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Articles 151 - 180 of 861

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Implementation Of An Occupancy-Based Monitoring Protocol For A Widespread And Cryptic Species, The New England Cottontail (Sylvilagus Transitionalis), Colin P. Shea, Mitchell J. Eaton, Darryl I. Mackenzie Oct 2020

Implementation Of An Occupancy-Based Monitoring Protocol For A Widespread And Cryptic Species, The New England Cottontail (Sylvilagus Transitionalis), Colin P. Shea, Mitchell J. Eaton, Darryl I. Mackenzie

United States Geological Survey: Staff Publications

Context. Designing effective long-term monitoring strategies is essential for managing wildlife populations. Implementing a cost-effective, practical monitoring program is especially challenging for widespread but locally rare species. Early successional habitat preferred by the New England cottontail (NEC) has become increasingly rare and fragmented, resulting in substantial declines from their peak distribution in the mid-1900s. The introduction of a possible competitor species, the eastern cottontail (EC),may also have played a role. Uncertainty surrounding how these factors have contributed to NEC declines has complicated management and necessitated development of an appropriate monitoring framework to understand possible drivers of distribution and dynamics.

Aims. …


Pan American Interactions Of Amazon Precipitation, Streamflow, And Tree Growth Extremes, D. W. Stahle, M. C. A. Torbenson, I. M. Howard, D. Granato-Souza, A. C. Barbosa, S. Feng, J. Schöngart, L. Lopez, R. Villalba, J. Villanueva, K. Fernandes Oct 2020

Pan American Interactions Of Amazon Precipitation, Streamflow, And Tree Growth Extremes, D. W. Stahle, M. C. A. Torbenson, I. M. Howard, D. Granato-Souza, A. C. Barbosa, S. Feng, J. Schöngart, L. Lopez, R. Villalba, J. Villanueva, K. Fernandes

Geosciences Faculty Publications and Presentations

Rainfall and river levels in the Amazon are associated with significant precipitation anomalies of opposite sign in temperate North and South America, which is the dominant mode of precipitation variability in the Americas that often arises during extremes of the El Niño/Southern Oscillation (ENSO). This co-variability of precipitation extremes across the Americas is imprinted on tree growth and is detected when new tree-ring chronologies from the eastern equatorial Amazon are compared with hundreds of moisture-sensitive tree-ring chronologies in mid-latitude North and South America from 1759 to 2016. Pan-American co-variability exists even though the seasonality of precipitation and tree growth only …


Repetitive Sampling And Control Threshold Improve 16s Rrna Gene Sequencing Results From Produced Waters Associated With Hydraulically Fractured Shale, Jenna L. Shelton, Elliott P. Barnhart, Leslie Ruppert, Aaron M. Jubb, Madalyn S. Blondes, Christina A. Devera Sep 2020

Repetitive Sampling And Control Threshold Improve 16s Rrna Gene Sequencing Results From Produced Waters Associated With Hydraulically Fractured Shale, Jenna L. Shelton, Elliott P. Barnhart, Leslie Ruppert, Aaron M. Jubb, Madalyn S. Blondes, Christina A. Devera

United States Geological Survey: Staff Publications

Sequencing microbial DNA from deep subsurface environments is complicated by a number of issues ranging from contamination to non-reproducible results. Many samples obtained from these environments – which are of great interest due to the potential to stimulate microbial methane generation – contain low biomass. Therefore, samples from these environments are difficult to study as sequencing results can be easily impacted by contamination. In this case, the low amount of sample biomass may be effectively swamped by the contaminating DNA and generate misleading results. Additionally, performing field work in these environments can be difficult, as researchers generally have limited access …


Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes, Adam J. Knox, Björn Lardner, Amy Yackel Adams, Robert N. Reed Aug 2020

Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes, Adam J. Knox, Björn Lardner, Amy Yackel Adams, Robert N. Reed

