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

Digital Commons Network™

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

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 15601 - 15630 of 17792

Full-Text Articles in Entire DC Network

Fish Species And Size Distribution And Abundance In Different Areas In Lake Victoria, Tanzania, A I Chande, H A Mhitu Oct 2005

Fish Species And Size Distribution And Abundance In Different Areas In Lake Victoria, Tanzania, A I Chande, H A Mhitu

Tanzania Journal of Science

The study was carried out to investigate fish species distribution and abundance in different areas and size structure variations according to depth in Lake Victoria, Tanzania. Data were collected using a bottom trawl net during rainy and dry seasons in 2002. The results show that there were significant differences in catch rates between rainy and dry seasons (F (12, 12) = 2.69; p < 0.05). The rainy season recorded higher catch rates (36.25 - 106.61 kg/hr) than during the dry season (14.30 - 67.90 kg/hr). The haplochromines catch rates were higher during the dry season (11.08 kg/hr) than during the rainy season (7.72 kg/hr), however, the differences were not significant (c2 = 0.60, df = 1, p > 0.05). The distribution of the fish species in different areas recorded a significant difference during the dry season (Q = 18.254, df = 8, P < 0.001), while during the rainy season the difference was not significant (Q = 10.667, df = 8, P > 0.001). Moreover, the results show that small individuals dominated in shallow waters …


Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri Oct 2005

Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri

School of Earth, Environmental, & Marine Sciences Faculty Publications

We tested the potential of estimating per-pixel gross primary production (GPP) directly from the MODIS enhanced vegetation index (EVI) and respiration directly from MODIS surface temperature (MOD11). Carbon flux data were obtained from 10 eddy covariance tower sites representing a wide range of North American vegetations. The correlation between across-site tower GPP and EVI was comparable (r = 0.77) to that between tower GPP and MOD17-GPP (r = 0.73), suggesting that EVI could be used to provide reasonably accurate direct estimates of GPP on a truly per-pixel basis. There was also a strong relationship (r2 = 0.67) between respiration and …


Prediction Of Sediment-Bound Nutrient Delivery From Semi-Arid California Watersheds, Emmanuel Gabet, Noah Fierer, Oliver Chadwick Oct 2005

Prediction Of Sediment-Bound Nutrient Delivery From Semi-Arid California Watersheds, Emmanuel Gabet, Noah Fierer, Oliver Chadwick

Faculty Publications

Soil carbon (C), nitrogen (N), and phosphorus (P) are lost from hillslopes in particulate forms through soil erosion. The fate of the eroded C (e.g., sequestration or oxidation) may affect the global C budget, and delivery of N and P to waterbodies can lead to eutrophication. Whereas the magnitude of particulate nutrient losses may be similar to or greater than dissolved losses, it is rarely estimated. We couple a sediment delivery model with measurements of C, N, and P in soil to account explicitly for hillslope sediment transport processes that yield sediment-bound nutrients to fluvial networks. The model is applied …


Successful Cropping In The High Rainfall Zone Of Western Australia : Crop Research And Extension In The Zone, Narelle Hill, Heping Zhang Dr., Tim Trezise, John Young, Natahan Moyes, Laurence Carslake, Neil C. Turner Dr, Walter Anderson, Michael Poole Oct 2005

Successful Cropping In The High Rainfall Zone Of Western Australia : Crop Research And Extension In The Zone, Narelle Hill, Heping Zhang Dr., Tim Trezise, John Young, Natahan Moyes, Laurence Carslake, Neil C. Turner Dr, Walter Anderson, Michael Poole

Bulletins 4000 -

This manual is a review of all the relevant and current information relating to cropping systems in the high rainfall cropping zone (HRZ) of Western Australia. It functions partly as the final report summarising research results and extension activities and discusses recommendations and potential outcomes of two 5-year GRDC-funded projects (DAW 673 and CSP 302), that aimed to increase the productivity of southern high rainfall cropping systems.


