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Articles 3691 - 3720 of 4182

Full-Text Articles in Natural Resources and Conservation

Windbreaks An Old System With A New Look, James R. Brandle Jan 2000

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 Jan 2000

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 Jan 2000

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 Jan 2000

Windbreak Practices, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane Jan 2000

Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane

School of Natural Resources: Faculty Publications

Lake Ogallala, located below Kingsley Dam which impounds Lake McConaughy in Keith County, Nebraska, is a 260-surface hectare lake with an average depth of approximately eight meters. The lake provides mUltiple uses including a sport fishery and a hydropower and irrigation regulation basin. Since the installation of the hydroelectric generating plant in 1984 (Kingsley Dam was constructed in 1942) and the continued eutrophication of Lake McConaughy, dissolved oxygen concentrations have generally declined in Lake Ogallala. Hypolimnetic withdrawal from Lake McConaughy results in depressed oxygen levels in Lake Ogallala during the mid to latter part of the summer, particularly in certain …


Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel Jan 2000

Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.


Potential Production And Environmental Effects Of Switchgrass And Traditional Crops Under Current And Greenhouse-Altered Climate In The Central United States: A Simulation Study, R.A. Brown, N.J. Rosenberg, Cynthia J. Hays, W.E. Easterling, L.O. Mearns Jan 2000

Potential Production And Environmental Effects Of Switchgrass And Traditional Crops Under Current And Greenhouse-Altered Climate In The Central United States: A Simulation Study, R.A. Brown, N.J. Rosenberg, Cynthia J. Hays, W.E. Easterling, L.O. Mearns

School of Natural Resources: Faculty Publications

If, as many climate change analysts _ speculate, industrial and other emissions of CO2 can be offset by substitution of biofuels, large areas of land, including agricultural land, may be converted to the production of biomass feedstocks. This paper explores the feasibility for the Missouri–Iowa–Nebraska–Kansas (MINK) region of the US of converting some agricultural land to the production of switchgrass (Panicum virgatum L.), a perennial warm season grass, as a biomass energy crop. The erosion productivity impact calculator (EPIC) crop growth model simulated production of corn (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), soybean ( …


Observed Climate Variability And Change Of Relevance To The Biosphere, David R. Easterling, Thomas R. Karl, Kevin P. Gallo, David A. Robinson, Kevin E. Trenberth, Aiguo Dai Jan 2000

Observed Climate Variability And Change Of Relevance To The Biosphere, David R. Easterling, Thomas R. Karl, Kevin P. Gallo, David A. Robinson, Kevin E. Trenberth, Aiguo Dai

School of Natural Resources: Faculty Publications

In this paper we review the current instrumental evidence regarding climate variations and change during the 20th century emphasizing those changes that are likely to have direct interactions with the biosphere.


The Spectral Contribution Of Carotenoids To Light Absorption And Reflectance In Green Leaves, Y. Zur, A. A. Gitelson, O. B. Chivkunova, M. N. Merzlyak Jan 2000

The Spectral Contribution Of Carotenoids To Light Absorption And Reflectance In Green Leaves, Y. Zur, A. A. Gitelson, O. B. Chivkunova, M. N. Merzlyak

School of Natural Resources: Faculty Publications

Absorbance and reflectance spectra in the visible and near infrared range of the spectrum, acquired for maple (Acer platanoides L.) leaves were studied. Standard deviation of absorbance spectra showed that in yellow to green leaves, with chlorophyll content at least up to 30 nmol/cm2, there is a spectral feature at 520 nm attributable to carotenoids. Reflectance around 520 nm also correlates closely with carotenoids content in yellow to green leaves. Thus, this spectral feature at 520 nm could be used as a measure of carotenoids content in green leaves and plants.


Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell Jan 2000

Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the …


Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Gary D. Willson Jan 2000

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

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 …


Remote Monitoring Of Selected Ground-Water Dominated Lakes In The Nebraska Sand Hills, David C. Gosselin, Donald C. Rundquist, Stuart K. Mcfeeters Jan 2000

Remote Monitoring Of Selected Ground-Water Dominated Lakes In The Nebraska Sand Hills, David C. Gosselin, Donald C. Rundquist, Stuart K. Mcfeeters

School of Natural Resources: Faculty Publications

The Landsat-Multispectral Scanner (MSS) data were used to measure lake area fluctuations (1972-1989) for 130 groundwater dominated lakes in the Western Lakes Region of the Nebraska Sand Hills. In general, the pattern shown in lake area hydrographs was similar to that for in-situ lake elevations. In-situ lake-elevation data verify that remote monitoring of surface- area fluctuations, even at relatively coarse spatial resolution, is not only practical and useful, but also it elucidates the hydrologic characteristics of groundwater-dominated lakes of the Sand Hills. The apparent differences in behavior between lakes in the northern and southern portions of the study area may …


Process-Oriented Environmental Change Curriculum-Development Workshops, David C. Gosselin, Sherri Lowrey, Steven John Meyer Jan 2000

Process-Oriented Environmental Change Curriculum-Development Workshops, David C. Gosselin, Sherri Lowrey, Steven John Meyer

School of Natural Resources: Faculty Publications

To improve scientific literacy, K-12 educators need to: develop the ability to use and analyze data, incorporate data into their curriculum, and interact with teachers from other disciplines to create interdisciplinary units. A Process-Oriented Environmental Change Education workshop was conducted for eleven interdisciplinary teams, consisting of 21 teachers, in 1997 and 1998. The National Science Standards provided the criteria for the organization of the workshop. Inquiry and interpretation exercises helped to expand scientific knowledge and skills as well as the teachers’ use of technology. We explicitly discussed the uncertainty of science through group discussions and problem-solving activities. More than 85% …


The Effect Of Structure On The Drag Force Of A Windbreak, James R. Brandle Jan 2000

The Effect Of Structure On The Drag Force Of A Windbreak, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.


Agroforestry In The United States: Research And Technology Transfer Needs For The Next Millennium Jan 2000

Agroforestry In The United States: Research And Technology Transfer Needs For The Next Millennium

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

If society's needs and aspirations for forestderived goods, services, and amenities truely are to be met, we must find ways of augmenting traditional forestry by gleaning some portion of these benefits from agricultural lands. For example: windbreaks, riparian forest buffers, hybrid poplar trees, farm woodlots, and grazing/timber systems.


Geochemical Evidence For An Eolian Sand Dam Across The North And South Platte Rivers In Nebraska, Daniel R. Muhs, James B. Swinehart, David B. Loope, Josh Been, Shannon A. Mahan, Charles A. Bush Jan 2000

Geochemical Evidence For An Eolian Sand Dam Across The North And South Platte Rivers In Nebraska, Daniel R. Muhs, James B. Swinehart, David B. Loope, Josh Been, Shannon A. Mahan, Charles A. Bush

School of Natural Resources: Faculty Publications

Geochemical and geomorphic data from dune fields in southwestern Nebraska provide new evidence that the Nebraska Sand Hills once migrated across the North and South Platte rivers and dammed the largest tributary system to the Missouri River. The Lincoln County and Imperial dune fields, which lie downwind of the South Platte River, have compositions intermediate between the Nebraska Sand Hills (quartz-rich) and northeastern Colorado dunes (K-feldspar-rich). The most likely explanation for the intermediate composition is that the Lincoln County and Imperial dunes are derived in part from the Nebraska Sand Hills and in part from the South Platte River. The …


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, 2000- February 28, 2001, E. A. Walter-Shea, S. B. Verma Jan 2000

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, 2000- February 28, 2001, E. A. Walter-Shea, S. B. Verma

School of Natural Resources: Documents and Reviews

No abstract provided.


