Natural Resources and Conservation Commons^™

Evaluating Chloroplast Dna In Prehistoric Texas Coprolites: Medicinal, Dietary, Or Ambient Ancient Dna? (Galley Proofs), Karl J. Reinhard, Sérgio M. Chaves, John G. Jones, Alena M. Iñiguez

School of Natural Resources: Faculty Publications

Molecular analysis of coprolites from Hinds Cave, Texas recovered chloroplast DNA sequences. The sequences were interpreted as evidence of diet. We analyzed 19 Hinds Cave coprolites to evaluate the potential sources of the chloroplast DNA (cpDNA) and compared our results to previous studies. This review shows that some cpDNA sequences could be from well-known prehistoric plants foods. Some other sequences could have come from ambient plant material in the guts of small animals eaten by humans in antiquity. Using pollen concentration analysis, we identify sources of ambient plant material which could have been inhaled or imbibed. It is even possible …

Trends In Twentieth-Century U.S. Snowfall Using A Quality-Controlled Dataset, Kenneth E. Kunkel, Michael Palecki, Leslie Ensor, Kenneth Hubbard, David Robinson, Kelly Redmond, David Easterling

School of Natural Resources: Faculty Publications

A quality assessment of daily manual snowfall data has been undertaken for all U.S. long-term stations and their suitability for climate research. The assessment utilized expert judgment on the quality of each station. Through this process, the authors have identified a set of stations believed to be suitable for analysis of trends. Since the 1920s, snowfall has been declining in the West and the mid-Atlantic coast. In some places during recent years the decline has been more precipitous, strongly trending downward along the southern margins of the seasonal snow region, the southern Missouri River basin, and parts of the Northeast. …

Trends In Twentieth-Century U.S. Extreme Snowfall Seasons, Kenneth E. Kunkel, Michael A. Palecki, Leslie Ensor, David Easterling, Kenneth Hubbard, David Robinson, Kelly Redmond

School of Natural Resources: Faculty Publications

Temporal variability in the occurrence of the most extreme snowfall years, both those with abundant snowfall amounts and those lacking snowfall, was examined using a set of 440 quality-controlled, homogenous U.S. snowfall records. The frequencies with which winter-centered annual snowfall totals exceeded the 90th and 10th percentile thresholds at individual stations were calculated from 1900–01 to 2006–07 for the conterminous United States, and for 9 standard climate regions. The area-weighted conterminous U.S. results do not show a statistically significant trend in the occurrence of either high or low snowfall years for the 107-yr period, but there are regional trends. Large …

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

School of Natural Resources: Faculty Publications

No abstract provided.

Eco-Geomorphic Implications Of Hillslope Aspect: Inferences From Analysis Of Landscape Morphology In Central New Mexico, Erkan Istanbulluoglu, Omer Yetemen, Enrique R. Vivoni, Hugo A. Gutierrez-Jurado, Rafael L. Bras

School of Natural Resources: Faculty Publications

We investigate the influence of hillslope aspect on landscape morphology in central New Mexico, where differences in soils, vegetation, and landforms are observed between mesic north-facing and xeric south-facing slopes. Slope–area and curvature–area relations, derived from a Digital Elevation Model (DEM), are used to characterize the opposing hillslope morphologies. In all geologies and elevation ranges studied, topographic data reveal significantly steeper slopes in north-facing aspects, and shallower slopes in south-facing aspects. North-facing slope curvatures are also greater than south-facing curvatures. Using a conceptual slope-area model, we suggest that for a given drainage area, steeper north-facing slopes imply lower soil erodibility. …

Buffered, Lagged, Or Cooled? Disentangling Hyporheic Influences On Temperature Cycles In Stream Channels, Alicia S. Arrigoni, Geoffrey C. Poole, Leal A. K. Mertes, Scott J. O'Daniel, William W. Woessner, Steven A. Thomas

School of Natural Resources: Faculty Publications

We monitored summertime base flow water temperatures of hyporheic discharge to surface water in main, side, and spring channels located within the bank-full scour zone of the gravel- and cobble-bedded Umatilla River, Oregon, USA. Diel temperature cycles in hyporheic discharge were common, but spatially variable. Relative to the main channel’s diel cycle, hyporheic discharge locations typically had similar daily mean temperatures, but smaller diel ranges (compressed by 2 to 6°C) and desynchronized phases (offset by 0 to 6 h). In spring channels (which received only hyporheic discharge), surface water diel cycles were also compressed (by 2 to 6°C) and desynchronized …

Application Of A Routing Model For Detecting Channel Flow Changes With Minimal Data, Jozsef Szilagyi, Nicholas Pinter, Rob Venczel

School of Natural Resources: Faculty Publications

No abstract provided.

