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Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

Filter Total Items: 77868

Prioritizing restoration areas to conserve multiple sagebrush-associated wildlife species Prioritizing restoration areas to conserve multiple sagebrush-associated wildlife species

Strategic restoration of altered habitat is one method for addressing worldwide biodiversity declines. Within the sagebrush steppe of western North America, habitat degradation has been linked to declines in many species, making restoration a priority for managers; however, limited funding, spatiotemporal variation in restoration success, and the need to manage for diverse wildlife...
Authors
Courtney Jean Duchardt, Adrian P. Monroe, Julie A. Heinrichs, Michael S. O’Donnell, David R. Edmunds, Cameron L. Aldridge

Enhanced terrestrial runoff during Oceanic Anoxic Event 2 on the North Carolina Coastal Plain, USA Enhanced terrestrial runoff during Oceanic Anoxic Event 2 on the North Carolina Coastal Plain, USA

A global increase in the strength of the hydrologic cycle drove an increase in the flux of terrigenous sediments into the ocean during the Cenomanian–Turonian Oceanic Anoxic Event 2 (OAE2) and was an important mechanism driving nutrient enrichment and thus organic carbon burial. This global change is primarily known from isotopic records, but global average data do not tell us anything...
Authors
Christopher M Lowery, Jean Self-Trail, Craig Barrie

Extensibility of U-net neural network model for hydrographic feature extraction and implications for hydrologic modeling Extensibility of U-net neural network model for hydrographic feature extraction and implications for hydrologic modeling

Accurate maps of regional surface water features are integral for advancing ecologic, atmospheric and land development studies. The only comprehensive surface water feature map of Alaska is the National Hydrography Dataset (NHD). NHD features are often digitized representations of historic topographic map blue lines and may be outdated. Here we test deep learning methods to automatically...
Authors
Larry V. Stanislawski, Ethan J. Shavers, Shaowen Wang, Zhe Jiang, E. Lynn Usery, Evan Moak, Alexander Duffy, Joel Schott

Assessing habitat change and migration of barrier islands Assessing habitat change and migration of barrier islands

Barrier islands are dynamic environments that experience gradual change from waves, tides, and currents, and rapid change from extreme storms. These islands are expected to change drastically over the coming century due to accelerated sea-level rise and changes in frequency and intensity of storm events. The dynamic nature of barrier islands coupled with the importance of these...
Authors
Nicholas Enwright, Lei Wang, P. Soupy Dalyander, Hongqing Wang, Michael Osland, Rangley C. Mickey, Robert L. Jenkins, Elizabeth Godsey

Ecogeographic variation and taxonomic boundaries in Large Treeshrews (Scandentia, Tupaiidae: Tupaia tana Raffles, 1821) from Southeast Asia Ecogeographic variation and taxonomic boundaries in Large Treeshrews (Scandentia, Tupaiidae: Tupaia tana Raffles, 1821) from Southeast Asia

The Large Treeshrew, Tupaia tana Raffles, 1821, is a small mammal (~205 g) from Southeast Asia with a complicated taxonomic history. Currently, 15 subspecies are recognized from Borneo, Sumatra, and smaller islands, and many were originally differentiated based on minor pelage differences and small sample sizes. We explored intraspecific variation in T. tana using quantitative...
Authors
Maya M. Juman, Neal Woodman, Link E. Olson, Eric J. Sargis

Strategic testing approaches for targeted disease monitoring can be used to inform pandemic decision-making Strategic testing approaches for targeted disease monitoring can be used to inform pandemic decision-making

More than 1.6 million Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) tests were administered daily in the United States at the peak of the epidemic, with a significant focus on individual treatment. Here, we show that objective-driven, strategic sampling designs and analyses can maximize information gain at the population level, which is necessary to increase situational...
Authors
James D. Nichols, Tiffany L. Bogich, Emily Howerton, Ottar N. Bjornstad, Rebecca K. Borchering, Matthew J. Ferrari, Murali Haran, Christopher P. Jewell, Kim M. Pepin, William J. M. Probert, Juliet R. C. Pulliam, Michael C. Runge, Michael J. Tildesley, Cecile Viboud, Katriona Shea

