Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

40783 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 537, results 13401 - 13425

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
MMI: Multimodel inference or models with management implications?
J. Fieberg, Douglas H. Johnson
2015, Journal of Wildlife Management (79) 708-718
We consider a variety of regression modeling strategies for analyzing observational data associated with typical wildlife studies, including all subsets and stepwise regression, a single full model, and Akaike's Information Criterion (AIC)-based multimodel inference. Although there are advantages and disadvantages to each approach, we suggest that there is no unique...
Summer declines in activity and body temperature offer polar bears limited energy savings
J.P. Whiteman, H.J. Harlow, George M. Durner, R. Anderson-Sprecher, Shannon E. Albeke, Eric V. Regehr, Steven C. Amstrup, M. Ben-David
2015, Science (349) 295-298
Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of...
Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States
David M. Bell, John B. Bradford, William K. Lauenroth
2015, Ecology, Evolution, and Systematics (96) 1835-1845
Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as...
Self-similar rupture implied by scaling properties of volcanic earthquakes occurring during the 2004-2008 eruption of Mount St. Helens, Washington
Rebecca M. Harrington, Grzegorz Kwiatek, Seth C. Moran
2015, Journal of Geophysical Research B: Solid Earth (120) 1966-1982
We analyze a group of 6073 low-frequency earthquakes recorded during a week-long temporary deployment of broadband seismometers at distances of less than 3 km from the crater at Mount St. Helens in September of 2006. We estimate the seismic moment (M0) and spectral corner frequency (f0) using a spectral ratio approach...
Temperature profile around a basaltic sill intruded into wet sediments
Leslie Baker, Andrew Bernard, William C. Rember, Moses P. Milazzo, Colin M. Dundas, Oleg Abramov, Laszlo P. Keszthelyi
2015, Journal of Volcanology and Geothermal Research (302) 81-86
The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a...
Novel associations between contaminant body burdens and biomarkers of reproductive condition in male Common Carp along multiple gradients of contaminant exposure in Lake Mead National Recreation Area, USA
Reynaldo Patino, Matthew M. VanLandeghem, Steven L. Goodbred, Erik Orsak, Jill A. Jenkins, Kathy R. Echols, Michael R. Rosen, Leticia Torres
2015, General and Comparative Endocrinology (219) 112-124
Adult male Common Carp were sampled in 2007/08 over a full reproductive cycle at Lake Mead National Recreation Area. Sites sampled included a stream dominated by treated wastewater effluent, a lake basin receiving the streamflow, an upstream lake basin (reference), and a site below Hoover Dam. Individual body burdens for...
Genetic diversity is related to climatic variation and vulnerability in threatened bull trout
Ryan Kovach, Clint C. Muhlfeld, Alisa A. Wade, Brian K. Hand, Diane C. Whited, Patrick W. DeHaan, Robert K. Al-Chokhachy, Gordon Luikart
2015, Global Change Biology (21) 2510-2524
Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelic...
The Effect of modeled recharge distribution on simulated groundwater availability and capture
Fred D. Tillman, Donald R. Pool, Stanley A. Leake
2015, Groundwater (53) 378-388
Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins...
Similarities and differences in 13C and 15N stable isotope ratios in two non-lethal tissue types from shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820)
R. J. DeVries, Harold L. Schramm Jr.
2015, Journal of Applied Ichthyology (31) 474-478
We tested the hypothesis that δ13C and δ15N signatures of pectoral spines would provide measures of δ13C and δ15N similar to those obtained from fin clips for adult shovelnose sturgeon Scaphirhynchus platorynchus. Thirty-two shovelnose sturgeon (fork length [FL] = 500–724 mm) were sampled from the lower Mississippi River, USA on 23 February 2013. Isotopic...
Chloride concentrations, loads, and yields in four watersheds along Interstate 95, southeastern Connecticut, 2008-11: factors that affect peak chloride concentrations during winter storms
Craig J. Brown, John R. Mullaney, Jonathan Morrison, Joseph W. Martin, Thomas J. Trombley
2015, Scientific Investigations Report 2015-5057
Chloride (Cl-) concentrations and loads and other water chemistry characteristics were assessed to evaluate potential effects of road-deicer applications on streamwater quality in four watersheds along Interstate 95 (I–95) in southeastern Connecticut from November 1, 2008, through September 30, 2011. Streamflow and water quality were studied in the Four Mile...
