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Full-Text Articles in Other Earth Sciences

Integrating Land Cover Modeling And Adaptive Management To Conserve Endangered Species And Reduce Catastrophic Fire Risk, David Breininger, Brean Duncan, Mitchell Eaton, Fred Johnson, James Nichols Jul 2014

Integrating Land Cover Modeling And Adaptive Management To Conserve Endangered Species And Reduce Catastrophic Fire Risk, David Breininger, Brean Duncan, Mitchell Eaton, Fred Johnson, James Nichols

United States Geological Survey: Staff Publications

Land cover modeling is used to inform land management, but most often via a two-step process, where science informs how management alternatives can influence resources, and then, decision makers can use this information to make decisions. A more efficient process is to directly integrate science and decision-making, where science allows us to learn in order to better accomplish management objectives and is developed to address specific decisions. Co-development of management and science is especially productive when decisions are complicated by multiple objectives and impeded by uncertainty. Multiple objectives can be met by the specification of trade offs, and relevant uncertainty …

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Sex-Biased Gene Flow Among Elk In The Greater Yellowstone Ecosystem, Brian K. Hand, Shanyuan Chen, Neil Anderson, Albano Beja-Pereira, Paul C. Cross, Michael Ebinger, Hank Edwards, Robert A. Garrott, Marty D. Kardos, Matt Kauffman, Erin L. Landguth, Arthur Middleton, Brandon Scurlock, P.J. White, Pete Zager, Michael K. Schwartz, Gordon Luikart Jun 2014

Sex-Biased Gene Flow Among Elk In The Greater Yellowstone Ecosystem, Brian K. Hand, Shanyuan Chen, Neil Anderson, Albano Beja-Pereira, Paul C. Cross, Michael Ebinger, Hank Edwards, Robert A. Garrott, Marty D. Kardos, Matt Kauffman, Erin L. Landguth, Arthur Middleton, Brandon Scurlock, P.J. White, Pete Zager, Michael K. Schwartz, Gordon Luikart

United States Geological Survey: Staff Publications

We quantified patterns of population genetic structure to help understand gene flow among elk populations across the Greater Yellowstone Ecosystem. We sequenced 596 base pairs of the mitochondrial control region of 380 elk from eight populations. Analysis revealed high mitochondrial DNA variation within populations, averaging 13.0 haplotypes with high mean gene diversity (0.85). The genetic differentiation among populations for mitochondrial DNA was relatively high (FST = 0.161; P = 0.001) compared to genetic differentiation for nuclear microsatellite data (FST = 0.002; P = 0.332), which suggested relatively low female gene flow among populations. The estimated ratio of male to female …

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Nongeocentric Axial Dipole Field Behavior During The Mono Lake Excursion, Robert M. Negrini, Daniel T. Mccuan, Robert A. Horton, James D. Lopez, William S. Cassata, James E.T. Channell, Kenneth L. Verosub, Jeffrey R. Knott, Robert S. Coe, Joseph C. Liddicoat, Steven P. Lund, Larry V. Benson, Andrei M. Sarna-Wojcicki Mar 2014

Nongeocentric Axial Dipole Field Behavior During The Mono Lake Excursion, Robert M. Negrini, Daniel T. Mccuan, Robert A. Horton, James D. Lopez, William S. Cassata, James E.T. Channell, Kenneth L. Verosub, Jeffrey R. Knott, Robert S. Coe, Joseph C. Liddicoat, Steven P. Lund, Larry V. Benson, Andrei M. Sarna-Wojcicki

United States Geological Survey: Staff Publications

A new record of the Mono Lake excursion (MLE) is reported from the Summer Lake basin of Oregon, USA. Sediment magnetic properties indicate magnetite as the magnetization carrier and imply suitability of the sediments as accurate recorders of the magnetic field including relative paleointensity (RPI) variations. The magnitudes and phases of the declination, inclination, and RPI components of the new record correlate well with other coeval but lower resolution records from western North America including records from the Wilson Creek Formation exposed around Mono Lake. The virtual geomagnetic pole (VGP) path of the new record is similar to that from …

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Geology – Future Continent, Joy Wulke Feb 2014

Geology – Future Continent, Joy Wulke

The Transdisciplinary STEAM+ Journal

Terra Mirabila, a multi-media presentation illustrating the geological story of Stony Creek Granite back through complex sequence of geological events that spanned some 600 million years of early history.

