Skip to main content
U.S. flag

An official website of the United States government

Articles

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: 77848

Minimizing extinction risk in the face of uncertainty: Developing conservation strategies for 2 rapidly declining forest bird species on Kaua‘i Island Minimizing extinction risk in the face of uncertainty: Developing conservation strategies for 2 rapidly declining forest bird species on Kaua‘i Island

Many species around the world are declining precipitously as a result of multiple threats and changing climate. Managers tasked with protecting species often face difficult decisions in regard to identifying which threats should be addressed, given limited resources and uncertainty in the success of any identified management action. On Kaua‘i Island, Hawai‘i, USA, forest bird species...
Authors
Eben H. Paxton, Lisa H. Crampton, John Vetter, Megan Laut, Lainie Berry, Steve Morey

Exposure to crop production alters cecal prokaryotic microbiota, inflates virulome and resistome in wild prairie grouse Exposure to crop production alters cecal prokaryotic microbiota, inflates virulome and resistome in wild prairie grouse

Chemically intensive crop production depletes wildlife food resources, hinders animal development, health, survival, and reproduction, and it suppresses wildlife immune systems, facilitating emergence of infectious diseases with excessive mortality rates. Gut microbiota is crucial for wildlife's response to environmental stressors. Its composition and functionality are sensitive to diet...
Authors
Sergei V. Drovetski, Brian K. Schmidt, Jonas Ethan Lai, Michael S. Gross, Michelle L. Hladik, Kenan Oguz Matterson, Natalie Karouna-Renier

Air, land, and water variables associated with the first appearance and current spatial distribution of toxic Prymnesium parvum blooms in reservoirs of the Southern Great Plains, USA Air, land, and water variables associated with the first appearance and current spatial distribution of toxic Prymnesium parvum blooms in reservoirs of the Southern Great Plains, USA

This study examined the association of air, land, and water variables with the first historical occurrence and current distribution of toxic Prymnesium parvum blooms in reservoirs of the Brazos River and Colorado River, Texas (USA). One impacted and one reference reservoir were selected per basin. Land cover and use variables were estimated for the whole watershed (WW) and a 0.5-km zone...
Authors
Shisbeth Tabora-Sarmientoa, Reynaldo Patino, Carlos Portillo-Quintero, Cade Coldren

The effect of diagenesis and acetolysis on the preservation of morphology and ultrastructural features of pollen The effect of diagenesis and acetolysis on the preservation of morphology and ultrastructural features of pollen

Pollen morphology on its own and in conjunction with other characteristics has elucidated the origin and evolution of various plant groups. Previous studies of fossil pollen rarely discuss the effects of diagenesis and sample preparation on pollen characteristics, i.e., variability in staining, pollen morphology, and pollen wall ultrastructural characteristics. This paper examines the...
Authors
Michael Zavada, Paul C. Hackley

Incorporating snowmelt into daily estimates of recharge using a state-space model of infiltration Incorporating snowmelt into daily estimates of recharge using a state-space model of infiltration

A state-space model (SSM) of infiltration estimates daily groundwater recharge using time-series of groundwater-level altitude and meteorological inputs (liquid precipitation, snowmelt, and evapotranspiration). The model includes diffuse and preferential flow through the unsaturated zone, where preferential flow is a function of liquid precipitation and snowmelt rates and a threshold...
Authors
Allen M. Shapiro, Frederick Day-Lewis, William M. Kappel, John H. Williams

The potential of semi-structured citizen science data as a supplement for conservation decision-making: Validating the performance of eBird against targeted avian monitoring efforts The potential of semi-structured citizen science data as a supplement for conservation decision-making: Validating the performance of eBird against targeted avian monitoring efforts

Methods are being developed to capitalize on citizen science data for research and monitoring, but these data are rarely used within established decision-making frameworks of wildlife agencies. Citizen science data are often collected at higher resolution and extent than targeted monitoring programs, and may provide complementary information. Here, we demonstrate that carefully filtered...
Authors
Erica Francis Stuber, Orin Robinson, Emily R. Bjerre, Mark C. Otto, Brian A. Millsap, Guthrie S. Zimmerman, Michael G. Brasher, Kevin M. Ringelman, Auriel Fournier, Aaron Yetter, Jennifer Isola, Viviana Ruiz-Gutierrez

