Articles
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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.
Filter Total Items: 78946
No long-term effect of black bear removal on elk calf recruitment in the southern Appalachians No long-term effect of black bear removal on elk calf recruitment in the southern Appalachians
In 2001 and 2002, 52 elk (Cervus canadensis; 21 males, 31 females), originally obtained from Elk Island National Park, Alberta, Canada, were transported and released into Cataloochee Valley in the northeastern portion of Great Smoky Mountains National Park (GRSM, Park), North Carolina, USA. The annual population growth rate (λ) was negative (0.996, 95% CI = 0.945–1.047) and predation by...
Authors
Joseph G. Yarkovich, Jessica L. Braunstein, Jennifer M. Mullinax, Joseph D. Clark
Sea ice concentration decline in an important Adélie penguin molt area Sea ice concentration decline in an important Adélie penguin molt area
Unlike in many polar regions, the spatial extent and duration of the sea ice season have increased in the Ross Sea sector of the Southern Ocean during the satellite era. Simultaneously, populations of Adélie penguins, a sea ice obligate, have been stable or increasing in the region. Relationships between Adélie penguin population growth and sea ice concentration are complex, with sea ice...
Authors
Annie E. Schmidt, Amélie Lescroël, Simeon Lisovski, Megan Elrod, Dennis Jongsomjit, Katie M. Dugger, Grant Ballard
The use of semiochemicals for attracting and repelling invasive ambrosia beetles (Coleoptera: Curculionidae) in ʻōhiʻa (Metrosideros polymorpha) forests The use of semiochemicals for attracting and repelling invasive ambrosia beetles (Coleoptera: Curculionidae) in ʻōhiʻa (Metrosideros polymorpha) forests
Early detection of invasive species is critical for preventing ecological and economic damage and maintaining ecosystem health. In Hawaiʻi, a complex of generalist ambrosia beetle species in the tribe Xyleborini (Coleoptera: Scolytinae) are threatening the health and productivity of forests and crops due to their association with tree diseases such as rapid ʻōhiʻa death (ROD) and key...
Authors
Kylle Roy, Helen R. Sofaer, Robert W. Peck, Ellen J. Dunkle, Dan Mikros, Sheri L. Smith, Matthew D. Ginzel
Biocrusts modulate carbon losses under warming across global drylands: A bayesian meta-analysis Biocrusts modulate carbon losses under warming across global drylands: A bayesian meta-analysis
Biocrusts are critical biological components of drylands and play an important role in soil carbon (C) cycling. However, the effect of biocrusts on soil CO2 exchange across global gradients of temperature and moisture is poorly understood. Moreover, their response to climate change remains highly uncertain. Bayesian hierarchical meta-analyses were performed on 47 published studies to...
Authors
Jingyao Sun, Kailiang Yu, Ning Chen, Seth M. Munson, Xinrong Li, Rongliang Jia
Thirty years of regional groundwater-quality trend studies in the United States: Major findings and lessons learned Thirty years of regional groundwater-quality trend studies in the United States: Major findings and lessons learned
Changes in groundwater quality have been evaluated for more than 2,200 wells in 25 Principal Aquifers in the United States based on repeated decadal sampling (once every 10 years) from 1988 to 2021. The purpose of this study is to identify contaminants with changing concentrations, the locations and magnitude of those changes, the factors driving those changes, the obstacles to...
Authors
Bruce D. Lindsey, Brandon J. Fleming, Phillip J. Goodling, Amanda Nicole May
Lipid metabolites index habitat quality for Canvasbacks on stopover areas during spring migration Lipid metabolites index habitat quality for Canvasbacks on stopover areas during spring migration
Nutrients acquired by ducks on spring migratory stopover areas influence survival and subsequent reproduction. Accordingly, wetland loss and degradation on stopover areas can lead to reduced refueling efficiency and have demographic consequences. Lipid metabolite concentrations in blood provide a useful index of daily mass change in wild birds and can be used to make inferences about...
Authors
Andrew Bouton, Michael J. Anteau, Eric J. Smith, Heath Hagy, Joseph Lancasster, Christopher Jacques
Two centuries of southwest Iceland annually-resolved marine temperature reconstructed from Arctica islandica shells Two centuries of southwest Iceland annually-resolved marine temperature reconstructed from Arctica islandica shells
Iceland's exposure to major ocean current pathways of the central North Atlantic makes it a useful location for developing long-term proxy records of past marine climate. Such records provide more detailed understanding of the full range of past variability which is necessary to improve predictions of future changes. We constructed a 225-year (1791–2015 CE) master shell growth chronology...
Authors
Madelyn Jean Mette, Carin Andersson, Bernd Schöne, Fabian Bonitz, Vilde Melvik, Tamara Trofimova, Martin Miles
Permethrin contamination of sawgrass marshes and potential risk for the imperiled Klot’s skipper butterfly (Euphyes pilatka klotsi) Permethrin contamination of sawgrass marshes and potential risk for the imperiled Klot’s skipper butterfly (Euphyes pilatka klotsi)
Nontarget effects from mosquito control operations are possible in habitats adjacent to areas targeted by ultra-low-volume (ULV) sprays of permethrin for adult mosquito control. We assessed the risks of permethrin exposure to butterflies, particularly the imperiled Klot's skipper, when exposed to ground-based ULV sprays. Samples of larval host plant leaves (sawgrass) were collected in...
Authors
Timothy Bargar, Michelle L. Hladik
Reach-scale associations between introduced Brook Trout and juvenile and stream-resident Bull Trout in Idaho Reach-scale associations between introduced Brook Trout and juvenile and stream-resident Bull Trout in Idaho
Objective
Authors
Nicholas S. Voss, Brett J. Bowersox, Michael C. Quist
Multi-year tracing of spatial and temporal dynamics of post-fire aeolian sediment transport using rare earth elements provide insights into grassland management Multi-year tracing of spatial and temporal dynamics of post-fire aeolian sediment transport using rare earth elements provide insights into grassland management
Aeolian sediment transport occurs as a function of, and with feedback to ecosystem changes and disturbances. Many desert grasslands are undergoing rapid changes in vegetation, including the encroachment of woody plants, which alters fire regimes and in turn can change the spatial and temporal patterns of aeolian sediment transport. We investigated aeolian sediment transport and spatial...
Authors
William Burger, Robert Van Pelt, David E. Grandstaff, Guan Wang, Temuulen T. Sankey, Junran Li, Joel B. Sankey, Sujith Ravi
Improved computational methods for probabilistic liquefaction hazard analysis Improved computational methods for probabilistic liquefaction hazard analysis
Current procedures for analysis of and design against liquefaction hazards focus primarily on the use of probabilistic ground motions at a single ground-shaking hazard level, with the cyclic loading represented by a peak ground acceleration (PGA) corresponding to a target return period and a single representative moment magnitude Mw. These parameters are typically used in conjunction...
Authors
Andrew James Makdisi, Steven L. Kramer
Probabilistic source classification of large tephra producing eruptions using supervised machine learning: An example from the Alaska-Aleutian arc Probabilistic source classification of large tephra producing eruptions using supervised machine learning: An example from the Alaska-Aleutian arc
Alaska contains over 130 volcanoes and volcanic fields that have been active within the last 2 million years. Of these, roughly 90 have erupted during the Holocene, with many characterized by at least one large explosive eruption. These large tephra-producing eruptions (LTPEs) generate orders of magnitude more erupted material than a “typical” arc explosive eruption and distribute ash...
Authors
Jordan Edward Lubbers, Matthew W. Loewen, Kristi L. Wallace, Michelle L. Coombs, Jason A. Addison