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Survival Of Hatchery Gulf Sturgeon (Acipenser Oxyrinchus Desotoi Mitchill, 1815) In The Suwannee River, Florida: A 19-Year Evaluation, K. J. Sulak, M. T. Randall, J. P. Clugston Feb 2014

Survival Of Hatchery Gulf Sturgeon (Acipenser Oxyrinchus Desotoi Mitchill, 1815) In The Suwannee River, Florida: A 19-Year Evaluation, K. J. Sulak, M. T. Randall, J. P. Clugston

United States Geological Survey: Staff Publications

An experimental release of 1192 hatchery-reared, individually PIT tagged, 220 days old (296–337 mm TL) Gulf sturgeon, Acipenser oxyrinchus desotoi, was undertaken in 1992 in the Suwannee River, Florida. The original objectives of the 1992 release experiment were to: (1) evaluate survival rate of cultured Gulf sturgeon in the wild vs survival rate of their wild 1992 cohort counterparts, (2) determine the differential effect of release site within the river upon long-term survival, and (3) evaluate comparative growth rates of recaptured hatchery vs captured wild 1992 cohort Gulf sturgeon. The present investigation addressed those original objectives, plus an additional fourth …

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How Mangrove Forests Adjust To Rising Sea Level, Ken W. Krauss, Karen L. Mckee, Catherine E. Lovelock, Donald R. Cahoon, Neil Saintilan, Ruth Reef, Luzhen Chen Jan 2014

How Mangrove Forests Adjust To Rising Sea Level, Ken W. Krauss, Karen L. Mckee, Catherine E. Lovelock, Donald R. Cahoon, Neil Saintilan, Ruth Reef, Luzhen Chen

United States Geological Survey: Staff Publications

Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation …

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The Inky Story Of The Dinky Oak Gall, Ken Sulak Jan 2014

The Inky Story Of The Dinky Oak Gall, Ken Sulak

United States Geological Survey: Staff Publications

Maybe you have noticed these little spheres before – but did not give them much thought. Or maybe, you puzzled: What are these wooden pearls? How did they get there? Well, a tiny wasp, called the pea galler wasp or gallfly, Belonocnema treatae, is the culprit. The diminutive female gallfly (one of nearly a thousand species in the gall wasp family Cynipidae), about the size of a fire ant, lays eggs on a freshly budded live oak leaf in spring. When the larva hatches, it produces a chemical that induces the oak to enclose it in a protective and …

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Integrating Land Cover Modeling And Adaptive Management To Conserve Endangered Species And Reduce Catastrophic Fire Risk, David Breininger, Brean Duncan, Mitchell J. Eaton, Fred Johnson, James Nichols Jan 2014

Integrating Land Cover Modeling And Adaptive Management To Conserve Endangered Species And Reduce Catastrophic Fire Risk, David Breininger, Brean Duncan, Mitchell J. Eaton, Fred Johnson, James Nichols

United States Geological Survey: Staff Publications

Land cover modeling is used to inform land management, but most often via a two-step process, where science informs how management alternatives can influence resources, and then, decision makers can use this information to make decisions. A more efficient process is to directly integrate science and decision-making, where science allows us to learn in order to better accomplish management objectives and is developed to address specific decisions. Co-development of management and science is especially productive when decisions are complicated by multiple objectives and impeded by uncertainty. Multiple objectives can be met by the specification of tradeoffs, and relevant uncertainty can …

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Interpreting The Paleozoogeography And Sea Level History Of Thermally Anomalous Marine Terrace Faunas: A Case Study From The Last Interglacial Complex Of San Clemente Island, California, Daniel R. Muhs, Lindsey T. Groves, R. Randall Schumann Jan 2014

Interpreting The Paleozoogeography And Sea Level History Of Thermally Anomalous Marine Terrace Faunas: A Case Study From The Last Interglacial Complex Of San Clemente Island, California, Daniel R. Muhs, Lindsey T. Groves, R. Randall Schumann

United States Geological Survey: Publications

Marine invertebrate faunas with mixtures of extralimital southern and extralimital northern faunal elements, called thermally anomalous faunas, have been recognized for more than a century in the Quaternary marine terrace record of the Pacific Coast of North America. Although many mechanisms have been proposed to explain this phenomenon, no single explanation seems to be applicable to all localities where thermally anomalous faunas have been observed. Here, we describe one such thermally anomalous fossil fauna that was studied on the second emergent marine terrace at Eel Point on San Clemente Island. The Eel Point terrace complex is a composite feature, consisting …

