Physical Sciences and Mathematics Commons^™

Avian Influenza Virus Prevalence In Migratory Waterfowl In The Central Flyway, 2007–2009, Scott R. Groepper, Scott E. Hygnstrom, Mark P. Vrtiska, Thomas J. Deliberto

School of Natural Resources: Faculty Publications

Highly pathogenic avian influenza (HPAI H5N1) poses risks to wild birds, poultry, and humans. Personnel with the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, state game agencies, and tribal cooperators collected >36,000 migratory birds from 2007–2009 to test for HPAI virus. Species from the dabbling duck, diving duck, and geese and swans functional groups were collected in all 10 states of the Central Flyway. Numerous combinations of the 16 hemaglutinin (H) and 9 neuraminidase (N) subtypes were discovered, but no HPAI H5N1 was found. The dabbling duck functional group had significantly higher (p < 0.001) prevalence of AIV than other functional groups and should be the focus of future surveillance.

Utility Of Improvised Video-Camera Collars For Collecting Contact Data From White-Tailed Deer: Possibilities In Disease Transmission Studies, Michael J. Lavelle, Scott E. Hygnstrom, Aaron M. Hildreth, Tyler A. Campbell, David B. Long, David G. Hewitt, Jeff Beringer, K. C. Vercauteren

School of Natural Resources: Faculty Publications

Rapidly evolving electronic technology enables wildlife researchers to collect previously unobtainable data. To explore possibilities of using deer-borne cameras (DBCs) to collect behavioral data from an animal’s point of view, we constructed DBCs and deployed them on 26 adult male whitetailed deer (Odocoileus virginianus) within a closed population (405-ha fenced area) in southern Texas just prior to the breeding season during autumn 2010. Our DBCs consisted of global positioning system collars with attached motion-activated trail cameras. We obtained 21,474 video clips from 17 functional DBCs over a period of 14 days. Individual-based data are invaluable in disease and …

Mid-Contract Management Of Conservation Reserve Program Grasslands Provides Benefits For Ring-Necked Pheasant Nest And Brood Survival, Ty W. Matthews, J. Scott Taylor, Larkin A. Powell

School of Natural Resources: Faculty Publications

Conservation Reserve Program (CRP) fields may provide good habitat for nesting and brood-rearing ring-necked pheasants (Phasianus colchicus) during early stages of succession. But, the success of hens in early successional CRP, relative to late successional CRP and other grassland habitats, has yet to be evaluated. The reproductive period is especially critical for populations of pheasants, and CRP’s benefits to hens and chicks may decrease as fields age because of loss of vegetative diversity, decrease in vegetation density, and accumulation of residual litter. During 2005– 2006, we evaluated spatial and temporal variation in nest and brood survival for radio-marked hen pheasants …

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

School of Natural Resources: Faculty Publications

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 …

Rural Inhabitant Perceptions Of Sandhill Cranes In Wintering Areas Of Northern Mexico, Ingrid Barcelo, Juan Carlos Guzmán-Aranda, Felipe Chávez-Ramírez, Larkin A. Powell

School of Natural Resources: Faculty Publications

Trends in the mid-continent population of sandhill cranes (Grus canadensis) indicate that the species is increasing. A large proportion of this population winters in northern Mexico where possible conflicts between local inhabitants and cranes can occur. We conducted interviews of 40 rural inhabitants living near wetlands used by cranes in three Mexican states. All interviewees had knowledge of cranes and were capable of describing them. The arrival of cranes affected 43% of interviewees. The negative effects were mainly destroyed crops with a subsequent diminished production. Seventy percent of those affected implemented scare tactics to deter the birds, while others (15%) …

Spatial Heterogeneity Across Five Rangelands Managed With Pyric-Herbivory, Devan Allen Mcgranahan, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

1. Many rangelands evolved under an interactive disturbance regime in which grazers respond to the spatial pattern of fire and create a patchy, heterogeneous landscape. Spatially heterogeneous fire and grazing create heterogeneity in vegetation structure at the landscape level (patch contrast) and increase rangeland biodiversity. We analyzed five experiments comparing spatially heterogeneous fire treatments to spatially homogeneous fire treatments on grazed rangeland along a precipitation gradient in the North American Great Plains.

