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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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.
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Quantifying the response of nitrogen speciation to hydrology in the Chesapeake Bay Watershed using a multilevel modeling approach Quantifying the response of nitrogen speciation to hydrology in the Chesapeake Bay Watershed using a multilevel modeling approach
Excessive nitrogen (N) inputs to coastal waters can lead to severe eutrophication and different chemical forms of N exhibit varying levels of effectiveness in fueling primary production. Efforts to mitigate N fluxes from coastal watersheds are often guided by models that predict changes in N loads as a function of changes in land use, management practices, and climate. However...
Authors
Isabella Bertani, Gopal Bhatt, Gary W. Shenk, Lewis C. Linker
Body size and digestive system shape resource selection by ungulates: A cross-taxa test of the forage maturation hypothesis Body size and digestive system shape resource selection by ungulates: A cross-taxa test of the forage maturation hypothesis
The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified...
Authors
Saeideh Esmaeili, Brett R. Jesmer, Shannon E. Albeke, Ellen O. Aikens, Kathryn A. Schoenecker, Sarah R.B. King, Briana Abrahms, Buuveibaatar Bayarbaatar, Jeffrey L. Beck, Randall Boone, Francesca Cagnacci, Simon Chamaillé-Jammes, Buyanaa Chimeddorj, Paul C. Cross, Nandintsetseg Dejid, Jagdag Enkhbyar, Ilya Fischhoff, Adam T. Ford, Kate Jenks, Mahmoud-Reza Hemami, Jacob D. Hennig, Takehiko Y. Ito, Petra Kaczensky, Matthew J. Kauffman, John D. C. Linnell, Badamjav Lkhagvasuren, John F. McEvoy, Joerg Melzheimer, Jerod A. Merkle, Thomas Mueller, Jeff Muntifering, Atle Mysterud, Kirk A. Olson, Manuela Panzacchi, John Payne, Luca Pedrotti, Geir R. Rauset, Daniel I. Rubenstein, Hall Sawyer, John D. Scasta, Johannes Signer, Melissa Songer, Jared A. Stabach, Seth Stapleton, Olav Strand, Siva R. Sundaresan, Dorj Usukhjargal, Ganbold Uuganbayar, John Fryxell, Jacob R. Goheen
Modeling the bioavailability of nickel and zinc to Ceriodaphnia dubia and Neocloeon triangulifer in toxicity tests with Natural Waters Modeling the bioavailability of nickel and zinc to Ceriodaphnia dubia and Neocloeon triangulifer in toxicity tests with Natural Waters
We studied biotic ligand model (BLM) predictions of toxicity of nickel (Ni) and zinc (Zn) in natural waters from Illinois and Minnesota USA which had combinations of pH, hardness, and dissolved organic carbon (DOC) more extreme than 99.7% of waters in a nationwide database. We conducted 7-d chronic tests with Ceriodaphnia dubia, and 96-hr acute test and 14-d chronic tests with Neocloeon
Authors
John M. Besser, Chris D. Ivey, Jeffery A. Steevens, Danielle M. Cleveland, David J. Soucek, Amy Dickinson, Eric J. Van Genderen, Adam C. Ryan, Chris E. Schlekat, Emily R. Garman, Elizabeth Middleton, Robert C. Santore
High-resolution remote sensing and multistate occupancy estimation identify drivers of spawning site selection in fall chum salmon (Oncorhynchus keta) across a sub-Arctic riverscape High-resolution remote sensing and multistate occupancy estimation identify drivers of spawning site selection in fall chum salmon (Oncorhynchus keta) across a sub-Arctic riverscape
Groundwater upwellings provide warmer, stable overwinter temperatures for developing salmon embryos, which may be particularly important in cold, braided, gravel-bed sub-Arctic rivers. We used a three-year time series of aerial counts and remote sensing to estimate the distribution of low and high aggregations of spawning fall chum salmon (Oncorhynchus keta), classify approximately 0.5...
Authors
Chelsea M. Clawson, Jeffrey A. Falke, Larissa L. Bailey, Joshua Rose, Anupma Prakash, Aaron E. Martin
Managing nonperennial headwater streams in temperate forests of the United States Managing nonperennial headwater streams in temperate forests of the United States
Forest management guidelines are designed to protect water quality from unintended effects of land use changes such as timber harvest, mining, or forest road construction. Although streams that periodically cease to flow (nonperennial) drain the majority of forested areas, these streams are not consistently included in forest management guidelines. This paper reviews management...
