Natural Resources Management and Policy Commons^™

Filter Strip Performance And Processes For Different Vegetation, Widths, And Contaminants, T. J. Schmitt, M. G. Dosskey, K. D. Hoagland

School of Natural Resources: Faculty Publications

Filter strips are widely prescribed to reduce contaminants in surface runoff from agricultural fields. Tbis study compared performance of different filter strip designs on several contaminants and evaluated the contribnting processes. Different vegetation types and widths were investigated using simulated runoff event on large plots (3 m X 7.5 or 15 m) having fine-textured soil and a 6 to 7% slope. Filter strips 7.5 and 15 m wide downslope greatly reduced concentrations of sediment in runoff (76-93%) and contaminants strongly associated with sediment (total P, 55-79%; permethrin, 27-83% [(3-phenoxyphenyl) methyl (±)-cis, trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylate ]). They had less effect on concentrations …

An Objective Method For Determining Principal Time Scales Of Coherent Eddy Structures Using Orthonormal Wavelets, Jozsef Szilagyi, Marc B. Parlange, Gabriel G. Katul, John D. Albertson

School of Natural Resources: Faculty Publications

No abstract provided.

Streamflow Depletion Investigations In The Republican River Basin: Colorado, Nebraska, And Kansas, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

A Revised Measurement Methodology For Conifer Needles Spectral Optical Properties: Evaluating The Influence Of Gaps Between Elements, Mark A. Mesarch, Elizabeth Walter-Shea, Gregory P. Asner, Elizabeth M. Middleton, Stephen Chan

School of Natural Resources: Faculty Publications

Gaps are unavoidable when compositing small or narrow plant parts (e.g., conifer needles, twigs, narrow leaves, and leaflets) on sample holders in preparation for measuring spectral optical properties. The Daughtry et al. (1989) (A new technique to measure the spectral properties of conifer needles. Remote Sens. Environ. 27:81-91.) method of measuring conifer needle optical properties utilizes a relatively large gap fraction (approximately 0.3-0.6) and needles painted black on one surface of the sample from which the gap fraction of the sample is indirectly determined. Following this protocol typically results in distortions in optical properties, including underestimates in transmittance (sometimes negative …

The Relative Importance Of Patch Area And Perimeter–Area Ratio To Grassland Breeding Birds, Christopher J. Helzer, Dennis E. Jelinski

School of Natural Resources: Faculty Publications

Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of …

The Nebraska Earth Science Education Network Electronic Communication Project, D. C. Gosselin, R. Feurer, S. Frack, A. Musson, L. Mayo, C. Karel, E. Schaefer, C. Snyder, J. Sarchett, M. L. Alfieri

School of Natural Resources: Faculty Publications

No abstract provided.

A Geomorphology-Based Semi-Distributed Watershed Model, J. Szilagyi, M. B. Parlange

School of Natural Resources: Faculty Publications

No abstract provided.

Relationship Between Ecosystem Productivity And Photosynthetically Active Radiation For Northern Peatlands, S. E. Frolkin, J.L. Bubier, T.R. Moore, T. Ball, L.M. Bellisario, A. Bhardwaj, P. Carroll, P.M. Crill, Peter M. Lafleur, J.H. Mccaughey, N.T. Roulet, A. E. Suyker, S.B. Verma, J.M. Waddington, G.J. Whiting

School of Natural Resources: Faculty Publications

We analyzed the relationship between new ecosystem exchange of carbon dioxide (NEE) and irradiance (as photosynthetic photon flux density of PPFD), using published and unpublished data that have been collected during midgrowing season for carbon balance studies at seven peatlands in North America and Europe. NEE measurements included both eddy-correlation tower and clear, static chamber methods, which gave very similar results. Data were analyzed by site, as aggregated data set for all peatland type (bog, poor fen, rich fen, and all fens) and as a single aggregated data set for all peatlands. In all cases, a fit with a rectangular …

Air Temperature Variations And Rice Productivity In Bangladesh: A Comparative Study Of The Performance Of The Yield And The Ceres-Rice Models, Rezaul Mahmood

