Publications
USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.
Filter Total Items: 3082
Forecasting the relative influence of environmental and anthropogenic stressors on polar bears Forecasting the relative influence of environmental and anthropogenic stressors on polar bears
Effective conservation planning requires understanding and ranking threats to wildlife populations. We developed a Bayesian network model to evaluate the relative influence of environmental and anthropogenic stressors, and their mitigation, on the persistence of polar bears (Ursus maritimus). Overall sea ice conditions, affected by rising global temperatures, were the most influential...
Authors
Todd C. Atwood, Bruce G. Marcot, David C. Douglas, Steven C. Amstrup, Karyn D. Rode, George M. Durner, Jeffrey F. Bromaghin
Automated mapping of persistent ice and snow cover across the western U.S. with Landsat Automated mapping of persistent ice and snow cover across the western U.S. with Landsat
We implemented an automated approach for mapping persistent ice and snow cover (PISC) across the conterminous western U.S. using all available Landsat TM and ETM+ scenes acquired during the late summer/early fall period between 2010 and 2014. Two separate validation approaches indicate this dataset provides a more accurate representation of glacial ice and perennial snow cover for the...
Authors
David J. Selkowitz, Richard R. Forster
A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells. A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells.
H9N2 influenza A viruses are on the list of potentially pandemic subtypes. Therefore, it is important to understand how genomic reassortment and genetic polymorphisms affect phenotypes of H9N2 viruses circulating in the wild bird reservoir. A comparative genetic analysis of North American H9N2 isolates of wild bird origin identified a naturally occurring reassortant virus containing gene...
Authors
Islam T.M. Hussein, Eric J. Ma, Brandt W. Meixell, Nichola J. Hill, Mark S. Lindberg, Randy A. Albrecht, Justin Bahl, Jonathan A. Runstadler
Increased water deficit decreases Douglas fir growth throughout western US forests Increased water deficit decreases Douglas fir growth throughout western US forests
Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas-fir (Pseudotsuga menziesii) chronologies from 122 locations that experience distinctly different climate in the western...
Authors
Christina M Restaino, David L. Peterson, Jeremy S. Littell
Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate
Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development below shallow lakes. Here we show high...
Authors
Christopher D. Arp, Benjamin M. Jones, Guido Grosse, Allen C. Bondurant, Vladimir E. Romanovksy, Kenneth M. Hinkel, Andrew D. Parsekian
Effects of Lead Exposure, Environmental Conditions, and Metapopulation Processes on Population Dynamics of Spectacled Eiders. Effects of Lead Exposure, Environmental Conditions, and Metapopulation Processes on Population Dynamics of Spectacled Eiders.
Spectacled eider Somateria fischeri numbers have declined and they are considered threatened in accordance with the US Endangered Species Act throughout their range. We synthesized the available information for spectacled eiders to construct deterministic, stochastic, and metapopulation models for this species that incorporated current estimates of vital rates such as nest success, adult...
Authors
Paul L. Flint, J. Barry Grand, Margaret R. Petersen, Robert F. Rockwell
Genome sequence of a novel H14N7 subtype influenza A virus isolated from a blue-winged teal (Anas discors) harvested in Texas, USA Genome sequence of a novel H14N7 subtype influenza A virus isolated from a blue-winged teal (Anas discors) harvested in Texas, USA
We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir.
Authors
Andrew M. Ramey, Andrew B. Reeves, Rebecca L. Poulson, Deborah L. Carter, Nicholas Davis-Fields, David E. Stallknecht
Waterfowl populations are resilient to immediate and lagged impacts of wildfires in the boreal forest Waterfowl populations are resilient to immediate and lagged impacts of wildfires in the boreal forest
Summary 1. Wildfires are the principal disturbance in the boreal forest, and their size and frequency are increasing as the climate warms. Impacts of fires on boreal wildlife are largely unknown, especially for the tens of millions of waterfowl that breed in the region. This knowledge gap creates significant barriers to the integrative management of fires and waterfowl, leading to fire...
Authors
Tyler Lewis, Joel A. Schmutz, Courtney L. Amundson, Mark S. Lindberg
Elements in whole blood of Northwestern Crows (Corvus caurinus) in Alaska: No evidence for an association with beak deformities Elements in whole blood of Northwestern Crows (Corvus caurinus) in Alaska: No evidence for an association with beak deformities
A recent outbreak of beak deformities among resident birds in Alaska has raised concern about environmental contamination as a possible underlying factor. We measured whole blood concentrations of 30 essential and nonessential elements to determine whether any were associated with beak deformities in Northwestern Crows (Corvus caurinus). We tested for differences between 1) adults with...
Authors
Caroline R. Van Hemert, Colleen M. Handel
Evidence for the exchange of blood parasites between North America and the Neotropics in blue-winged teal (Anas discors) Evidence for the exchange of blood parasites between North America and the Neotropics in blue-winged teal (Anas discors)
Blue-winged teal (Anas discors) are abundant, small-bodied dabbling ducks that breed throughout the prairies of the northcentral USA and central Canada and that winter in the southern USA and northern Neotropics. Given the migratory tendencies of this species, it is plausible that blue-winged teal may disperse avian pathogens, such as parasites causing avian malaria, between spatially...
Authors
Andrew M. Ramey, John A. Reed, Patrick Walther, Paul Link, Joel A. Schmutz, David C. Douglas, David E. Stallknecht, Catherine Soos
Wildfire risk as a socioecological pathology Wildfire risk as a socioecological pathology
Wildfire risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of wildfire risk could benefit from recognizing and accounting for these interactions in terms of...
Authors
A. Paige Fischer, Thomas A. Spies, Toddi A Steelman, Cassandra Moseley, Bart R. Johnson, John D. Bailey, Alan A Ager, Patrick S. Bourgeron, Susan Charnley, Brandon M. Collins, Jeffrey D Kline, Jessica E Leahy, Jeremy S. Littell, James D. A. Millington, Max Nielsen-Pincus, Christine S Olsen, Travis B Paveglio, Christopher I. Roos, Michelle M Steen-Adams, Forrest R Stevens, Jelena Vukomanovic, Eric M White, David M J S Bowman
A primer on potential impacts, management priorities, and future directions for Elodea spp. in high latitude systems: learning from the Alaskan experience A primer on potential impacts, management priorities, and future directions for Elodea spp. in high latitude systems: learning from the Alaskan experience
Invasive species introductions in Arctic and Subarctic ecosystems are growing as climate change manifests and human activity increases in high latitudes. The aquatic plants of the genus Elodea are potential invaders to Arctic and Subarctic ecosystems circumpolar and at least one species is already established in Alaska, USA. To illustrate the problems of preventing, eradicating...
Authors
Michael P. Carey, Suresh A Sethi, Sabrina J Larsen, Cecil F Rich