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Articles 2881 - 2910 of 3168

Full-Text Articles in Natural Resources Management and Policy

Climatology Of The Daily Temperature Range Annual Cycle In The United States, Daniel J. Leathers, Michael A. Palecki, David A. Robinson, Kenneth F. Dewey Feb 1998

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 Jan 1998

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 Jan 1998

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.


Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 1998- January 8, 1999, E. A. Walter-Shea, S. B. Verma Jan 1998

Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 1998- January 8, 1999, E. A. Walter-Shea, S. B. Verma

School of Natural Resources: Documents and Reviews

No abstract provided.


1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume I, Terri Hildebrand Jan 1998

1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume I, Terri Hildebrand

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This study resulted from an agreement between Nebraska Game and Parks Commission (NGPC) and the United States Fish and Wildlife Service (USFW). After the 1996 discovery of Spiranthes diluvialis, in western Nebraska, NGPC was seeking to determine the extent of the Nebraska population. Information on the wet meadow community of orchid occurrence in Nebraska and eastern Wyoming was needed. This report includes descriptions of communities inventoried, Spiranthes diluvialis populations, and additional species monitored by Nebraska and Wyoming Natural Heritage programs.

The 1996 discovery of Spiranthes diluvialis in Nebraska by Hazlett merited the need for further inventory for the species …


1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer Jan 1998

1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This report is prepared as a requirement of the 1998 Southeast Nebraska Prairie Survey contract between the Platte/Rainwater Basin Project Office of the Nature Conservancy and Robert F. Steinauer. The original contract called for the examination of Johnson County south of Highway 136, and Gage County east of Beatrice. Due to the scarcity of prairies in these areas, the survey region was expanded to include northern Johnson County, and southern Jefferson County.

Prairies in these areas were identified using infrared and black and white photos, driving on county and within grassland roads, and conversations with landowners. Heritage Program “Site Survey …


1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand Jan 1998

1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This study resulted from an agreement between Nebraska Game and Parks Commission (NGPC) and the United States Fish and Wildlife Service (USFW). After the 1996 discovery of Spiranthes diluvialis, in western Nebraska, NGPC was seeking to determine the extent of the Nebraska population. Information on the wet meadow community of orchid occurrence in Nebraska and eastern Wyoming was needed. This report includes descriptions of communities inventoried, Spiranthes diluvialis populations, and additional species monitored by Nebraska and Wyoming Natural Heritage programs.

Between May and September 1997, potential Spiranthes diluvialis habitat was inventoried for occurrences of the orchid. For all sites …


1998 Platte River Basin Ecosystem Symposium Proceedings Jan 1998

1998 Platte River Basin Ecosystem Symposium Proceedings

Water Current Newsletter

No abstract provided.


Terrestrial Natural Communities Of Nebraska - Version I, Gerry Steinauer, Steven B. Rolfsmeier Oct 1997

Terrestrial Natural Communities Of Nebraska - Version I, Gerry Steinauer, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

The Nebraska Natural Heritage Program has been collecting information and data including published literature, field observations and vegetation plot data over the last 10 years of development of Nebraska’s natural community classification. The classification contains 27 wetland and 36 upland communities including forest, woodland, shrubland, herbaceous, and sparsely vegetated (e.g. rock outcrop) types. The community types were distinguished primarily on plant species composition and to a lesser extent on soils, hydrology and geographic location. The classification contains descriptions of each community type that include dominant species, soils, range, and other ecological information. The classification is designed to be flexible enough …


Biology Of Shovelnose Sturgeon, Scaphirhynchus Platorynchus, In The Lower Platte River, Nebraska, Robin L. Hofpar Aug 1997

Biology Of Shovelnose Sturgeon, Scaphirhynchus Platorynchus, In The Lower Platte River, Nebraska, Robin L. Hofpar

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Integrating Agroforestry Into Usda Programs: A Task Force Report To The Usda Interagency Working Group On Agroforestry, W. J. Rietveld, James P. Lassoie, Charles A. Francis, William Farris, Catalino Blanche, Bruce Wight May 1997

Integrating Agroforestry Into Usda Programs: A Task Force Report To The Usda Interagency Working Group On Agroforestry, W. J. Rietveld, James P. Lassoie, Charles A. Francis, William Farris, Catalino Blanche, Bruce Wight

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

The task force collected and synthesized infonnation and recommended actions to develop the potential of agroforestry to help attain USDA sustainable development goals.


Effects Of Ultraviolet Radiation On Attached Diatom Growth And Distribution, Heather Lynn Emsley Hatsell May 1997

Effects Of Ultraviolet Radiation On Attached Diatom Growth And Distribution, Heather Lynn Emsley Hatsell

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Impacts Of Air Temperature Variations On The Boro Rice Phenology In Bangladesh: Implications For Irrigation Requirements, Rezaul Mahmood Apr 1997

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 Jan 1997

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 Jan 1997

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 Jan 1997

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 Jan 1997

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 Jan 1997

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.