Pcor Partnership Atlas, Wesley D. Peck, John A. Harju, Erin M. O'Leary, Steven A. Smith, James A. Sorensen, Edward N. Steadman, Charles R. Nelson, Lynette L. De Silva, John T. Litynski, David W. Fischer Oct 2005

Pcor Partnership Atlas, Wesley D. Peck, John A. Harju, Erin M. O'Leary, Steven A. Smith, James A. Sorensen, Edward N. Steadman, Charles R. Nelson, Lynette L. De Silva, John T. Litynski, David W. Fischer

EERC Maps and Infographics

The Plains CO2 Reduction (PCOR) Partnership Atlas introduces global climate change and provides a regional profile of CO2 sources and potential sinks across the PCOR Partnership region. Carbon sequestration offers a promising set of technologies through which CO2 can be stored for long periods of time.


Earth News, V29, Fall 2005, Department Of Earth Science, University Of Northern Iowa. Oct 2005

Earth News, V29, Fall 2005, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Earth Science Staff Activities
--- A T. rex Named Sue
--- Earth Science Seminar Series
--- From Ocean to Ice: GSI 2004 Spring Field Trip Highlights
--- Physical Geology Professor Keeps Passion for Teaching, Researching
--- Earth Science Majors
--- Sigma Gamma Epsilon - Gamma Sigma Chapter
--- 2005 Earth Science Graduates
--- Student Research Presentations
--- 2004-2005 Scholarship and Award Recipients
--- Student Internships
--- Gifts to the Department of Earth Science
--- Earth Science Alumni News


Coral Reef Ed-Ventures: An Environmental Education Program For School Children In San Pedro, Belize, H. Allen Curran, Susan Etheredge, Elizabeth Callaghan, Paulette M. Peckol Oct 2005

Coral Reef Ed-Ventures: An Environmental Education Program For School Children In San Pedro, Belize, H. Allen Curran, Susan Etheredge, Elizabeth Callaghan, Paulette M. Peckol

Geosciences: Faculty Publications

No abstract provided.


Mountain Plover Population Responses To Black-Tailed Prairie Dogs In Montana, Stephen J. Dinsmore, Gary C. White, Fritz L. Knopf Oct 2005

Mountain Plover Population Responses To Black-Tailed Prairie Dogs In Montana, Stephen J. Dinsmore, Gary C. White, Fritz L. Knopf

United States Geological Survey: Staff Publications

We studied a local population of mountain plovers (Charadrius montanus) in southern Phillips County, Montana, USA, from 1995 to 2000 to estimate annual rates of recruitment rate (f) and population change (λ). We used Pradel models, and we modeled λ as a constant across years, as a linear time trend, as year-specific, and with an additive effect of area occupied by prairie dogs (Cynomys ludovicianus). We modeled recruitment rate (f) as a function of area occupied by prairie dogs with the remaining model structure identical to the best model used to estimate λ. Our results indicated …


Nonlinear Dynamics In Ecosystem Response To Climatic Change: Case Studies And Policy Implications, Virginia R. Burkett, Douglas A. Wilcox, Wilcox Stottlemyer, Wylie Barrow, Dan Fagre, Jill Baron, Jeff Price, Jennifer L. Nielsen, Craig D. Allen, David L. Peterson, Greg Ruggerone, Thomas Doyle Sep 2005

Nonlinear Dynamics In Ecosystem Response To Climatic Change: Case Studies And Policy Implications, Virginia R. Burkett, Douglas A. Wilcox, Wilcox Stottlemyer, Wylie Barrow, Dan Fagre, Jill Baron, Jeff Price, Jennifer L. Nielsen, Craig D. Allen, David L. Peterson, Greg Ruggerone, Thomas Doyle

United States Geological Survey: Staff Publications

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of …


Geologic Map Of The Golden Throne Quadrangle, Wayne And Garfield Counties, Utah, Daniel H. Martin Sep 2005

Geologic Map Of The Golden Throne Quadrangle, Wayne And Garfield Counties, Utah, Daniel H. Martin

Theses and Dissertations

The Golden Throne Quadrangle is located within Capitol Reef National Park, south-central Utah. Geologic mapping of this 1:24,000 scale 7.5 minute quadrangle began in 2003 as the National Parks Service desired to have geologic maps at this scale produced within the park. Stratigraphically, ten bedrock formations and ten Quaternary deposits are exposed within the Golden Throne Quadrangle. Geologic formations range in age from Permian to Jurassic. This map contains details not included on previous geologic maps including; the members of the Carmel, Chinle, and Moenkopi Formations. Additionally, the Page Sandstone is herein mapped as an independent unit. Structurally the Golden …


Wetland Carbon Sinks In The Glaciated North American Prairie, University Of North Dakota. Energy And Environmental Research Center Sep 2005