United States Geological Survey: Staff Publications

Firearms are often used in lethal control of invasive vertebrates, but safety and regulatory aspects limit the circumstances under which they can be used. During August 2016 at the Brown Treesnake Project laboratory on Guam, we evaluated hobby‐grade Airsoft Electric Guns (AEGs; a lower powered, less‐hazardous, and less‐regulated alternative to firearms) for capture and control of small animals, with specific emphasis on invasive brown treesnakes (Boiga irregularis). Tests of AEGs differing in power with ammunition (plastic pellets) masses ranging from 0.20 to 0.39 g, fired at gelatin blocks from distances of 4, 8, and 12 m, showed that …


A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh Jul 2020

A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh

Environmental Science and Geology Faculty Research Publications

Risk-based prioritization for early detection monitoring is of utmost importance to prevent and mitigate invasive species impacts and is especially needed for large ecosystems where management resources are not sufficient to survey all locations susceptible to invasion. In this paper we describe a spatially-explicit and quantitative approach for identifying the highest risk sites for aquatic invasive species (AIS) introduction into the United States’ waters of the Laurentian Great Lakes, a vast inland sea with a surface area of 246,049 square km and a shoreline length of 16,431 km. We compiled data from geospatial metrics available across all of the US …


Studies Of Quaternary Depositional Systems Of The Coastal Plain And Inner Continental Shelf Along The Georgia Bight: South Carolina And Georgia, U.S.A., Joshua H. Long Jun 2020

Studies Of Quaternary Depositional Systems Of The Coastal Plain And Inner Continental Shelf Along The Georgia Bight: South Carolina And Georgia, U.S.A., Joshua H. Long

Electronic Theses and Dissertations

The Quaternary stratigraphy of the continental shelf offshore of South Carolina consists of stratigraphic units deposited in coastal plain, shallow marine, and shelfal environments bound by composite erosional surfaces that developed in response to numerous glacioeustatic cycles and overprinted by regional uplift. These units are commonly distributed laterally rather than stacked vertically, a function of the long-term, low shelf gradient and the resulting lack of accommodation. This study integrates high-resolution geological and geophysical data sets acquired offshore and onshore with existing data onshore into a comprehensive conceptual model describing the Quaternary geologic evolution of the coastal plain and continental shelf …


Great Basin Paleoclimate And Aridity Linked To Artic Warming And Tropical Pacific Sea Surface Temperature, Matthew S. Lachniet, Yemane Asmerom, Victor Polyak, Rhawn Denniston Jun 2020

Great Basin Paleoclimate And Aridity Linked To Artic Warming And Tropical Pacific Sea Surface Temperature, Matthew S. Lachniet, Yemane Asmerom, Victor Polyak, Rhawn Denniston

Geoscience Faculty Research

The arid southwestern United States is susceptible to sustained droughts that impact water resources and economic activity for millions of residents. Previous work has not systematically investigated the structure, timing, and possible forcings of Holocene Great Basin sub‐orbital hydroclimate changes, impeding our ability to understand the potential future controls on Southwestern aridity. The objective of this paper is to constrain the potential forcings on Holocene aridity and temperature, via comparison of new high‐resolution speleothem data, an Aridity Index synthesizing hydroclimate records, and linkages of Southwestern paleoclimate to other regions. The high‐resolution data from Leviathan Cave provide a paleoclimate record since …


Refining Interpretations Of A Deglacial Record In Gulf Of Mexico Marine Sediment Cores Using Foraminifera C-14 Dates And Multi-Proxy Sediment Analyses, Lindsey R. Monito May 2020

Refining Interpretations Of A Deglacial Record In Gulf Of Mexico Marine Sediment Cores Using Foraminifera C-14 Dates And Multi-Proxy Sediment Analyses, Lindsey R. Monito

Senior Honors Projects, 2020-current

The upper fourteen sections of three cores recovered from the International Marine Past Global Changes Study (IMAGES) VIII/Paleoceanography of the Atlantic and Geochemistry (PAGE) 127 expedition of 2002, are stratigraphic records of the climate and provenance variations that influenced sediment deposition in the Gulf of Mexico during the Pleistocene and Holocene. Though originally cored by the USGS for gas hydrate investigations, cores MD02-2535, MD02-2555, and MD02-2560 have been repurposed for undergraduate course-based paleoclimate research at JMU. Shipboard interpretations of the color reflectance data for these cores suggested that two dark stratigraphic intervals present in all of the cores were regional …


