Physical Sciences and Mathematics Commons^™

Test Of An Extended Mathematical Approach To Calculate Maize Leaf Area Index And Leaf Angle Distribution, Elizabeth A. Walter-Shea, Mark A. Mesarch

School of Natural Resources: Faculty Publications

No abstract provided.

Evaluation Of An Algorithm For Predicting Albedo In Heliotropic Crops, Elizabeth A. Walter-Shea, A. Weiss

School of Natural Resources: Faculty Publications

No abstract provided.

Value Of Incorporating Satellite-Derived Land Cover Data In Mm5/Place For Simulating Surface Temperatures, Todd M. Crawford, David J. Stensrud, Franz Mora, James W. Merchant, Peter J. Wetzel

School of Natural Resources: Faculty Publications

The Parameterization for Land–Atmosphere–Cloud Exchange (PLACE) module is used within the Fifth- Generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) to determine the importance of individual land surface parameters in simulating surface temperatures. Sensitivity tests indicate that soil moisture and the coverage and thickness of green vegetation [as manifested by the values of fractional green vegetation coverage (fVEG) and leaf area index (LAI)] have a large effect on the magnitudes of surface sensible heat fluxes. The combined influence of LAI and fVEG is larger than the influence of soil moisture on the partitioning of the surface energy …

Some Perspectives On Recent In Situ Air Temperature Observations: Modeling The Microclimate Inside The Radiation Shields*, X. Lin, Kenneth Hubbard, Elizabeth A. Walter-Shea, James Brandle, G.E. Meyer

School of Natural Resources: Faculty Publications

Air temperature measurement has inherent biases associated with the particular radiation shield and sensor deployed. The replacement of the Cotton Region Shelter (CRS) with the Maximum–Minimum Temperature System (MMTS) and the introduction of Automated Surface Observing System (ASOS) air temperature observing systems during the NWS modernization introduced bias shifts in federal networks that required quantification. In rapidly developing nonfederal networks, the Gill shield temperature systems are widely used. All of these systems house an air temperature sensor in a radiation shield to prevent radiation loading on the sensors; a side effect is that the air temperature entering a shield is …

Impacts Of Predation On Northern Bobwhite And Scaled Quail, Dale Rollins, John P. Carroll

School of Natural Resources: Faculty Publications

Northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) populations have declined throughout most of their distribution, and these declines have become more dramatic in recent years. In this review, we examine the role of predation in quail management. Predation is the major source of nest loss and of mortality for young and adult quail. Mean nest success across studies reviewed was 28%. Estimates of annual survival rates have varied from 5 to 26% for radiotelemetry studies and from 15 to 30% based on age-ratio studies. Breeding season survival estimates ranged from 13 to 51% in telemetry …

Bollgard Cotton: An Assessment Of Global Economic, Environmental, And Social Benefits, Julie M. Edge, John H. Benedict, John P. Carroll, H. Keith Reding

School of Natural Resources: Faculty Publications

Insect-protected crops like Bollgard (Monsanto Company, St. Louis) Bacillus thuringiensis (Bt) cotton are bringing cotton growers new alternatives to broad-spectrum insecticide use in integrated pest management. After five years (1996-2000) of commercial use, a number of benefits of Bt cotton technology to growers, the environment, and society at large have been reported; however, the benefits of the technology have not been examined to date from a holistic point of view. Accordingly, the objectives of this paper were to examine the potential economic, environmental, and social benefits of Bt cotton compared with broad-spectrum insecticide use, as reported in current literature, …

Field-Scale Remediation Of A Metolachlor-Contaminated Spill Site Using Zerovalent Iron, Steven Comfort, Patrick J. Shea, Thomas A. Machacek, H. Gaber, B.-T. Oh

School of Natural Resources: Faculty Publications

Pesticide spills are common occurrences at agricultural cooperatives and farmsteads. When inadvertent spills occur, chemicals normally beneficial can become point sources of ground and surface water contamination. We report results from a field trial where approximately 765 m³ of soil from a metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] spill site was treated with zerovalent iron (Fe⁰). Preliminary laboratory experiments confirmed metolachlor dechlorination by Fe⁰ in aqueous solution and that this process could be accelerated by adding appropriate proportions of Al₂(SO₄)₃ or acetic acid (CH₃COOH). The field project was …