Wetland Carbon Sinks In The Glaciated North American Prairie, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about Prairie Pothole Region wetlands and their potential to sequester carbon. Coordinated by Ducks Unlimited Canada, U.S. Geological Survey, and Plains CO2 Reduction (PCOR) Partnership. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Potential Impacts Of Climate Change On Agricultural Land Use Suitability : Wheat, Dennis Van Gool, Luke Vernon Aug 2005

Potential Impacts Of Climate Change On Agricultural Land Use Suitability : Wheat, Dennis Van Gool, Luke Vernon

Resource management technical reports

This publication considers the impact of climate change on wheat crops. While a model was first used, it was only partially validated against real data, hence the model is now used as a decision support system that allows people with crop, land resource and climate knowledge to determine potential impacts of climate change on crop growth and production in Western Australia.


The Impacts Of Sprawl On Biodiversity: The Ant Fauna Of The Lower Florida Keys, Elizabeth A. Forys, Craig R. Allen Aug 2005

The Impacts Of Sprawl On Biodiversity: The Ant Fauna Of The Lower Florida Keys, Elizabeth A. Forys, Craig R. Allen

United States Geological Survey: Staff Publications

Sprawling development can affect species composition by increasing the rate of invasion by non-native species, and decreasing the persistence of native species. This paper briefly reviews the scientific literature on the impacts of sprawl on biological diversity, with specific emphasis on the influence of sprawl on non-native species richness. We then explore the relationship between sprawl and biodiversity using a data set of ant species collected from 46 habitat patches located in the increasingly suburbanized Florida Keys, USA. We quantified sprawl as the proximity of roads and amount of development surrounding a habitat patch. Using bait transects, we identified 24 …


Age And Quality Of Ground Water And Sources Of Nitrogen In The Surficial Aquifers In Pumpkin Creek Valley, Western Nebraska, 2000, G. V. Steele, J. C. Cannia, S. S. Sibray, V. L. Mcguire Aug 2005

Age And Quality Of Ground Water And Sources Of Nitrogen In The Surficial Aquifers In Pumpkin Creek Valley, Western Nebraska, 2000, G. V. Steele, J. C. Cannia, S. S. Sibray, V. L. Mcguire

United States Geological Survey: Publications

Ground water is the source of drinking water for the residents of Pumpkin Creek Valley, western Nebraska. In this largely agricultural area, shallow aquifers potentially are susceptible to nitrate contamination. During the last 10 years, ground-water levels in the North Platte Natural Resources District have declined and contamination has become a major problem for the district. In 2000, the U.S. Geological Survey and the North Platte Natural Resources District began a cooperative study to determine the age and quality of the ground water and the sources of nitrogen in the aquifers in Pumpkin Creek Valley.

Water samples were collected from …


Investigating Nickel Partitioning In A Contaminant Aquifer, Suama Ndengu Aug 2005

Investigating Nickel Partitioning In A Contaminant Aquifer, Suama Ndengu

Masters Theses

Improved prediction of the transport and bioavailability of metals in contaminated sediments demands a better quantitative understanding of how metals partition between aqueous solutions and mineral phases. This research examines the partitioning of nickel in a contaminated aquifer from Grand Rapids, Ml. Contaminated aquifer sediments were examined using the five step Tessier et al. (1979) operationally defined sequential extraction procedure to determine the solid phase distribution of nickel in the aquifer sediments. Models used to guide remediation efforts at the contaminated site assume that Ni behavior can be predicted based on Ni adsorption onto ferrihydrite (HFO). Although sequential extraction results …


Factors Affecting Songbird Nest Survival And Brood Parasitism In The Rainwater Basin Region Of Nebraska, Max Post Van Der Burg Aug 2005

Factors Affecting Songbird Nest Survival And Brood Parasitism In The Rainwater Basin Region Of Nebraska, Max Post Van Der Burg

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

No abstract provided.


