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2011

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Articles 391 - 420 of 691

Full-Text Articles in Earth Sciences

Profiles In Science For Science Librarians: "What Lives Where, And Why": Alfred Russel Wallace, And The Field Of Biogeography, Charles H. Smith Jan 2011

Profiles In Science For Science Librarians: "What Lives Where, And Why": Alfred Russel Wallace, And The Field Of Biogeography, Charles H. Smith

DLPS Faculty Publications

Biogeography, the study of animal and plant distribution, has a history extending back to at least the eighteenth century. But it was not until the work of Charles Darwin and Alfred Russel Wallace in the mid-nineteenth century that it really came into its own as a science. Darwin’s importance notwithstanding, it was really Wallace who put the field on the map, and many of today’s research threads can be traced back to his influence. This article provides a summary review of Wallace’s life and work and biogeography as a field of study, including Wallace’s role in its development.


Soil Carbon Distribution In Alaska In Relation To Soil-Forming Factors, Kristofer D. Johnson, Jennifer Harden, A. David Mcguire, Norman B. Bliss, James G. Bockheim, Mark Clark, Teresa Nettleton-Hollingsworth, M. Torre Jorgenson, Evan S. Kane, Michelle Mack, Jonathan O'Donnell, Chien-Lu Ping, Edward A.G. Schuur, Merritt R. Turetsky, David W. Valentine Jan 2011

Soil Carbon Distribution In Alaska In Relation To Soil-Forming Factors, Kristofer D. Johnson, Jennifer Harden, A. David Mcguire, Norman B. Bliss, James G. Bockheim, Mark Clark, Teresa Nettleton-Hollingsworth, M. Torre Jorgenson, Evan S. Kane, Michelle Mack, Jonathan O'Donnell, Chien-Lu Ping, Edward A.G. Schuur, Merritt R. Turetsky, David W. Valentine

United States Geological Survey: Staff Publications

The direction and magnitude of soil organic carbon (SOC) changes in response to climate change remain unclear and depend on the spatial distribution of SOC across landscapes. Uncertainties regarding the fate of SOC are greater in high-latitude systems where data are sparse and the soils are affected by sub-zero temperatures. To address these issues in Alaska, a first-order assessment of data gaps and spatial distributions of SOC was conducted from a recently compiled soil carbon database. Temperature and landform type were the dominant controls on SOC distribution for selected ecoregions. Mean SOC pools (to a depth of 1-m) varied by …


Historic And Contemporary Trends Of The Conservation Reserve Program And Ring-Necked Pheasants In South Dakota, Chris Laingen Jan 2011

Historic And Contemporary Trends Of The Conservation Reserve Program And Ring-Necked Pheasants In South Dakota, Chris Laingen

Faculty Research and Creative Activity

Over the past century, the interactions between agricultural land use and government cropland retirement programs have affected pheasant population change. Two government land retirement programs that returned croplands to grasslands, Soil Bank in the 1960s and the current Conservation Reserve Program (CRP), help to illustrate these connections. From 2007 to 2010, South Dakota lost 41% of its CRP lands and experienced an 18% decline in pheasants per mile. However, because of where CRP expirations have occurred and where pheasant populations are found , some regional variability is seen. Western South Dakota (Region 1) had an 80% increase in pheasants per …


Adding Another Notch To America’S Corn Belt, Chris Laingen Jan 2011

Adding Another Notch To America’S Corn Belt, Chris Laingen

Faculty Research and Creative Activity

No abstract provided.


Discrete Brittle To Distributed Shearing; Results From Analysis Of The Deep Portions Of The Cajon Pass Drill Hole, James P. Evans, D Forand Jan 2011

Discrete Brittle To Distributed Shearing; Results From Analysis Of The Deep Portions Of The Cajon Pass Drill Hole, James P. Evans, D Forand

Geosciences Presentations

We performed systematic structural and geochemical analyses on a suite of cored rocks from the vertical Cajon Pass, California drill hole to characterize the deformation and alteration of fault-related rocks. The drill hole lies 4 km northeast of the San Andreas Fault (SAF), and observations of deformed crystalline rock in core and outcrop provide a sample of a 5-km vertical column adjacent to the steeply dipping Cleghorn fault and span the brittle to semi-brittle deformational regime at hydrothermal conditions. The rocks in the upper 500 m of the borehole are composed of sandstones and granitoid augen gneiss, with narrow fault …