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Identifying Sources Of Aeolian Mineral Dust: Present And Past, Daniel R. Muhs, Joseph M. Prospero, Matthew C. Baddock, Thomas E. Gill Jan 2014

Identifying Sources Of Aeolian Mineral Dust: Present And Past, Daniel R. Muhs, Joseph M. Prospero, Matthew C. Baddock, Thomas E. Gill

United States Geological Survey: Publications

Aeolian mineral dust is an important component of the Earth’s environmental systems, playing roles in the planetary radiation balance, as a source of fertilizer for biota in both terrestrial and marine realms and as an archive for understanding atmospheric circulation and paleoclimate in the geologic past. Crucial to understanding all of these roles of dust is the identification of dust sources. Here we review the methods used to identify dust sources active at present and in the past. Contemporary dust sources, produced by both glaciogenic and non-glaciogenic processes, can be readily identified by the use of Earth-orbiting satellites. These data …

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Coastal Tectonics On The Eastern Margin Of The Pacific Rim: Late Quaternary Sea-Level History And Uplift Rates, Channel Islands National Park, California, Usa, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Stephen B. Devogel, Scott A. Minor, Deanna Laurel Jan 2014

Coastal Tectonics On The Eastern Margin Of The Pacific Rim: Late Quaternary Sea-Level History And Uplift Rates, Channel Islands National Park, California, Usa, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Stephen B. Devogel, Scott A. Minor, Deanna Laurel

United States Geological Survey: Staff Publications

The Pacific Rim is a region where tectonic processes play a significant role in coastal landscape evolution. Coastal California, on the eastern margin of the Pacific Rim, is very active tectonically and geomorphic expressions of this include uplifted marine terraces. There have been, however, conflicting estimates of the rate of late Quaternary uplift of marine terraces in coastal California, particularly for the northern Channel Islands. In the present study, the terraces on San Miguel Island and Santa Rosa Island were mapped and new age estimates were generated using uranium-series dating of fossil corals and amino acid geochronology of fossil mollusks. …

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Exposure And Food Web Transfer Of Pharmaceuticals In Ospreys (Pandion Haliaetus): Predictive Model And Empirical Data, Rebecca S. Lazarus, Barnett A. Rattner, Bryan W. Brooks, Bowen Du, Peter C. Mcgowan, Vicki S. Blazer, Mary Ann Ottinger Jan 2014

Exposure And Food Web Transfer Of Pharmaceuticals In Ospreys (Pandion Haliaetus): Predictive Model And Empirical Data, Rebecca S. Lazarus, Barnett A. Rattner, Bryan W. Brooks, Bowen Du, Peter C. Mcgowan, Vicki S. Blazer, Mary Ann Ottinger

United States Geological Survey: Staff Publications

The osprey (Pandion haliaetus) is a well‐known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water–fish–osprey food web. A screening‐level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting “wastewater effluent dominated” or “dilution dominated” scenarios were combined with pH‐specific bioconcentration factors (BCFs) to predict uptake in fish. Residues in fish and osprey food intake rate were used to calculate the daily intake (DI) of compounds by an adult female osprey. Fourteen pharmaceuticals and a drug …

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Adverse Outcome Pathway And Risks Of Anticoagulant Rodenticides To Predatory Wildlife, Barnett A. Rattner, Rebecca S. Lazarus, John E. Elliott, Richard F. Shore, Nico Van Den Brink Jan 2014

Adverse Outcome Pathway And Risks Of Anticoagulant Rodenticides To Predatory Wildlife, Barnett A. Rattner, Rebecca S. Lazarus, John E. Elliott, Richard F. Shore, Nico Van Den Brink

United States Geological Survey: Staff Publications

Despite a long history of successful use, routine application of some anticoagulant rodenticides (ARs) may be at a crossroad due to new regulatory guidelines intended to mitigate risk. An adverse outcome pathway for ARs was developed to identify information gaps and end points to assess the effectiveness of regulations. This framework describes chemical properties of ARs, established macromolecular interactions by inhibition of vitamin K epoxide reductase, cellular responses including altered clotting factor processing and coagulopathy, organ level effects such as hemorrhage, organism responses with linkages to reduced fitness and mortality, and potential consequences to predator populations. Risk assessments have led …