Distribution Patterns Of Lentic-Breeding Amphibians In Relation To Ultraviolet Radiation Exposure In Western North America, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Paul Stephen Corn, Stephen A. Diamond, Peter C. Trenham, Dan B. Fagre Jul 2005

Distribution Patterns Of Lentic-Breeding Amphibians In Relation To Ultraviolet Radiation Exposure In Western North America, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Paul Stephen Corn, Stephen A. Diamond, Peter C. Trenham, Dan B. Fagre

United States Geological Survey: Staff Publications

An increase in ultraviolet-B (UV-B) radiation has been posited to be a potential factor in the decline of some amphibian population. This hypothesis has received support from laboratory and field experiments showing that current levels of UV-B can cause embryo mortality in some species, but little research has addressed whether UV-B is influencing the distribution of amphibian populations. We compared patterns of amphibian presence to sitespecific estimates of UV-B dose at 683 ponds and lakes in Glacier, Olympic, and Sequoia–Kings Canyon National Parks. All three parks are located in western North America, a region with a concentration of documented amphibian …


Estimated Ultraviolet Radiation Doses In Wetlands In Six National Parks, Stephen A. Diamond, Peter C. Trenham, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Stacey L. Stark, David Bradford, P. Stephen Corn, Ken Czarnowski, Paul D. Brooks, Dan Fagre, Bob Breen, Naomi E. Detenbeck, Kathy Tonnessen Jul 2005

Estimated Ultraviolet Radiation Doses In Wetlands In Six National Parks, Stephen A. Diamond, Peter C. Trenham, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Stacey L. Stark, David Bradford, P. Stephen Corn, Ken Czarnowski, Paul D. Brooks, Dan Fagre, Bob Breen, Naomi E. Detenbeck, Kathy Tonnessen

United States Geological Survey: Staff Publications

Ultraviolet-B radiation (UV-B, 280–320-nm wavelengths) doses were estimated for 1024 wetlands in six national parks: Acadia (Acadia), Glacier (Glacier), Great Smoky Mountains (Smoky), Olympic (Olympic), Rocky Mountain (Rocky), and Sequoia/ Kings Canyon (Sequoia). Estimates were made using ground-based UV-B data (Brewer spectrophotometers), solar radiation models, GIS tools, field characterization of vegetative features, and quantification of DOC concentration and spectral absorbance. UV-B dose estimates were made for the summer solstice, at a depth of 1 cm in each wetland. The mean dose across all wetlands and parks was 19.3 W-h m-2 (range of 3.4–32.1 W-h m-2). The mean …


Holocene Hydrologic Variation At Lake Titicaca, Bolivia/Peru, And Its Relationship To North Atlantic Climate Variation, P. A. Baker, Sherilyn C. Fritz, J. Garland, E. Ekdahl Jul 2005

Holocene Hydrologic Variation At Lake Titicaca, Bolivia/Peru, And Its Relationship To North Atlantic Climate Variation, P. A. Baker, Sherilyn C. Fritz, J. Garland, E. Ekdahl

Department of Earth and Atmospheric Sciences: Faculty Publications

A growing number of sites in the Northern Hemisphere show centennial- to millennial-scale climate variation that has been correlated with change in solar variability or with change in North Atlantic circulation. However, it is unclear how (or whether) these oscillations in the climate system are manifest in the Southern Hemisphere because of a lack of sites with suitably high sampling resolution. In this paper, we reconstruct the lake-level history of Lake Titicaca, using the carbon isotopic content of sedimentary organic matter, to evaluate centennial-to millennial-scale precipitation variation and its phasing relative to sites in the Northern Hemisphere. The pattern and …


A Late Devonian Isoetalean Lycopsid, Otzinachsonia Beerboweri Gen. Et Sp Nov., From North-Central Pennsylvania, Usa, Walter L. Cressler, H W. Pfefferkorn Jul 2005

A Late Devonian Isoetalean Lycopsid, Otzinachsonia Beerboweri Gen. Et Sp Nov., From North-Central Pennsylvania, Usa, Walter L. Cressler, H W. Pfefferkorn

Earth & Space Sciences Faculty Publications

No abstract provided.