A Comparative Integrated Geophysical Study Of Horseshoe Chimney Cave, Colorado Bend State Park, Texas, Wesley A. Brown, Kevin W. Stafford, Melinda G. Shaw-Faulkner, Andy Grubbs Jan 2011

A Comparative Integrated Geophysical Study Of Horseshoe Chimney Cave, Colorado Bend State Park, Texas, Wesley A. Brown, Kevin W. Stafford, Melinda G. Shaw-Faulkner, Andy Grubbs

Faculty Publications

An integrated geophysical study was performed over a known cave in Colorado Bend State Park (CBSP), Texas, where shallow karst features are common within the Ellenberger Limestone. Geophysical survey such as microgravity, ground penetrating radar (GPR), direct current (DC) resistivity, capacitively coupled (CC) resistivity, induced polarization (IP) and ground conductivity (GC) measurements were performed in an effort to distinguish which geophysical method worked most effectively and efficiently in detecting the presence of subsurface voids, caves and collapsed features. Horseshoe Chimney Cave (HCC), which is part of a larger network of cave systems, provides a good control environment for this research. …


Subaerial Freshwater Stromatolites In Deer Cave, Sarawak – A Unique Geobiological Cave Formation, Joyce Lundberg, Donald A. Mcfarlane Jan 2011

Subaerial Freshwater Stromatolites In Deer Cave, Sarawak – A Unique Geobiological Cave Formation, Joyce Lundberg, Donald A. Mcfarlane

WM Keck Science Faculty Papers

A suite of distinctive freshwater subaerial phosphatic stromatolites is developed close to the northeastern entrance of Deer Cave, Gunung Mulu National Park, Sarawak, Borneo, in conditions of very low light but ample supply of nutrients from guano. These stromatolites are not particulate; they are composed of alternating layers of more porous and more dense amorphous hydroxylapatite. This biomineralization occurs as moulds of coccoid (the majority) and filamentous (less abundant) cyanobacteria. Mineralization occurs at a pH of ~ 7.0 in the extracellular sheaths and in micro-domains of varying carbonate content in the surrounding mucus of the biofilm. The most recent surfaces …


Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf Jan 2011

Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf

National Drought Mitigation Center: Faculty Publications

Social factors, such as farming methods, have an impact on farm vulnerability to drought, but have received little research or policy attention. Some researchers and advocates have argued that sustainable agriculture systems are less vulnerable to climate risk than conventional systems because sustainable agriculture requires producers to have skills promoting adaptability. In this paper, we investigate producers’ perceptions on the use of sustainable agriculture in reducing drought risk, and what they believe would help them better adapt to drought. We surveyed and interviewed farmer members of two sustainable agriculture organizations in Nebraska, USA, during a multi-year drought period from 1999 …


The Global Drought Monitor Portal, Michael J. Brewer, Richard R. Heim Jr. Jan 2011

The Global Drought Monitor Portal, Michael J. Brewer, Richard R. Heim Jr.

National Drought Mitigation Center: Faculty Publications

Drought monitoring, assessment, response, mitigation, adaptation, and early warning systems have been created in a number of countries around the world, and some regional and continental efforts have been successful. However, the creation of a Global Drought Early Warning System (GDEWS) remains elusive. A GDEWS incorporates forecasting and research improvements, in addition to monitoring, impact, planning, mitigation and adaptation and recovery information. At a series of workshops in 2010, the U.S. National Integrated Drought Information System (NIDIS) agreed to take the first step toward a GDEWS, the formation of a Global Drought Monitoring Portal (GDMP). This effort currently covers three …


Geologic Map Of The Ganiki Planitia Quadrangle (V–14), Venus, Eric B. Grosfils, Sylvan M. Long, Elizabeth M. Venechuk, Debra M. Hurwitz, Joseph W. Richards, Brian Kastl, Dorothy E. Drury, Johanna S. Hardin Jan 2011

Geologic Map Of The Ganiki Planitia Quadrangle (V–14), Venus, Eric B. Grosfils, Sylvan M. Long, Elizabeth M. Venechuk, Debra M. Hurwitz, Joseph W. Richards, Brian Kastl, Dorothy E. Drury, Johanna S. Hardin

