Old groundwater in parts of the upper Patapsco aquifer, Atlantic Coastal Plain, Maryland, USA: Evidence from radiocarbon, chlorine-36 and helium-4
Niel Plummer, John R. Eggleston, Jeff P. Raffensperger, Andrew G. Hunt, Gerolamo C. Casile, D. C. Andreasen
2012, Hydrogeology Journal (20) 1269-1294
Apparent groundwater ages along two flow paths in the upper Patapsco aquifer of the Maryland Atlantic Coastal Plain, USA, were estimated using 14C, 36Cl and 4He data. Most of the ages range from modern to about 500 ka, with one sample at 117 km downgradient from the recharge area dated by radiogenic...
The population structure of Escherichia coli isolated from subtropical and temperate soils
Muruleedhara N. Byappanahalli, Tao Yan, Matthew J. Hamilton, Satoshi Ishii, Roger S. Fujioka, Richard L. Whitman, Michael J. Sadowsky
2012, Science of the Total Environment (417-418) 273-279
While genotypically-distinct naturalized Escherichia coli strains have been shown to occur in riparian soils of Lake Michigan and Lake Superior watersheds, comparative analyses of E. coli populations in diverse soils across a range of geographic and climatic conditions have not been investigated. The main objectives of this study were to:...
Elevated CO2 did not mitigate the effect of a short-term drought on biological soil crusts
Timothy M. Wertin, Susan L. Phillips, Sasha C. Reed, Jayne Belnap
2012, Biology and Fertility of Soils (48) 797-805
Biological soil crusts (biocrusts) are critical components of arid and semi-arid ecosystems that contribute significantly to carbon (C) and nitrogen (N) fixation, water retention, soil stability, and seedling recruitment. While dry-land ecosystems face a number of environmental changes, our understanding of how biocrusts may respond to such perturbation remains notably...
On the causes of mid-Pliocene warmth and polar amplification
Daniel J. Lunt, Alan M. Haywood, Gavin A. Schmidt, Ulrich Salzmann, Paul J. Valdes, Harry J. Dowsett, Claire A. Loptson
2012, Earth and Planetary Science Letters (321-322) 128-138
The mid-Pliocene (~ 3 to 3.3 Ma ago), is a period of sustained global warmth in comparison to the late Quaternary (0 to ~ 1 Ma ago), and has potential to inform predictions of long-term future climate change. However, given that several processes potentially contributed, relatively little is understood about...
Monitoring oral temperature, heart rate, and respiration rate of West Indian manatees (Trichechus manatus) during capture and handling in the field
Arthur W. Wong, Robert K. Bonde, Jessica Siegal-Willott, M. Andrew Stamper, James Colee, James A. Powell, James P. Reid, Charles J. Deutsch, Kendal E. Harr
2012, Aquatic Mammals (38) 1-16
West Indian manatees (Trichechus manatus) are captured, handled, and transported to facilitate conservation, research, and rehabilitation efforts. Monitoring manatee oral temperature (OT), heart rate (HR), and respiration rate (RR) during out-of-water handling can assist efforts to maintain animal well-being and improve medical response to evidence of declining health. To determine...
Over 100 years of environmental change recorded by foraminifers and sediments in a large Gulf of Mexico estuary, Mobile Bay, AL, USA
Lisa E. Osterman, Christopher G. Smith
2012, Estuarine and Continental Shelf Science (115) 345-358
The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ∼100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel <a...
North slope of Alaska
Jonathan Bart, Stephen Brown, Brad Andres, Robert Platte, Ann Manning
Jonathan Bart, Victoria Johnston, editor(s)
2012, Book chapter, Arctic shorebirds in North America: A decade of monitoring
No abstract available....
Mercury exposure may suppress baseline corticosterone levels in juvenile birds
Garth Herring, Joshua T. Ackerman, Mark P. Herzog
2012, Environmental Science & Technology (46) 6339-6346
Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations...
Magnetostratigraphy susceptibility for the Guadalupian Series GSSPs (Middle Permian) in Guadalupe Mountains National Park and adjacent areas in West Texas
Bruce R. Wardlaw, Brooks B. Ellwood, Lance L. Lambert, Jonathan H. Tomkin, Gordon L. Bell, Galina P. Nestell
2012, Geological Society, London, Special Publications (373) 21-21
Here we establish a magnetostratigraphy susceptibility zonation for the three Middle Permian Global boundary Stratotype Sections and Points (GSSPs) that have recently been defined, located in Guadalupe Mountains National Park, West Texas, USA. These GSSPs, all within the Middle Permian Guadalupian Series, define (1) the base of the Roadian Stage...