Andrill Mcmurdo Ice Shelf Project Scientific Prospectus, Timothy R. Naish, Ross D. Powell, Peter J. Barrett, Huw Horgan, Gavin B. Dunbar, Gary S. Wilson, Richard Levy, Natalie Robinson, L. Carter, Alex R. Pyne, Frank Niessen, Stephen Bannister, Natalie Balfour, Detlef Damaske, Stuart Henrys, Phil Kyke, Terry Wilson Jun 2005

Andrill Mcmurdo Ice Shelf Project Scientific Prospectus, Timothy R. Naish, Ross D. Powell, Peter J. Barrett, Huw Horgan, Gavin B. Dunbar, Gary S. Wilson, Richard Levy, Natalie Robinson, L. Carter, Alex R. Pyne, Frank Niessen, Stephen Bannister, Natalie Balfour, Detlef Damaske, Stuart Henrys, Phil Kyke, Terry Wilson

ANDRILL Project Information

Response of Antarctic ice sheets to projected greenhouse warming of up to 5.8!C by the end of the century is not known. Models on which predictions are based need to be constrained by geological data of the ancient ice sheets during times when Earth is known to have been warmer than today. The marine-based West Antarctic Ice Sheet (WAIS) and its fringing ice shelves are hypothesized (Clark et al., 2002; Weaver et al., 2003; Stocker, 2003) and documented (Scherer et al., 1998) to have collapsed during past “super-interglacial” warm extremes when global sea-level was more than 5m higher than today. …


"Got Rocks?" An Inquiry-Based Geology Program For 3rd To 5th Grades In Conjunction With The Museum Of Science, Jennifer D. Todd Jun 2005

"Got Rocks?" An Inquiry-Based Geology Program For 3rd To 5th Grades In Conjunction With The Museum Of Science, Jennifer D. Todd

Critical and Creative Thinking Capstones Collection

How can the Boston Museum of Science be of help to classroom teachers when planning a field trip? The synthesis presents a set of lesson plans for 3rd to 5th grade science teachers in the Boston area, with an ultimate goal of promoting students’ critical and creative thinking in their classroom units on rocks and minerals. The program was designed especially for those in the New England area because these states are within proximity to take a field trip to the Boston Museum of Science. The institution has many rocks and mineral samples from around the world and in the …


A Memorial To D. Craig Edwards (1939-2004), H. Allen Curran, Hilary Edwards Lithgow Jun 2005

A Memorial To D. Craig Edwards (1939-2004), H. Allen Curran, Hilary Edwards Lithgow

Geosciences: Faculty Publications

No abstract provided.


Laurance Lake Temperature Model, Chris Berger, Scott A. Wells, Robert Leslie Annear Jun 2005

Laurance Lake Temperature Model, Chris Berger, Scott A. Wells, Robert Leslie Annear

Civil and Environmental Engineering Faculty Publications and Presentations

Laurance Lake is a reservoir located in Hood River County, Oregon (Figure 1). It is located at the base on Mt. Hood in Oregon (see Figure 2 and Figure 3), discharges into the Middle Fork of the Hood River. The reservoir was constructed in 1968 for irrigation storage and has a capacity 3564 acre- feet at full pool. Since the river vio lates temperature standards, this study has been designed to construct a hydrodynamic and temperature model of Laurance reservoir in order to assess strategies for improving temperatures in the Middle Fork River.

The objectives of the study are then …


Integrated Recombinant Protein Expression And Purification Platform Based On Ralstonia Eutropha, Gavin C. Barnard, Jesse D. Mccool, David W. Wood, Tillman U. Gerngross May 2005

Integrated Recombinant Protein Expression And Purification Platform Based On Ralstonia Eutropha, Gavin C. Barnard, Jesse D. Mccool, David W. Wood, Tillman U. Gerngross

Dartmouth Scholarship

Protein purification of recombinant proteins constitutes a significant cost of biomanufacturing and various efforts have been directed at developing more efficient purification methods. We describe a protein purification scheme wherein Ralstonia eutropha is used to produce its own “affinity matrix,” thereby eliminating the need for external chromatographic purification steps. This approach is based on the specific interaction of phasin proteins with granules of the intracellular polymer poly


The Effect Of Scaling-Up On Remotely Derived Leaf Area Index Estimators In The Brazilian Amazon, John I. Menzies May 2005

The Effect Of Scaling-Up On Remotely Derived Leaf Area Index Estimators In The Brazilian Amazon, John I. Menzies

All-Inclusive List of Electronic Theses and Dissertations

This research compared a traditional statistical technique with artificial neural networks to determine their effectiveness for modeling LAI in the Santarem region of the Brazilian Amazon. In addition, different satellite sensors in the form of ETM+, ASTER, MO DIS, and IKONOS were used to assess if spatial and spectral resolutions play a role in the ability to estimate LAI. This study focused on the following: (1) Determining if neural networks perform more accurately than multiple regression for LAI modeling (2) the effectiveness of different resolution satellite data including ETM+, ASTER, MODIS, and IKONOS for LAI estimation; (3) determining if spatial …