Authors
Stephanie K. Kampf, Kathleen Dwyer, Matthew P. Fairchild, Jason B. Dunham, Craig D. Snyder, Kristin L. Jaeger, Charles H. Luce, John C. Hammond, Codie Wilson, Margaret Zimmer, Marielle Sidell
Applying biodiversity metrics as surrogates to a habitat conservation plan Applying biodiversity metrics as surrogates to a habitat conservation plan
Unabated urbanization has led to environmental degradation and subsequent biodiversity loss across the globe. As an outcome of unmitigated land use, multi-jurisdictional agencies have developed land use plans that attempt to protect threatened or endangered species across selected areas by which some trade-offs between harm to species and additional conservation approaches are allowed...
Authors
Kenneth G. Boykin, William G. Kepner, Alexa McKerrow
Interlaboratory comparison of SARS-CoV2 molecular detection assays in use by U.S. veterinary diagnostic laboratories Interlaboratory comparison of SARS-CoV2 molecular detection assays in use by U.S. veterinary diagnostic laboratories
The continued search for intermediate hosts and potential reservoirs for SARS-CoV2 makes it clear that animal surveillance is critical in outbreak response and prevention. Real-time RT-PCR assays for SARS-CoV2 detection can easily be adapted to different host species. U.S. veterinary diagnostic laboratories have used the CDC assays or other national reference laboratory methods to test...
Authors
Kaiping Deng, Steffen Uhlig, Hon S. Ip, Mary Lea Killian, Laura Goodman, Sarah Nemser, Jodie Ulaszek, Shannon Pickens, Robert Newkirk, Matthew Kmet, Kirsten Frost, Karina Hettwer, Bertrand Colson, Kapil Nichani, Anja Schlier, Andriy Tkachenko, Ravinder Reddy, Renate Reimshuessel
Multiple melt source origin of the Line Islands (Pacific Ocean) Multiple melt source origin of the Line Islands (Pacific Ocean)
The Line Islands volcanic chain in the central Pacific Ocean exhibits many characteristics of a hotspot-generated seamount chain; however, the lack of a predictable age progression has stymied previous models for the origin of this feature. We combined plate-tectonic reconstructions with seamount age dates and available geochemistry to develop a new model that involves multiple melt...
Authors
Robert Pockalny, Ginger Barth, Barry Eakins, Katherine A. Kelley, Christina Wertman
Sage-grouse population dynamics are adversely impacted by overabundant feral horses Sage-grouse population dynamics are adversely impacted by overabundant feral horses
In recent decades, feral horse (Equus caballus; horse) populations increased in sagebrush (Artimesia spp.) ecosystems, especially within the Great Basin, to the point of exceeding maximum appropriate management levels (AMLmax), which were set by land administrators to balance resource use by feral horses, livestock, and wildlife. Concomitantly, greater sage-grouse (Centrocercus...
Authors
Peter S. Coates, Shawn T. O’Neil, Diana A. Munoz, Ian Dwight, John C. Tull
Golden Eagle dietary shifts following wildfire and shrub loss have negative consequences for nestling survivorship Golden Eagle dietary shifts following wildfire and shrub loss have negative consequences for nestling survivorship
Wildfires and invasive species have caused widespread changes in western North America’s shrub-steppe landscapes. The bottom–up consequences of degraded shrublands on predator ecology and demography remain poorly understood. We used a before–after paired design to study whether Golden Eagle (Aquila chrysaetos) diet and nestling survivorship changed following wildfires in southwestern...
Authors
Julie A. Heath, Michael N. Kochert, Karen Steenhof
The products of primary magma fragmentation finally revealed by pumice agglomerates The products of primary magma fragmentation finally revealed by pumice agglomerates
Following rapid decompression in the conduit of a volcano, magma breaks into ash- to block-sized fragments, powering explosive sub-Plinian and Plinian eruptions that may generate destructive pyroclastic falls and flows. It is thus crucial to assess how magma breaks up into fragments. This task is difficult, however, because of the subterranean nature of the entire process and because the...
Authors
Thomas Giachetti, Kathy Trafton, Joshua Wiejaczka, James E. Gardner, James M. Watkins, Tom Shea, Heather M. Wright
The local responses of aquatic ecosystems to adjacent grassland conservation: Can streams of dreams exist in a degraded riverscape? The local responses of aquatic ecosystems to adjacent grassland conservation: Can streams of dreams exist in a degraded riverscape?
Landscape homogenization and the removal of riparian areas have altered stream ecosystems worldwide. Numerous conservation programmes attempt to improve water quality and increase instream habitat heterogeneity to elicit desired biological responses. However, the effectiveness of many conservation efforts on isolated stream fragments remains unknown, especially in grassland regions.The...
Authors
David A. Schumann, Katie N. B. Graeb, Jarrett Pfrimmer, Joshua D. Stafford, Steven R. Chipps