Pomona Faculty Publications and Research

Our current research focuses on addressing four specific questions. Has the dominant style of volcanic expression within the quadrangle varied in a systematic fashion over time? Does the tectonic deformation within the quadrangle record significant regional patterns that vary spatially or temporally, and if so what are the scales, orientations and sources of the stress fields driving this deformation? If mantle upwelling and downwelling have played a significant role in the formation of Atla Regio and Atalanta Planitia as has been proposed, does the geology of Ganiki Planitia record evidence of northwest-directed lateral mantle flow connecting the two sites? Finally, …


Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss Jan 2011

Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss

Honors Papers

The San Andreas Fault marks one of the most tectonically active regions of the United States, producing frequent earthquakes that have decimated major population centers throughout central and southern California. Its northern regions have been thoroughly studied, but the complex behavior of the southeast portion of the fault is often neglected, in spite of its potential to nucleate a major earthquake within the next few centuries. In this study, I examined the magnetic traits of the Bishop Ash, a well-dated marker horizon of volcanic ash, to assess deformation adjacent to this part of the fault at hand-sample scale. To this …


Stable Isotopic Constraints Of The Turpan Basin In Northwestern China, Allen J. Schaen Jan 2011

Stable Isotopic Constraints Of The Turpan Basin In Northwestern China, Allen J. Schaen

Undergraduate Review

Stable isotopic analysis of sedimentary rocks can be used to reconstruct past geologic changes in the elevation and climate of topographic features such as mountain ranges and plateaus. The Tibetan Plateau is an ideal field laboratory for conducting this type of study because of the Plateau’s extreme topographic relief and relatively recent geologic growth. Here we present oxygen and carbon isotope compositions from a suite of sedimentary rock samples taken from the western Turpan Basin in northwestern China. This area of the basin collects sediment from weathering and erosion of the Bogda Shan located to the north. The goal of …


Triggering Of Volcanic Activity By Large Earthquakes, Dulcinea M. Avouris Jan 2011

Triggering Of Volcanic Activity By Large Earthquakes, Dulcinea M. Avouris

Dissertations, Master's Theses and Master's Reports - Open

Statistical analyses of temporal relationships between large earthquakes and volcanic eruptions suggest seismic waves may trigger eruptions even over great (>1000 km) distances, although the causative mechanism is not well constrained. In this study the relationship between large earthquakes and subtle changes in volcanic activity was investigated in order to gain greater insight into the relationship between dynamic stresses propagated by surface waves and volcanic response. Daily measurements from the Ozone Monitoring Instrument (OMI), onboard the Aura satellite, provide constraints on volcanic sulfur-dioxide (SO2) emission rates as a measure of subtle changes in activity. Time series of …


Recurrent Voluminous Sector Collapses At Volcán Barú, Panama, Julie A. Herrick Jan 2011

Recurrent Voluminous Sector Collapses At Volcán Barú, Panama, Julie A. Herrick

Dissertations, Master's Theses and Master's Reports - Open

Two volcanic debris avalanche deposits (VDADs), both attributed to sector collapse at Volcán Barú, Panama, have been identified after an investigation of deposits that covered more than a thousand square kilometers. The younger Barriles Deposit is constrained by two radiocarbon ages that are ~9 ka; the older Caisán Deposit is at or beyond the radiocarbon range, >43,500 ybp. The total runout length of the Caisán Deposit was ~50 km and it covers 1190 km2. The Barriles Deposit extended to about 45 km and covered an area of 966 km2, overlapping most of the Caisán. The VDADs …


Dynamics And Kinematics Of Eruptive Activity At Fuego Volcano, Guatemala 2005-2009, John J. Lyons Jan 2011

Dynamics And Kinematics Of Eruptive Activity At Fuego Volcano, Guatemala 2005-2009, John J. Lyons

Dissertations, Master's Theses and Master's Reports - Open

Volcanoes are the surficial expressions of complex pathways that vent magma and gasses generated deep in the Earth. Geophysical data record at least the partial history of magma and gas movement in the conduit and venting to the atmosphere. This work focuses on developing a more comprehensive understanding of explosive degassing at Fuego volcano, Guatemala through observations and analysis of geophysical data collected in 2005 – 2009. A pattern of eruptive activity was observed during 2005 – 2007 and quantified with seismic and infrasound, satellite thermal and gas measurements, and lava flow lengths. Eruptive styles are related to variable magma …


