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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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Vegetation type conversion in the US Southwest: Frontline observations and management responses Vegetation type conversion in the US Southwest: Frontline observations and management responses
Forest and nonforest ecosystems of the western United States are experiencing major transformations in response to land-use change, climate warming, and their interactive effects with wildland fire. Some ecosystems are transitioning to persistent alternative types, hereafter called “vegetation type conversion” (VTC). VTC is one of the most pressing management issues in the southwestern...
Authors
Christopher H. Guiterman, Rachel M. Gregg, Laura Marshall, Jill Beckmann, Phillip J. van Mantgem, Donald A. Falk, Jon Keeley, Anthony C. Caprio, Jonathan D. Coop, Paula J. Fornwalt, Collin Haffey, R. Keala Hagmann, Stephen Jackson, Ann M. Lynch, Ellis Q. Margolis, Christopher Marks, Marc D. Meyer, Hugh Safford, Alexandra Dunya Syphard, Alan H. Taylor, Craig Wilcox, Dennis Carril, Carolyn Armstrong Enquist, David W. Huffman, Jose Iniguez, Nicole A. Molinari, Christina M Restaino, Jens T. Stevens
Long-term change in metabolism phenology in north temperate lakes Long-term change in metabolism phenology in north temperate lakes
The phenology of dissolved oxygen (DO) dynamics and metabolism in north temperate lakes offers a basis for comparing metabolic cycles over multi-year time scales. Although proximal control over lake DO can be attributed to metabolism and physical processes, how those processes evolve over decades largely remains unexplored. Metabolism phenology may reveal the importance of coherence...
Authors
Robert Ladwig, Alison P. Appling, Austin D. Delany, Hilary A. Dugan, Qiantong Gao, Noah R. Lottig, Jemma Stachelek, Paul C. Hanson
Late Holocene human-environment interactions on the central California coast, USA, inferred from Morro Bay salt marsh sediments Late Holocene human-environment interactions on the central California coast, USA, inferred from Morro Bay salt marsh sediments
Coastal salt marshes and estuaries provide valuable ecosystem services, yet are susceptible to alteration from human activities. Records of past environmental change in these ecosystems can elucidate relationships between human activities, such as land-use practices, and physical and ecological processes, such as sediment accretion and vegetation changes. To reconstruct the environmental...
Authors
Ellie Broadman, Liam M. Reidy, David Wahl
Streambank and floodplain geomorphic change and contribution to watershed material budgets Streambank and floodplain geomorphic change and contribution to watershed material budgets
Stream geomorphic change is highly spatially variable but critical to landform evolution, human infrastructure, habitat, and watershed pollutant transport. However, measurements and process models of streambank erosion and floodplain deposition and resulting sediment fluxes are currently insufficient to predict these rates in all perennial streams over large regions. Here we measured...
Authors
Gregory E. Noe, Kristina G. Hopkins, Peter Claggett, Edward R. Schenk, Marina J. Metes, Labeeb Ahmed, Thomas Rossiter Doody, Cliff R. Hupp
Ecological divergence of wild birds drives avian influenza spillover and global spread Ecological divergence of wild birds drives avian influenza spillover and global spread
The diversity of influenza A viruses (IAV) is primarily hosted by two highly divergent avian orders: Anseriformes (ducks, swans and geese) and Charadriiformes (gulls, terns and shorebirds). Studies of IAV have historically focused on Anseriformes, specifically dabbling ducks, overlooking the diversity of hosts in nature, including gull and goose species that have successfully adapted to...
Authors
Nichola J. Hill, Mary Anne Bishop, Nidia S. Trovao, Katherine Ineson, Anne Schaefer, Wendy B. Puryear, Katherine Zhou, Alexa Foss, Dan Clark, Ken McKenzie, Jonathan D. Gass, Laura Borkenhagen, Jeffrey S. Hall, Jonathan A. Runstadler
Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere
For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe...