National assessment of shoreline change: historical change along the north coast of Alaska, U.S.-Canadian border to Icy Cape
Ann E. Gibbs, Bruce M. Richmond
2015, Open-File Report 2015-1048
Beach erosion is a persistent problem along most open-ocean shores of the United States. Along the Arctic coast of Alaska, coastal erosion is widespread, may be accelerating, and is threatening defense and energy-related infrastructure, coastal habitats, and Native communities. As coastal populations continue to expand and infrastructure and habitat are...
Linking degradation status with ecosystem vulnerability to environmental change
David G. Angeler, Didier L. Baho, Craig R. Allen, Richard K. Johnson
2015, Oecologia (178) 899-913
Environmental change can cause regime shifts in ecosystems, potentially threatening ecosystem services. It is unclear if the degradation status of ecosystems correlates with their vulnerability to environmental change, and thus the risk of future regime shifts. We assessed resilience in acidified (degraded) and circumneutral (undegraded) lakes with long-term data (1988–2012),...
Spatial and temporal variability in growth of southern flounder (Paralichthys lethostigma)
Stephen R. Midway, Tyler Wagner, Stephen A. Arnott, Patrick Biondo, Fernando Martinez-Andrade, Thomas F. Wadsworth
2015, Fisheries Research (167) 323-332
Delineation of stock structure is important for understanding the ecology and management of many fish populations, particularly those with wide-ranging distributions and high levels of harvest. Southern flounder (Paralichthys lethostigma) is a popular commercial and recreational species along the southeast Atlantic coast and Gulf of Mexico, USA. Recent studies have...
Building a multi-scaled geospatial temporal ecology database from disparate data sources: Fostering open science through data reuse
Patricia A. Soranno, E.G. Bissell, Kendra S. Cheruvelil, Samuel T. Christel, Sarah M. Collins, C. Emi Fergus, Christopher T. Filstrup, Jean-Francois Lapierre, Noah R. Lotting, Samantha K. Oliver, Caren E. Scott, Nicole J. Smith, Scott Stopyak, Shuai Yuan, Mary Tate Bremigan, John A. Downing, Corinna Gries, Emily N. Henry, Nick K. Skaff, Emily H. Stanley, Craig A. Stow, Pang-Ning Tan, Tyler Wagner, Katherine E. Webster
2015, GigaScience (4)
Although there are considerable site-based data for individual or groups of ecosystems, these datasets are widely scattered, have different data formats and conventions, and often have limited accessibility. At the broader scale, national datasets exist for a large number of geospatial features of land, water, and air that are needed...
Use of structured decision making to identify monitoring variables and management priorities for salt marsh ecosystems
Hilary A. Neckles, James E. Lyons, Glenn R. Guntenspergen, W. Gregory Shriver, Susan C. Adamowicz
2015, Estuaries and Coasts (38) 1215-1232
Most salt marshes in the USA have been degraded by human activities, and coastal managers are faced with complex choices among possible actions to restore or enhance ecosystem integrity. We applied structured decision making (SDM) to guide selection of monitoring variables and management priorities for salt marshes within the National...
Use of dynamic occupancy models to assess the response of Darters (Teleostei: Percidae) to varying hydrothermal conditions in a southeastern United States tailwater
C.P. Shea, Phillip William Bettoli, K. M. Potoka, C. F. Saylor, P. W. Shute
2015, River Research and Applications (31) 676-691
During the past 100 years, most large rivers in North America have been altered for flood control, hydropower, navigation or water supply development. Although these activities clearly provide important human services, their associated environmental disturbances can profoundly affect stream-dwelling organisms. We used dynamic multi-species occupancy models combined with a trait-based approach...
Tree mortality predicted from drought-induced vascular damage
William R.L. Anderegg, Alan L. Flint, Cho-ying Huang, Lorraine E. Flint, Joseph A. Berry, Frank W. Davis, John S. Sperry, Christopher B. Field
2015, Nature Geoscience (8) 367-371
The projected responses of forest ecosystems to warming and drying associated with twenty-first-century climate change vary widely from resiliency to widespread tree mortality1, <a id="ref-link-3"...
Sea level and turbidity controls on mangrove soil surface elevation change
Catherine E. Lovelock, Maria Fernanda Adame, Vicki Bennion, Matthew Hayes, Ruth Reef, Nadia Santini, Donald R. Cahoon
2015, Estuarine, Coastal and Shelf Science (153) 1-9
Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on...
