Modelling pinniped abundance and distribution by combining counts at terrestrial sites and in-water sightings
Steven L. Whitlock, Jamie N. Womble, James T. Peterson
2020, Ecological Modelling (420)
Pinnipeds are commonly monitored using aerial photographic surveys at land- or ice-based sites, where animals come ashore for resting, pupping, molting, and to avoid predators. Although these counts form the basis for monitoring population change over time, they do not provide information...
Seismicity of the Earth 1900–2018
Gavin P. Hayes, Gregory M. Smoczyk, Antonio H. Villasenor, Kevin P. Furlong, Harley M. Benz
2020, Scientific Investigations Map 3446
This map illustrates 119 years of global seismicity in the context of global plate tectonics and the Earth’s physiography. Primarily designed for use by earth scientists, engineers, and educators, this map provides a comprehensive overview of strong (magnitude [M] 5.5 and larger) earthquakes since 1900. The map clearly identifies the...
Determining the drivers of suspended sediment dynamics in tidal marsh-influenced estuaries using high-resolution ocean color remote sensing
Xiaohe Zhang, Cedric Fichot, Carly Baracco, Ruizhe Guo, Sydney Neugebauer, Zachary Bengtsson, Neil K. Ganju, Sergio Fagherazzi
2020, Remote Sensing (240)
Sediment budgets are a critical metric to assess coastal marsh vulnerability to sea-level rise and declining riverine sediment inputs. However, calculating accurate sediment budgets is challenging in tidal marsh-influenced estuaries where suspended sediment concentrations (SSC) typically vary on scales of hours and meters, and where SSC dynamics are driven by...
Blind testing of shoreline evolution models
Jennifer Montaño, Giovanni Coco, Jose Antolinez, Tomas Beuzen, Karin R. Bryan, Laura Cagigal, Bruno Castelle, Mark Davidson, Evan B. Goldstein, Raimundo Ibaceta, Déborah Idier, Bonnie C. Ludka, Sina Masoud-Ansari, Fernando Mendez, A. Brad Murray, Nathaniel G. Plant, Katherine Ratlif, Arthur Robinet, Ana Rueda, Nadia Sénéchal, Joshua Simmons, Kristen Splinter, Scott Stephens, Ian Townend, Sean Vitousek, Kilian Vos
2020, Scientific Reports (10)
Beaches around the world continuously adjust to daily and seasonal changes in wave and tide conditions, which are themselves changing over longer time-scales. Different approaches to predict multi-year shoreline evolution have been implemented; however, robust and reliable predictions of shoreline evolution are still problematic even in short-term scenarios (shorter than...
A random forest approach for bounded outcome variables
Leonie Weinhold, Matthias Schmid, Richard M. Mitchell, Kelly O. Maloney, Marvin N. Wright, Moritz Berger
2020, Journal of Computational and Graphical Statistics (29) 639-658
Random forests have become an established tool for classication and regres- sion, in particular in high-dimensional settings and in the presence of non-additive predictor-response relationships. For bounded outcome variables restricted to the unit interval, however, classical modeling approaches based on mean squared error loss may severely suer as they do not account for heteroscedasticity...
Timing of Cenozoic extension in the southern Stillwater Range and Dixie Valley, Nevada
Joseph P. Colgan, Samuel Johnstone, David L. Shuster
2020, Tectonics (39)
The Dixie Valley fault bounds the east side of the Stillwater Range in west‐central Nevada and last ruptured in 1954. Offset basalts indicate that slip began more recently than ~14 Ma, and prior work has interpreted the southern segment as an active low‐angle normal fault. Oligocene...
A spatially explicit, empirical estimate of tree-based biological nitrogen fixation in forests of the United States
Anika Staccone, Wenying Liao, Steven S. Perakis, Jana Compton, Christopher L. Clark, Duncan Menge
2020, Global Biogeochemical Cycles (34)
Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom‐up approaches to quantify tree‐based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska....
Flea sharing among sympatric rodent hosts: implications for potential plague effects on a threatened sciurid
Amanda R. Goldberg, Courtney J. Conway, Dean E. Biggins
2020, Ecosphere (11)
For vector-borne diseases, the abundance and competency of different vector species and their host preferences will impact the transfer of pathogens among hosts. Sylvatic plague is a lethal disease caused by the primarily flea-borne bacterium Yersinia pestis. Sylvatic plague was introduced into the western United States in the...