Climate From The Mcmurdo Dry Valleys, Antarctica, 1986–2017: Surface Air Temperature Trends And Redefined Summer Season, Maciej K. Obryk, Peter T. Doran, Andrew G. Fountain, M. Myers, Christopher P. Mckay May 2020

Climate From The Mcmurdo Dry Valleys, Antarctica, 1986–2017: Surface Air Temperature Trends And Redefined Summer Season, Maciej K. Obryk, Peter T. Doran, Andrew G. Fountain, M. Myers, Christopher P. Mckay

Geology Faculty Publications and Presentations

The weather of the McMurdo Dry Valleys, Antarctica, the largest ice‐free region of the Antarctica, has been continuously monitored since 1985 with currently 14 operational meteorological stations distributed throughout the valleys. Because climate is based on a 30‐year record of weather, this is the first study to truly define the contemporary climate of the McMurdo Dry Valleys. Mean air temperature and solar radiation based on all stations were −20°C and 102 Wm−2, respectively. Depending on the site location, the mean annual air temperatures on the valleys floors ranged between −15°C and −30°C, and mean annual solar radiation varied …


Analyzing The Effects Of Of Seasonal Land Cover And Precipitation On The Sediment Delivery Ratio Of An Agriculture Dominated Watershed., Jonah Liebman May 2020

Analyzing The Effects Of Of Seasonal Land Cover And Precipitation On The Sediment Delivery Ratio Of An Agriculture Dominated Watershed., Jonah Liebman

Electronic Theses and Dissertations

Soil erosion is of escalating importance as increasing population and climate change have put increasing pressures on agricultural food production. Vegetation and precipitation are two factors that control the amount of soil erosion extant within a region. Sediment delivery ratios (SDRs) assess the ratio of soil eroded from a watershed system that is permanently removed from the system through stream sediment discharge. Using 1) river discharge and sediment concentration data and 2) the Revised Universal Soil Loss Equation (RUSLE), this thesis analyzes fluctuations in monthly SDRs for an average hydroclimatological crop-harvest season for the Senachwine Creek watershed, IL. Through calculating …


Adjusting The Lens Of Invasion Biology To Focus On The Impacts Of Climate-Driven Range Shifts, Piper D. Wallingford, Toni Lyn Morelli, Jenica M. Allen, Evelyn M. Beaury, Dana M. Blumenthal, Bethany A. Bradley, Jeffrey S. Dukes, Regan Early, Emily J. Fusco, Deborah E. Goldberg, Inés Ibáñez, Brittany B. Laginhas, Montserrat Vilà, Cascade J.B. Sorte May 2020

Adjusting The Lens Of Invasion Biology To Focus On The Impacts Of Climate-Driven Range Shifts, Piper D. Wallingford, Toni Lyn Morelli, Jenica M. Allen, Evelyn M. Beaury, Dana M. Blumenthal, Bethany A. Bradley, Jeffrey S. Dukes, Regan Early, Emily J. Fusco, Deborah E. Goldberg, Inés Ibáñez, Brittany B. Laginhas, Montserrat Vilà, Cascade J.B. Sorte

United States Geological Survey: Staff Publications

As Earth’s climate rapidly changes, species range shifts are considered key to species persistence. However, some range-shifting species will alter community structure and ecosystem processes. By adapting existing invasion risk assessment frameworks, we can identify characteristics shared with high-impact introductions and thus predict potential impacts. There are fundamental differences between introduced and range-shifting species, primarily shared evolutionary histories between range shifters and their new community. Nevertheless, impacts can occur via analogous mechanisms, such as wide dispersal, community disturbance and low biotic resistance. As ranges shift in response to climate change, we have an opportunity to develop plans to facilitate advantageous …


Increased Drought Severity Tracks Warming In The United States’ Largest River Basin, Justin T. Martin, Gregory T. Pederson, Connie A. Woodhouse, Edward R. Cook, Gregory J. Mccabe, Kevin J. Anchukaitis, Erika K. Wise, Patrick J. Erger, Larry Dolan, Marketa Mcguire, Subhrendu Gangopadhyay, Katherine J. Chase, Jeremy S. Litell, Stephen T. Gray, Scott St. George, Jonathan M. Friedman, David J. Sauchyn, Jeannine-Marie St-Jacques, John King Apr 2020