Authors
Timothy Meehan, Sarah P. Saunders, William DeLuca, Nicole L Michel, Joanna Grand, JIll Deppe, MIguel JImenez, Erika Knight, Nathaniel E. Seavy, Melanie A. Smith, Lotem Taylor, Chad Witko, Michael Akresh, David S. Barber, David Bayne, James Beasley, Jerrold L. Belant, Richard O Bierregaard, Keith L. Bildstein, Than J. Boves, John N. Brzorad, Steven B. Campbell, Antonio Celis-Murillo, Hillary Cooke, Robert Domenech, Laurie J. Goodrich, Elizabeth A. Gow, Aaron Haines, Michael T. Hallworth, Jason M. Hill, Amanda E. Holland, Scott Jennings, Roland Kays, Tommy King, Kent MacFarland, Stewart Mckenzie, Peter P. Marra, Rebbeca McCabe, Kent P. McFarland, Michael J. McGrady, John Melcer, Ryan Norris, Russell Norvell, Olin Rhodes Jr., Christopher C. Rimmer, Amy L. Scarpignato, Adam Shreading, Jesse Watson, Chad Wilsey
Whooping and sandhill cranes visit upland ponds proportional to migration phenology on the Texas coast Whooping and sandhill cranes visit upland ponds proportional to migration phenology on the Texas coast
Two crane species, whooping cranes (Grus americana) and sandhill cranes (Antigone canadensis), overwinter along the Texas Gulf Coast. Periodic, extreme drought conditions have prompted concerns that potential freshwater limitations could hinder conservation of cranes, especially endangered whooping cranes. In response, land managers constructed and maintained freshwater ponds in upland...
Authors
Matthew J Butler, Kristine L. Metzger, Colt R. Sanspree, James W. Cain, Grant M Harris
Changes in waterfowl migration phenologies in central North America: Implications for future waterfowl conservation Changes in waterfowl migration phenologies in central North America: Implications for future waterfowl conservation
Globally, migration phenologies of numerous avian species have shifted over the past half-century. Despite North American waterfowl being well researched, published data on shifts in waterfowl migration phenologies remain scarce. Understanding shifts in waterfowl migration phenologies along with potential drivers is critical for guiding future conservation efforts. Therefore, we utilized
Authors
Kent Andersson, Craig A. Davis, Grant Harris, David A. Haukos
Accelerated sea-level rise is suppressing CO2 stimulation of tidal marsh productivity: A 33-year study Accelerated sea-level rise is suppressing CO2 stimulation of tidal marsh productivity: A 33-year study
Accelerating relative sea-level rise (RSLR) is threatening coastal wetlands. However, rising CO2 concentrations may also stimulate carbon sequestration and vertical accretion, counterbalancing RSLR. A coastal wetland dominated by a C3 plant species was exposed to ambient and elevated levels of CO2 in situ from 1987 to 2019 during which time ambient CO2 concentration increased 18% and sea...
Authors
Chunwu Zhu, J. Adam Langley, Lewis H. Ziska, Donald R. Cahoon, J. Patrick Megonigal
Variation of cisco egg size among Laurentian Great Lakes populations Variation of cisco egg size among Laurentian Great Lakes populations
Many fish species display inter-population and inter-individual egg size variation. Intra-specific differences in egg size seemingly reflect both energetic experiences of individual spawning fish and long-term population responses to differing ecosystems. Optimal egg size theory implies that selection influences a population’s mean egg size in response to its early-life environment...
Authors
Scott T Koenigbauer, Daniel L. Yule, Kristopher Dey, Chris Olds, Michael J. Connerton, Tomas O Hook
Combining process-based and data-driven approaches to forecast beach and dune change Combining process-based and data-driven approaches to forecast beach and dune change
Producing accurate hindcasts and forecasts with coupled models is challenging due to complex parameterizations that are difficult to ground in observational data. We present a calibration workflow that utilizes a series of machine learning algorithms paired with Windsurf, a coupled beach-dune model (Aeolis, the Coastal Dune Model, and XBeach), to produce hindcasts and forecasts of...
Authors
Michael Itzkin, Laura J. Moore, Peter Ruggiero, Paige A. Hovenga, Sally D. Hacker
Velocity modeling of supercritical pore fluids through porous media under reservoir conditions with applications for petroleum secondary migration and carbon sequestration plumes Velocity modeling of supercritical pore fluids through porous media under reservoir conditions with applications for petroleum secondary migration and carbon sequestration plumes
Computational methods to characterize secondary migration in porous media traditionally rely on fluid transport equations with assumptions of time invariance, such as flowpath modeling of buoyancy vectors, statistical percolation algorithms, capillary pressure curves, or a form of Darcy’s Law which presumes instantaneous fluid transport. However, in petroleum systems modeling, the...
Authors
Lauri A. Burke