Terrestrial Natural Communities Of Nebraska - Version Ii, Gerry Steinauer, Steven B. Rolfsmeier Jan 2000

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

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

For more than a decade, The Nature Conservancy (TNC) and state natural heritage programs, including the Nebraska Natural Heritage Program (NNHP), have used a “coarse filter/fine filter” approach to preserving biological diversity (The Nature Conservancy, 1994). This approach involves identification and protection of natural communities (coarse filter) as well as rare species (fine filter). Identifying and protecting representative examples of natural communities ensures conservation of most species, biotic interactions and ecological processes. Those species that “fall through” the community filters are generally the rare species. Identification and protection of viable occurrences of rare species serves as the fine filter for …


Conservation In A Highly Fragmented Landscape: The Central Tallgrass Prairie Ecoregional Conservation Plan, The Central Tallgrass Prairie Ecoregion Planning Team Jan 2000

Conservation In A Highly Fragmented Landscape: The Central Tallgrass Prairie Ecoregional Conservation Plan, The Central Tallgrass Prairie Ecoregion Planning Team

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

With the adoption of Conservation by Design in 1995, The Nature Conservancy recognized the importance of working at larger scales to achieve our mission which is: the long-term survival of all viable native species and community types through the design and conservation of portfolios of sites within ecoregions. The Conservancy set forth to design conservation plans on an ecoregional basis by working closely with various conservation partners. These plans are intended to provide a framework within which the Conservancy and our partners, such as the Natural Heritage Programs, can make decisions regarding conservation actions to be taken at the …


Investigating Ground And Surface Water In The Republican River Basin Of Nebraska Using Water Chemistry And Environmental Isotopes, Jennifer J. Schellpeper Dec 1999

Investigating Ground And Surface Water In The Republican River Basin Of Nebraska Using Water Chemistry And Environmental Isotopes, Jennifer J. Schellpeper

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

Recent legal battles concerning water use initiated an investigation of the stream/aquifer relationships in the Republican River Basin located in southwest Nebraska. Ground and surface water was analyzed for tritium, deuterium, 18O, and major ions. Temperature, pH, conductivity and alkalinity were determined on-site. Samples were collected during 1997 and 1998 from irrigation wells throughout the entire basin. Localized interactions between groundwater and surface water were examined during twenty-four hour pump tests performed on the irrigation wells screened in the alluvium along the river valley and its tributaries. These data show there are differences between the ground and surface waters …


Ecology Of Elk In Northwestern Nebraska: Demographics, Effects Of Human Disturbance, And Characteristics Of Calving Habitat, Bruce A. Stillings Dec 1999

Ecology Of Elk In Northwestern Nebraska: Demographics, Effects Of Human Disturbance, And Characteristics Of Calving Habitat, Bruce A. Stillings

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

No abstract provided.


Reconnaissance Survey Of Lewis And Clark On The Missouri National Recreational River, Nebraska And South Dakota, Anne P. Diffendal, Gary E. Moulton, Michael Shambaugh-Miller, Robert F. Diffendal Jr. Dec 1999

Reconnaissance Survey Of Lewis And Clark On The Missouri National Recreational River, Nebraska And South Dakota, Anne P. Diffendal, Gary E. Moulton, Michael Shambaugh-Miller, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Part I
Lewis and Clark on the Middle Missouri by Gary E. Moulton
Appendix: Principal Sites and Events
Select Bibliography

Part II
Locating Lewis and Clark Sites
Site #1 Floyd's Bluff
Site #2 Gass's Election
Site #3 Ionia Volcano
Site #4 1804 Mouth of the Vermillion River
Site #5 Spirit Mound
Site #6 Shannon's Absence
Site #7 Calumet Bluff
Site #8 "Ancient Fortifications"
Site #9 Mouth of the Niobrara River
Site # 10 Old Baldy


Local And Landscape Factors Affecting Nest Site Selection And Nest Success Of Burrowing Owls In Western Nebraska, Rebecca T. Ekstein Dec 1999

Local And Landscape Factors Affecting Nest Site Selection And Nest Success Of Burrowing Owls In Western Nebraska, Rebecca T. Ekstein

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

No abstract provided.


