δ15N constraints on long-term nitrogen balances in temperate forests
S.S. Perakis, E.R. Sinkhorn, J.E. Compton
2011, Oecologia (167) 793-807
Biogeochemical theory emphasizes nitrogen (N) limitation and the many factors that can restrict N accumulation in temperate forests, yet lacks a working model of conditions that can promote naturally high N accumulation. We used a dynamic simulation model of ecosystem N and δ15N to evaluate which combination of N input...
Mercury export from the Yukon River Basin and potential response to a changing climate
P. F. Schuster, Robert G. Striegl, G. R. Aiken, David P. Krabbenhoft, J. F. Dewild, K. Butler, B. Kamark, M. Dornblaser
2011, Environmental Science & Technology (45) 9262-9267
We measured mercury (Hg) concentrations and calculated export and yield from the Yukon River Basin (YRB) to quantify Hg flux from a large, permafrost-dominated, high-latitude watershed. Exports of Hg averaged 4400 kg Hg yr–1. The average annual yield for the YRB during the study period was 5.17 μg m–2 yr–1, which...
Nutrient sources and transport in the Missouri River Basin, with emphasis on the effects of irrigation and reservoirs
J.B. Brown, L.A. Sprague, J.A. Dupree
2011, Journal of the American Water Resources Association (47) 1034-1060
SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and...
Determinants of fish assemblage structure in Northwestern Great Plains streams
J.A. Mullen, R.G. Bramblett, C.S. Guy, A.V. Zale, D.W. Roberts
2011, Transactions of the American Fisheries Society (140) 271-281
Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages...
Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California
Juraj Majzlan, Charles N. Alpers, Christian Bender Koch, R. Blaine McCleskey, Satish B.C. Myneni, John M. Neil
2011, Chemical Geology (284) 296-305
The Iron Mountain Mine Superfund site in California is a prime example of an acid mine drainage (AMD) system with well developed assemblages of sulfate minerals typical for such settings. Here we present and discuss the vibrational (infrared), X-ray absorption, and M??ssbauer spectra of a number of these phases, augmented...
Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers
P.V. Sundareshwar, S. Upadhayay, M. Abessa, S. Honomichl, B. Berdanier, S. A. Spaulding, C. Sandvik, A. Trennepohl
2011, Geophysical Research Letters (38)
In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large "blooms" in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal...
Deciphering fluid sources of hydrothermal systems: A combined Sr- and S-isotope study on barite (Schwarzwald, SW Germany)
S. Staude, S. Gob, K. Pfaff, F. Strobele, W. R. Premo, G. Markl
2011, Chemical Geology (286) 1-20
Primary and secondary barites from hydrothermal mineralizations in SW Germany were investigated, for the first time, by a combination of strontium (Sr) isotope systematics (87Sr/86Sr), Sr contents and δ34S values to distinguish fluid sources and precipitation mechanisms responsible for their formation. Barite of Permian age derived its Sr solely from...
Molecular detection of vertebrates in stream water: A demonstration using rocky mountain tailed frogs and Idaho giant salamanders
C.S. Goldberg, D. S. Pilliod, R.S. Arkle, L.P. Waits
2011, PLoS ONE (6)
Stream ecosystems harbor many secretive and imperiled species, and studies of vertebrates in these systems face the challenges of relatively low detection rates and high costs. Environmental DNA (eDNA) has recently been confirmed as a sensitive and efficient tool for documenting aquatic vertebrates in wetlands and in a large river...
Development of an aquatic pathogen database (AquaPathogen X) and its utilization in tracking emerging fish virus pathogens in North America
E.J. Emmenegger, E. Kentop, T.M. Thompson, S. Pittam, A. Ryan, D. Keon, J.A. Carlino, J. Ranson, R.B. Life, R.M. Troyer, K.A. Garver, Gael Kurath
2011, Journal of Fish Diseases (34) 579-587
The AquaPathogen X database is a template for recording information on individual isolates of aquatic pathogens and is freely available for download (http://wfrc.usgs.gov). This database can accommodate the nucleotide sequence data generated in molecular epidemiological studies along with the myriad of abiotic and biotic traits associated with isolates of various...
In situ measurements of post-fire debris flows in southern California: Comparisons of the timing and magnitude of 24 debris-flow events with rainfall and soil moisture conditions
J. W. Kean, D.M. Staley, S.H. Cannon
2011, Journal of Geophysical Research F: Earth Surface (116)
Debris flows often occur in burned steeplands of southern California, sometimes causing property damage and loss of life. In an effort to better understand the hydrologic controls on post-fire debris-flow initiation, timing and magnitude, we measured the flow stage, rainfall, channel bed pore fluid pressure and hillslope soil-moisture accompanying 24...
Impacts of past climate and sea level change on Everglades wetlands: placing a century of anthropogenic change into a late-Holocene context
Debra A. Willard, C.E. Bernhardt
2011, Climatic Change (107) 59-80
We synthesize existing evidence on the ecological history of the Florida Everglades since its inception ~7 ka (calibrated kiloannum) and evaluate the relative impacts of sea level rise, climate variability, and human alteration of Everglades hydrology on wetland plant communities. Initial freshwater peat accumulation began between 6 and 7 ka...
The significance of turbulent flow representation in single-continuum models
Thomas Reimann, C. Rehrl, W.B. Shoemaker, T. Geyer, S. Birk
2011, Water Resources Research (47)
Karst aquifers exhibit highly conductive features caused from rock dissolution processes. Flow within these structures can become turbulent and therefore can be expressed by nonlinear gradient functions. One way to account for these effects is by coupling a continuum model with a conduit network. Alternatively, turbulent flow can be considered...
