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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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Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes Surface elevation change dynamics in coastal marshes along the northwestern Gulf of Mexico: Anticipating effects of rising sea-level and intensifying hurricanes
Accelerated sea-level rise and intensifying hurricanes highlight the need to better understand surface elevation change in coastal wetlands. We used the surface elevation table-marker horizon approach to measure surface elevation change in 14 coastal marshes along the northwestern Gulf of Mexico, within five National Wildlife Refuges in Texas (USA). During the 2014–2019 study period, the...
Authors
Jena A. Moon, Laura Feher, Tiffany C. Lane, William Vervaeke, Michael Osland, Douglas M. Head, Bogdan Chivoiu, David R. Stewart, Darren Johnson, James Grace, Kristine L. Metzger, Nicole M. Rankin
Decadal-scale phenology and seasonal climate drivers of migratory baleen whales in a rapidly warming marine ecosystem Decadal-scale phenology and seasonal climate drivers of migratory baleen whales in a rapidly warming marine ecosystem
Species' response to rapid climate change can be measured through shifts in timing of recurring biological events, known as phenology. The Gulf of Maine is one of the most rapidly warming regions of the ocean, and thus an ideal system to study phenological and biological responses to climate change. A better understanding of climate-induced changes in phenology is needed to effectively...
Authors
Dan Pendleton, Morgan Tingley, Laura Ganley, Kevin Friedland, Charlie Mayo, Moria Brown, Brigid McKenna, Adrian Jordaan, Michelle Staudinger
Histochemical evidence for nitrogen‐transfer Endosymbiosis in non‐photosynthetic cells of leaves and inflorescence bracts of angiosperms Histochemical evidence for nitrogen‐transfer Endosymbiosis in non‐photosynthetic cells of leaves and inflorescence bracts of angiosperms
We used light and confocal microscopy to visualize bacteria in leaf and bract cells of more than 30 species in 18 families of seed plants. Through histochemical analysis, we detected hormones (including ethylene and nitric oxide), superoxide, and nitrogenous chemicals (including nitric oxide and nitrate) around bacteria within plant cells. Bacteria were observed in epidermal cells...
Authors
April Micci, Qiuwei Zhang, Xiaoqian Chang, Kathryn Kingsley, Linsey Park, Peerapol Chiaranunt, Raquele Strickland, Fernando Velazquez, Sean Lindert, Matthew T. Elmore, Philip L. Vines, Sharron Crane, Ivelisse Irizarry, Kurt P. Kowalski, David Johnston-Monje, James F. White
Can’t see the flowers for the trees: Factors driving floral abundance within early-successional forests in the central Appalachian Mountains Can’t see the flowers for the trees: Factors driving floral abundance within early-successional forests in the central Appalachian Mountains
Silviculture can be a powerful tool for restoring and enhancing habitat for forest-dependent wildlife. In eastern North America, regenerating timber harvests support abundant wildflowers that provide essential forage for native pollinators. Factors driving floral resource availability within regenerating forests remain almost entirely unstudied. Recent efforts to increase the area of...
Authors
Codey L. Mathis, Daren J. McNeil, Monica R. Lee, Christina M. Grozinger, Clint R.V. Otto, Jeffery L. Larkin
The Pliocene-to-present course of the Tennessee River The Pliocene-to-present course of the Tennessee River
The Tennessee River, a primary drainage of the southern Appalachians and significant sediment source for the Gulf of Mexico, is generally considered to be the product of captures that rerouted the river from a more direct gulfward course. Sedimentary and genetic evidence indicates that a paleo-Tennessee flowed into the Mobile Basin through the late Miocene, although alternate models...
Authors
William E. Odom, Darryl E. Granger
Grassy–herbaceous land moderates regional climate effects on honey bee colonies in the Northcentral US Grassy–herbaceous land moderates regional climate effects on honey bee colonies in the Northcentral US
The lack of seasonally sustained floral resources (i.e. pollen and nectar) is considered a primary global threat to pollinator health. However, the ability to predict the abundance of flowering resources for pollinators based upon climate, weather, and land cover is difficult due to insufficient monitoring over adequate spatial and temporal scales. Here we use spatiotemporally...
