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

165626 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 941, results 23501 - 23525

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Monitoring water content dynamics of biological soil crusts
Michael H. Young, Lynn F. Fenstermaker, Jayne Belnap
2017, Journal of Arid Environments (142) 41-49
Biological soil crusts (hereafter, “biocrusts”) dominate soil surfaces in nearly all dryland environments. To better understand the influence of water content on carbon (C) exchange, we assessed the ability of dual-probe heat-pulse (DPHP) sensors, installed vertically and angled, to measure changes in near-surface water content. Four DPHP sensors were installed...
Seasonal fecundity and costs to λ are more strongly affected by direct than indirect predation effects across species
Joseph A. LaManna, Thomas E. Martin
2017, Ecology (98) 1829-1838
Increased perceived predation risk can cause behavioral and physiological responses to reduce direct predation mortality, but these responses can also cause demographic costs through reduced reproductive output. Such indirect costs of predation risk have received increased attention in recent years, but the relative importance of direct vs. indirect predation costs...
Glacierized headwater streams as aquifer recharge corridors, subarctic Alaska
Anna K. Lilledahl, Anne Gadeke, Shad O’Neel, T. A. Gatesman, T. A. Douglas
2017, Geophysical Research Letters (44) 6876-6885
Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2),...
Seasonal movements and multiscale habitat selection of Whooping Crane (Grus americana) in natural and agricultural wetlands
Bradley A. Pickens, Sammy L. King, Phillip L. Vasseur, Sara E. Zimorski, Will Selman
2017, Waterbirds (40) 322-333
Eleven of 15 species of cranes (family: Gruidae) are considered vulnerable or endangered, and the increase of agriculture and aquaculture at the expense of natural wetlands and grasslands is a threat to Gruidae worldwide. A reintroduced population of Whooping Crane (Grus americana) was studied in coastal and agricultural wetlands of...
Numerical simulations of sand production in interbedded hydrate-bearing sediments during depressurization
Shun Uchida, Jeen-Shang Lin, Evgeniy Myshakin, Yongkoo Seol, Timothy S. Collett, Ray Boswell
2017, Conference Paper, Proceeding of the 9th International Conference on Gas Hydrates
Geomechanical behavior of hydrate-bearing sediments during gas production is complex, involving changes in hydrate-dependent mechanical properties. When interbedded clay layers are present, the complexity is more pronounced because hydrate dissociation tends to occur preferentially in the sediments adjacent to the clay layers due to clay layers acting as a heat...
10Be dating of late Pleistocene megafloods and Cordilleran Ice Sheet retreat in the northwestern United States
Andrea M. Balbas, Aaron M. Barth, Peter U. Clark, Jorie Clark, Marc A. Caffee, Jim E. O'Connor, Victor R. Baker, Kevin Konrad, Bruce Bjornstad
2017, Geology (45) 583-586
During the late Pleistocene, multiple floods from drainage of glacial Lake Missoula further eroded a vast anastomosing network of bedrock channels, coulees, and cataracts, forming the Channeled Scabland of eastern Washington State (United States). However, the timing and exact pathways of these Missoula floods remain poorly constrained, thereby limiting our...
Population characteristics and the influence of discharge on Bluehead Sucker and Flannelmouth Sucker
Zachary B. Klein, Matthew J. Breen, Michael C. Quist
2017, Copeia (105) 375-388
Rivers are among some of the most complex and important ecosystems in the world. Unfortunately, many fishes endemic to rivers have suffered declines in abundance and distribution suggesting that alterations to lotic environments have negatively influenced native fish populations. Of the 35 fishes native to the Colorado River basin (CRB),...
Intra-reach headwater fish assemblage structure
James E. McKenna Jr.
2017, The Open Ecology Journal (10) 1-12
Large-scale conservation efforts can take advantage of modern large databases and regional modeling and assessment methods. However, these broad-scale efforts often assume uniform average habitat conditions and/or species assemblages within stream reaches....
Gradients in Catostomid assemblages along a reservoir cascade
Leandro E. Miranda, Kevin R. Keretz, Chelsea R. Gilliland
2017, River Research and Applications (33) 983-990
Serial impoundment of major rivers leads to alterations of natural flow dynamics and disrupts longitudinal connectivity. Catostomid fishes (suckers, family Catostomidae) are typically found in riverine or backwater habitats yet are able to persist in impounded river systems. To the detriment of conservation, there is limited information about distribution of...