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Determining Hillslope Diffusion Rates In A Boreal Forest: Quaternary Fluvial Terraces In The Nenana River Valley, Central Alaska Range, Laurel Anne Walker Jan 2014

Determining Hillslope Diffusion Rates In A Boreal Forest: Quaternary Fluvial Terraces In The Nenana River Valley, Central Alaska Range, Laurel Anne Walker

Theses and Dissertations--Earth and Environmental Sciences

The subarctic boreal forest biome is predicted to experience higher magnitudes of warming than other biomes due to climate change. The effects of this warming will be pronounced in areas underlain by discontinuous permafrost where melting permafrost and distinct changes in vegetation patterns are expected. To better understand rates of hillslope diffusion in the boreal forest I have used a geomorphic process modeling approach, using data from a sequence of Quaternary fluvial terraces located in the Nenana River valley of central Alaska. I hypothesized that diffusion rates here would be slower when compared to the mid-latitudes, and faster on north …

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Nongeocentric Axial Dipole Field Behavior During The Mono Lake Excursion, Robert M. Negrini, Daniel T. Mccuan, Robert A. Horton, James D. Lopez, William S. Cassata, James E. T. Channell, Kenneth L. Verosub, Jeffrey R. Knott, Robert S. Coe, Joseph C. Liddicoat, Steven P. Lund, Larry Benson, Andrei M. Sarna-Wojcicki Jan 2014

Nongeocentric Axial Dipole Field Behavior During The Mono Lake Excursion, Robert M. Negrini, Daniel T. Mccuan, Robert A. Horton, James D. Lopez, William S. Cassata, James E. T. Channell, Kenneth L. Verosub, Jeffrey R. Knott, Robert S. Coe, Joseph C. Liddicoat, Steven P. Lund, Larry Benson, Andrei M. Sarna-Wojcicki

United States Geological Survey: Staff Publications

A new record of the Mono Lake excursion (MLE) is reported from the Summer Lake Basin of Oregon, USA. Sediment magnetic properties indicate magnetite as the magnetization carrier and imply suitability of the sediments as accurate recorders of the magnetic field including relative paleointensity (RPI) variations. The magnitudes and phases of the declination, inclination, and RPI components of the new record correlate well with other coeval but lower resolution records from western North America including records from the Wilson Creek Formation exposed around Mono Lake. The virtual geomagnetic pole (VGP) path of the new record is similar to that from …

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Wetland Reserve Program Enhances Site Occupancy And Species Richness In Assemblages Of Anuran Amphibians In The Mississippi Alluvial Valley, Usa, Susan C. Walls, J. Hardin Waddle, Stephen P. Faulkner Jan 2014

Wetland Reserve Program Enhances Site Occupancy And Species Richness In Assemblages Of Anuran Amphibians In The Mississippi Alluvial Valley, Usa, Susan C. Walls, J. Hardin Waddle, Stephen P. Faulkner

United States Geological Survey: Staff Publications

We measured amphibian habitat use to quantify the effectiveness of conservation practices implemented under the Wetland Reserve Program (WRP), an initiative of the U.S. Department of Agriculture’s Natural Resources Conservation Service. From February to June 2007, we quantified calling male anurans in cultivated cropland, former cultivated cropland restored through the WRP, and mature bottomland hardwood forest. Sites were located in two watersheds within the Mississippi Alluvial Valley of Arkansas and Louisiana, USA. We estimated detection probability and site occupancy within each land use category using a Bayesian hierarchical model of community species occurrence, and derived an estimate of species richness …

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Mapping Irrigated Areas In Afghanistan Over The Past Decade Using Modis Ndvi, Md. Shahriar Pervez, Michael Budde, James Rowland Jan 2014

Mapping Irrigated Areas In Afghanistan Over The Past Decade Using Modis Ndvi, Md. Shahriar Pervez, Michael Budde, James Rowland

United States Geological Survey: Staff Publications

Agricultural production capacity contributes to food security in Afghanistan and is largely dependent on irrigated farming, mostly utilizing surface water fed by snowmelt. Because of the high contribution of irrigated crops (> 80%) to total agricultural production, knowing the spatial distribution and year-to-year variability in irrigated areas is imperative to monitoring food security for the country. We used 16-day composites of the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to create 23-point time series for each year from 2000 through 2013. Seasonal peak values and time series were used in a threshold-dependent decision tree …