Sedimentary Petrology And Provenance Of The Teddy Creek Group Sw Montana, Renee Holt Jan 2011

Sedimentary Petrology And Provenance Of The Teddy Creek Group Sw Montana, Renee Holt

Undergraduate Review

A previously undocumented sequence of sedimentary rocks has been identified within SW Montana and informally named the Teddy Creek Group (TCG). This project focuses on the field relations, mineral compositions, and textures of these rocks to determine their origin and relationship to the more regionally extensive Cenozoic Renova Formation.


State Of The Climate In 2010, Jessica Blunden, Derek S. Arndt, Molly O. Baringer Jan 2011

State Of The Climate In 2010, Jessica Blunden, Derek S. Arndt, Molly O. Baringer

United States Department of Commerce: Staff Publications

Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin and near-record high North Atlantic basin hurricane activity. The remaining five main hurricane basins experienced below- to well-below-normal tropical cyclone activity. The negative phase of the Arctic Oscillation was a major driver of Northern Hemisphere temperature patterns during 2009/10 winter and again in late …


Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands, Seungoon Chung, Makram T. Suidan, Albert D. Venosa Jan 2011

Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands, Seungoon Chung, Makram T. Suidan, Albert D. Venosa

United States Environmental Protection Agency: Publications

Sugarcane bagasse was partially acetylated to enhance its oil-wicking ability in saturated environments while holding moisture for hydrocarbon biodegradation. The water sorption capacity of raw bagasse was reduced fourfold after treatment, which indicated considerably increased hydrophobicity but not a limited capability to hold moisture for hydrocarbon biodegradation. Characterization results by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and surface area analyzer suggested that treated bagasse exhibited enhanced hydrophobicity and surface area. Oil wicking test results indicate that treated bagasse is more effective in wicking oil from highly saturated environments than raw bagasse and suggest that application …


Time-Lapse Three-Dimensional Inversion Of Complex Conductivity Data Using An Active Time Constrained (Atc) Approach, M. Karaoulis, A. Revil, D. D. Werkema, B. J. Minsley, W. F. Woodruff, A. Kemna Jan 2011

Time-Lapse Three-Dimensional Inversion Of Complex Conductivity Data Using An Active Time Constrained (Atc) Approach, M. Karaoulis, A. Revil, D. D. Werkema, B. J. Minsley, W. F. Woodruff, A. Kemna

United States Environmental Protection Agency: Publications

Induced polarization (more precisely the magnitude and phase of impedance of the subsurface) is measured using a network of electrodes located at the ground surface or in boreholes. This method yields important information related to the distribution of permeability and contaminants in the shallow subsurface. We propose a new time-lapse 3-D modelling and inversion algorithm to image the evolution of complex conductivity over time.We discretize the subsurface using hexahedron cells. Each cell is assigned a complex resistivity or conductivity value. Using the finite-element approach, we model the in-phase and out-of-phase (quadrature) electrical potentials on the 3-D grid, which are then …


Ddt And Other Organohalogen Pesticides In Aquatic Organisms, Nancy Beckvar, Guilherme R. Lotufo Jan 2011

Ddt And Other Organohalogen Pesticides In Aquatic Organisms, Nancy Beckvar, Guilherme R. Lotufo

United States Environmental Protection Agency: Publications

Organohalogen (OH) compounds are persistent hydrocarbon compounds containing a halogen group, often chlorine or bromine, that substitutes for hydrogen atoms in different positions in the hydrocarbon. They may occur naturally, but this chapter's focus is on synthetically produced compounds, mainly organochlorines, that were produced for use as pesticides. Nine OH compounds (aldrin, chlordane, dichlorodiphenyltrichloroethane [DDT], dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene) are in the top 12 list of particularly toxic and persistent organic pollutants (POPs) identified by the Stockholm Convention treaty implemented in 2004 under the United Nations Environment Program (UNEP). More than 90 countries have signed on to …


Characteristics Of Suspended And Streambed Sediment Within Constructed Chutes And The Main Channel At Upper Hamburg And Glovers Point Bends, Missouri River, Nebraska, 2008, Brenda K. Woodward, David L. Rus Jan 2011