School of Natural Resources: Faculty Publications

Potential increase in air temperature due to climatic change and inter-annual climatic variability and its impacts on crop productivity is of major concern to crop scientists. A number of physically-based models have been developed and applied to estimate crop–environment relationships. In the present study the performance of two such models (the YIELD and the CERES-Rice) are discussed. These two models are used to estimate boro rice productivity under normal and abnormal climate scenarios in Bangladesh. This study finds that boro rice productivity at Mymensingh predicted by the YIELD is higher than the prediction by the CERES-Rice. Productivity estimates for Barisal …

Climatology Of The Daily Temperature Range Annual Cycle In The United States, Daniel J. Leathers, Michael A. Palecki, David A. Robinson, Kenneth F. Dewey

School of Natural Resources: Faculty Publications

Many researchers are presently interested in detecting long-term trends in annual or seasonal daily temperature range (DTR), and attributing these changes to anthropogenic origins. However, very little work has been done to confirm the mechanisms that are important to determining the long-term average annual cycle of the DTR. Therefore, the focus of this work is to examine the spatial and temporal difference in the DTR average annual cycle across the United States, and to associate the patterns of these cycles with potential causal variables. Three major types of DTR annual cycle exist in the United States: high sun season maximum …

Optical Properties Of Canopy Elements In Black Spruce, Jack Pine And Aspen Stands In Saskatchewan, Canada, Elizabeth A. Walter-Shea, Mark A. Mesarch

School of Natural Resources: Faculty Publications

No abstract provided.

Unique Frontal Sinuses In Fossil And Living Hyaenidae (Mammalia, Carnivora): Description And Interpretation, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.

Impacts Of Air Temperature Variations On The Boro Rice Phenology In Bangladesh: Implications For Irrigation Requirements, Rezaul Mahmood

School of Natural Resources: Faculty Publications

Air temperature significantly affects crop phenology. Numerous experiments have shown that prevailing air temperature determines the length of crop growth stages. Irrigation field requirements depend on the length of the crop growth stages. In the present study, a physically based parametric model, YIELD, has been applied to estimate the impacts of fluctuating air temperature (due to inter-annual climatic variability and global warming) on evapotranspiration water requirements and the length of growth stages of the irrigated boro rice in Bangladesh. The YIELD model is crop specific and crop-growth-stage specific which is a compromise between area-specific regression models and complex crop growth …

Spectral Information Content Of The Boreal Forest, Elizabeth A. Walter-Shea

School of Natural Resources: Faculty Publications

No abstract provided.

Internal Anatomy Of The Snout And Paranasal Sinuses Of Hyaenodon (Mammalia, Creodonta), R. M. Joeckel, H.W. Bond, G.W. Kabalka

School of Natural Resources: Faculty Publications

No abstract provided.

Water-Balance Modeling In A Changing Environment: Reductions In Unconfined Aquifer Levels In The Area Between The Danube And Tisza Rivers In Hungary, Jozsef Szilagyi, Charles Vorosmarty

School of Natural Resources: Faculty Publications

No abstract provided.

Ecological Water Treatment System For Removal Of Phosphorus And Nitrogen From Polluted Water, Ray W. Drenner, Donald J. Day, Stacy J. Basham, J. Durward Smith, Susan I. Jensen

School of Natural Resources: Faculty Publications

We propose that phosphorus and nitrogen can be removed from polluted water using an ecological water treatment system consisting of periphyton and fish. In the proposed system, polluted water flows through a series of vessels, and the nutrients are taken up by periphyton growing on porous screens. Algal-grazing fish feed on the periphyton and either assimilate or egest the nutrients in mucus-bound feces that settle from the water into a sediment trap. Both the fish and their feces can be harvested as nutrient sinks. In this study we examined the effects of an algal-grazing cichlid (Tilapia mossambica) and …

Domestic Well Water Quality In Rural Nebraska: Focus On Nitrate-Nitrogen, Pesticides And Coliform Bacteria, D. C. Gosselin, J. Headrick, R. Tremblay, X. H. Chen, S. E. Summerside

School of Natural Resources: Faculty Publications

No abstract provided.