The Prairie Naturalist Volume 31 No.4 December 1999 Nov 1999

The Prairie Naturalist Volume 31 No.4 December 1999

The Prairie Naturalist

THE FISHES OF THE UPPER MOREAU RIVER ▪ T. M. Loomis, C. R. Berry, Jr., and J. Erickson

DO INTERNAL FIRE LANES AFFECT NEST DEPREDATION RATES IN PRAIRIES? ▪ K. A. Warren and M. R. Ryan

SPECIES COMPOSITION AND TROPHIC STRUCTURE OF INSECT COMMUNITIES IN TEXAS PRAIRIES. ▪ G. N. Cameron and E. H. Bryant

FIDELITY OF MALLARDS TO ARTIFICIAL NESTING STRl!CTURES ▪ T. Yerkes

OBSERVATIONS ON REPRODUCTION IN THREE SPECIES OF BATS ▪ D. W. Sparks, J. R. Choate, and R. J. Winn

EARLIEST SEASONAL RECORD OF REPRODUCTION IN THE HOARY BAT ON THE NORTHERN GREAT PLAINS ▪ T. …


Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr. Oct 1999

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts. First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …


Soil Moisture Within The Windbreak/Crop Interface And A Comparison Of Three Types Of Sensors For Measuring Soil Water Content, Qingjiang Hou Aug 1999

Soil Moisture Within The Windbreak/Crop Interface And A Comparison Of Three Types Of Sensors For Measuring Soil Water Content, Qingjiang Hou

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

No abstract provided.


The Prairie Naturalist Volume 31, No.3 September 1999 Aug 1999

The Prairie Naturalist Volume 31, No.3 September 1999

The Prairie Naturalist

HANTA VIRUS INFECTION IN NORTH DAKOTA SMALL MAMMALS: 1994,1995 ▪ R. W. Seabloom, J. J. Feist, and S L. McDonough

AMERICAN WOODCOCK IN COLORADO ▪ C. E. Braun

AVIFAUNA OF AN EARLY SUCCESSIONAL HABITAT ALONG THE MIDDLE MISSOURI RIVER ▪ D. L. Swanson

REPRODUCTIVE STATUS OF FLEA BEETLES IN NORTH DAKOTA AND SOUTH DAKOTA ▪ M. A. Brinkman and S. A. Clay

NUTRIENT AND ENERGY CHARACTERISTICS OF INVERTEBRATES FROM TWO LOCATIONS IN KANSAS ▪ S. G. Papon, R. J. Robel, and K. Kemp

BOOK REVIEWS

The Wood Warblers ▪ M. G. Knutson

A Fascination With Birds. ▪ J. A. Dechant …


Central Platte River Forests: Breeding Birds And Woody Vegetation, Barbara K. Good Aug 1999

Central Platte River Forests: Breeding Birds And Woody Vegetation, Barbara K. Good

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

No abstract provided.


The Prairie Naturalist Volume 31, No.2 June 1999 Jun 1999

The Prairie Naturalist Volume 31, No.2 June 1999

The Prairie Naturalist

SPATlAL VARIATION IN POPULATION CHARACTERISTICS OF SHOVELNOSE STURGEON IN THE KANSAS RIVER ▪ M. C. Quist and C. S. Guy

INFLUENCE OF FIRE AND TRAPPING EFFORT ON GROUND BEETLES IN A RECONSTRUCTED TALLGRASS PRAIRIE ▪ K. J. Larsen and J. B. Williams

FISH ASSEMBLAGES AND HABITAT RELATIONSHIPS IN A SMALL NORTHERN GREAT PLAINS STREAM ▪ C. A. Barfoot and R. G. White

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA 1998 ▪ R. N. Randall

NEW RECORDS OF THE PYGMY SHREW IN SOUTHEAST SOUTH DAKOTA ▪ C. B. King, G. M. Wilson, and P. D. Sudman

BUFFLEHEAD BROOD IN NORTHEASTERN SOUTH DAKOTA …


Intermediate Rings Between A Local Domain And Its Completion, William Heinzer, Christel Rotthaus, Sylvia Wiegand Apr 1999

Intermediate Rings Between A Local Domain And Its Completion, William Heinzer, Christel Rotthaus, Sylvia Wiegand

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We consider the structure of certain intermediate domains between a local Noetherian domain Rand an ideal-adic completion R* of R that arise as the intersection of R* with a field containing R. In the case where the intersection domain A can be expressed as a directed union of localized polynomial extension rings of R, the computation of A is easier. We examine conditions for this to happen. We also present examples to motivate and illustrate the concepts considered.