Monthly Fractional Green Vegetation Cover Associated With Land Cover Classes Of The Conterminous Usa, Kevin P. Gallo, Dan Tarpley, Ken Mitchell, Ivan Csiszar, Timothy Owen, Brad Reed

School of Natural Resources: Faculty Publications

The land cover classes developed under the coordination of the International Geosphere-Biosphere Programme Data and Information System (IGBP-DIS) have been analyzed for a study area that includes the Conterminous United States and portions of Mexico and Canada

Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie

School of Natural Resources: Faculty Publications

In order to determine the prevalence and distribution of the human pathogen, Escherichia coli O157:H7, in free-ranging deer, hunters were asked to collect and submit fecal samples from deer harvested during a regular firearm season (14–22 November 1998). Prior to the season, 47% of the hunters with permits in the southeastern Nebraska (USA) study area indicated a willingness to participate in the study. Approximately 25% of successful hunters in the area submitted deer fecal samples. Escherichia coli O157:H7 was cultured from four (0.25%) of 1,608 total samples submitted. All of the fecal samples that were properly identified (1,426) and all …

Non-Destructive And Remote Sensing Techniques For Estimation Of Vegetation Status, Anatoly A. Gitelson, M. N. Merzlyak, Y. Zur, R. Stark, U. Gritz

School of Natural Resources: Faculty Publications

The goal of this work is to develop non-destructive techniques that can conveniently, rapidly and accurately assess crop physiological status and objectively evaluate plant responses to environmental factors, both natural and anthropogenic. High spectral resolution reflectance and absorption spectra of different and unrelated plant species were analyzed to determine spectral variability and information content in the visible and near-infrared spectrum at leaf and canopy levels. Techniques were developed to quantitatively retrieve chlorophyll, carotenoid and anthocyanin content from reflectance in a wide range of pigment content and composition.

Techniques for vegetation fraction retrieval those based on channels in visible range of …

Remote Estimation Of Vegetation Fraction In Corn Canopies, D. Rundquist, Anatoly A. Gitelson, D. Derry, J. Ramirez, R. Stark, Galina P. Keydan

School of Natural Resources: Faculty Publications

The aim of the paper was to test two new techniques that make use of channels in the visible range of the spectrum only to estimate vegetation fraction in corn canopies. High spectral resolution radiometers were employed to measure spectral reflectance, and the information content of spectra was investigated. Radiances in spectral channels of MODIS and MERIS were used to calculate Visible Atmospherically Resistant Indices, VARI_green=(R_green- R_red)/(R_green+R_red-R_blue) and VARI₇₀₀=(R₇₀₀-1.7*R_red+0.7*R_blue)/(R₇₀₀+2.3*R_red-1.3*R_blue). The indices allowed for estimation …

Geochemical Evolution Of Ground Water In The Great Plains (Dakota) Aquifer Of Nebraska: Implications For The Management Of A Regional Aquifer System, David C. Gosselin, F. Edwin Harvey, Carol D. Frost

School of Natural Resources: Faculty Publications

The Great Plains (Dakota) aquifer system is one of the most extensive in North America, extending from the Arctic Circle to New Mexico, and underlies approximately 94% of Nebraska. In Nebraska, we do not have the physical ground water monitoring data at the scale that is necessary to manage ground water flow systems. However, first-order management strategies for this regional aquifer can be developed by understanding the geochemical evolution of the ground water. Using major-ion water chemistry data from 203 wells in 19 counties in eastern Nebraska, reconnaissance δ¹⁸O, δD, and δ⁸⁷Sr data, and two geochemical …

Estimating Abundance Of Galliformes: Tools And Application, Michael J. Conroy, John P. Carroll