Quantifying Atmospheric Nitrogen Deposition As A Nonpoint Source Pollution And Its Potential Effects On The Mullica River-Great Bay Ecosystem, Jennifer Haag May 2005

Quantifying Atmospheric Nitrogen Deposition As A Nonpoint Source Pollution And Its Potential Effects On The Mullica River-Great Bay Ecosystem, Jennifer Haag

Theses, Dissertations and Culminating Projects

To characterize atmospheric nitrogen deposition and its potential impact on the Mullica River-Great Bay Estuary, atmospheric sampling was conducted at Rutgers University Marine Field Station in Tuckerton, New Jersey from March 2004 to March 2005. A total of 52 precipitation samples were collected on an event basis using a MIC wet-only automatic precipitation sampler. A total of 23 aerosol samples were also taken during this period of time with a high-volume aerosol sampler. Chemical analysis was performed using a Dionex Ion Chromatograph to determine the concentrations of nitrate and ammonium in precipitation and associated with aerosols. Nitrate concentrations for precipitation …


Humic And Fulvic Acids: Effects On Plant Nutrition And Growth, Jason Tew May 2005

Humic And Fulvic Acids: Effects On Plant Nutrition And Growth, Jason Tew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humic substances are reported to improve plant growth and nutrient uptake, with iron the most studied nutrient. The most common forms of iron in soils are iron oxides, which are stable under aerobic conditions and unavailable for plant uptake. Iron deficient plants become chlorotic, which reduces growth and yield. To determine if humic substances can reduce iron chlorosis, five commercially available organic acids were tested on maize grown in sand columns at high pH. The dry granular humic acid from Aldrich Chemical Company applied at 84.4 g/liter of sand by volume (5% by mass) and 1 g/liter added with irrigation …


Establising A High-Frequency Standard Reference Sequence Stratigraphy, Sea-Level Curve, And Biostratigraphy For Morrowan Strata Of The Lower Absaroka I Time Slice Based Upon The Bird Spring Formation, Arrow Canyon, Nevada, Kristen Phelps Briggs Apr 2005

Establising A High-Frequency Standard Reference Sequence Stratigraphy, Sea-Level Curve, And Biostratigraphy For Morrowan Strata Of The Lower Absaroka I Time Slice Based Upon The Bird Spring Formation, Arrow Canyon, Nevada, Kristen Phelps Briggs

Theses and Dissertations

For the same reasons which prompted its ratification in 1990 as the Global Stratotype Section and Point for the Mid-Carboniferous boundary, namely, section completeness, abundant fossils, and excellent exposure, the Morrowan Arrow Canyon Bird Spring strata is recommended as a candidate standard sequence stratigraphic reference for the Morrowan portion of the Lower Absaroka I supersequence. The stratigraphic architecture of Morrowan strata in Arrow Canyon was largely controlled by high-amplitude (100-m), high-frequency sea-level changes. Outcrop data and facies stacking patterns define 59 fifth-order fundamental cycles. These fundamental cycles stack into ten third-order sequences with an average duration of 320 ka. Changes …


Adoption Of Riparian Forest Buffers On Private Lands In Nebraska, Usa, Peter Skelton, Scott J. Josiah, James W. King, James R. Brandle, Glenn A. Helmers, Charles A. Francis Apr 2005

Adoption Of Riparian Forest Buffers On Private Lands In Nebraska, Usa, Peter Skelton, Scott J. Josiah, James W. King, James R. Brandle, Glenn A. Helmers, Charles A. Francis

Department of Agricultural Leadership, Education, and Communication: Faculty Publications

Pesticide and nutrient runoff from agricultural fields is a socio-environmental problem in the Midwestern United States. Riparian forest buffers (RFBs) are a proven conservation practice that effectively manage this problem, though adoption rates are low. A mail survey was conducted to determine differences between adopter and nonadopter characteristics and attitudes with regard to the use of RFBs. Data were collected from 48 RFB adopters and 261 RFB nonadopters in two Nebraska watersheds. Inferential and multivaririate statistics were used to identify differences between adapter status and producer status groups. About half (50.8%) the respondents were nonproducers. Nonproducers are agricultural landowners not …