Overwintering tadpoles and loss of fitness correlates in Polypedates braueri tadpoles that use artificial pools in a lowland agroecosystem
Juei-Ling Hsu, Yeong-Choy Kam, Gary M. Fellers
2012, Herpetologica (68) 184-194
We studied growth, development, and metamorphic traits of Polypedates braueri tadpoles in Taiwan to elucidate the cause of tadpole overwintering in man-made water containers in lowland orchards on the Bagua Terrace. Polypedates braueri bred from March to August, but tadpoles were present year round. Laboratory experiments demonstrated that tadpole overwintering...
Molecular characterization and comparison of shale oils generated by different pyrolysis methods
Justin E. Birdwell, Jang Mi Jin, Sunghwan Kim
2012, Energy & Fuels (26)
Shale oils generated using different laboratory pyrolysis methods have been studied using standard oil characterization methods as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI) and atmospheric photoionization (APPI) to assess differences in molecular composition. The pyrolysis oils were generated from samples of...
Photodissolution of soil organic matter
L.M. Mayer, K.R. Thornton, L.L. Schick, J.D. Jastrow, Jennifer W. Harden
2012, Geoderma (170) 314-321
Sunlight has been shown to enhance loss of organic matter from aquatic sediments and terrestrial plant litter, so we tested for similar reactions in mineral soil horizons. Losses of up to a third of particulate organic carbon occurred after continuous exposure to full-strength sunlight for dozens of hours, with similar...
Evaluating the demographic buffering hypothesis with vital rates estimated for Weddell seals from 30years of mark-recapture data
J.J. Rotella, William A. Link, T. Chambert, G.E. Stauffer, R.A. Garrott
2012, Journal of Animal Ecology (81) 162-173
1. Life‐history theory predicts that those vital rates that make larger contributions to population growth rate ought to be more strongly buffered against environmental variability than are those that are less important. Despite the importance of the theory for predicting demographic responses to changes in the environment, it is not yet...
Determination of sediment provenance by unmixing the mineralogy of source-area sediments: The "SedUnMix" program
John T. Andrews, D. D. Eberl
2012, Marine Geology (291-294) 24-33
Along the margins of areas such as Greenland and Baffin Bay, sediment composition reflects a complex mixture of sources associated with the transport of sediment in sea ice, icebergs, melt-water and turbidite plumes. Similar situations arise in many contexts associated with sediment transport and with the mixing of sediments from...
Effects of high fire frequency in creosote bush scrub vegetation of the Mojave Desert
M.L. Brooks
2012, International Journal of Wildland Fire (21) 61-68
Plant invasions can increase fire frequency in desert ecosystems where fires were historically infrequent. Although there are many resource management concerns associated with high frequency fire in deserts, fundamental effects on plant community characteristics remain largely unstudied. Here I describe the effects of fire frequency on creosote bush scrub vegetation...
Mineral parageneses, regional architecture, and tectonic evolution of Franciscan metagraywackes, Cape Mendocino-Garberville-Covelo 30' x 60' quadrangles, northwest California
W. G. Ernst, Robert J. McLaughlin
2012, Tectonics (31)
The Franciscan Complex is a classic subduction-zone assemblage. In northwest California, it comprises a stack of west vergent thrust sheets: westernmost Eastern Belt outliers; Central Belt mélange; Coastal Belt Yager terrane; Coastal Belt Coastal terrane; Coastal Belt King Range/False Cape terranes. We collected samples and determined P-T conditions of recrystallization...
Timing of wet snow avalanche activity: An analysis from Glacier National Park, Montana, USA.
Erich H. Peitzsch, Jordy Hendrikx, Daniel B. Fagre
2012, Conference Paper, Proceedings, 2012 International Snow Science Workshop
Wet snow avalanches pose a problem for annual spring road opening operations along the Going-to-the-Sun Road (GTSR) in Glacier National Park, Montana, USA. A suite of meteorological metrics and snow observations has been used to forecast for wet slab and glide avalanche activity. However, the timing of spring wet slab...