Statistical analysis of soil geochemical data to identify pathfinders associated with mineral deposits: An example from the Coles Hill uranium deposit, Virginia, USA
Denise M. Levitan, Carl E. Zipper, Patricia Donovan, Madeline E. Schreiber, Robert R. Seal, Mark A. Engle, John A. Chermak, Robert J. Bodnar, Daniel K. Johnson, Joseph G. Aylor Jr.
2015, Journal of Geochemical Exploration (154) 238-251
Soil geochemical anomalies can be used to identify pathfinders in exploration for ore deposits. In this study, compositional data analysis is used with multivariate statistical methods to analyse soil geochemical data collected from the Coles Hill uranium deposit, Virginia, USA, to identify pathfinders associated with this deposit. Elemental compositions and...
Methods used to parameterize the spatially-explicit components of a state-and-transition simulation model
Rachel Sleeter, William Acevedo, Christopher E. Soulard, Benjamin M. Sleeter
2015, AIMS Environmental Science (2) 668-693
Spatially-explicit state-and-transition simulation models of land use and land cover (LULC) increase our ability to assess regional landscape characteristics and associated carbon dynamics across multiple scenarios. By characterizing appropriate spatial attributes such as forest age and land-use distribution, a state-and-transition model can more effectively simulate the pattern and spread of...
Tectonic and sedimentary linkages between the Belt-Purcell basin and southwestern Laurentia during the Mesoproterozoic ca. 1.60-1.40 Ga
James V. Jones III, Christohper G Dainel, Michael F Doe
2015, Lithosphere (7) 465-472
Mesoproterozoic sedimentary basins in western North America provide key constraints on pre-Rodinia craton positions and interactions along the western rifted margin of Laurentia. One such basin, the Belt-Purcell basin, extends from southern Idaho into southern British Columbia and contains a >18-km-thick succession of siliciclastic sediment deposited ca. 1.47–1.40 Ga. The...
Soil surface organic layers in Arctic Alaska: spatial distribution, rates of formation, and microclimatic effects
Carson Baughman, Daniel H. Mann, David L. Verbyla, Michael L. Kunz
2015, Journal of Geophysical Research: Biogeosciences (120) 1150-1164
Organic layers of living and dead vegetation cover the ground surface in many permafrost landscapes and play important roles in ecosystem processes. These soil surface organic layers (SSOLs) store large amounts of carbon and buffer the underlying permafrost and its contained carbon from changes in aboveground climate. Understanding the dynamics of SSOLs...
Downscaling global land-use/land-cover projections for use in region-level state-and-transition simulation modeling
Jason T. Sherba, Benjamin M. Sleeter, Adam W. Davis, Owen P. Parker
2015, AIMS Environmental Science (2) 623-647
Global land-use/land-cover (LULC) change projections and historical datasets are typically available at coarse grid resolutions and are often incompatible with modeling applications at local to regional scales. The difficulty of downscaling and reapportioning global gridded LULC change projections to regional boundaries is a barrier to the use of these datasets...
Global volcanic hazards and risk
S. K. Brown, S. C. Loughlin, R. S. J. Sparks, C. Vye-Brown, J. Barclay, E. Calder, E. Cottrell, G. Jolly, J.C. Komorowski, Charlie Mandeville, C. Newhall, J. Palma, S. Potter, G. Valentine
S. C. Loughlin, R. S. J. Sparks, S. K. Brown, S. F. Jenkins, C. Vye-Brown, editor(s)
2015, Book chapter, Global Volcanic Hazards and Risk
An estimated 800 million people live within 100 km of an active volcano in 86 countries and additional overseas territories worldwide [see Chapter 4 and Appendix B]1. Volcanoes are compelling evidence that the Earth is a dynamic planet characterised by endless change and renewal. Humans have always found volcanic activity...
Patterns and predictability in the intra-annual organic carbon variability across the boreal and hemiboreal landscape
Julia K. Hytteborn, Johan Temnerud, Richard B. Alexander, Elizabeth W. Boyer, Martyn N. Futter, Mats Froberg, Joel Dahne, Kevin H. Bishop
2015, Science of the Total Environment (520) 260-269
Factors affecting total organic carbon (TOC) concentrations in 215 watercourses across Sweden were investigated using parameter parsimonious regression approaches to explain spatial and temporal variabilities of the TOC water quality responses. We systematically quantified the effects of discharge, seasonality, and long-term trend as factors controlling intra-annual (among year) and...