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United States Geological Survey: Staff Publications

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Full-Text Articles in Other Environmental Sciences

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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Evidence Of Songbird Intoxication From Rozol Application At A Black-Tailed Prairie Dog Colony, Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. Rice Jun 2013

Evidence Of Songbird Intoxication From Rozol Application At A Black-Tailed Prairie Dog Colony, Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. Rice

United States Geological Survey: Staff Publications

Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide RozolH (0.005% chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained chlorophacinone residue concentrations of 0.59 and 0.49 mg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored …

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Influence Of Management And Precipitation On Carbon Fluxes In Great Plains Grasslands, Matthew Rigge, Bruce K. Wylie, Li Zhang, Stephen P. Boyte Jan 2013

Influence Of Management And Precipitation On Carbon Fluxes In Great Plains Grasslands, Matthew Rigge, Bruce K. Wylie, Li Zhang, Stephen P. Boyte

United States Geological Survey: Staff Publications

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data …

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Modeling Rain-Fed Maize Vulnerability To Droughts Using The Standardized Precipitation Index From Satellite Estimated Rainfall-Southern Malawi Case Study, Harikishan Jayanthi, Gregory J. Husak, Chris Funk, Tamuka Magadzire, Adams Chavula, James P. Verdin Jan 2013

Modeling Rain-Fed Maize Vulnerability To Droughts Using The Standardized Precipitation Index From Satellite Estimated Rainfall-Southern Malawi Case Study, Harikishan Jayanthi, Gregory J. Husak, Chris Funk, Tamuka Magadzire, Adams Chavula, James P. Verdin

United States Geological Survey: Staff Publications

During 1990s, disaster risk reduction emerged as a novel, proactive approach to managing risks from natural hazards. The World Bank, USAlD, and other international donor agencies began making efforts to mainstream disaster risk reduction in countries whose population and economies were heavily dependent on rain-fed agriculture. This approach has more significance in light of the increasing climatic hazard patterns and the climate scenarios projected for different hazard prone countries in the world. The Famine Early Warning System Network (FEWS NET) has been monitoring the food security issues in the sub-Saharan Africa, Asia and in Haiti. FEWS NET monitors the rainfall …

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Characterizing Ledaps Surface Reflectance Products By Comparisons With Aeronet, Field Spectrometer, And Modis Data, T.K. Maiersperger, P.L. Scaramuzza, L. Leigh, S. Shrestha, K.P. Gallo, C.B. Jenkerson, J.L. Dwyer Jan 2013

Characterizing Ledaps Surface Reflectance Products By Comparisons With Aeronet, Field Spectrometer, And Modis Data, T.K. Maiersperger, P.L. Scaramuzza, L. Leigh, S. Shrestha, K.P. Gallo, C.B. Jenkerson, J.L. Dwyer

United States Geological Survey: Staff Publications

This study provides a baseline quality check on provisional Landsat Surface Reflectance (SR) products as generated by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software. Characterization of the Landsat SR products leveraged comparisons between aerosol optical thickness derived from LEDAPS and measured by Aerosol Robotic Network (AERONET), as well as reflectance correlations with field spectrometer and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results consistently indicated similarity between LEDAPS and alternative data products in longer wavelengths over vegetated areas with no adjacent water, while less reliable performance was …

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Radiocarbon Dating Late Quaternary Loess Deposits Using Small Terrestrial Gastropod Shells, Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, E. Arthur Bettis Iii Jan 2013

Radiocarbon Dating Late Quaternary Loess Deposits Using Small Terrestrial Gastropod Shells, Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, E. Arthur Bettis Iii

United States Geological Survey: Staff Publications

No abstract provided.

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Impacts Of Migratory Sandhill Cranes (Grus Canadensis) On Microbial Water Quality In The Central Platte River, Nebraska, Usa, Jason R. Vogel, Dale W. Griffin, Hon S. Ip, Nicholas J. Ashbolt, Matthew T. Moser, Jingrang Lu, Mary K. Beitz, Hodon Ryu, Jorge W. Santo Domingo Jan 2013

Impacts Of Migratory Sandhill Cranes (Grus Canadensis) On Microbial Water Quality In The Central Platte River, Nebraska, Usa, Jason R. Vogel, Dale W. Griffin, Hon S. Ip, Nicholas J. Ashbolt, Matthew T. Moser, Jingrang Lu, Mary K. Beitz, Hodon Ryu, Jorge W. Santo Domingo

United States Geological Survey: Staff Publications

Wild birds have been shown to be significant sources of numerous types of pathogens that are relevant to humans and agriculture. The presence of large numbers of migratory birds in such a sensitive and important ecosystem as the Platte River in central Nebraska, USA, could potentially serve a significant source of birdderived pathogens in the water/sediment and riverine environment. In 2009 and 2010, a study was completed to investigate the potential water-quality impacts of Sandhill Cranes and Snow Geese on the microbial water quality of the central Platte River during their spring migration period. Fecal material, river-bottom sediment, and water …