Wolf population dynamics in the U.S. Northern Rocky Mountains are affected by recruitment and human-caused mortality
J.A. Gude, M.S. Mitchell, Robin E. Russell, C.A. Sime, E.E. Bangs, L.D. Mech, R.R. Ream
2012, Journal of Wildlife Management (76) 108-118
Reliable analyses can help wildlife managers make good decisions, which are particularly critical for controversial decisions such as wolf (Canis lupus) harvest. Creel and Rotella (2010) recently predicted substantial population declines in Montana wolf populations due to harvest, in contrast to predictions made by Montana Fish, Wildlife and Parks (MFWP)....
Rapid microsatellite identification from illumina paired-end genomic sequencing in two birds and a snake
T.A. Castoe, A.W. Poole, A. P. J. de Koning, K.L. Jones, D.F. Tomback, Sara J. Oyler-McCance, Jennifer A. Fike, S.L. Lance, J.W. Streicher, E.N. Smith, D.D. Pollock
2012, PLoS ONE (7)
Identification of microsatellites, or simple sequence repeats (SSRs), can be a time-consuming and costly investment requiring enrichment, cloning, and sequencing of candidate loci. Recently, however, high throughput sequencing (with or without prior enrichment for specific SSR loci) has been utilized to identify SSR loci. The direct “Seq-to-SSR” approach has an...
Ecoregional analysis of nearshore sea-surface temperature in the North Pacific
M.C. Payne, C.A. Brown, D.A. Reusser, H. Lee II
2012, PLoS ONE (7)
The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. To better understand present temperature regimes, we assembled a 29-year nearshore time series of...
Response of an algal assemblage to nutrient enrichment and shading in a Hawaiian stream
S.H. Stephens, A.M.D. Brasher, C.M. Smith
2012, Hydrobiologia (683) 135-150
To investigate the effects of nitrate enrichment, phosphate enrichment, and light availability on benthic algae, nutrient-diffusing clay flowerpots were colonized with algae at two sites in a Hawaiian stream during spring and autumn 2002 using a randomized factorial design. The algal assemblage that developed under the experimental conditions was investigated...
Time lapse photography as an approach to understanding glide avalanche activity
Jordy Hendrikx, Erich H. Peitzsch, Daniel B. Fagre
2012, Conference Paper, Proceedings, 2012 International Snow Science Workshop
Avalanches resulting from glide cracks are notoriously difficult to forecast, but are a recurring problem for numerous avalanche forecasting programs. In some cases glide cracks are observed to open and then melt away in situ. In other cases, they open and then fail catastrophically as large, full-depth avalanches. Our understanding...
Measuring Historical Coastal Change using GIS and the Change Polygon Approach
M.J. Smith, R.G. Cromley
2012, Transactions in GIS (16) 3-15
This study compares two automated approaches, the transect‐from‐baseline technique and a new change polygon method, for quantifying historical coastal change over time. The study shows that the transect‐from‐baseline technique is complicated by choice of a proper baseline as well as generating transects that intersect with each other rather than with...
Holocene aridification of India
C. Ponton, L. Giosan, T.I. Eglinton, D.Q. Fuller, J.E. Johnson, P. Kumar, Timothy S. Collett
2012, Geophysical Research Letters (39)
Spanning a latitudinal range typical for deserts, the Indian peninsula is fertile instead and sustains over a billion people through monsoonal rains. Despite the strong link between climate and society, our knowledge of the long‐term monsoon variability is incomplete over the Indian subcontinent. Here we reconstruct the Holocene paleoclimate in...
Tidally driven export of dissolved organic carbon, total mercury, and methylmercury from a mangrove-dominated estuary
Brian A. Bergamaschi, D. P. Krabbenhoft, George Aiken, Eduardo Patino, D.G. Rumbold, William H. Orem
2012, Environmental Science & Technology (46) 1371-1378
The flux of dissolved organic carbon (DOC) from mangrove swamps accounts for 10% of the global terrestrial flux of DOC to coastal oceans. Recent findings of high concentrations of mercury (Hg) and methylmercury (MeHg) in mangroves, in conjunction with the common co-occurrence of DOC and Hg species, have raised concerns...