Characteristics Of Suspended And Streambed Sediment Within Constructed Chutes And The Main Channel At Upper Hamburg And Glovers Point Bends, Missouri River, Nebraska, 2008, Brenda K. Woodward, David L. Rus

United States Geological Survey: Water Reports and Publications

The Umited States Army Corps of Engineers, Omaha District, as part of the Missouri River Bank Stabilization and Navigation Mitigation Project, has constructed 17 off-channel chutes along the channelized Missouri River, downstream from Sioux City, Iowa, to increase habitat diversity. To better understand characteristics of suspended and streambed sediment within these constructed chutes, the United States Geological Survey (USGS) investigated specific aspects of chute design and function in relation to sediment characteristics including: (1) effects of inlet structures; (2) changes occurring between the inlet and the outlet of a chute; (3) effects of chutes on sediment characteristics in the main …


Sediment Samples And Channel-Geometry Data, Lower Platte River Watershed, Nebraska, 2010, Nathaniel J. Schaepe, Jason S. Alexander Jan 2011

Sediment Samples And Channel-Geometry Data, Lower Platte River Watershed, Nebraska, 2010, Nathaniel J. Schaepe, Jason S. Alexander

United States Geological Survey: Water Reports and Publications

The relation between channel width and stream physical habitat in the lower Platte River in eastern Nebraska was studied as part of the lower Platte River Cumulative Impact Study. The purpose of this component was to document the grain-size distribution of sediment deposited as specific types of physical features, such as sandbars, banks, and stream beds within different hydraulic habitats, within the lower Platte River system. In so doing, the major sources of sediment for sandbar creation downstream are described. Sediment samples were collected from 11 reaches of the lower Platte River from Silver Creek, Nebraska, to the mouth of …


Helicopter Electromagnetic And Magnetic Geophysical Survey Data, Swedeburg And Sprague Study Areas, Eastern Nebraska, May 2009, B. D. Smith, J. D. Abraham, J. C. Cannia, B. J. Minsley, L. B. Ball, Gregory V. Steele, M. Deszcz-Pan Jan 2011

Helicopter Electromagnetic And Magnetic Geophysical Survey Data, Swedeburg And Sprague Study Areas, Eastern Nebraska, May 2009, B. D. Smith, J. D. Abraham, J. C. Cannia, B. J. Minsley, L. B. Ball, Gregory V. Steele, M. Deszcz-Pan

United States Geological Survey: Water Reports and Publications

This report is a release of digital data from a helicopter electromagnetic and magnetic survey conducted by Fugro Airborne Surveys in areas of eastern Nebraska as part of a joint hydrologic study by the Lower Platte North and Lower Platte South Natural Resources Districts, and the Umited States Geological Survey (USGS). The survey flight lines covered 1,418.6 line km (882 line mile). The survey was flown from April 22 to May 2, 2009. The objective of the contracted survey was to improve the understanding of the relation between surface water and groundwater systems critical to developing groundwater models used in …


Selected Approaches To Estimate Water-Budget Components Of The High Plains, 1940 Through 1949 And 2000 Through 2009, Jennifer S. Stanton, Sharon L. Qi, Derek W. Ryter, Sarah E. Falk, Natalie A. Houston, Steven M. Peterson, Stephen M. Westenbroek, Scott C. Christenson Jan 2011

Selected Approaches To Estimate Water-Budget Components Of The High Plains, 1940 Through 1949 And 2000 Through 2009, Jennifer S. Stanton, Sharon L. Qi, Derek W. Ryter, Sarah E. Falk, Natalie A. Houston, Steven M. Peterson, Stephen M. Westenbroek, Scott C. Christenson

United States Geological Survey: Water Reports and Publications

The High Plains aquifer, underlying almost 112 million acres in the central United States, is one of the largest aquifers in the Nation. It is the primary water supply for drinking water, irrigation, animal production, and industry in the region. Expansion of irrigated agriculture throughout the past 60 years has helped make the High Plains one of the most productive agricultural regions in the Nation. Extensive withdrawals of groundwater for irrigation have caused water-level declines in many parts of the aquifer and increased concerns about the long-term sustainability of the aquifer.