Increased Drought Severity Tracks Warming In The United States’ Largest River Basin, Justin T. Martin, Gregory T. Pederson, Connie A. Woodhouse, Edward R. Cook, Gregory J. Mccabe, Kevin J. Anchukaitis, Erika K. Wise, Patrick J. Erger, Larry Dolan, Marketa Mcguire, Subhrendu Gangopadhyay, Katherine J. Chase, Jeremy S. Litell, Stephen T. Gray, Scott St. George, Jonathan M. Friedman, David J. Sauchyn, Jeannine-Marie St-Jacques, John King

United States Geological Survey: Staff Publications

Across the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the “turn-of-the-century drought,” was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking. Here we examine 1,200 y of streamflow from a network of 17 new tree-ring–based reconstructions for gages across the upper Missouri basin and an independent reconstruction of warm-season regional temperature in order to place the recent drought in a long-term climate context. We find that temperature has …


Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans Apr 2020

Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans

Sustainability Seminar Series

Ocean circulation plays a critical role in the Earth’s climate system through the storage and transfer of heat and carbon dioxide. The North Atlantic and Southern Ocean are of particular interest because these are regions where deep-water components of global circulation develop. Dr. Romans uses the deep-sea sedimentary record to reconstruct past ocean circulation and its relationship to past climatic and tectonic conditions. He integrates information from a broad range of spatial and temporal scales, from seismic-reflection data that reveals regional sedimentation patterns to high resolution records based on quantitative grain-size analysis from cores. Dr. Romans will present research from …


Cave Airflow Mechanism Of A Crevice-Type Cave: A Case Study From Czechia, Martin Kašing, Jan Lenart Apr 2020

Cave Airflow Mechanism Of A Crevice-Type Cave: A Case Study From Czechia, Martin Kašing, Jan Lenart

International Journal of Speleology

At present, crevice-type caves are investigated mainly by means of geomorphic and geophysical methods. Microclimatic research of this type of caves is underrepresented and is often limited to temperature and humidity measurement only. Yet, microclimatic research of such caves can significantly help in the management and conservation of caves, speleological exploration or analysis of speleothems. Being the first ever research of ventilation within a crevice-type cave, a complex analysis of cave ventilation was performed within the Velká Ondrášova Cave, a crevice-type cave in the Outer Western Carpathians, Czechia. Long-term temperature recording, airflow tracing within the cave, and a total of …


Rockhounding, Seafaring, And Other Material Tales For The End Of The World, Noemie Fortin Mar 2020

Rockhounding, Seafaring, And Other Material Tales For The End Of The World, Noemie Fortin

The Goose

In the face of accelerated environmental degradation and climate instability, the future of the Earth and of all life on earth is difficult to visualize. Therefore, the different mediums through which we consider environmental issues are just as important as the actions we take to address them. Focusing on three projects combining art, science, and activism, this article suggests a compilation of material tales. They tell stories of plastic rocks and aluminum nuggets where the protagonists are partly finely crafted objects, partly waste materials, and sometimes both at once. Artists Kelly Jazvac, Yesenia Thibeault-Picazo, and the collective Studio Swine collaborate …


David Quentin Bowen: A Memorial, John T. Andrews, David R. Bridgland, Peter U. Clark, Thomas M. Cronin, Claude Hillaire-Marcel, Darrel Maddy, Gifford H. Miller, Daniel R. Muhs, Colin V. Murray-Wallace Jan 2020

David Quentin Bowen: A Memorial, John T. Andrews, David R. Bridgland, Peter U. Clark, Thomas M. Cronin, Claude Hillaire-Marcel, Darrel Maddy, Gifford H. Miller, Daniel R. Muhs, Colin V. Murray-Wallace

United States Geological Survey: Staff Publications

The Quaternary community lost a giant and a leader on October 5, 2020, when David Quentin Bowen, known to many as “DQ” and founding editor of Quaternary Science Reviews, passed away in Cardiff. Born on February 14, 1938 in Llanelli, SouthWales, he received his PhD at University College London. David’s 50 years of contributions to our science cannot be adequately summarized in a brief memorial but past, present, and future generations of Quaternary scientists will long remember his landmark achievements in publishing, his scientific contributions, and his personal and professional class in all his endeavors.


