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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.

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Metal accumulation varies with life history, size, and development of larval amphibians Metal accumulation varies with life history, size, and development of larval amphibians

Amphibian larvae are commonly used as indicators of aquatic ecosystem health because they are susceptible to contaminants. However, there is limited information on how species characteristics and trophic position influence contaminant loads in larval amphibians. Importantly, there remains a need to understand whether grazers (frogs and toads [anurans]) and predators (salamanders) provide
Authors
Kelly L. Smalling, Emily Bea Oja, Danielle M. Cleveland, Jon D Davenport, Collin A. Eagles-Smith, Evan H. Campbell Grant, Patrick M. Kleeman, Brian J. Halstead, Kenzi M Stemp, Brian J. Tornabene, Zachary J Bunnell, Blake R. Hossack

Exploring the potential of electrospray-Orbitrap for stable isotope analysis using nitrate as a model Exploring the potential of electrospray-Orbitrap for stable isotope analysis using nitrate as a model

Widely used isotope ratio mass spectrometers have limited capabilities to measure metabolites, drugs, or small polyatomic ions without the loss of structural isotopic information. A new approach has recently been introduced that uses electrospray ionization Orbitrap to measure multidimensional isotope signatures of intact polar compounds. Using nitrate as a model compound, this study...
Authors
Andreas Hilkert, J.K. Bohlke, Stanley J. Mroczkowski, Kyle L. Fort, Konstantin Aizikov, Xinchen T. Wang, Sebastian H. Kopf, Cajetan Neubauer

Experimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation Experimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation

Tropical forest canopies cycle vast amounts of carbon, yet we still have a limited understanding of how these critical ecosystems will respond to climate warming. We implemented in situ leaf-level + 3°C experimental warming from the understory to the upper canopy of two Puerto Rican tropical tree species, Guarea guidonia and Ocotea sintenisii. After approximately 1 month of continuous...
Authors
Kelsey R. Carter, Tana E. Wood, Sasha C. Reed, Kaylie M. Butts, Molly A. Cavaleri

Spatiotemporal dynamics of insect pollinator communities in sagebrush steppe associated with weather and vegetation Spatiotemporal dynamics of insect pollinator communities in sagebrush steppe associated with weather and vegetation

The conservation of native insect pollinators is hampered by a lack of information about environmental factors influencing pollinator communities. We investigated how insect pollinator communities, composed of bees (Hymenoptera), butterflies and moths (Lepidoptera), and flies (Diptera), are influenced by spatial and temporal aspects of the environment in sagebrush steppe shrublands. We...
Authors
Ashley Rohde, David S. Pilliod

Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin

Background:229m229m. Manure-contaminated wells were associated with groundwater recharge and the area size of nearby agricultural land. Wells positive for any fecal-associated microbe, regardless of source, were associated with septic system density and manure storage proximity modified by bedrock depth. Well construction was generally not related to contamination, indicating land use...
Authors
Mark A. Borchardt, Joel P. Stokdyk, Burney A Kieke, Maureen A. Muldoon, Susan K. Spencer, Aaron D. Firnstahl, Davina Bonness, Randall J. Hunt, Tucker R. Burch

Ecological engineering with oysters enhances coastal resilience efforts Ecological engineering with oysters enhances coastal resilience efforts

Coastal areas are especially vulnerable to habitat loss, sea-level rise, and other climate change effects. Oyster-dominated eco-engineered reefs have been promoted as integral components of engineered habitats enhancing coastal resilience through provision of numerous ecological, morphological, and socio-economic services. However, the assessed ‘success’ of these eco-engineered oyster...
Authors
M. S. N. Chowdhury, Megan K. La Peyre, L. D. Coen, R. L. Morris, M. W. Luckenbach, T. Ysebaert, B. Walles, A. C. Smaal

Mapping the vulnerability of giant sequoias after extreme drought in California using remote sensing Mapping the vulnerability of giant sequoias after extreme drought in California using remote sensing

Between 2012 and 2016, California suffered one of the most severe droughts on record. During this period Sequoiadendron giganteum (giant sequoias) in the Sequoia and Kings Canyon National Parks (SEKI), California, USA experienced canopy water content (CWC) loss, unprecedented foliage senescence, and, in a few cases, death. We present an assessment of the vulnerability of giant sequoia...
Authors
Andres Baeza, Roberta E. Martin, Nathan L. Stephenson, Adrian J. Das, Paul Hardwick, Koren R. Nydick, Jeff Mallory, Michèle Slaton, Kirk Evans, Gregory P. Asner

Hyperspectral narrowband data propel gigantic leap in the earth remote sensing Hyperspectral narrowband data propel gigantic leap in the earth remote sensing

Hyperspectral narrowbands (HNBs) capture data as nearly continuous “spectral signatures” rather than a “few spectral data points” along the electromagnetic spectrum as with multispectral broadbands (MBBs). Almost all of satellite remote sensing of the Earth in the twentieth century was conducted using MBB data from sensors such as the Landsat-series, Advanced Very High-Resolution...
Authors
Prasad Thenkabail, Itiya P. Aneece, Pardhasaradhi Teluguntla, Adam Oliphant

Perceived barriers to the use of assisted colonization for climate sensitive species in the Hawaiian Islands Perceived barriers to the use of assisted colonization for climate sensitive species in the Hawaiian Islands

Conservation actions to safeguard climate change vulnerable species may not be utilized due to a variety of perceived barriers. Assisted colonization, the intentional movement and release of an organism outside its historical range, is one tool available for species predicted to lose habitat under future climate change scenarios, particularly for single island or single mountain range...
Authors
Shannon Rivera, Lucas Berio Fortini, Sheldon M. Plentovich, Melissa Price

Reconstruction of an extreme flood hydrograph and morphodynamics of a meander bend in a high-peak discharge variability river (Powder River, USA) Reconstruction of an extreme flood hydrograph and morphodynamics of a meander bend in a high-peak discharge variability river (Powder River, USA)

Understanding of morphodynamic processes associated with large-scale floods has recently improved following significant advances of modern technologies. Nevertheless, a clear link between flood discharge and in-channel sedimentation processes remains to be resolved. The hydrological and geomorphological data available for the meandering Powder River (Montana, USA) since 1977 makes it a...
Authors
Massimiliano Ghinassi, John A. Moody

An International Virtual Workshop on Global Seismology and Tectonics (IVWGST‐2020) An International Virtual Workshop on Global Seismology and Tectonics (IVWGST‐2020)

An International Virtual Workshop on Global Seismology and Tectonics (IVWGST‐2020) was organized by the Geoscience and Technology Division of Council of Scientific and Industrial Research—North East Institute of Science and Technology, Jorhat, India from 14 to 25 September 2020. This workshop predominantly catered to undergraduate, postgraduate, and Ph.D. students, scientists, and...
Authors
Santanu Baruah, Chandan Dey, Prachurjya Borthakur, G. Narahari Sastry, Andrew J. Michael
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