School of Natural Resources: Faculty Publications

A large number of techniques are available for assessing populations of vertebrates. However, application of many of those techniques to Galliformes is hampered by a variety of constraints. These problems are often magnified by poor understanding of the biology of many species of concern, and an absence of valid estimates of abundance and demographic parameters. Researchers interested in developing estimates of Galliformes populations must address a number of key issues before collecting field data, to avoid biases in the resulting population estimates. General guidance exists for the identification of appropriate population estimation techniques, and a dichotomous key has been developed …

Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Garry D. Wilson

School of Natural Resources: Faculty Publications

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the …

The Effectiveness Of The Asos, Mmts, Gill, And Crs Air Temperature Radiation Shields*, K. G. Hubbard, X. Lin, E.A. Walter-Shea

School of Natural Resources: Faculty Publications

Periodic upgrades of air temperature measurement systems in surface weather station networks cause data discontinuities. From a climatological viewpoint, it is necessary to evaluate the air temperature data discontinuities when air temperature radiation shields are upgraded. This study was undertaken to investigate the effectiveness of four common air temperature radiation shields including the Automated Surface Observing System (ASOS), the Maximum–Minimum Temperature System (MMTS), the Gill, and the Cotton Region Shelter (CRS) shields. The solar radiation shielding effectiveness for each shield under typical grass ground surface and different artificial surfaces (black, white, and aluminum) were investigated. The shield effectiveness was evaluated …

Correlations Between Burrowing Owl And Black-Tailed Prairie Dog Declines: A 7-Year Analysis, Martha J. Desmond, Julie A. Savidge, Kent M. Eskridge

School of Natural Resources: Faculty Publications

Concern over the status of species associated with prairie dog colonies has increased with the recent proposed listing of black-tailed prairie dogs (Cynomys ludovicianus). We monitored burrowing owl (Athene cunicularia) populations and prairie dog densities in 17 black-tailed prairie dog colonies in the Nebraska panhandle between 1990 and 1996. All prairie dog colonies were controlled at least once during the study. We observed a 63% decline in nesting pairs of burrowing owls and significant declines in burrow densities. Results indicated a time lag in owl response to changes in active burrow densities. However, in the later …

A Flexible K-12 Weather Data Collection And Education Program, Mark A. Mesarch, S. J. Meyer, David C. Gosselin

School of Natural Resources: Faculty Publications

The Nebraska Earth Science Education Network (NESEN) is an organization within the University of Nebraska-Lincoln whose objectives are to: 1) promote and enhance K-12 earth science education in Nebraska, 2) improve teacher knowledge and understanding so that students become better informed about the complexities of environmental and natural resources issues and 3) enhance the transfer of earth science information to the K-12 teaching community (Gosselin, Mohlman, Mesarch & Meyer, 1996; Gosselin et al., 1999). To achieve this last objective NESEN developed the Students and Teachers Exchanging Data, Information and Ideas (STEDII) program with the help of support from the National …

Evaluation And Assessment Of Agrichemical Contaminants In The Creighton, Ne Area, Mark E. Burbach, Roy F. Spalding

School of Natural Resources: Faculty Publications

The Lewis and Clark Natural Resources District (LCNRD) has reported elevated nitrate- nitrogen (NO3-N) concentrations in ground water near Creighton, NE. The U.S. Environmental Protection Agency has set a maximum contaminant level (MCL) of 10 mg/L for NO3-N in public water supplies. NO3-N in the city of Creighton municipal drinking water wells and several rural domestic and irrigation wells have exceeded the MCL. The city of Creighton has constructed a reverse-osmosis water treatment system at a cost of $1.1 million to reduce the NO3-N concentration below the MCL in its water supply. In response to this NO3-N contamination problem the …

The Eos Prototype Validation Exercise (Prove) At Jornada: Overview And Lessons Learned, J. L. Privette, G. P. Asner, J. Conel, K. F. Huemmrich, R. Olson, A. Rango, A. F. Rahman, K. Thome, Elizabeth A. Walter-Shea