Quantification of water-budget components is a prerequisite for effective …


Demographic Responses Of Least Terns And Piping Plovers To The 2011 Missouri River Flood—A Large-Scale Case Study, Michael J. Anteau, Mark H. Sherfy, Terry L. Shaffer, Rose J. Swift, Dustin L. Toy, Colin M. Dovichin Jan 2011

Demographic Responses Of Least Terns And Piping Plovers To The 2011 Missouri River Flood—A Large-Scale Case Study, Michael J. Anteau, Mark H. Sherfy, Terry L. Shaffer, Rose J. Swift, Dustin L. Toy, Colin M. Dovichin

United States Geological Survey: Publications

2011 led to substantial changes in abundance and distribution of unvegetated sand habitat. This river system is a major component of the breeding range for interior Least terns (Sternula antillarum; “terns”) and piping plovers (Charadrius melodus; “plovers”), both of which are Federally listed ground-nesting birds that prefer open, unvegetated sand and gravel nesting substrates on sandbars and shorelines. The 2011 flood inundated essentially all tern and plover nesting habitat during 2011, but it had potential to generate post-flood habitat conditions that favored use by terns and plovers in subsequent years. We compared several tern and plover demographic parameters during the …


A Trans-Dimensional Bayesian Markov Chain Monte Carlo Algorithm For Model Assessment Using Frequency-Domain Electromagnetic Data, Burke J. Minsley Jan 2011

A Trans-Dimensional Bayesian Markov Chain Monte Carlo Algorithm For Model Assessment Using Frequency-Domain Electromagnetic Data, Burke J. Minsley

United States Geological Survey: Staff Publications

A meaningful interpretation of geophysical measurements requires an assessment of the space of models that are consistent with the data, rather than just a single, ‘best’ model which does not convey information about parameter uncertainty. For this purpose, a trans-dimensional Bayesian Markov chain Monte Carlo (MCMC) algorithm is developed for assessing frequency domain electromagnetic (FDEM) data acquired from airborne or ground-based systems. By sampling the distribution of models that are consistent with measured data and any prior knowledge, valuable inferences can be made about parameter values such as the likely depth to an interface, the distribution of possible resistivity values …


Hydrogeophysical Investigations At Hidden Dam, Raymond, California, Burke J. Minsley, Bethany L. Burton, Scott Ikard, Michael H. Powers Jan 2011

Hydrogeophysical Investigations At Hidden Dam, Raymond, California, Burke J. Minsley, Bethany L. Burton, Scott Ikard, Michael H. Powers

United States Geological Survey: Staff Publications

Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, …


The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane Jan 2011

The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane

United States Geological Survey: Staff Publications

Many endangered species laws provide exceptions to legislated prohibitions through incidental take provisions as long as take is the result of unintended consequences of an otherwise legal activity. These allowances presumably invoke the theory of demographic compensation, commonly applied to harvested species, by allowing limited harm as long as the probability of the species’ survival or recovery is not reduced appreciably. Demographic compensation requires some density-dependent limits on survival or reproduction in a species’ annual cycle that can be alleviated through incidental take. Using a population model for piping plovers in the Great Plains, we found that when the population …


Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz Jan 2011

Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz

United States Geological Survey: Staff Publications

Selenium (Se) is a metalloid trace element that birds and other wildlife need in small amounts for good health. The main purpose of this chapter is to interpret tissue concentrations of Se. However, because food is the main source of Se accumulation for birds and other wildlife, and because dietary concentrations for effects on bird reproduction have been reported, we also provide interpretive information on Se in the diet.

Se deficiencies in domestic poultry and livestock occur in some parts of the world and must be corrected by additions of Se to the diet. However, the range of dietary concentrations …


History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott Jan 2011

History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott

United States Geological Survey: Staff Publications

The detection and interpretation of contaminants in tissues of wildlife belongs to the field of toxicology, a scientific discipline with a long, intriguing, and illustrious history (reviewed by Hayes 1991, Gallo 2001, Gilbert and Hayes 2006, Wax 2006). We review its history briefly, to provide a context for understanding the use of tissue residues in toxicology, and to explain how their use has developed over time. Because so much work has been conducted on mercury, and dioxins and polychlorinated biphenyls (PCBs), separate case histories are included that describe the evolution of the use of tissue concentrations to assess exposure and …