Radiation And Gas Exchange Of Understory Species At Boreas: Research Annual Performance Report For Period June 15, 1997- June 14, 1998, E. A. Walter-Shea, T. J. Arkebauer Jan 1997

Radiation And Gas Exchange Of Understory Species At Boreas: Research Annual Performance Report For Period June 15, 1997- June 14, 1998, E. A. Walter-Shea, T. J. Arkebauer

School of Natural Resources: Documents and Reviews

No abstract provided.


1997 Rapid Ecological Assessment Northern Great Plains Steppe Ecoregion: Western And Central South Dakota, Northwestern Nebraska, Eastern Wyoming, A Final Report, Terri Hildebrand Jan 1997

1997 Rapid Ecological Assessment Northern Great Plains Steppe Ecoregion: Western And Central South Dakota, Northwestern Nebraska, Eastern Wyoming, A Final Report, Terri Hildebrand

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

In an effort to gain a more complete understanding of existing vegetative communities of the Northern Great Plains Steppe Ecoregion, rapid ecological assessment was undertaken throughout the ecoregion during the field season of 1997. Field office personnel of The Nature Conservancy and private contractors evaluated previously delineated regions in accordance with methodology determined in May of 1997. The following document presents results of the rapid ecological assessments performed by Hildebrand Contracting. The purpose of this document is to provide The Nature Conservancy with information to help determine the vegetative features of regions sampled. The specific areas and boundaries for evaluation …


1997 Platte River Basin Ecosystem Symposium Proceedings Jan 1997

1997 Platte River Basin Ecosystem Symposium Proceedings

Water Current Newsletter

No abstract provided.


Histomorphological Responses Of Red Shiner (Cyprinella Lutrensis) To Atrazine, Terbufos, And Their Mixture, Ibrahim A. Messaad Dec 1996

Histomorphological Responses Of Red Shiner (Cyprinella Lutrensis) To Atrazine, Terbufos, And Their Mixture, Ibrahim A. Messaad

School of Natural Resources: Dissertations, Theses, and Student Research

Alterations of normal histomorphology of fish tissues, behavior, and thermal tolerance are recognized by environmental toxicologists and fish biologists as powerful tools indicating diverse biochemical and physiological changes. Toxicity of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), terbufos (S-(((1,1-dimethyl-ethyl)thio)methyl)O,O-diethyl phosphorodithioate), and their mixture to red shiner (Cyprinella lutrensis) at 23$\sp\circ$C and 30$\sp\circ$C was investigated in 14-d bioassays after 14-d acclimation. During the bioassays, fish behavior, indications of toxicosis, and external anomalies were observed. After the bioassays, the critical thermal maximum (CTM) was determined. Fish also were preserved for examinations of gill, liver, and kidney tissues using scanning electron microscopy (SEM) and light microscopy (LM). SEM …


The Effects Of Wet Meadow Fragmentation On Grassland Birds, Christopher J. Helzer Dec 1996

The Effects Of Wet Meadow Fragmentation On Grassland Birds, Christopher J. Helzer

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Propagation Of Juniperus For Conservation Plantings In The Great Plains, Scott Allen Lee Aug 1996

Propagation Of Juniperus For Conservation Plantings In The Great Plains, Scott Allen Lee

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


The Biology Of Alewife Alosa Pseudoharengus In Lake Ogallala, Nebraska, Eric A. Laux Aug 1996

The Biology Of Alewife Alosa Pseudoharengus In Lake Ogallala, Nebraska, Eric A. Laux

School of Natural Resources: Dissertations, Theses, and Student Research

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 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 …


Growth And Yield Of Snap Beans (Phaseolus Vulgaris L.) As Affected By Shelterbelts And Planting Dates, Mohd Nazip Suratman May 1996

Growth And Yield Of Snap Beans (Phaseolus Vulgaris L.) As Affected By Shelterbelts And Planting Dates, Mohd Nazip Suratman

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Thermal Tolerances Of Platte River Fishes: Field And Laboratory Studies, Brett P. Fessell May 1996

Thermal Tolerances Of Platte River Fishes: Field And Laboratory Studies, Brett P. Fessell

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Chronic Effects Of Baseflow Levels Of Atrazine On Platte River Algae, Karen J. Nelson May 1996

Chronic Effects Of Baseflow Levels Of Atrazine On Platte River Algae, Karen J. Nelson

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Influence Of Prey Availability On Walleye (Stizostedion Vitreum), Mark T. Porath May 1996

Influence Of Prey Availability On Walleye (Stizostedion Vitreum), Mark T. Porath

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.