Authors
Gabriela Quinlan, Douglas B. Sponsler, Hannah Gaines-Day, Harper McMinn-Sauder, Clint R.V. Otto, Autumn Smart, Theotime Colin, Claudio Gratton, Rufus Isaacs, Reed Johnson, Meghan O. Milbrath, Christina M. Grozinger
Rub tree use and selection by American black bears and grizzly bears in northern Yellowstone National Park Rub tree use and selection by American black bears and grizzly bears in northern Yellowstone National Park
Several of the world's bear species exhibit tree-rubbing behavior, which is thought to be a form of scent-marking communication. Many aspects of this behavior remain unexplored, including differences in rub tree selection between sympatric bear species. We compiled rub tree data collected on Yellowstone National Park's Northern Range (USA) and compared rub tree selection of sympatric...
Authors
Nathaniel R. Bowersock, H. Okada, Andrea R. Litt, Kerry A. Gunther, Frank T. van Manen
Ephemeral stream network extraction from lidar-derived elevation and topographic attributes in urban and forested landscapes Ephemeral stream network extraction from lidar-derived elevation and topographic attributes in urban and forested landscapes
Under-representations of headwater channels in digital stream networks can result in uncertainty in the magnitude of headwater habitat loss, stream burial, and watershed function. Increased availability of high-resolution (
Authors
Marina J. Metes, Daniel K. Jones, Matthew E. Baker, Andrew J. Miller, Dianna M. Hogan, J.V. Loperfido, Kristina G. Hopkins
Repeated genetic targets of natural selection underlying adaptation of euryhaline fishes to changing salinity Repeated genetic targets of natural selection underlying adaptation of euryhaline fishes to changing salinity
Ecological transitions across salinity boundaries have led to some of the most important diversification events in the animal kingdom, especially among fishes. Adaptations accompanying such transitions include changes in morphology, diet, whole-organism performance, and osmoregulatory function, which may be particularly prominent since divergent salinity regimes make opposing demands on...
Authors
Jonathan P Velotta, Stephen D. McCormick, Andrew Whitehead, Catherine S Durso, Eric T. Schultz
Managing macropods without poisoning ecosystems Managing macropods without poisoning ecosystems
A recent review of the management of hyperabundant macropods in Australia proposed that expanded professional shooting is likely to lead to better biodiversity and animal welfare outcomes. While the tenets of this general argument are sound, it overlooks one important issue for biodiversity and animal health and welfare: reliance on toxic lead-based ammunition. Lead poisoning poses a...
Authors
Jordan O Hampton, James M. Pay, Todd E. Katzner, Jon M Arnemo, Mark A Pokras, Eric Buenz, Niels Kanstrup, Vernon G Thomas, Marcela Uhart, Sergio A Lambertucci, Oliver Krone, Navinder J Singh, Vinny Naidoo, Mayumi Ishizuka, Keisuke Saito, Bjorn Helander, Rhys E. Green
Subspecies differentiation and range-wide genetic structure are driven by climate in the California gnatcatcher, a flagship species for coastal sage scrub conservation Subspecies differentiation and range-wide genetic structure are driven by climate in the California gnatcatcher, a flagship species for coastal sage scrub conservation
Understanding genetic structure and diversity within species can uncover associations with environmental and geographic attributes that highlight adaptive potential and inform conservation and management. The California gnatcatcher, Polioptila californica, is a small songbird found in desert and coastal scrub habitats from the southern end of Baja California Sur to Ventura County...
Authors
Amy G. Vandergast, Barbara E. Kus, Dustin A. Wood, Elizabeth R. Milano, Kristine L. Preston
Regional walrus abundance estimate in the United States Chukchi Sea in autumn Regional walrus abundance estimate in the United States Chukchi Sea in autumn
Human activities (e.g., shipping, tourism, oil, gas development) have increased in the Chukchi Sea because of declining sea ice. The declining sea ice itself and these activities may affect Pacific walrus (Odobenus rosmarus divergens) abundance; however, previous walrus abundance estimates have been notably imprecise. When sea ice is absent from the eastern Chukchi Sea, walruses in...
Authors
Anthony S. Fischbach, Rebecca L. Taylor, Chadwick V. Jay