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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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Tree regrowth duration map from LCMAP collection 1.0 land cover products in the conterminous United States, 1985–2017 Tree regrowth duration map from LCMAP collection 1.0 land cover products in the conterminous United States, 1985–2017
Forest covers about one-third of the land area of the conterminous United States (CONUS) and plays an important role in offsetting carbon emissions and supporting local economies. Growing interest in forests as relatively cost-effective nature-based climate solutions, particularly restoration and reforestation activities, has increased the demand for information on forest regrowth and...
Authors
Qiang Zhou, George Z. Xian, Josephine Horton, Danika F. Wellington, Grant Domke, Roger F. Auch, Congcong Li, Zhe Zhu
The role of microtopography and resident species in post-disturbance recovery of arid habitats in Hawaiʻi The role of microtopography and resident species in post-disturbance recovery of arid habitats in Hawaiʻi
Habitat-suitability indices (HSI) have been employed in restoration to identify optimal sites for planting native species. Often, HSI are based on abiotic variables and do not include biotic interactions, even though similar abiotic conditions can favor both native and nonnative species. Biotic interactions such as competition may be especially important in invader-dominated habitats...
Authors
Stephanie G. Yelenik, Eli Rose, Susan Cordell, Michelle Victoria, James R. Kellner
Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019 Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019
Satellite imagery is commonly used to map surface water extents over time, but many approaches yield discontinuous records resulting from cloud obstruction or image archive gaps. We applied the Dynamic Surface Water Extent (DSWE) model to downscaled (250-m) daily Moderate Resolution Imaging Spectroradiometer (MODIS) data in Google Earth Engine to generate monthly surface water maps for...
Authors
Roy E. Petrakis, Christopher E. Soulard, Eric K. Waller, Jessica J. Walker
A water quality barometer for Chesapeake Bay: Assessing spatial and temporal patterns using long-term monitoring data A water quality barometer for Chesapeake Bay: Assessing spatial and temporal patterns using long-term monitoring data
This paper develops a barometer that indexes water quality in the Chesapeake Bay and summarizes quality over spatial regions and temporal periods. The barometer has a basis in risk assessment and hydrology, and is a function of three different metrics of water quality relative to numerical criteria: relative frequency of criterion attainment; magnitude of deviation from a numerical...
Authors
A.R. Zahran, Qian Zhang, Peter J. Tango, E.P. Smith
Response of riparian vegetation to short- and long-term hydrologic variation Response of riparian vegetation to short- and long-term hydrologic variation
Increasing demand for river water now conflicts with an increasing desire to maintain riparian ecosystems. Efficiently managing river flows for riparian vegetation requires an understanding of the time scale of flow effects, but this information is limited by the absence of long-term studies of vegetation change in response to flow variation. To investigate the influence of short- and...
Authors
Jonathan M. Friedman, Abigail M. Eurich, Gregor T. Auble, Michael L. Scott, Patrick B. Shafroth, Polly P Gibson
The need to step-up monitoring of Asian bears The need to step-up monitoring of Asian bears
Many wildlife species are threatened in Asia, including the five species of terrestrial bears (Asiatic black, Ursus thibetanus; brown, U. arctos; sloth, Melursus ursinus; sun, Helarctos malayanus; giant panda, Ailuropoda melanoleuca): many populations of these bears are thought to be declining or imperiled by small population size. Here our aim is to document how population assessments...
Authors
David L. Garshelis, Karine Pigeon, Mei-hsiu Hwang, Michael Proctor, William J. McShea, Angela K. Fuller, Dana J. Morin
Predicting near-term effects of climate change on nitrogen transport to Chesapeake Bay Predicting near-term effects of climate change on nitrogen transport to Chesapeake Bay
Understanding effects of climate change on nitrogen fate and transport in the environment is critical to nutrient management. We used climate projections within a previously calibrated spatially referenced regression (SPARROW) model to predict effects of expected climate change over 1995 through 2025 on total nitrogen fluxes to Chesapeake Bay and in watershed streams. Assuming nitrogen...
Authors
Scott Ator, Gregory E. Schwarz, Andrew J. Sekellick, Gopal Bhatt
A novel method for conducting a geoenvironmental assessment of undiscovered ISR-amenable uranium Resources: Proof-of-concept in the Texas Coastal Plain A novel method for conducting a geoenvironmental assessment of undiscovered ISR-amenable uranium Resources: Proof-of-concept in the Texas Coastal Plain
A geoenvironmental assessment methodology was developed to estimate waste quantities and disturbances that could be associated with the extraction of undiscovered uranium resources and identify areas on the landscape where uranium and other constituents of potential concern (COPCs) that may co-occur with uranium deposits in this region are likely to persist, if introduced into the...
Authors
Tanya J. Gallegos, Victoria G. Stengel, Katherine Walton-Day, Johanna Blake, Andrew Teeple, Delbert G Humberson, Steven M. Cahan, Douglas Yager, Kent D Becher
Processes and mechanisms of coastal woody-plant mortality Processes and mechanisms of coastal woody-plant mortality
Observations of woody plant mortality in coastal ecosystems are globally widespread, but the overarching processes and underlying mechanisms are poorly understood. This knowledge deficiency, combined with rapidly changing water levels, storm surges, atmospheric CO2, and vapor pressure deficit, creates large predictive uncertainty regarding how coastal ecosystems will respond to global...
Authors
Nate G. McDowell, Marilyn Ball, Ben Bond-Lamberty, Matthew L. Kirwan, Ken Krauss, J. Patrick Megonigal, Maurizio Mencuccini, Nicholas D. Ward, Michael N. Weintraub, Vanessa Bailey
Habitat edges influence the distribution of nest predators for Seaside Sparrows, but not nest placement or success Habitat edges influence the distribution of nest predators for Seaside Sparrows, but not nest placement or success
Nest failure for coastal marsh bird species is primarily caused by predation and nest flooding. As sea level rise makes nest flooding more likely, the threat of nest predation will constrain the potential adaptive responses of marsh nesting species. Thus, understanding the predictors of nest predation is important for the conservation of salt marsh-dwelling bird species, such as the...
Authors
Corina D. Newsome, Elizabeth Ann Hunter
U-Pb and fission-track data from zircon and apatite resolve latest- and post-Alleghanian thermal histories along the Fall Line of the Atlantic margin of the southeastern United States U-Pb and fission-track data from zircon and apatite resolve latest- and post-Alleghanian thermal histories along the Fall Line of the Atlantic margin of the southeastern United States
Although the Atlantic continental margin of the eastern United States is an archetypal passive margin, episodes of rejuvenation following continental breakup are increasingly well documented. To better constrain this history of rejuvenation along the southern portion of this continental margin, we present zircon U-Pb (ZUPb) age, zircon fission-track (ZFT) age, apatite U-Pb (AUPb) age...
Authors
William H. Craddock, Paul O'Sullivan, Ryan J. McAleer
Vadose zone thickness limits pore-fluid pressures and acceleration in a large, slow-moving landslide Vadose zone thickness limits pore-fluid pressures and acceleration in a large, slow-moving landslide
The rate and timing of hydrologically forced landslides is a complex function of precipitation patterns, material properties, topography, and groundwater hydrology. In the simplest form, however, slopes fail when subsurface pore pressure grows large enough to exceed the Mohr-Coulomb failure criterion. The capacity for pore pressure rise in a landslide is determined in part by the...
Authors
C.R. Murphy, N.J. Finnegan, Ferdinand K.J. Oberle