Real-time geomagnetic monitoring for space weather-related applications: Opportunities and challenges
Jeffrey J. Love, Carol Finn
2017, Space Weather (15) 820-827
An examination is made of opportunities and challenges for enhancing global, real-time geomagnetic monitoring that would be beneficial for a variety of operational projects. This enhancement in geomagnetic monitoring can be attained by expanding the geographic distribution of magnetometer stations, improving the quality of magnetometer data, increasing acquisition sampling rates,...
Complex networks of functional connectivity in a wetland reconnected to its floodplain
Laurel G. Larsen, Susan Newman, Colin Saunders, Judson Harvey
2017, Water Resources Research (53) 6089-6108
Disturbances such as fire or flood, in addition to changing the local magnitude of ecological, hydrological, or biogeochemical processes, can also change their functional connectivity—how those processes interact in space. Complex networks offer promise for quantifying functional connectivity in watersheds. The approach resolves connections between nodes in space based on...
Species distribution models for a migratory bird based on citizen science and satellite tracking data
Christopher L. Coxen, Jennifer K. Frey, Scott A. Carleton, Daniel P. Collins
2017, Global Ecology and Conservation (11) 298-311
Species distribution models can provide critical baseline distribution information for the conservation of poorly understood species. Here, we compared the performance of band-tailed pigeon (Patagioenas fasciata) species distribution models created using Maxent and derived from two separate presence-only occurrence data sources in New Mexico: 1) satellite tracked birds and 2) observations...
Species’ traits help predict small mammal responses to habitat homogenization by an invasive grass
Joseph P. Ceradini, Anna D. Chalfoun
2017, Ecological Applications (27) 1451-1465
Invasive plants can negatively affect native species, however, the strength, direction, and shape of responses may vary depending on the type of habitat alteration and the natural history of native species. To prioritize conservation of vulnerable species, it is therefore critical to effectively predict species’ responses to invasive plants, which...
Comparison of American Fisheries Society (AFS) standard fish sampling techniques and environmental DNA for characterizing fish communities in a large reservoir
Christina R. Perez, Scott A. Bonar, Jon J. Amberg, Bridget Ladell, Christopher B. Rees, William T. Stewart, Curtis J. Gill, Chris Cantrell, Anthony Robinson
2017, North American Journal of Fisheries Management (37) 1010-1027
Recently, methods involving examination of environmental DNA (eDNA) have shown promise for characterizing fish species presence and distribution in waterbodies. We evaluated the use of eDNA for standard fish monitoring surveys in a large reservoir. Specifically, we compared the presence, relative abundance, biomass, and relative percent composition of Largemouth Bass Micropterus...
Plant diversity increases with the strength of negative density dependence at the global scale
Joseph A. LaManna, Scott A. Mangan, Alfonso Alonso, Norman Bourg, Warren Y. Brockelman, Sarayudh Bunyavejchewin, Li-Wan Chang, Jyh-Min Chiang, George B. Chuyong, Keith Clay, Richard Condit, Susan Cordell, Stuart J. Davies, Tucker J. Furniss, Christian P. Giardina, I.A.U. Nimal Gunatilleke, C.V. Savitri Gunatilleke, Fangliang He, Robert W. Howe, Stephen P. Hubbell, Chang-Fu Hsieh, Faith M. Inman-Narahari, David Janik, Daniel J. Johnson, David Kenfack, Lisa Korte, Kamil Kral, Andrew J. Larson, James A. Lutz, Sean M. McMahon, William J. McShea, Herve R. Memiaghe, Anuttara Nathalang, Vojtech Novotny, Perry S. Ong, David A. Orwig, Rebecca Ostertag, Geoffrey G. Parker, Richard P. Phillips, Lawren Sack, I-Fang Sun, J. Sebastian Tello, Duncan W. Thomas, Benjamin L. Turner, Dilys M. Vela Diaz, Tomas Vrska, George D. Weiblen, Amy Wolf, Sandra Yap, Jonathan A. Myers
2017, Science (356) 1389-1392
Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree...