Testing Glacial Isostatic Adjustment Models Of Last-Interglacial Sea Level History In The Bahamas And Bermuda, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Eugene S. Schweig, Mark P. Rowe Jan 2020

Testing Glacial Isostatic Adjustment Models Of Last-Interglacial Sea Level History In The Bahamas And Bermuda, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Eugene S. Schweig, Mark P. Rowe

United States Geological Survey: Staff Publications

Part of the spatial variation in the apparent sea-level record of the last interglacial (LIG) period is due to the diverse response of coastlines to glacial isostatic adjustment (GIA) processes, particularly where coastlines were close to the Laurentide Ice Sheet during the past two glacial periods. We tested modeled LIG paleo-sea levels on New Providence Island (NPI), Bahamas and Bermuda by investigating emergent coral patch reefs and oolitic/peloidal beach deposits. Corals with closed-system histories collected from patch reefs on NPI have ages of 128-118 ka and ooids/peloids from beach ridges have closed-system ages of 128-116 ka. Elevations of patch reefs …


Uptake, Metabolism, And Elimination Of Fungicides From Coated Wheat Seeds In Japanese Quail (Coturnix Japonica), Michael S. Gross, Thomas G. Bean, Michelle L. Hladik, Barnett A. Rattner, Kathryn M. Kuivila Jan 2020

Uptake, Metabolism, And Elimination Of Fungicides From Coated Wheat Seeds In Japanese Quail (Coturnix Japonica), Michael S. Gross, Thomas G. Bean, Michelle L. Hladik, Barnett A. Rattner, Kathryn M. Kuivila

United States Geological Survey: Staff Publications

Pesticides coated to the seed surface potentially pose an ecological risk to granivorous birds that consume incompletely buried or spilled seeds. To assess the toxicokinetics of seeds treated with current-use fungicides, Japanese quail ( Coturnix japonica) were orally dosed with commercially coated wheat seeds. Quail were exposed to metalaxyl, tebuconazole, and fludioxonil at either a low dose (0.0655, 0.0308, and 0.0328 mg/kg of body weight, respectively) or a high dose (0.196, 0.0925, and 0.0985 mg/kg of body weight, respectively). Fungicides were rapidly absorbed and distributed to tissues. Tebuconazole was metabolized into tert-butylhydroxy-tebuconazole. All compounds were eliminated to below detection limits …


Adjusting The Lens Of Invasion Biology To Focus On The Impacts Of Climate-Driven Range Shifts, Piper D. Wallingford, Toni Lyn Morelli, Jenica M. Allen, Evelyn M. Beaury, Dana M. Blumenthal, Bethany A. Bradley, Jeffrey S. Dukes, Regan Early, Emily J. Fusco, Deborah E. Goldberg, Inés Ibáñez, Brittany B. Laginhas, Montserrat Vilà, Cascade J.B. Sorte Jan 2020

Adjusting The Lens Of Invasion Biology To Focus On The Impacts Of Climate-Driven Range Shifts, Piper D. Wallingford, Toni Lyn Morelli, Jenica M. Allen, Evelyn M. Beaury, Dana M. Blumenthal, Bethany A. Bradley, Jeffrey S. Dukes, Regan Early, Emily J. Fusco, Deborah E. Goldberg, Inés Ibáñez, Brittany B. Laginhas, Montserrat Vilà, Cascade J.B. Sorte

United States Geological Survey: Staff Publications

As Earth’s climate rapidly changes, species range shifts are considered key to species persistence. However, some range-shifting species will alter community structure and ecosystem processes. By adapting existing invasion risk assessment frameworks, we can identify characteristics shared with high-impact introductions and thus predict potential impacts. There are fundamen- tal differences between introduced and range-shifting species, primarily shared evolutionary histories between range shifters and their new community. Nevertheless, impacts can occur via analogous mechanisms, such as wide dispersal, community disturbance and low biotic resistance. As ranges shift in response to climate change, we have an opportunity to develop plans to facilitate …