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Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks Jan 2013

Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks

United States Geological Survey: Staff Publications

High-latitude lakes are important for terrestrial carbon dynamics and waterfowl habitat driving a need to better understand controls on lake area changes. To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate remotely sensed imagery with lake water isotope compositions and hydroclimatic parameters. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half …

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Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti Jan 2013

Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti

United States Geological Survey: Staff Publications

Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age mega fauna was more diverse in species and possibly contained 6x more individual animals than live in the region today. Mega faunal biomass during the last ice age may have been 30x greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly …

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Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs Jan 2013

Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is aeolian silt visible in the field as a sedimentary body. It covers a significant portion of the land surface of the Earth. Loess thickness, particle size, and carbonate content decrease downwind from sources, useful trends for paleowinds. Many loess sections consist of relatively thick deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition slowed significantly. Loess in most regions was deposited during glacial periods and paleosols formed during interglacial periods. Loess has the potential to record the timing and environment of glacial–interglacial cycles of the Quaternary on many continents.

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The Floodplain Food Web Mosaic: A Study Of Its Importance To Salmon And Steelhead With Implications For Their Recovery, J. Ryan Bellmore, Colden V. Baxter, Kyle Martens, Patrick J. Connolly Jan 2013

The Floodplain Food Web Mosaic: A Study Of Its Importance To Salmon And Steelhead With Implications For Their Recovery, J. Ryan Bellmore, Colden V. Baxter, Kyle Martens, Patrick J. Connolly

United States Geological Survey: Staff Publications

Although numerous studies have attempted to place species of interest within the context of food webs, such efforts have generally occurred at small scales or disregard potentially important spatial heterogeneity. If food web approaches are to be employed to manage species, studies are needed that evaluate the multiple habitats and associated webs of interactions in which these species participate. Here, we quantify the food webs that sustain rearing salmon and steelhead within a floodplain landscape of the Methow River, Washington, USA, a location where restoration has been proposed to restore side channels in an attempt to recover anadromous fishes. We …

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Predictive Models For Escherichia Coli Concentrations At Inland Lake Beaches And Relationship Of Model Variables To Pathogen Detection, Donna S. Francy, Erin A. Stelzer, Joseph W. Duris, Amie M. G. Brady, John H. Harrison, Heather E. Johnson, Michael W. Ware Jan 2013

Predictive Models For Escherichia Coli Concentrations At Inland Lake Beaches And Relationship Of Model Variables To Pathogen Detection, Donna S. Francy, Erin A. Stelzer, Joseph W. Duris, Amie M. G. Brady, John H. Harrison, Heather E. Johnson, Michael W. Ware

United States Geological Survey: Staff Publications

Predictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models for Escherichia coli and to understand the links between E. coli concentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites …

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The Malthusian–Darwinian Dynamic And The Trajectory Of Civilization, Jeffrey C. Nekola, Craig D. Allen, James H. Brown, Joseph R. Burger, Ana D. Davidson, Trevor S. Fristoe, Marcus J. Hamilton, Sean T. Hammond, Astrid Kodric-Brown, Norman Mercado-Silva, Jordan G. Okie Jan 2013

The Malthusian–Darwinian Dynamic And The Trajectory Of Civilization, Jeffrey C. Nekola, Craig D. Allen, James H. Brown, Joseph R. Burger, Ana D. Davidson, Trevor S. Fristoe, Marcus J. Hamilton, Sean T. Hammond, Astrid Kodric-Brown, Norman Mercado-Silva, Jordan G. Okie

United States Geological Survey: Staff Publications

Two interacting forces influence all populations: the Malthusian dynamic of exponential growth until resource limits are reached, and the Darwinian dynamic of innovation and adaptation to circumvent these limits through biological and/or cultural evolution. The specific manifestations of these forces in modern human society provide an important context for determining how humans can establish a sustainable relationship with the finite Earth.

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Reproductive Health Of Yellow Perch Perca Flavescens In Selected Tributaries Of The Chesapeake Bay, Vicki S. Blazer, Alfred E. Pinkney, Jill A. Jenkins, Luke R. Iwanowicz, Steven Minkkinen, Rassa O. Draugelis-Dale, James H. Uphoff Jan 2013

Reproductive Health Of Yellow Perch Perca Flavescens In Selected Tributaries Of The Chesapeake Bay, Vicki S. Blazer, Alfred E. Pinkney, Jill A. Jenkins, Luke R. Iwanowicz, Steven Minkkinen, Rassa O. Draugelis-Dale, James H. Uphoff

