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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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Assessment of disease risk associated with potential removal of anthropogenic barriers to Mojave desert tortoise (Gopherus agassizii) population connectivity Assessment of disease risk associated with potential removal of anthropogenic barriers to Mojave desert tortoise (Gopherus agassizii) population connectivity
The Mojave Desert tortoise (Gopherus agassizii), federally listed as threatened, has suffered habitat loss and fragmentation due to human activities. Upper respiratory tract disease (URTD), a documented health threat to desert tortoises, has been detected at the Large-Scale Translocation Study Site (LSTS) in southwestern Nevada, US, a fenced recipient site for translocated animals. Our...
Authors
Tristan L. Burgess, Josephine Braun, Carmel L Witte, Nadine Lamberski, Field. Kimberleigh J, Linda J. Allison, Roy C. Averill-Murray, K. Kristina Drake, Kenneth E. Nussear, Todd Esque, Bruce A Rideout
Reconstructing paleohydrology in the northwest Great Basin since the last deglaciation using Paisley Caves fish remains (Oregon, U.S.A.) Reconstructing paleohydrology in the northwest Great Basin since the last deglaciation using Paisley Caves fish remains (Oregon, U.S.A.)
The arid northwest Great Basin underwent substantial hydroclimate changes in the past 15,000 years, greatly affecting its desert ecosystems and prehistoric people. There are conflicting interpretations of the timing of hydrologic changes in this region, requiring more records to resolve the dominant climatic drivers. The Paisley Caves archaeological site, located near former pluvial Lake...
Authors
Adam M. Hudson, Meaghan M Emery-Wetherell, Patrick M Lubinski, Virginia L. Butler, Deanna N Grimstead, Dennis L Jenkins
Establishment and survival of subalpine fir (Abies lasiocarpa) in meadows of Olympic National Park, Washington Establishment and survival of subalpine fir (Abies lasiocarpa) in meadows of Olympic National Park, Washington
Establishment of trees in subalpine meadows is a potential indicator of ecological effects of climate change. Tree establishment is a multi-year process including cone and seed production, germination, establishment, and growth, with each demographic step possibly sensitive to different climate limitations. While most studies have focused on one or a few steps, this study follows a...
Authors
Andrea Woodward, Jonathan A. Soll
Robust projections of future fire probability for the conterminous United States Robust projections of future fire probability for the conterminous United States
Globally increasing wildfires have been attributed to anthropogenic climate change. However, providing decision makers with a clear understanding of how future planetary warming could affect fire regimes is complicated by confounding land use factors that influence wildfire and by uncertainty associated with model simulations of climate change. We use an ensemble of statistically...
Authors
Peng Gao, Adam J. Terando, John A Kupfer, J. Morgan Varner, Michael C. Stambaugh, Ting L Lei, J. Kevin Hiers
A small proportion of breeders drive American bullfrog invasion of the Yellowstone River floodplain, Montana A small proportion of breeders drive American bullfrog invasion of the Yellowstone River floodplain, Montana
The American bullfrog (Lithobates catesbeianus) is a non-native invader of aquatic habitats across the northwestern United States. It recently invaded the Yellowstone River, Montana, and has spread to over 140 km of floodplain habitat. We analyzed seven microsatellites in 528 tadpoles sampled across nearly the entire Yellowstone River invasion (about 140 river km) to characterize...
Authors
Daniel M. Bingham, Adam Sepulveda, Sally Painter
Sources of volcanic tremor associated with the summit caldera collapse during the 2018 east rift eruption of Kīlauea Volcano, Hawai'i Sources of volcanic tremor associated with the summit caldera collapse during the 2018 east rift eruption of Kīlauea Volcano, Hawai'i
Volcanic tremor occurring at the beginning of the 2018 Kīlauea eruption is characterized using both seismic and tilt data recorded at the Kīlauea summit. An automatic seismic network-based approach detects several types of tremor including (a) 0.5–1 Hz long-period tremor preceding the eruption, located at the south-southwest edge of Halema'uma'u Crater and attributed to the quasi-steady...
Authors
J. Soubestre, B. Chouet, Phillip B. Dawson
Repeated large-scale mechanical treatment of invasive Typha under increasing water levels promotes floating mat formation and wetland methane emissions Repeated large-scale mechanical treatment of invasive Typha under increasing water levels promotes floating mat formation and wetland methane emissions
Invasive species management typically aims to promote diversity and wildlife habitat, but little is known about how management techniques affect wetland carbon (C) dynamics. Since wetland C uptake is largely influenced by water levels and highly productive plants, the interplay of hydrologic extremes and invasive species is fundamental to understanding and managing these ecosystems...
Authors
Olivia Fayne Johnson, Abha Panda, Shane C. Lishawa, Beth A. Lawrence
Willow drives changes in arthropod communities of northwestern Alaska: Ecological implications of shrub expansion Willow drives changes in arthropod communities of northwestern Alaska: Ecological implications of shrub expansion
Arthropods serve as complex linkages between plants and higher-level predators in Arctic ecosystems and provide key ecosystem services such as pollination and nutrient cycling. Arctic plant communities are changing as tall woody shrubs expand onto tundra, but potential effects on arthropod abundance and food web structure remain unclear. Changes in vegetation structure can alter the...
Authors
Molly Mcdermott, Patricia Doak, Colleen M. Handel, Greg A. Breed, Christa Mulder
Modeling effects of disturbance across life history strategies of stream fishes Modeling effects of disturbance across life history strategies of stream fishes
A central goal of population ecology is to establish linkages between life history strategy, disturbance, and population dynamics. Globally, disturbance events such as drought and invasive species have dramatically impacted stream fish populations and contributed to sharp declines in freshwater biodiversity. Here, we used RAMAS-Metapop to construct stage-based demographic metapopulation...
Authors
Robert J. Fournier, Nick R. Bond, Daniel D. Magoulick
Stress controls rupture extent and maximum magnitude of induced earthquakes Stress controls rupture extent and maximum magnitude of induced earthquakes
Seismic hazard forecasts of induced seismicity often require estimates of the maximum possible magnitude (Mmax). Empirical models suggest that maximum magnitudes, or expected number of earthquakes, are related to the volume of injected fluid. We perform a suite of 3D physics-based earthquake simulations with rate- and state-dependent friction, systematically varying the area of the...
Authors
K. A. Kroll, Elizabeth S. Cochran
An empirically based simulation model to inform flow management for endangered species conservation An empirically based simulation model to inform flow management for endangered species conservation
Increasing water demand, water development, and ongoing climate change have driven extensive changes to the hydrology, geomorphology and biology of arid-land rivers globally, driving an increasing need to understand how annual hydrologic conditions affect the distribution and abundance of imperiled desert fish populations. We analyzed the relationship between annual hydrologic conditions...
Authors
Timothy E. Walsworth, Phaedra E. Budy
Development of soil radiocarbon profiles in a reactive transport framework Development of soil radiocarbon profiles in a reactive transport framework
Today, there is a greater appreciation for the importance of the physical protection of carbon (C) through interactions with mineral surfaces, isolation from microbes, and the important role of transport in shaping soil properties and controlling moisture limitations on decomposition. As our paradigm for soil organic carbon (SOC) preservation changes, so too should our representation of...
Authors
Jennifer Druhan, Corey Lawrence