Improving The Validation Of Model-Simulated Crop Yield Response To Climate Change: An Application To The Epic Model* Jour. Ser. No. 11339 Nebraska Ag. Res. Div., William E. Easterling, Xiafen Chen, Cynthia Hays, James R, Brandle, Hehui Zang

School of Natural Resources: Faculty Publications

Crop models have been used extensively to simulate yield response to various scenarios of climate change. Such simulations have been inadequately validated, limiting their utility in policy analysis. In this research, it is argued that the performance of crop models during recent years of extreme weather conditions relative to current normals may give a better indication of the validity of model simulations of crop yields in response to climate change than performance during the full range of climate conditions (as is done now). Twenty years of the climate record (1971-1990) are separated into different growing season temperature and precipitation classes …

Surface Exchange Of Water Vapour Between An Open Sphagnum Fen And The Atmosphere, S. B. Verma

School of Natural Resources: Faculty Publications

No abstract provided.

Conifer Shoot Bidirectional Scattering: Methodology And Preliminary Results, E.A. Walter-Shea, M.A. Mesarch

School of Natural Resources: Faculty Publications

No abstract provided.

The Local Effect Of Intermittency On The Inertial Subrange Energy Spectrum Of The Atmospheric Surface Layer, Jozsef Szilagyi, Gabriel G. Katul, Marc B. Parlange, John D. Albertson, Anthony T. Cahill

School of Natural Resources: Faculty Publications

No abstract provided.

Scale Issues In Soil Moisture Modelling: Problems And Prospects, Rezaul Mahmood

School of Natural Resources: Faculty Publications

Soil moisture storage is an important component of the hydrological cycle and plays a key role in land-surface-atmosphere interaction. The soil-moisture storage equation in this study considers precipitation as an input and soil moisture as a residual term for runoff and evapotranspiration. A number of models have been developed to estimate soil moisture storage and the components of the soil-moisture storage equation. A detailed discussion of the implication of the scale of application of these models reports that it is not possible to extrapolate processes and their estimates from the small to the large scale. It is also noted that …

A Model To Evaluate Windbreak Protection Efficiency, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

The Economic Impact Of Field Shelterbelts In The Northern Great Plains, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Toward An Integrated Regional Research Program On Global Change And The Nation's Major Grasslands: Second Annual Report, Great Plains Regional Center-Nigec

School of Natural Resources: Faculty Publications

I DIRECTOR'S REPORT:

A GPRC Research Framework and Thrusts

B FY94 GPRC Grant Competition

C Synopsis of Current Projects 1 Thrust 1: Impacts of Climate Change 2 Thrust 2: Measuring and Modeling Net Carbon Exchange 3 Other Projects

D Summary and Recommendations of FY94 GPRC PI's Workshop 1 Biogeochemical Cycling Group 2 Climate Scenarios Group 3 Managed and Unmanaged Ecosystem Impacts Group 4 Scaling Group 5 Actions Prompted by the Workshop

E Research Integration with ARM-CART: Eco-ARM

F Future Directions for the GPRC

Appendix I-A: Biogeochemical Cycling Group Workshop Report • Appendix I-B: Climate Change Scenarios Group Workshop Report • …

Tectonic And Paleoclimatic Significance Of A Locally Prominent Upper Pennsylvanian (Virgilian/Stephanian) Weathering Profile, Iowa And Nebraska, U.S.A, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.

Paleosols Below The Ames Marine Unit (Upper Pennsylvanian, Virgilian, Conemaugh Group) In The Appalachian Basin, U.S.A.: Variability On An Ancient Depositional Landscape., R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.

Seasonal Land-Cover Regions Of The United States, Thomas R. Loveland, James W. Merchant, Jesslyn F. Brown, Donald O. Ohlen, Bradley C. Reed, Paul Olson, John Hutchinson

School of Natural Resources: Faculty Publications

Research on global change has been hindered by deficiencies in the availability Wand quality of land-cover data (Mather and Sdasyuk 1991; Townshend 1992). To address this deficiency, the U.S. Geological Survey (USGS) and the University of Nebraska- Lincoln have collaborated in developing a method of land-cover characterization that is suitable for research on global change and on regional patterns of land cover (Loveland et al. 1991; Brown et al. 1993). This methodology is based upon statistical analysis of multidate, meteorological satellite imagery acquired by the National Oceanic and Atmospheric Administration's (NOAA) Advanced Very High Reso- lution Radiometer (AVHRR) sensor complemented …

Effects Of Bromide And Iodide On Stalk Secretion In The Biofouling Diatom Achnanthes Longipes (Bacillariophyceae), Kyle D. Hoagland, Lisa M. Johnson, Michael R. Gretz

School of Natural Resources: Faculty Publications

No abstract provided.