Detecting subtle change from dense landsat time series: Case studies of mountain pine beetle and spruce beetle disturbance Detecting subtle change from dense landsat time series: Case studies of mountain pine beetle and spruce beetle disturbance

In contrast to abrupt changes caused by land cover conversion, subtle changes driven by a shift in the condition, structure, or other biological attributes of land often lead to minimal and slower alterations of the terrestrial surface. Accurate mapping and monitoring of subtle change are crucial for an early warning of long-term gradual change that may eventually result in land cover...
Authors
Su Ye, John Rogan, Zhe Zhu, Todd Hawbaker, Sarah J. Hart, Robert A. Andrus, Arjan J.H. Meddens, Jeffery A. Hicke, J. Ronald Eastman, Dominik Kulakowski

Holocene depositional history inferred from single-grain luminescence ages in southern California, North America Holocene depositional history inferred from single-grain luminescence ages in southern California, North America

Significant sediment flux and deposition in a sedimentary system are influenced by climate changes, tectonics, lithology, and the sedimentary system's internal dynamics. Identifying the timing of depositional periods from stratigraphic records is a first step to critically evaluate the controls of sediment flux and deposition. Here, we show that ages of single-grain K-feldspar...
Authors
Sourav Saha, Seulgi Moon, Nathan D. Brown, Edward J. Rhodes, Katherine M. Scharer, Devin McPhillips, Sally F. McGill, Bryan A. Castillo

Incorporating water quality analysis into navigation assessments as demonstrated in the Mississippi River Basin Incorporating water quality analysis into navigation assessments as demonstrated in the Mississippi River Basin

A description of historical and ambient water quality conditions is often required as part of navigational studies. This paper describes a series of tools developed by the USGS that can aid navigation managers in developing water quality assessments. The tools use R, a statistical software program, and provide methods to retrieve historical streamflow and water quality data, summarize...
Authors
Barbara Kleiss, Jennifer C. Murphy, Casey M. Mayne, Jake P. Allgeier, Amanda B. Edmondson, Katrina C. Ginsberg, Keaton E. Jones, Timothy J. Lauth, Emily L. Moe, Julie W. Murphy, Mead Allison

Most rivers and streams run dry every year Most rivers and streams run dry every year

The flowing waters of surface rivers and streams efficiently transport sediment, organic material and nutrients, among other things, from hillsides and overland areas to downstream lakes, reservoirs and the ocean. Along the way, rivers and streams (hereafter referred to collectively as streams) provide important resources for our communities and support rich, complex ecosystems. Non...
Authors
Kristin Jaeger

Recovery and analysis of ancient beetle DNA from subfossil packrat middens using high-throughput sequencing Recovery and analysis of ancient beetle DNA from subfossil packrat middens using high-throughput sequencing

The study of ancient DNA is revolutionizing our understanding of paleo-ecology and the evolutionary history of species. Insects are essential components in many ecosystems and constitute the most diverse group of animals. Yet they are largely neglected in ancient DNA studies. We report the results of the first targeted investigation of insect ancient DNA to positively identify subfossil...
Authors
Aaron D. Smith, Marcin J. Kaminski, Kojun Kanda, Andrew D. Sweet, Julio L. Betancourt, Camille A. Holmgren, Elisabeth Hempel, Federica Alberti, Michael Hofreiter

Translocations maintain genetic diversity and increase connectivity in sea otters, Enhydra lutris Translocations maintain genetic diversity and increase connectivity in sea otters, Enhydra lutris

Sea otters, Enhydra lutris, were once abundant along the nearshore areas of the North Pacific. The international maritime fur trade that ended in 1911 left 13 small remnant populations with low genetic diversity. Subsequent translocations into previously occupied habitat resulted in several reintroduced populations along the coast of North America. We sampled sea otters between 2008 and...
Authors
Shawn E. Larson, Roderick B. Gagne, James L. Bodkin, Michael J. Murray, Katherine Ralls, Lizabeth Bowen, Raphael Leblois, Sylvain Piry, Maria Cecilia Penedo, M. Tim Tinker, Holly B. Ernest
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