School of Natural Resources: Faculty Publications

The Earth Observing System (EOS) instrument teams must validate the operational products they produce from the Terra spacecraft data. As a pilot for future validation activities, four EOS teams (MODIS, MISR, ASTER, and Landsat-7) and community experts conducted an 11-day field campaign in May 1997 near Las Cruces, NM. The goals of the Prototype Validation Exercise (PROVE) included (1) gaining experience in the collection and use of field data for EOS product validation; (2) developing coordination, measurement, and data-archiving protocols; and (3) compiling a synoptic land and atmospheric data set for testing algorithms. PROVE was held at the USDA-Agricultural Research …

Airflow Characteristics Of Commonly Used Temperature Radiation Shields*, X. Lin, Kenneth G. Hubbard, George E. Meyer

School of Natural Resources: Faculty Publications

The air temperature radiation shield is a key component in air temperature measurement in weather station networks; however, it is widely recognized that significant errors in the measured air temperature exist due to insufficient airflow past the air temperature sensor housed inside the shield. During the last several decades, the U.S. National Weather Service has employed a number of different shields in air temperature measurements. This paper focuses on the airflow characteristics inside air temperature shields including the Maximum–Minimum Temperature System (MMTS), the Gill shields, and the Cotton Region Shelter (CRS).

Average airspeed profiles and airflow efficiency inside the shields …

Extralimital Records Of The Mexican Free-Tailed Bat (Tadarida Brasilensis Mexicana) In The Central United States And Their Biological Significance, Hugh H. Genoways, Patricia W. Freeman, Cary Grell

School of Natural Resources: Faculty Publications

Two new records of Tadarida brasiliensis mexicana are reported from Nebraska. The literature records of this taxon from the central United States are summarized. In this region of North America, these bats occupy a “natal range” where the species carries on regular reproductive activities and the populations are relatively stable, including California, Arizona, New Mexico, Texas, and Oklahoma. To the north of the natal range of T. b. mexicana is a “pioneering zone” where, under favorable conditions, the species is capable of reproducing and conducting its normal activities. The pioneering zone of the Mexican free-tailed bat includes Barber and Comanche …

Shifting Distributional Patterns Of Mammals In Nebraska, Russell A. Benedict, Hugh H. Genoways, Patricia W. Freeman

School of Natural Resources: Faculty Publications

New distributional records are presented for 20 species of mammals in Nebraska. The majority of these records appear to represent changes in geographic distribution rather than just better sampling in poorly known areas. One group of mammals, including the opossum, northern myotis, evening bat, red bat, woodchuck, white-footed mouse, and gray fox, is expanding westward, probably in response to increasing woodlands along river systems. Another group, including the meadow vole, masked shrew, and least weasel, is expanding southward, possibly in response to new prey species and changing microclimates. The eastern woodrat appears to be expanding northward in eastern Nebraska. The …

The Eos Prototype Validation Exercise (Prove) At Jornada: Overview And Lessons Learned, J. L. Privette, G. P. Asner, J. Conel, K. R. Huemmrich, R. Olson, A. Rango, A. F. Rahman, K. Thome, Elizabeth A. Walter-Shea

School of Natural Resources: Faculty Publications

The Earth Observing System (EOS) instrument teams must validate the operational products they produce from the Terra spacecraft data. As a pilot for future validation activities, four EOS teams (MODIS, MISR, ASTER, and Landsat-7) and community experts conducted an 11-day field campaign in May 1997 near Las Cruces, NM. The goals of the Prototype Validation Exercise (PROVE) included (1) gaining experience in the collection and use of field data for EOS product validation; (2) developing coordination, measurement, and data-archiving protocols; and (3) compiling a synoptic land and atmospheric data set for testing algorithms. PROVE was held at the USDA-Agricultural Research …

Forestry's Role In Sustainable Agriculture, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Determination Of Drag Properties Of A Shelterbelt From Measurements And A Numerical Model, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Pressure Perturbations Around Shelterbelts: Measurements And Model Results, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks An Old System With A New Look, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks: Are They Effective?, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Silvopastoral Systems In The Pine Ridge Of Nebraska, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreak Practices, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.