United States Geological Survey: Staff Publications

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations …

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Performance Of Human Fecal Anaerobe-Associated Pcr-Based Assays In A Multi-Laboratory Method Evaluation Study, Blythe A. Layton, Yiping Cao, Darcy L. Ebentier, Kaitlyn Hanley, Elisenda Balleste, Joao Brandao, Muruleedhara Byappanahalli, Reagan Converse, Andreas H. Farnleitner, Jennifer Gentry-Shields, Maribeth L. Gidley, Michele Gourmelon, Chang Soo Lee, Jiyoung Lee, Solen Lozach, Tania Madi, Wim G. Meijer, Rachel Noble, Lindsay Peed, Georg H. Reischer, Raquel Rodrigues, Joan B. Rose, Alexander Schriewer, Chris Sinigalliano, Sangeetha Srinivasan, Jill Stewart, Laurie C. Van De Werfhorst, Dan Wang, Richard Whitman, Stefan Wuertz, Jenny Jay, Patricia A. Holden, Alexandria B. Boehm, Orin Shanks, John F. Griffith Jan 2013

Performance Of Human Fecal Anaerobe-Associated Pcr-Based Assays In A Multi-Laboratory Method Evaluation Study, Blythe A. Layton, Yiping Cao, Darcy L. Ebentier, Kaitlyn Hanley, Elisenda Balleste, Joao Brandao, Muruleedhara Byappanahalli, Reagan Converse, Andreas H. Farnleitner, Jennifer Gentry-Shields, Maribeth L. Gidley, Michele Gourmelon, Chang Soo Lee, Jiyoung Lee, Solen Lozach, Tania Madi, Wim G. Meijer, Rachel Noble, Lindsay Peed, Georg H. Reischer, Raquel Rodrigues, Joan B. Rose, Alexander Schriewer, Chris Sinigalliano, Sangeetha Srinivasan, Jill Stewart, Laurie C. Van De Werfhorst, Dan Wang, Richard Whitman, Stefan Wuertz, Jenny Jay, Patricia A. Holden, Alexandria B. Boehm, Orin Shanks, John F. Griffith

United States Geological Survey: Staff Publications

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while …

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Human-Caused Mortality Influences Spatial Population Dynamics: Pumas In Landscapes With Varying Mortality Risks, Jesse R. Newby, L. Scott Mills, Toni K. Ruth, Daniel H. Pletscher, Michael S. Mitchell, Howard B. Quigley, Kerry M. Murphy, Rich Desimone Jan 2013

Human-Caused Mortality Influences Spatial Population Dynamics: Pumas In Landscapes With Varying Mortality Risks, Jesse R. Newby, L. Scott Mills, Toni K. Ruth, Daniel H. Pletscher, Michael S. Mitchell, Howard B. Quigley, Kerry M. Murphy, Rich Desimone

United States Geological Survey: Staff Publications

An understanding of how stressors affect dispersal attributes and the contribution of local populations to multi-population dynamics are of immediate value to basic and applied ecology. Puma (Puma concolor) populations are expected to be influenced by inter-population movements and susceptible to human induced source–sink dynamics. Using long-term datasets we quantified the contribution of two puma populations to operationally define them as sources or sinks. The puma population in the Northern Greater Yellowstone Ecosystem (NGYE) was largely insulated from human-induced mortality by Yellowstone National Park. Pumas in the western Montana Garnet Mountain system were exposed to greater human-induced mortality, …

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A Causal Examination Of The Effects Of Confounding Factors On Multimetric Indices, Donald R. Schoolmaster Jr., James B. Grace, E. William Schweiger, Brian R. Mitchell, Glenn R. Guntenspergen Jan 2013

A Causal Examination Of The Effects Of Confounding Factors On Multimetric Indices, Donald R. Schoolmaster Jr., James B. Grace, E. William Schweiger, Brian R. Mitchell, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The development of multimetric indices (MMIs) as a means of providing integrative measures of ecosystem condition is becoming widespread. An increasingly recognized problem for the interpretability of MMIs is controlling for the potentially confounding influences of environmental covariates. Most common approaches to handling covariates are based on simple notions of statistical control, leaving the causal implications of covariates and their adjustment unstated. In this paper, we use graphical models to examine some of the potential impacts of environmental covariates on the observed signals between human disturbance and potential response metrics. Using simulations based on various causal networks, we show how …

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An Algorithmic And Information-Theoretic Approach To Multimetric Index Construction, Donald R. Schoolmaster Jr., James B. Grace, E. William Schweiger, Glenn R. Guntenspergen, Brian R. Mitchell, Kathryn M. Miller, Amanda M. Little Jan 2013

An Algorithmic And Information-Theoretic Approach To Multimetric Index Construction, Donald R. Schoolmaster Jr., James B. Grace, E. William Schweiger, Glenn R. Guntenspergen, Brian R. Mitchell, Kathryn M. Miller, Amanda M. Little

United States Geological Survey: Staff Publications

The use of multimetric indices (MMIs), such as the widely used index of biological integrity (IBI), to measure, track, summarize and infer the overall impact of human disturbance on biological communities has been steadily growing in recent years. Initially, MMIs were developed for aquatic communities using preselected biological metrics as indicators of system integrity. As interest in these bioassessment tools has grown, so have the types of biological systems to which they are applied. For many ecosystem types the appropriate biological metrics to use as measures of biological integrity are not known a priori. As a result, a variety of …

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