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Structural Equation Models Of Vmt Growth In Us Urbanised Areas, Reid Ewing, Shima Hamidi, Frank Gallivan, Arthur C. Nelson, James B. Grace Jan 2014

Structural Equation Models Of Vmt Growth In Us Urbanised Areas, Reid Ewing, Shima Hamidi, Frank Gallivan, Arthur C. Nelson, James B. Grace

United States Geological Survey: Staff Publications

Vehicle miles travelled (VMT) is a primary performance indicator for land use and transportation, bringing with it both positive and negative externalities. This study updates and refines previous work on VMT in urbanised areas, using recent data, additional metrics and structural equation modelling (SEM). In a cross-sectional model for 2010, population, income and freeway capacity are positively related to VMT, while gasoline prices, development density and transit service levels are negatively related. Findings of the cross-sectional model are generally confirmed in a more tightly controlled longitudinal study of changes in VMT between 2000 and 2010, the first model of its …

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Merging Remote Sensing Data And National Agricultural Statistics To Model Change In Irrigated Agriculture, Jesslyn F. Brown, Md Shahriar Pervez Jan 2014

Merging Remote Sensing Data And National Agricultural Statistics To Model Change In Irrigated Agriculture, Jesslyn F. Brown, Md Shahriar Pervez

United States Geological Survey: Staff Publications

Over 22 million hectares (ha) of U.S. croplands are irrigated. Irrigation is an intensified agricultural land use that increases crop yields and the practice affects water and energy cycles at, above, and below the land surface. Until recently, there has been a scarcity of geospatially detailed information about irrigation that is comprehensive, consistent, and timely to support studies tying agricultural land use change to aquifer water use and other factors. This study shows evidence for a recent overall net expansion of 522 thousand ha across the U.S. (2.33%) and 519 thousand ha (8.7%) in irrigated cropped area across the High …

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Comparing Crop Land Net Primary Production Estimates From Inventory, A Satellite-Based Model, And A Process-Based Model In The Midwest Of The United States Zhengpeng, Zhengpeng Li, Shuguang Liu, Zhengxi Tan, Normann B. Bliss, Claudia J. Young, Tristram O. West, Stephen M. Ogle Jan 2014

Comparing Crop Land Net Primary Production Estimates From Inventory, A Satellite-Based Model, And A Process-Based Model In The Midwest Of The United States Zhengpeng, Zhengpeng Li, Shuguang Liu, Zhengxi Tan, Normann B. Bliss, Claudia J. Young, Tristram O. West, Stephen M. Ogle

United States Geological Survey: Staff Publications

Accurately quantifying the spatial and temporal variability of net primary production (NPP) for crop-lands is essential to understand regional cropland carbon dynamics. We compared three NPP estimates for croplands in the Midwestern United States: inventory-based estimates using crop yield data from the U.S. Department of Agriculture (USDA) National Agricultural Statistics Service (NASS); estimates from the satellite-based Moderate Resolution Imaging Spectro radiometer (MODIS) NPP product; and esti-mates from the General Ensemble bio geochemical Modeling System (GEMS) process-based model. The three methods estimated mean NPP in the range of 469–687 g C m−2yr−1and total NPP in the range …

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Summary Of The Snowmastodon Project Special Volume: A High-Elevation, Multi-Proxy Biotic And Environmental Record Of Mis 6–4 From The Ziegler Reservoir Fossil Site, Snowmass Village, Colorado, Usa, Ian M. Miller, Jeffrey S. Pigati, R. Scott Anderson, Kirk R. Johnson, Shannon A. Mahan, Thomas A. Ager, Richard G. Baker, Maarten Blaauw, Jordon Bright, Peter M. Brown, Bruce Bryant, Zachary T. Calamari, Paul E. Carrara, Michael D. Cherney, John R. Demboski, Scott A. Elias, Daniel C. Fisher, Harrison J. Gray, Danielle R. Haskett, Jeffrey S. Honke, Stephen T. Jackson, Gonzalo Jiménez- Moreno, Douglas Kline, Eric M. Leonard, Nathaniel A. Lifton, Carol Lucking, H. Gregory Mcdonald, Dane M. Miller, Daniel R. Muhs, Stephen E. Nash, Cody Newton, James B. Paces, Lesley Petrie, Mitchell A. Plummer, David F. Porinchu, Adam N. Rountrey, Eric Scott, Joseph J.W. Sertich, Saxon E. Sharpe, Gary L. Skipp, Laura E. Strickland, Richard K. Stucky, Robert S. Thompson, Jim Wilson Jan 2014

