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Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1996

University of Nebraska - Lincoln

School of Natural Resources: Faculty Publications

Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Prairie Legacies - Mammals, Russell A. Benedict, Patricia W. Freeman, Hugh H. Genoways Nov 1996

Prairie Legacies - Mammals, Russell A. Benedict, Patricia W. Freeman, Hugh H. Genoways

School of Natural Resources: Faculty Publications

Few North American ecosystems have been as dramatically altered by humans as the prairies of the Great Plains. Occupying the immense interior of North America, these deceiving grassland oceans hid their complexity and diversity from many early travelers who saw this area merely as an obstacle to overcome in their westward journeys. But for the careful observer, prairies hold a tremendous quantity of life, arranged in a diverse mosaic of patches ranging in scale from minute anthills to the vastness of the Nebraska Sandhills or Kansas Flint Hills. Not only is a given ridgetop subdivided into a number of areas …

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Reproductive Success Of Grasshopper Sparrows In Relation To Edge, Jennifer M. Delisle, Julie A. Savidge Sep 1996

Reproductive Success Of Grasshopper Sparrows In Relation To Edge, Jennifer M. Delisle, Julie A. Savidge

School of Natural Resources: Faculty Publications

Using an index based on observations of breeding behaviors, we estimated reproductive success of 31 territorial grasshopper sparrows (Ammodramus savannarum) on Conservation Reserve Program fields in southeast Nebraska. Reproductive success was 52%, and no difference was detected between birds holding interior (>100 m from the edge) vs. edge territories. However, grasshopper sparrows appeared to avoid nesting within 50 m of edge habitats. Territories ranged from 0.36-1.24 ha, and territory size did not differ between successful and unsuccessful males.

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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 Jun 1996

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 …

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Surface Exchange Of Water Vapour Between An Open Sphagnum Fen And The Atmosphere, S. B. Verma Jan 1996

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.

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Conifer Shoot Bidirectional Scattering: Methodology And Preliminary Results, E.A. Walter-Shea, M.A. Mesarch Jan 1996

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

School of Natural Resources: Faculty Publications

No abstract provided.

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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 Jan 1996

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.

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The Influence Of Land Use/Land Cover On Climatological Values Of The Diurnal Temperature Range, Kevin P. Gallo, David R. Easterling, Thomas C. Peterson Jan 1996

The Influence Of Land Use/Land Cover On Climatological Values Of The Diurnal Temperature Range, Kevin P. Gallo, David R. Easterling, Thomas C. Peterson

School of Natural Resources: Faculty Publications

The diurnal temperature range (DTR) at weather observation stations that make up the U.S. Historical Climatology Network was evaluated with respect to the predominant land use/land cover associated with the stations within three radii intervals (100, 1000, and 10 000 m) of the stations. Those stations that were associated with predominantly rural land use/land cover (LULC) usually displayed the greatest observed DTR, whereas those associated with urban related land use or land cover displayed the least observed DTR. The results of this study suggest that significant differences in the climatological DTR were observed and could be attributed to the predominant …

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Estimation Of Seasonal Dynamics Of Pasture And Crop Productivity In Kazakhstan Using Noaa/Avhrr Data, Anatoly A. Gitelson, Felix Kogan, Lev Spivak, Edige Zakarin, Lubov Lebed Jan 1996

Estimation Of Seasonal Dynamics Of Pasture And Crop Productivity In Kazakhstan Using Noaa/Avhrr Data, Anatoly A. Gitelson, Felix Kogan, Lev Spivak, Edige Zakarin, Lubov Lebed

School of Natural Resources: Faculty Publications

Recently, NOAA developed the AVHRR-based Vegetation Condition Index (VCI) for drought monitoring. This index was used for estimating pasture and crop productivity in Kazakhstan. The results of VCI-derived vegetation conditions were compared with vegetation density, biomass and reflectance measured in different climatic and ecological zones with elevation from 200 to 700 m and a large range of the NDVI variation (over space and season) from 0.05 to 0.47. An estimation error of AVHRR-derived vegetation density was less than 16 per cent. First time it was shown that the VCI-derived vegetation condition data can be effectively used for quantitative assessments of …

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Novel Algorithms For Remote Sensing Of Chlorophyll Content In Higher Plant Leaves, Anatoly A. Gitelson, Mark N. Merzlyak, Yuri Grits Jan 1996

Novel Algorithms For Remote Sensing Of Chlorophyll Content In Higher Plant Leaves, Anatoly A. Gitelson, Mark N. Merzlyak, Yuri Grits

School of Natural Resources: Faculty Publications

The general features of reflectance spectra of higher plant leaves are considered with special reference to remote sensing of chlorophyll. Wavelengths with maximum sensitivity to chlorophyll content were found in the wide spectral range from 550 to 630 nm and near 700 nm. The wavelength of the red edge position of the reflectance spectrum correlated very closely with the reflectance at 550 and 700 nm. The ratios of reflectances in the near infra-red range of the spectrum (above 750 nm) to that at 700 nm RNIR/R700 and RNIR/R550 were directly proportional to the leaves' …

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Windbreak Management, Craig Stange Jan 1996

Windbreak Management, Craig Stange

School of Natural Resources: Faculty Publications

The windbreaks on your farm are an important part of the agricultural landscape. They provide protection for the farmstead, livestock, and crops; provide habitat for wildlife; and contribute to an overall healthy environment for you and your family. They are living systems with youth, maturity, and old age. Like any other living thing they need proper care and management in order to continue to function at their best.

Windbreak management requires an understanding of how your windbreak works. Your goal is to maintain the health and vigor of individual trees and shrubs while maintaining the overall structure of the windbreak …

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Windbreaks For Snow Management, James R. Brandle, H. Doak Nickerson Jan 1996

Windbreaks For Snow Management, James R. Brandle, H. Doak Nickerson

School of Natural Resources: Faculty Publications

In areas of high winds and blowing snow, windbreaks can reduce the amount of effort spent on snow management. They can be designed to spread snow across a large area or to confine it to a relatively small storage area. The design of your windbreak will depend on your objective. Field windbreaks designed to distribute snow evenly across a field should be tall and porous. In contrast, windbreaks designed to capture snow and control drifting should have multiple rows with high density. There is no one set design, number of rows, or width of planting that is ideal for every …

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Scale Issues In Soil Moisture Modelling: Problems And Prospects, Rezaul Mahmood Jan 1996

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 …

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