Pinus sylvestris). A sampling grid was established across a section of the shelterbelt on Tomek silt loam (fine, smectitic, mesic Pachic Argiudolls). Four soil …

Departures From Gibrat’S Law, Discontinuities And City Size Distributions, Ahjond S. Garmestani, Craig R. Allen, Colin M. Gallagher, John Mittelstaedt

School of Natural Resources: Faculty Publications

Cities are complex, self-organizing, evolving systems and the emergent patterns they manifest provide insight into the dynamic processes in urban systems. This article analyses city size distributions, by decade, from the south-eastern region of the US for the years 1860–1990. It determines if the distributions are clustered into size classes and documents changes in the pattern of size classes over time. A statistical hypothesis test was also performed to detect dependence between city size and growth using discrete probability calculations under the assumption of Gibrat’s law. The city size distributions for the south-eastern region of the US were discontinuous, with …

Parasite Findings In Archeological Remains: Diagnosis And Interpretation, Adauto Arajuo, Karl J. Reinhard, Luiz Fernando Ferreira

School of Natural Resources: Faculty Publications

Paleoparasitology has contributed to resolving the debate about the peopling of the Americas and determining the antiquity of human parasite infection. Hookworm (Ancylostomidae) and whipworm (Trichuris trichiura) and other exclusive human intestinal parasites have been recorded in pre-Columbian America. These parasite species originated in pre-hominids and have accompanied humans across continents when people went out of Africa. However, for those human populations that crossed the Bering Land Bridge from Siberia to Alaska, cold climate conditions hampered parasite transmission. Alternative migration routes have been proposed to explain the presence of these parasites in pre-Columbian populations in the Americas. Other …

Increase In Near-Surface Atmospheric Moisture Content Due To Land Use Changes: Evidence From The Observed Dewpoint Temperature Data, Rezaul Mamood, Kenneth G. Hubbard, Ronnie D. Leeper, Stuart A. Foster

School of Natural Resources: Faculty Publications

Land use change can significantly affect root zone soil moisture, surface energy balance, and near-surface atmospheric temperature and moisture content. During the second half of the twentieth century, portions of the North American Great Plains have experienced extensive introduction of irrigated agriculture. It is expected that land use change from natural grass to irrigated land use would significantly increase nearsurface atmospheric moisture content. Modeling studies have already shown an enhanced rate of evapotranspiration from the irrigated areas. The present study analyzes observed dewpoint temperature (Td) to assess the affect of irrigated land use on near-surface atmospheric moisture content. This investigation …

Hunter-Gatherer Use Of Small Animal Food Resources: Coprolite Evidence, Karl J. Reinhard, J. R. Ambler, C. R. Szuter

School of Natural Resources: Faculty Publications

Faunal remains are commonly found in coprolites and provide direct evidence of animal consumption. An evaluation of hunter-gatherer coprolites from the Southwest United States shows that animal bone in coprolites can be used to assess patterns of hunting, food preparation, and general importance of small animals in diet. This is demonstrated by a comparison of faunal assemblages between two hunter-gatherer sites with respect to small animal hunting strategies. The sites are Dust Devil Cave on the Colorado Plateau, an Archaic winter habitation, and Hinds Cave, a warm season Archaic habitation in the lower Pecos of Texas. The results indicate that …

Patterns Of Fish Diversity In A Mainstem Missouri River Reservoir And Associated Delta In South Dakota And Nebraska, Usa, Mark A. Kaemingk, Brian D.S. Graeb, Christopher W. Hoagstrom, David W. Willis

School of Natural Resources: Faculty Publications

There is an expansive and expanding delta at the confluence of the Niobrara and Missouri Rivers in the Lewis and Clark Reservoir. The delta provides diverse aquatic habitat that is somewhat similar to the historic Missouri River and to remnant river habitats. As such, the delta may have relatively high fish species diversity compared to lentic reservoir habitats. To compare patterns of fish diversity between the delta and reservoir habitats, we collected fish in several nursery habitats in both areas using four gear types (seine, gill net, electrofisher and fyke net) on three occasions (July, August and September) in 2005. …

Linking Flux Network Measurements To Continental Scale Simulations: Ecosystem Carbon Dioxide Exchange Capacity Under Non-Water-Stressed Conditions, Katherine B. Owen, John Tenhunen, Markus Reichstein, Quan Wang, Eva Falge, Ralf Geyer, Xiangming Xiaos, Paul Stoy, Christof Ammann, Altaf Arain, Marc Aubinet, Mika Aurela, Christian Bernhofer, Bogdan Chojnicki, Andre Granier, Thomas Gruenwald, Julian Hadley, Bernard Heinesch, David Hollinger, Alexander Knohl, Werner Kutsch, Annalea Lohila, Tilden Meyers, Eddy Moors, Christine Moureaux, Kim Pilegaard, Nobuko Saigusa, Shashi Verma, Timo Vesala, Chris Vogel

School of Natural Resources: Faculty Publications

This paper examines long-term eddy covariance data from 18 European and 17 North American and Asian forest, wetland, tundra, grassland, and cropland sites under nonwater- stressed conditions with an empirical rectangular hyperbolic light response model and a single layer two light-class carboxylase-based model. Relationships according to ecosystem functional type are demonstrated between empirical and physiological parameters, suggesting linkages between easily estimated parameters and those with greater potential for process interpretation. Relatively sparse documentation of leaf area index dynamics at flux tower sites is found to be a major difficulty in model inversion and flux interpretation. Therefore, a simplification of the …