2. We predicted that, across the precipitation gradient, management for heterogeneity increases both patch contrast and variance in the composition of plant functional groups. Furthermore, we predicted that …

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

School of Natural Resources: Faculty Publications

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 …

Gross Primary Production And Ecosystem Respiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems Over 8 Years, Andrew E. Suyker, Shashi B. Verma

School of Natural Resources: Faculty Publications

The objective of this study is to examine interannual variability of carbon dioxide exchange and relevant controlling factors in irrigated and rainfed maize–soybean agroecosystems. The mean annual gross primary production (GPP) of irrigated and rainfed maize was 1796 ± 92 g C m⁻² y⁻¹ (±standard deviation) and 1536 ± 74 g C m⁻² y⁻¹, respectively. Mean annual GPP of soybean (average of irrigated and rainfed crops) was about 56% that of maize. Light use efficiency of maize and soybean during clear sky conditions were 1.96 ± 0.10 and 1.37 ± 0.06 g C MJ^{−1 …}

Interannual And Spatial Impacts Of Phenological Transitions, Growing Season Length, And Spring And Autumn Temperatures On Carbon Sequestration: A North America Flux Data Synthesis, Chaoyang Wu, Alemu Gonsamo, Jing Ming Chen, Werner A. Kurz, David T. Price, Peter M. Lafleur, Rachhpal S. Jassal, Danilo Dragoni, Gil Bohrer, Christopher M. Gough, Shashi B. Verma, Andrew E. Suyker, J. William Munger

School of Natural Resources: Faculty Publications

Understanding feedbacks of ecosystem carbon sequestration to climate change is an urgent step in developing future ecosystem models. Using 187 site-years of flux data observed at 24 sites covering three plant functional types (i.e. evergreen forests (EF), deciduous forests (DF) and non-forest ecosystems (NF) (e.g., crop, grassland, wetland)) in North America, we present an analysis of both interannual and spatial relationships between annual net ecosystem production (NEP) and phenological indicators, including the flux-based carbon uptake period (CUP) and its transitions, degree-day-derived growing season length (GSL), and spring and autumn temperatures. Diverse responses were acquired between annul NEP and these indicators …

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

School of Natural Resources: Faculty Publications

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 …

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

School of Natural Resources: Faculty Publications

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 …

Interpretation Of Hydrologic Trends From A Water Balance Perspective: The Role Of Groundwater Storage In The Budyko Hypothesis, Erkan Istanbulluoglu, Tiejun Wang, Olivia M. Wright, John D. Lenters

School of Natural Resources: Faculty Publications

We investigate the observed positive trends in annual runoff in several basins in central Nebraska using the Budyko hypothesis as a diagnostic tool. In basins where runoff is dominated by base flow we found that the estimated annual evapotranspiration (ET_a) to precipitation (P) ratio (ET_a/P) from data is negatively related to the aridity index (ET_p/P, where ET_p is potential annual evapotranspiration). This observation is inconsistent with the Budyko hypothesis. We hypothesized that the observed negative trend results from significant interannual changes in basin water storage. This hypothesis is tested using data from groundwater …

Is Pretenure Interdisciplinary Research A Career Risk?, E. V. Fischer, K. R. M. Mackey, D. F. Cusack, L. R. G. Desantis, L. Hartzell-Nichols, J. A. Lutz, J. Melbourne-Thomas, R. Meyer, Diego Andrés Riveros-Iregui, C. J. B. Sorte, J. R. Taylor, S. A. White

School of Natural Resources: Faculty Publications

Despite initiatives to promote interdisciplinary research, early-career academics continue to perceive professional risks to working at the interface between traditional disciplines. Unexpectedly, the inherent practical challenges of interdisciplinary scholarship, such as new methodologies and lexicons, are not the chief source of the perceived risk. The perception of risk is pervasive across disciplines, and it persists despite efforts to support career development for individuals with common interests [Mitchell and Weiler, 2011]. Suggestions that interdisciplinary work can go unrewarded in academia [Clark et al., 2011] foster a concern that targeting interdisciplinary questions, such as those presented by climate change, will pose problems …

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

School of Natural Resources: Faculty Publications

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 …

Establishing Winter Origins Of Migrating Lesser Snow Geese Using Stable Isotopes, Viviane Hénaux, Larkin A. Powell, Mark P. Vrtiska, Keith A. Hobson

School of Natural Resources: Faculty Publications

Increases in Snow Goose (Chen caerulescens) populations and large-scale habitat changes in North America have contributed to the concentration of migratory waterfowl on fewer wetlands, reducing resource availability, and enhancing risks of disease transmission. Predicting wintering locations of migratory individuals is critical to guide wildlife population management and habitat restoration. We used stable carbon (δ¹³C), nitrogen (δ ¹⁵N), and hydrogen (δ²H) isotope ratios in muscle tissue of wintering Snow Geese to discriminate four major wintering areas, the Playa Lake Region, Texas Gulf Coast, Louisiana Gulf Coast, and Arkansas, and infer the wintering locations …

Seasonal Variation In Heat Fluxes, Predicted Emissions Of Malodorants, And Wastewater Quality Of An Anaerobic Swine Waste Lagoon, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

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

School of Natural Resources: Faculty Publications

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

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

School of Natural Resources: Faculty Publications

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

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

School of Natural Resources: Faculty Publications

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

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

School of Natural Resources: Faculty Publications

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