Co-occurrence and occupancy dynamics of mourning doves and Eurasian collared-doves
Adam W. Green, Helen Sofaer, David L Otis, Nicholas J. Van Lanen
2020, Journal of Wildlife Management (84) 775-785
Understanding how land cover and potential competition with invasive species shape patterns of occupancy, extirpation, and colonization of native species across a landscape can help target management for declining native populations. Mourning dove (Zenaida macroura) populations have declined throughout the United States from 1965–2015. The expansion of the Eurasian collared‐dove...
Cryptic and extensive hybridization between ancient lineages of American crows
David Slager, Kevin Epperly, Renee Ha, Sievert Rohwer, Christopher W. Woodall, Caroline R. Van Hemert, John Klicka
2020, Molecular Ecology (29) 956-969
Most species and therefore most hybrid zones have historically been defined using phenotypic characters. However, both speciation and hybridization can occur with negligible morphological differentiation. Recently developed genomic tools provide the means to better understand cryptic speciation and hybridization. The Northwestern Crow (Corvus caurinus) and American Crow (Corvus brachyrhynchos) are...
Global physical controls on estuarine habitat distribution during sea levelchange: Consequences for genetic diversification through time
Greer A. Dolby, Arturo M. Bedolla, S. Bennett, David K. Jacobs
2020, Global and Planetary Change (187)
Determining the extrinsic (physical) factors controlling speciation and diversification of species through time is of key interest in paleontology and evolutionary biology. The role of sea-level change in shaping species richness patterns of marginal marine species has received much attention, but with variable conclusions. Recent work combining genetic data and Geographical Information Systems...
"Modified Unified Method" of carp capture
Duane Chapman
2020, Fact Sheet 2020-3005
Populations of Hypophthalmichthys molitrix (silver carp) and Hypophthalmichthys nobilis (bighead carp), (together referred to herein as “bigheaded carp”) have increased exponentially in the greater Mississippi River Basin. Detrimental effects on native fish and economically important fisheries have occurred where these invasive, filter-feeding fish are abundant. The Unified Method, a harvest...
Groundwater withdrawals and regional flow paths at and near Willow Grove and Warminster, Pennsylvania—Data compilation and preliminary simulations for conditions in 1999, 2010, 2013, 2016, and 2017
Daniel J. Goode, Lisa A. Senior
2020, Open-File Report 2019-1137
In 2014, groundwater samples from residential and public supply wells in the vicinity of two former U.S. Navy bases at Willow Grove and Warminster, and an active Air National Guard Station at Horsham, Bucks and Montgomery Counties, Pennsylvania, were found to have concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate...
Northward migration of the Oregon forearc on the Gales Creek fault
Ray Wells, Richard J. Blakely, Sean Bemis
2020, Geosphere (16) 660-684
The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset...
Did ice-charging generate volcanic lightning during the 2016–2017 eruption of Bogoslof volcano, Alaska?
Alexa R. Van Eaton, David J. Schneider, Cassandra Marie Smith, Matthew M. Haney, John J. Lyons, Ryan Said, David Fee, Robert H. Holzworth, Larry G. Mastin
2020, Bulletin of Volcanology (82)
The 2016–2017 shallow submarine eruption of Bogoslof volcano in Alaska injected plumes of ash and seawater to maximum heights of ~ 12 km. More than 4550 volcanic lightning strokes were detected by the World Wide Lightning Location Network (WWLLN) and Vaisala’s Global Lightning Dataset (GLD360) over 9 months. Lightning...
Discrimination of biological scatterers in polarimetric weather radar data: Opportunities and challenges
Sidney Gauthreaux, Robert H. Diehl
2020, Remote Sensing (12)
For radar aeroecology studies, the identification of the type of scatterer is critically important. Here, we used a random forest (RF) algorithm to develop a variety of scatterer classification models based on the backscatter values in radar resolution volumes of six radar variables (reflectivity, radial velocity, spectrum width, differential...
Modeling pathogen dispersal in marine fish and shellfish
Danielle L Cantrell, Maya L. Groner, Tal Ben-Horin, Jon Grant, Crawford W. Revie
2020, Trends in Parasitology (36) 239-249
Bio-physical models are a useful tool for understanding dispersal and transmission of marine pathogens. While utilized for larval dispersal models, they are only recently being used in epidemiological studies and are currently underutilized by the marine epidemiology field. Bio-physical models are useful for spatial planning and coastal management. For example, they...