Uptake, Metabolism, And Elimination Of Fungicides From Coated Wheat Seeds In Japanese Quail (Coturnix Japonica), Michael S. Gross, Thomas G. Bean, Michelle L. Hladik, Barnett A. Rattner, Kathryn M. Kuivila Jan 2020

Uptake, Metabolism, And Elimination Of Fungicides From Coated Wheat Seeds In Japanese Quail (Coturnix Japonica), Michael S. Gross, Thomas G. Bean, Michelle L. Hladik, Barnett A. Rattner, Kathryn M. Kuivila

United States Geological Survey: Staff Publications

Pesticides coated to the seed surface potentially pose an ecological risk to granivorous birds that consume incompletely buried or spilled seeds. To assess the toxicokinetics of seeds treated with current-use fungicides, Japanese quail ( Coturnix japonica) were orally dosed with commercially coated wheat seeds. Quail were exposed to metalaxyl, tebuconazole, and fludioxonil at either a low dose (0.0655, 0.0308, and 0.0328 mg/kg of body weight, respectively) or a high dose (0.196, 0.0925, and 0.0985 mg/kg of body weight, respectively). Fungicides were rapidly absorbed and distributed to tissues. Tebuconazole was metabolized into tert-butylhydroxy-tebuconazole. All compounds were eliminated to below detection limits …


Corrigendum To "Upper Water Structure And Mixed Layer Depth In Tropical Waters: The Seats Station In The Northern South China Sea, Jen-Hua Tai, George T.F. Wong, Xiaoju Pan Jan 2020

Corrigendum To "Upper Water Structure And Mixed Layer Depth In Tropical Waters: The Seats Station In The Northern South China Sea, Jen-Hua Tai, George T.F. Wong, Xiaoju Pan

OES Faculty Publications

No abstract provided.


Estimating Abiotic Thresholds For Sagebrush Condition Class In The Western United States, Stephen Boyte, Bruce K. Wylie, Yingxin Gu, Donald J. Major Jan 2020

Estimating Abiotic Thresholds For Sagebrush Condition Class In The Western United States, Stephen Boyte, Bruce K. Wylie, Yingxin Gu, Donald J. Major

United States Geological Survey: Staff Publications

Sagebrush ecosystems of the western United States can transition from extended periods of relatively stable conditions to rapid ecological change if acute disturbances occur. Areas dominated by native sagebrush can transition from species-rich native systems to altered states where non-native annual grasses dominate, if resistance to annual grasses is low. The non-native annual grasses provide relatively little value to wildlife, livestock, and humans and function as fuel that increases fire frequency. The more land area covered by annual grasses, the higher the potential for fire, thus reducing the potential for native vegetation to reestablish, even when applying restoration treatments. Mapping …


Deuterium Excess And 17o-Excess Variability In Meteoric Water Across The Pacific Northwest, Usa, John Bershaw, Dougal Hansen, Andrew Schauer Jan 2020

Deuterium Excess And 17o-Excess Variability In Meteoric Water Across The Pacific Northwest, Usa, John Bershaw, Dougal Hansen, Andrew Schauer

Geology Faculty Publications and Presentations

High-precision triple oxygen isotope analysis of water has given rise to a novel second-order parameter, 17O-excess (often denoted as δ17O), which describes the deviation from a reference relationship between δ18O and δ17O. This tracer, like deuterium excess (d-excess), is affected by kinetic fractionation (diffusion) during phase changes within the hydrologic cycle. However, unlike d-excess, 17O-excess is present in paleowater proxy minerals and is not thought to vary significantly with temperature. This makes it a promising tool in paleoclimate research, particularly in relatively arid continental regions where traditional approaches have produced equivocal results. …


Assessing The Accuracy Of A Uav Snow Depth Survey: Utqiagvik (Barrow), Alaska Calm Grid, Ian Nichols Jan 2020