Comment On "Comparison Of 15 Evaporation Models Applied To A Small Mountain Lake In The Northeastern Usa", Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

Riparian Zone Evapotranspiration From Diurnal Groundwater-Level Fluctuations, Zoltan Gribovszki, Peter Kalicz, Jozsef Szilagyi, Mihaly Kucsara

School of Natural Resources: Faculty Publications

No abstract provided.

Evapotranspiration Calculation On The Basis Of The Riparian Zone Water Balance, Zoltan Gribovszki, Peter Kalicz, Mihaly Kucsara, Jozsef Szilagyi, Peter Vig

School of Natural Resources: Faculty Publications

No abstract provided.

Interpretation And Evaluation Of Combined Measurement Techniques For Soil Co2 Efflux: Discrete Surface Chambers And Continuous Soil Co2 Concentration Probes, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Howard E. Epstein, Daniel L. Welsch

School of Natural Resources: Faculty Publications

Soil CO₂ efflux is a large respiratory flux from terrestrial ecosystems and a critical component of the global carbon (C) cycle. Lack of process understanding of the spatiotemporal controls on soil CO₂ efflux limits our ability to extrapolate from fluxes measured at point scales to scales useful for corroboration with other ecosystem level measures of C exchange. Additional complications are introduced by the effects of soil water content seasonality and rainfall on the performance of measurement techniques. In this paper we present measurements of soil CO₂ efflux made at two contrasting sites within a characteristic subalpine forest …

Vertical Profile And Temporal Variation Of Chlorophyll In Maize Canopy: Quantitative “Crop Vigor” Indicator By Means Of Reflectance-Based Techniques, Verónica Ciganda, Anatoly A. Gitelson, James S. Schepers

School of Natural Resources: Faculty Publications

Chlorophyll (Chl) content is among the most important crop biophysical characteristics. Chlorophyll can be related to photosynthetic capacity, thus, productivity, developmental stage, and canopy stresses. The objective of this study was to quantify and characterize the temporal variation of Chl content in the vertical profile of maize (Zea mays L.) canopies by means of a reflectance-based, nondestructive methodology. A recently developed technique that relates leaf reflectance with leaf pigment content has been used for accurate leaf Chl estimation. The technique employs reflectance in two spectral bands: in the red edge (720-730 nm) and in the near infrared (770-800 nm). …

Application Of Spectral Remote Sensing For Agronomic Decisions, J. L. Hatfield, Anatoly A. Gitelson, James S. Schepers, C. L. Walthall

School of Natural Resources: Faculty Publications

Remote sensing has provided valuable insights into agronomic management over the past 40 yr. The contributions of individuals to remote sensing methods have lead to understanding of how leaf reflectance and leaf emittance changes in response to leaf thickness, species, canopy shape, leaf age, nutrient status, and water status. Leaf chlorophyll and the preferential absorption at different wavelengths provides the basis for utilizing reflectance with either broad-band radiometers typical of current satellite platforms or hyperspectral sensors that measure reflectance at narrow wavebands. Understanding of leaf reflectance has lead to various vegetative indices for crop canopies to quantify various agronomic parameters, …

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.

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 …

Mammals Of Nebraska: Checklist, Key, And Bibliography, Hugh H. Genoways, Justin D. Hoffman, Patricia Freeman, Kenneth N. Geluso, Russell A. Benedict, Jeffrey J Huebschman

University of Nebraska State Museum: Staff and Affiliates, Publications

The Recent mammalian fauna of Nebraska is composed of 89 native species, 8 domestic species that can have feral populations, and 4 wild species introduced by humans, but not by intentional action. Thus, the included checklist and dichotomous key contain 101 species of mammals. Of the native species, 36 are rodents, 20 carnivores, 13 bats, 7 shrews and mole, 7 even-toed ungulates, 4 rabbits and hares, 1 armadillo, and 1 opossum. Another 8 species are identified as potentially occurring in peripheral areas of Nebraska. The bibliography includes 1693 entries that each contain data concerning one or more species of mammals …

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 …

A Synthesis Of Live Fuel Moisture And Wildland Fire And Development Of A National Historical Live Fuel Moisture Database, William M. Jolly Dr.