Mule deer habitat selection following vegetation thinning treatments in New Mexico
Grant E. Sorensen, David W. Kramer, James W. Cain III, Chase A. Taylor, Philip S. Gipson, Mark C. Wallace, Robert D. Cox, Warren B. Ballard
2020, Wildlife Society Bulletin (44) 122-129
Mule deer (Odocoileus hemionus) survival and population growth in north-central New Mexico, USA, was previously reported to be limited by nutritional constraints due to poor forage conditions in degraded habitats. Management recommendations suggested thinning of pinyon–juniper to improve habitat quality for mule deer. To evaluate the...
Effect of copper salts on hydrothermal oxidative decarboxylation: A study of phenylacetic acid
Xuan Fu, Megan Jamison, Aaron M. Jubb, Yiju Liao, Alexandria Aspin, Kyle Hayes, Christopher R. Glein, Ziming Yang
2020, Chemical Communications (London) (56) 2791-2794
Decarboxylation of carboxylic acids is favored under hydrothermal conditions, and can be influenced by dissolved metals. Here, we use phenylacetic acid as a model compound to study its hydrothermal decarboxylation in the presence of copper(II) salts but no O2. Our results showed a strong oxidizing role of copper in facilitating...
Category count models for adaptive management of metapopulations: Case study of an imperiled salamander
Katherine M. O’Donnell, Paul L. Fackler, Fred A. Johnson, Mathieu Bonneau, Julien Martin, Susan C. Walls
2020, Conservation Science and Practice (2)
Managing spatially structured populations of imperiled species presents many challenges. Spatial structure can make it difficult to predict population responses to potential recovery activities, and learning through experimentation may not be advised if it could harm threatened populations. Adaptive management provides an appealing framework when experimentation is considered too risky...
Evidence of wildfires and elevated atmospheric oxygen at the Frasnian–Famennian boundary in New York (USA): Implications for the Late Devonian mass extinction
Zeyang Liu, David Selby, Paul C. Hackley, Jeffrey Over
2020, Geological Society of America Bulletin (132) 2043-2054
The Devonian Period experienced significant fluctuations of atmospheric oxygen (O2) levels (∼25–13%), for which the extent and timing are debated. Also characteristic of the Devonian Period, at the Frasnian–Famennian (F–F) boundary, is one of the “big five” mass extinction events of the Phanerozoic. Fossilized charcoal...
Assessment of multi-stressors on compositional turnover of diatom, invertebrate and fish assemblages along an urban gradient in Pacific Northwest streams (USA)
Ian R. Waite, Yangdong Pan, Patrick Edwards
2020, Ecological Indicators (112)
This study is part of the regional stream-quality assessment (RSQA) conducted by the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project. The purpose of this study is to examine small streams along land-use and stressor gradients at the regional scale and to evaluate the relative importance of instream...
Diatom enumeration method influences biological assessments of southeastern USA streams
Meredith Tyree, Daren M. Carlisle, Sarah A. Spaulding
2020, Freshwater Science (39) 183-195
Current fixed-count enumeration methods for benthic diatoms are likely inadequate for most research and monitoring objectives. These methods underestimate taxa richness and may fail to detect losses of species caused by human impacts. Consequently, the full potential of diatoms is not realized in current assessments of biological integrity or species...
Preferential elution of ionic solutes in melting snowpacks: Improving process understanding through field observations and modeling in the Rocky Mountains
Diogo Costa, Graham A. Sexstone, J.W. Pomeroy, Donald H. Campbell, David W. Clow, M. Alisa Mast
2020, Science of the Total Environment (710) 1-15
The preferential elution of ions from melting snowpacks is a complex problem that has been linked to temporary acidification of water bodies. However, the understanding of these processes in snowpacks around the world, including the polar regions that are experiencing unprecedented warming and melting, remains limited despite being instrumental...
Groundwater availability of the Northern High Plains aquifer in Colorado, Kansas, Nebraska, South Dakota, and Wyoming
Steven M. Peterson, Jonathan P. Traylor, Moussa Guira
2020, Professional Paper 1864
Executive SummaryThe Northern High Plains aquifer underlies about 93,000 square miles of Colorado, Kansas, Nebraska, South Dakota, and Wyoming and is the largest subregion of the nationally important High Plains aquifer. Irrigation, primarily using groundwater, has supported agricultural production since before 1940, resulting in nearly $50 billion in sales in...