Summary Of The Snowmastodon Project Special Volume: A High-Elevation, Multi-Proxy Biotic And Environmental Record Of Mis 6–4 From The Ziegler Reservoir Fossil Site, Snowmass Village, Colorado, Usa, Ian M. Miller, Jeffrey S. Pigati, R. Scott Anderson, Kirk R. Johnson, Shannon A. Mahan, Thomas A. Ager, Richard G. Baker, Maarten Blaauw, Jordon Bright, Peter M. Brown, Bruce Bryant, Zachary T. Calamari, Paul E. Carrara, Michael D. Cherney, John R. Demboski, Scott A. Elias, Daniel C. Fisher, Harrison J. Gray, Danielle R. Haskett, Jeffrey S. Honke, Stephen T. Jackson, Gonzalo Jiménez- Moreno, Douglas Kline, Eric M. Leonard, Nathaniel A. Lifton, Carol Lucking, H. Gregory Mcdonald, Dane M. Miller, Daniel R. Muhs, Stephen E. Nash, Cody Newton, James B. Paces, Lesley Petrie, Mitchell A. Plummer, David F. Porinchu, Adam N. Rountrey, Eric Scott, Joseph J.W. Sertich, Saxon E. Sharpe, Gary L. Skipp, Laura E. Strickland, Richard K. Stucky, Robert S. Thompson, Jim Wilson

United States Geological Survey: Staff Publications

In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones …

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Radiocarbon Dating Loess Deposits In The Mississippi Valley Using Terrestrial Gastropod Shells (Polygyridae, Helicinidae, And Discidae), Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, David A. Grimley, Jeffrey C. Nekola Jan 2014

Radiocarbon Dating Loess Deposits In The Mississippi Valley Using Terrestrial Gastropod Shells (Polygyridae, Helicinidae, And Discidae), Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, David A. Grimley, Jeffrey C. Nekola

United States Geological Survey: Staff Publications

Small terrestrial gastropod shells (mainly Succineidae) have been used successfully to date late Quaternary loess deposits in Alaska and the Great Plains. However, Succineidae shells are less common in loess deposits in the Mississippi Valley compared to those of the Polygyridae, Helicinidae, and Discidae families. In this study, we conducted several tests to determine whether shells of these gastropods could provide reliable ages for loess deposits in the Mississippi Valley. Our results show that most of the taxa that we investigated incorporate small amounts (1–5%) of old carbon from limestone in their shells, meaning that they should yield ages that …

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Geologic Setting And Stratigraphy Of The Ziegler Reservoir Fossil Site, Snowmass Village, Colorado, Jeffrey S. Pigati, Ian M. Miller, Kirk R. Johnson, Jeffrey S. Honke, Paul E. Carrara, Daniel R. Muhs, Gary Skipp, Bruce Bryant Jan 2014

Geologic Setting And Stratigraphy Of The Ziegler Reservoir Fossil Site, Snowmass Village, Colorado, Jeffrey S. Pigati, Ian M. Miller, Kirk R. Johnson, Jeffrey S. Honke, Paul E. Carrara, Daniel R. Muhs, Gary Skipp, Bruce Bryant

United States Geological Survey: Staff Publications

The geologic setting of the Ziegler Reservoir fossil site is somewhat unusual—the sediments containing the Pleistocene fossils were deposited in a lake on top of a ridge. The lake basin was formed near Snowmass Village, Colorado (USA) when a glacier flowing down Snowmass Creek Valley became thick enough to overtop a low point in the eastern valley wall and entered the head of Brush Creek Valley. When the glacier retreated at about 155–130 ka, near the end of Marine Oxygen Isotope Stage 6, the Brush Creek Valley lobe left behind a moraine that impounded a small alpine lake. The lake …

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Toxicity Of Pb‐Contaminated Soil To Japanese Quail (Coturnix Japonica) And The Use Of The Blood–Dietary Pb Slope In Risk Assessment, W. Nelson Beyer, Yu Chen, Paula Henry, Thomas May, David Mosby, Barnett A. Rattner, Valerie I. Shearn-Bochsler, Daniel Sprague, John Weber Jan 2014