Assessing The Accuracy Of A Uav Snow Depth Survey: Utqiagvik (Barrow), Alaska Calm Grid, Ian Nichols

Dissertations, Master's Theses and Master's Reports

Active layer depth and snow depth are annually collected across the Circumpolar Active Layer Monitoring (CALM) Network to observe the response of the active layer and near-surface permafrost to climate change over decadal-time scales. Snow depth is typically measured using a graduated steel probe at each grid node but, in this paper, we explore the viability of using Unmanned Aerial Vehicle (UAV) (drone) technology to collect snow depth measurements at the 1 km2 Utqiagvik (Barrow), Alaska CALM grid. This is achieved by comparing estimated UAV snow depths to measured snow depths collected using a MagnaProbe (MP) at each of …


Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton Jan 2020

Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton

United States Geological Survey: Staff Publications

There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a habitat, or soundscape, contains information about multiple taxa and may circumvent species identification, but robust statistical technology for characterizing community-level attributes is lacking. Here, we present the Acoustic Space Occupancy Model, a flexible hierarchical framework designed to account for detection artifacts from acoustic surveys in order to model biologically relevant variation in acoustic space …


Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis, Liba Pejchar Jan 2020

Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis, Liba Pejchar

United States Geological Survey: Staff Publications

Aim: Human development and agriculture can have transformative and homogenizing effects on natural systems, shifting the composition of ecological communities towards non-native and native species that tolerate or thrive under human-dominated conditions. These impacts cannot be fully captured by summarizing species presence, as they include dramatic changes to patterns of species abundance. However, how human land use patterns and species invasions intersect to shape patterns of abundance and dominance within ecological communities is poorly understood even in well-known taxa.

Location: Conterminous United States.

Time period: 2010–2012.

Major taxa studied: Passeriformes.

Methods: We analyse continental-scale monitoring data to study the proportional …


Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy Jan 2020

Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy

United States Geological Survey: Staff Publications

Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates …


Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis Jan 2020

Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis

United States Geological Survey: Staff Publications

Aim: Human development and agriculture can have transformative and homogenizing effects on natural systems, shifting the composition of ecological communities towards non-native and native species that tolerate or thrive under human-dominated conditions. These impacts cannot be fully captured by summarizing species presence, as they include dramatic changes to patterns of species abundance. However, how human land use patterns and species invasions intersect to shape patterns of abundance and dominance within ecological communities is poorly understood even in well-known taxa.

Location: Conterminous United States.

Time period: 2010–2012.

Major taxa studied: Passeriformes.

Methods: We analyse continental-scale monitoring data to study the proportional …


Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton Jan 2020

Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton

United States Geological Survey: Staff Publications

There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a habitat, or soundscape, contains information about multiple taxa and may circumvent species identification, but robust statistical technology for characterizing community-level attributes is lacking. Here, we present the Acoustic Space Occupancy Model, a flexible hierarchical framework designed to account for detection artifacts from acoustic surveys in order to model biologically relevant variation in acoustic space …


Characterization Of Pallid Sturgeon (Scaphirhynchus Albus) Spawning Habitat In The Lower Missouri River, Caroline M. Elliott, Aaron J. Delonay, Kimberly Chojnacki, Robert B. Jacobson Jan 2020

Characterization Of Pallid Sturgeon (Scaphirhynchus Albus) Spawning Habitat In The Lower Missouri River, Caroline M. Elliott, Aaron J. Delonay, Kimberly Chojnacki, Robert B. Jacobson

United States Geological Survey: Staff Publications

Acipenseriformes (sturgeons and paddlefish) globally have declined throughout their range due to river fragmentation, habitat loss, overfishing, and degradation of water quality. In North America, pallid sturgeon (Scaphirhynchus albus) populations have experienced poor to no recruitment, or substantial levels of hybridization with the closely related shovelnose sturgeon (S. platorynchus). The Lower Missouri River is the only portion of the species’ range where successful reproduction and recruitment of genetically pure pallid sturgeon have been documented. This paper documents spawning habitat and behavior on the Lower Missouri River, which comprises over 1,300 km of unfragmented river habitat. The …