Using predictions from multiple anthropogenic threats to estimate future population persistence of an imperiled species Using predictions from multiple anthropogenic threats to estimate future population persistence of an imperiled species

Imperiled species face numerous and diverse anthropogenic threats to their persistence, and wildlife managers charged with making conservation decisions benefit from a sound understanding of how populations, species, and ecosystems will respond to future changes in threats to biodiversity. In southeastern North America, the gopher tortoise (Gopherus polyphemus) is a keystone species in...
Authors
Brian Folt, Michael Marshall, Jo Anna Emanuel, Michelina Dziadzio, Jane Cooke, Lourdes Mena, Matthew Hinderliter, Scott Hoffmann, Nicole Rankin, John Tupy, Conor P. McGowan

Compression behavior of hydrate-bearing sediments Compression behavior of hydrate-bearing sediments

This work experimentally explores porosity, compressibility, and the ratio of horizontal to vertical effective stress (K0) in hydrate-bearing sandy silts from Green Canyon Block 955 in the deep-water Gulf of Mexico. The samples have an in situ porosity of 0.38 to 0.40 and a hydrate saturation of more than 80%. The hydrate-bearing sediments are stiffer than the equivalent hydrate-free...
Authors
Yi Fang, Peter Flemings, John Germaine, Hugh Daigle, Stephen C. Phillips, Joshua O’Connell

Permeability of methane hydrate-bearing sandy silts in the deep-water Gulf of Mexico (Green Canyon Block 955) Permeability of methane hydrate-bearing sandy silts in the deep-water Gulf of Mexico (Green Canyon Block 955)

Permeability is one of the most crucial properties governing fluid flow in methane hydrate reservoirs. This paper presents a comprehensive permeability analysis of hydrate-bearing sandy silt pressure-cored from Green Canyon Block 955 (GC 955) in the deep-water Gulf of Mexico. We developed an experimental protocol to systematically characterize the transport and petrophysical properties...
Authors
Yi Fang, Peter Flemings, Hugh Daigle, Stephen C. Phillips, Joshua O’Connell

Assessing conservation and management actions with ecosystem services better communicates conservation value to the public Assessing conservation and management actions with ecosystem services better communicates conservation value to the public

Fish and wildlife populations are under unprecedented threats from changes in land use and climate. With increasing threats comes a need for an expanded constituency that can contribute to the public support and financial capital needed for habitat conservation and management. Using an ecosystem services approach can provide a framework for a more holistic accounting of conservation...
Authors
David M. Mushet, Max Post van der Burg, Michael J. Anteau

Integrated geochemical approach to determine the source of methane in gas hydrate from Green Canyon Block 955 in the Gulf of Mexico Integrated geochemical approach to determine the source of methane in gas hydrate from Green Canyon Block 955 in the Gulf of Mexico

Massive volumes of gas are sequestered within gas hydrate in subsurface marine sediments in the Gulf of Mexico. Methane associated with gas hydrate is a potentially important economic resource and a significant reservoir of carbon within the global carbon cycle. Nevertheless, uncertainties remain about the genetic source (e.g., microbial, thermogenic) and possible migration history of...
Authors
Myles T. Moore, Stephen C. Phillips, Ann Cook, Thomas H. Darrah

A forested wetland at a climate-induced tipping-point: 17-year demographic evidence of widespread tree recruitment failure A forested wetland at a climate-induced tipping-point: 17-year demographic evidence of widespread tree recruitment failure

Regeneration and survival of forested wetlands are affected by environmental variables related to the hydrologic regime. Climate change, specifically alterations to precipitation patterns, may have outsized effects on these forests. In Tennessee, USA, precipitation has increased by 15% since 1960. The goal of our research was to assess the evidence for whether this change in...
Authors
Jonathan Evans, Sarah McCarthy-Neumann, Angus Pritchard, Jennifer M. Cartwright, William J. Wolfe
Was this page helpful?