Joint Fire Science Program Research Project Reports

Live fuels are a key component to the wildland fuel complex but little is know about their contribution to fire danger or fire behavior. This review attempts to quantify our current understanding of the role that live fuels play in combustion and how those characteristics are quantified into prediction systems that fire managers use to assess fire danger or fire behavior as well as how live fuel parameters for those systems are measured. We review how live fuels are incorporated into three fire danger and fire behavior prediction systems that have found widespread use throughout the world. We discuss the …

Behaveplus And Flammap Technology Transfer, Patricia Andrews, Mark Finney

Joint Fire Science Program Research Project Reports

This project was conducted in response to the need identified under Task 1 (RFP 2005-4)—extension of technology transfer activities beyond the conclusion of successfully completed JFSP funded projects or other applicable wildland fire research. Development of the BehavePlus fire modeling system and the FlamMap fire behavior analysis and mapping system and supporting technology transfer material was funded in part under JFSP project #98-1-8-02. After successful completion of that project, development of those systems and supporting material continued under other funding. FlamMap was used in JFSP project #01-1-3-21 “Cumulative effects of fuel management on landscape-scale fire behavior and effects.” A significant …

Bringing The Fire Effects Information System Up-To-Date And Improving Service To Land Managers, Jane Kapler Smith, Fire Modeling Institute Information Team

Joint Fire Science Program Research Project Reports

This project delivers up-to-date, science-based information about species nominated by wildland managers for revision in or addition to the Fire Effects Information System (FEIS). FEIS now provides 1,081 literature reviews covering 1,139 taxa. This JFSP task has supported the rewriting of 9% of FEIS reviews, addition of reviews that increase FEIS content by 9%, and small updates to 25% of the database. Each FEIS species review addresses the basic biology of the species, fire regimes, fire's role in the life history and persistence of the species, competition and successional patterns, and issues regarding fuel management, prescribed fire, and postfire rehabilitation. …

Burn Severity Mapping Using Simulation Modeling And Satellite Imagery, Robert E. Keane, Eva C. Karau, Elizabeth Reinhardt

Joint Fire Science Program Research Project Reports

As wildfires becomes an increasingly important issue affecting our nation’s landscapes, fire managers must quickly assess possible adverse fire effects to efficiently allocate resources for rehabilitation or remediation. While burn severity maps derived from satellite imagery can provide a landscape view of relative fire impacts, fire effects simulation models can also provide spatial fire severity estimates along with the biotic context in which to interpret severity. In this project, we evaluated two methods of mapping burn severity for four wildfires in western Montana using 64 plots as field reference: 1) an image-based burn severity mapping approach using the Differenced Normalized …

Carbon Cycling At The Landscape Scale: The Effect Of Changes In Climate And Fire Frequency On Age Distribution, Stand Structure, And Net Ecosystem Production., Michael G. Ryan, Daniel M. Kashian, Erica A.H. Smithwick, William H. Romme, Monica G. Turner, Daniel B. Tinker

Joint Fire Science Program Research Project Reports

Understanding the interactions between climate, fire and forest characteristics-- and how carbon dynamics are affected by these factors--remains an important challenge in ecology. As the size and severity of fires in the western US continues to increase (Westerling et al. 2006), it has become increasingly important to understand carbon dynamics in response to fire. In this study, we investigated these key interactions in the landscape of Yellowstone National Park (YNP). We asked how initial post-fire heterogeneity in forest structure (especially tree density and stand age) controls carbon dynamics over the full life cycle of individual forest stands, and how climate-mediated …

Delayed Tree Mortality Following Fire In Western Conifers, Sheri Smith, Danny Chuck, Elizabeht Reinhardt, Kevin Ryan, Charles Mchugh

Joint Fire Science Program Research Project Reports

We developed 3-year post-fire mortality models for 12 western conifer species by pooling data collected from multiple fire-injury studies. Models were developed for white fir, red fir, subalpine fir, incense cedar, western larch, lodgepole pine, whitebark pine, ponderosa pine, Jeffrey pine, sugar pine, Engelmann spruce, and Douglas-fir. Two sets of models were created, one for use in pre-fire planning where only crown injury and DBH were potential variables, and a second, optimal model for use in post-fire planning that used all significant variables. Predictive accuracy of all models was compared to the accuracy of the mortality model currently used in …