Feature-based and statistical methods for analyzing the Deepwater Horizon oil spill with AVIRIS imagery
R.S. Rand, R. N. Clark, K.E. Livo
2011, Proceedings of SPIE (8158)
The Deepwater Horizon oil spill covered a very large geographical area in the Gulf of Mexico creating potentially serious environmental impacts on both marine life and the coastal shorelines. Knowing the oil's areal extent and thickness as well as denoting different categories of the oil's physical state is important for...
Treading lightly on shifting ground: The direction and motivation of future geological research
A.C. Witt
2011, Episodes (34) 78-81
The future of the geosciences and geological research will involve complex scientific challenges, primarily concerning global and regional environmental issues, in the next 20-30 years. It is quite reasonable to suspect, based on current political and socioeconomic events, that young geoscientists will be faced with and involved in helping to...
Globally Gridded Satellite observations for climate studies
K.R. Knapp, S. Ansari, C.L. Bain, M.A. Bourassa, M.J. Dickinson, Chris Funk, C.N. Helms, C.C. Hennon, C.D. Holmes, G. J. Huffman, J.P. Kossin, H.-T. Lee, A. Loew, G. Magnusdottir
2011, Bulletin of the American Meteorological Society (92) 893-907
Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial...
Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska
Benjamin M. Jones, G. Grosse, C.D. Arp, M.C. Jones, Anthony K.M. Walter, V.E. Romanovsky
2011, Journal of Geophysical Research: Biogeosciences (116)
Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst...
Historical summer base flow and stormflow trends for New England rivers
Glenn A. Hodgkins, Robert W. Dudley
2011, Water Resources Research (47)
River base flow is important to aquatic ecosystems, particularly because of its influence on summer water temperatures. Summer (June through September) daily mean streamflows were separated into base flow and stormflow components by use of an automated method at 25 stations in the New England region of the United States...
OBIS-USA: a data-sharing legacy of the census of marine life
G.R. Sedberry, D.G. Fautin, M. Feldman, M.D. Fornwall, P. Goldstein, R.P. Guralnick
2011, Oceanography (24) 166-173
The United States Geological Survey's Biological Informatics Program hosts OBIS-USA, the US node of the Ocean Biogeographic Information System (OBIS). OBIS-USA gathers, coordinates, applies standard formats to, and makeswidely available data on biological collections in marine waters of the United States and other areas where US investigators have collected data...
Environmental controls of wood entrapment in upper Midwestern streams
Eric C. Merten, Jacques Finlay, Lucinda Johnson, Raymond Newman, Heinz Stefan, Bruce C. Vondracek
2011, Hydrological Processes (25) 593-602
Wood deposited in streams provides a wide variety of ecosystem functions, including enhancing habitat for key species in stream food webs, increasing geomorphic and hydraulic heterogeneity and retaining organic matter. Given the strong role that wood plays in streams, factors that influence wood inputs, retention and transport are critical to...
Fish community and bioassessment responses to stream network position
N.P. Hitt, P. L. Angermeier
2011, Journal of the North American Benthological Society (30) 296-309
If organisms move beyond the boundaries of local sampling units, regional metacommunity dynamics could undermine the ability of bioassessment studies to characterize local environmental quality. We tested the prediction that fish dispersal influences local fish community structure and bioassessment metrics as a function of site position within stream networks. We...
Overpressure generation by load transfer following shale framework weakening due to smectite diagenesis
R.W. Lahann, R.E. Swarbrick
2011, Geofluids (11) 362-375
Basin model studies which have addressed the importance of smectite conversion to illite as a source of overpressure in the Gulf of Mexico have principally relied on a single‐shale compaction model and treated the smectite reaction as only a fluid‐source term. Recent fluid pressure interpretation and shale petrology studies indicate...
Surface-water nutrient conditions and sources in the United States Pacific Northwest
D.R. Wise, H.M. Johnson
2011, Journal of the American Water Resources Association (47) 1110-1135
The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well...
Agricultural practices and residual corn during spring crane and waterfowl migration in Nebraska
Mark H. Sherfy, Michael J. Anteau, A.A. Bishop
2011, Journal of Wildlife Management (75) 995-1003
Nebraska's Central Platte River Valley (CPRV) is a major spring‐staging area for migratory birds. Over 6 million ducks, geese, and sandhill cranes (Grus canadensis) stage there en route to tundra, boreal forest, and prairie breeding habitats, storing nutrients for migration and reproduction by consuming primarily corn remaining in fields after...
A multitracer approach for characterizing interactions between shallow groundwater and the hydrothermal system in the Norris Geyser Basin area, Yellowstone National Park
W.P. Gardner, David D. Susong, D. K. Solomon, H.P. Heasler
2011, Geochemistry, Geophysics, Geosystems (12)
Multiple environmental tracers are used to investigate age distribution, evolution, and mixing in local‐ to regional‐scale groundwater circulation around the Norris Geyser Basin area in Yellowstone National Park. Springs ranging in temperature from 3°C to 90°C in the Norris Geyser Basin area were sampled for stable isotopes of hydrogen and...
Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA
R. W. Healy, T.T. Bartos, C. A. Rice, M.P. McKinley, B. D. Smith
2011, Journal of Hydrology (403) 37-48
The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface...