Toxicity Of Pb‐Contaminated Soil To Japanese Quail (Coturnix Japonica) And The Use Of The Blood–Dietary Pb Slope In Risk Assessment, W. Nelson Beyer, Yu Chen, Paula Henry, Thomas May, David Mosby, Barnett A. Rattner, Valerie I. Shearn-Bochsler, Daniel Sprague, John Weber

United States Geological Survey: Staff Publications

This study relates tissue concentrations and toxic effects of Pb in Japanese quail (Coturnix japonica) to the dietary exposure of soil‐borne Pb associated with mining and smelting. From 0% to 12% contaminated soil, by weight, was added to 5 experimental diets (0.12 to 382mg Pb/kg, dry wt) and fed to the quail for 6 weeks. Benchmark doses associated with a 50% reduction in delta‐aminolevulinic acid dehydratase activity were 0.62mg Pb/kg in the blood, dry wt, and 27mg Pb/kg in the diet. Benchmark doses associated with a 20% increase in the concentration of erythrocyte protoporphyrin were 2.7mg Pb/kg in …

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Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols Jan 2014

Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols

United States Geological Survey: Staff Publications

Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model …

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Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification, Brett T. Mcclinktock, Larissa L. Bailey, Brian P. Dreher, William A. Link Jan 2014

Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification, Brett T. Mcclinktock, Larissa L. Bailey, Brian P. Dreher, William A. Link

United States Geological Survey: Staff Publications

As noninvasive sampling techniques for animal populations have become more popular, there has been increasing interest in the development of capture-recapture models that can accommodate both imperfect detection and misidentification of individuals (e.g., due to genotyping error). However, current methods do not allow for individual variation in parameters, such as detection or survival probability. Here we develop misidentification models for capture-recapture data that can simultaneously account for temporal variation, behavioral effects and individual heterogeneity in parameters. To facilitate Bayesian inference using our approach, we extend standard probit regression techniques to latent multinomial models where the dimension and zeros of the …

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Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols Jan 2014

Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols

United States Geological Survey: Staff Publications

Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model …

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Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification1, Brett T. Mcclintock, Larissa L. Bailey, Brian P. Dreher, William A. Link Jan 2014

Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification1, Brett T. Mcclintock, Larissa L. Bailey, Brian P. Dreher, William A. Link

United States Geological Survey: Staff Publications

As noninvasive sampling techniques for animal populations have become more popular, there has been increasing interest in the development of capture-recapture models that can accommodate both imperfect detection and misidentification of individuals (e.g., due to genotyping error). However, current methods do not allow for individual variation in parameters, such as detection or survival probability. Here we develop misidentification models for capture-recapture data that can simultaneously account for temporal variation, behavioral effects and individual heterogeneity in parameters. To facilitate Bayesian inference using our approach, we extended standard probit regression techniques to latent multinomial models where the dimension and zeros of the …

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Loess Records, Daniel R. Muhs, Stephen R. Cattle, Onn Crouvi, Denis-Didier Rousseau, Jimin Sun, Marcelo A. Zárate Jan 2014

Loess Records, Daniel R. Muhs, Stephen R. Cattle, Onn Crouvi, Denis-Didier Rousseau, Jimin Sun, Marcelo A. Zárate

United States Geological Survey: Staff Publications

Loess is aeolian sediment, dominated by silt-sized particles, that is identifiable in the field as a distinct sedimentary body. It covers a significant portion of the land surface of the Earth and as such constitutes one of the most important archives of long-term dust deposition. Large tracts of loess cover Europe, Asia, South America, and North America, and smaller loess bodies are found covering parts of Africa, the Middle East, New Zealand, and Australia. Loess thickness, particle size, and carbonate content decrease downwind from sources, trends that are powerful tools for reconstructing paleowinds. Many loess sections consist of relatively thick …

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Evidence Of Repeated Wildfires Prior To Human Occupation On San Nicolas Island, California, Jeffrey S. Pigati, John P. Mcgeehin, Gary L. Skipp, Daniel R. Muhs Jan 2014

Evidence Of Repeated Wildfires Prior To Human Occupation On San Nicolas Island, California, Jeffrey S. Pigati, John P. Mcgeehin, Gary L. Skipp, Daniel R. Muhs

United States Geological Survey: Staff Publications

Understanding how early humans on the California Channel Islands might have changed local fire regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ~37 and 25 ka (thousands of calibrated 14C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and discrete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features …

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