Downscaling wind and wavefields for 21st century coastal flood hazard projections in a region of complex terrain
Andrea C. O'Neill, Li H. Erikson, Patrick L. Barnard
2017, Earth and Space Science (4) 314-334
While global climate models (GCMs) provide useful projections of near-surface wind vectors into the 21st century, resolution is not sufficient enough for use in regional wave modeling. Statistically downscaled GCM projections from Multivariate Adaptive Constructed Analogues provide daily averaged near-surface winds at an appropriate spatial resolution for wave modeling within...
Habitat associations of juvenile Burbot in a tributary of the Kootenai River
Zachary S. Beard, Michael C. Quist, Ryan S. Hardy, Tyler J. Ross
2017, Transactions of the American Fisheries Society (146) 1008-1015
Burbot Lota lota in the lower Kootenai River, Idaho, have been the focus of extensive conservation efforts, particularly conservation aquaculture. One of the primary management strategies has been the release of Burbot into small tributaries in the Kootenai River basin, such as Deep Creek. Since 2012, approximately 12,000 juvenile Burbot have been...
Grassland bird productivity in warm season grass fields in southwest Wisconsin
Carolyn M. Byers, Christine Ribic, David W. Sample, John D. Dadisman, Michael Guttery
2017, The American Midland Naturalist (178) 47-63
Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are...
Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA
Camila K. Cerqueira-Cezar, Peter C. Thompson, Shiv K. Verma, Joseph Mowery, Rafael Calero-Bernal, Fernando H. Antunes Murata, David R. Sinnett, Caroline R. Van Hemert, Benjamin M. Rosenthal, Jitender P. Dubey
2017, Parasitology Research (116) 1871-1878
The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of...
Reproductive ecology, spawning behavior, and juvenile distribution of Mountain Whitefish in the Madison River, Montana
Jan K. Boyer, Christopher S. Guy, Molly A. H. Webb, Travis B. Horton, Thomas E. McMahon
2017, Transactions of the American Fisheries Society (146) 939-954
Mountain Whitefish Prosopium williamsoni were historically common throughout much of the U.S. Intermountain West. However, within the last decade Mountain Whitefish have exhibited population-level declines in some rivers. In the Madison River, Montana, anecdotal evidence indicates Mountain Whitefish abundance has declined and the population is skewed toward larger individuals, which is typically...
Numerical studies of depressurization-induced gas production from an interbedded marine turbidite gas hydrate reservoir model
Evgeniy Myshakin, Jeen-Shang Lin, Shun Uchida, Yongkoo Seol, Timothy S. Collett, Ray Boswell
2017, Conference Paper, Proceeding of the 9th International Conference on Gas Hydrates
The numerical simulation of thin hydrate-bearing sand layers interbedded with mud layers is investigated. In this model, the lowest hydrate layer occurs at the base of gas hydrate stability and overlies a thinly-interbedded saline aquifer. The predicted gas rates reach 6.25 MMscf/day (1.77 x 105 m3 /day) after 90 days...
Integration of vegetation community spatial data into a prescribed fire planning process at Shenandoah National Park, Virginia (USA)
John A. Young, Carolyn G. Mahan, Melissa Forder
2017, Natural Areas Journal (37) 394-405
Many eastern forest communities depend on fire for regeneration or are enhanced by fire as a restoration practice. However, the use of prescribed fire in the mesic forested environments and the densely populated regions of the eastern United States has been limited. The objective of our research was to develop...
Tributary use by imperiled Flannelmouth and Bluehead Suckers in the upper Colorado River Basin
Gregory S. Fraser, Dana L. Winkelman, Kevin R. Bestgen, Kevin G. Thompson
2017, Transactions of the American Fisheries Society (146) 858-871
Habitat alterations and establishment of nonnative fishes have reduced the distributions of Flannelmouth Sucker Catostomus latipinnis and Bluehead Sucker C. discobolus to less than 50% of their historical ranges in the Colorado River basin. Tributaries are sometimes less altered than main-stem habitat in the basin and may be important to support various life history...
Population dynamics of brown trout (Salmo trutta) in Spruce Creek Pennsylvania: A quarter-century perspective
Gary D. Grossman, Robert F. Carline, Tyler Wagner
2017, Freshwater Biology (62) 1143-1154
We examined the relationship between density-independent and density-dependent factors on the demography of a dense, relatively unexploited population of brown trout in Spruce Creek Pennsylvania between 1985 and 2011.Individual PCAs of flow and temperature data elucidated groups of years with multiple high flow versus multiple low flow...