Effects of habitat management treatments on plant community composition and biomass in a Montane wetland
Jane E. Austin, Janet R. Keough, W.H. Pyle
2007, Wetlands (27) 570-587
Grazing and burning are commonly applied practices that can impact the diversity and biomass of wetland plant communities. We evaluated the vegetative response of wetlands and adjacent upland grasslands to four treatment regimes (continuous idle, fall prescribed burning followed by idle, annual fall cattle grazing, and rotation of summer grazing...
Paleoecology of the Late Pennsylvanian-age Calhoun coal bed and implications for long-term dynamics of wetland ecosystems
Debra A. Willard, T.L. Phillips, Alicia D. Lesnikowska, William A. DiMichele
2007, International Journal of Coal Geology (69) 21-54
Quantitative plant assemblage data from coal balls, miospores, megaspores, and compression floras from the Calhoun coal bed (Missourian) of the Illinois Basin (USA) are used to interpret spatial and temporal changes in plant communities in the paleo-peat swamp. Coal-ball and miospore floras from the Calhoun coal bed are dominated strongly...
Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake
M.J. Olsen, S.F. Bartlett, B.J. Solomon
2007, Earthquake Spectra (23) 95-113
This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data...
Bottom sediments and pore waters near a hydrothermal vent in Lake Baikal (Frolikha Bay)
L.Z. Granina, J. Klerkx, E. Callender, M. Leermakers, L.P. Golobokova
2007, Russian Geology and Geophysics (48) 237-246
We discuss the redox environments and the compositions of bottom sediments and sedimentary pore waters in the region of a hydrothermal vent in Frolikha Bay, Lake Baikal. According to our results, the submarine vent and its companion nearby spring on land originate from a common source. The most convincing evidence...
The effects of flooding and sedimentation on seed germination of two bottomland hardwood tree species
Aaron R. Pierce, S.L. King
2007, Wetlands (27) 588-594
Flooding and sedimentation are two of the dominant disturbances that influence tree species composition and succession in floodplain forests. The importance of these disturbances may be most notable during the germination and establishment phases of plant succession. Channelization of most alluvial systems in the southeastern United States has caused dramatic...
Geology and complex collapse mechanisms of the 3.72 Ma Hannegan caldera, North Cascades, Washington, USA
David S. Tucker, Wes Hildreth, Tom Ullrich, Richard M. Friedman
2007, Geological Society of America Bulletin (119) 329-342
Contiguous ring faults of the 8 × 3.5 km Hannegan caldera enclose the Hannegan volcanics in the Cascade arc of northern Washington. The caldera collapsed in two phases, which each erupted rhyolitic ignimbrite (72.3%–75.2% SiO2). The first collapse phase, probably trap-door style, erupted...
USGS national surveys and analysis projects: Preliminary compilation of integrated geological datasets for the United States
Suzanne W. Nicholson, Douglas B. Stoeser, Frederic H. Wilson, Connie L. Dicken, Steve Ludington
2007, Conference Paper
The growth in the use of Geographic nformation Systems (GS) has highlighted the need for regional and national digital geologic maps attributed with age and rock type information. Such spatial data can be conveniently used to generate derivative maps for purposes that include mineral-resource assessment, metallogenic studies, tectonic studies, human...
Seismoelectric data processing for surface surveys of shallow targets
S.S. Haines, A. Guitton, B. Biondi
2007, Geophysics (72)
The utility of the seismoelectric method relies on the development of methods to extract the signal of interest from background and source-generated coherent noise that may be several orders-of-magnitude stronger. We compare data processing approaches to develop a sequence of preprocessing and signal/noise separation and to quantify the noise level...
Late quaternary temperature record from buried soils of the North American Great Plains
L. Nordt, J. Von Fischer, L. Tieszen
2007, Geology (35) 159-162
We present the first comprehensive late Quaternary record of North American Great Plains temperature by assessing the behavior of the stable isotopic composition (δ13C) of buried soils. After examining the relationship between the δ13C of topsoil organic matter and July temperature from 61 native prairies within a latitudinal range of...
Sinter-vein correlations at Buckskin Mountain, National district, Humboldt County, Nevada
P.G. Vikre
2007, Economic Geology (102) 193-224
At Buckskin Mountain (elev 2,650 m, 8,743 ft), Humboldt County, Nevada, a hydrothermal system, imposed on a middle Miocene volcanic sequence with contrasting permeabilities and tensile strengths, produced alteration assemblages controlled by elevation, from Hg-mineralized sinter to subjacent precious metal veins over a vertical distance exceeding 790 m. Sinter and...
The viability of a nonenzymatic reductive citric acid cycle - Kinetics and thermochemistry
D.S. Ross
2007, Origins of Life and Evolution of the Biosphere (37) 61-65
The likelihood of a functioning nonenzymatic reductive citric acid cycle, recently proposed as the precursor to biosynthesis on early Earth, is examined on the basis of the kinetics and thermochemistry of the acetate → pyruvate → oxaloacetate → malate sequence. Using data derived from studies of...
Role of burning season on initial understory vegetation response to prescribed fire in a mixed conifer forest
E. E. Knapp, D.W. Schwilk, J.M. Kane, Jon E. Keeley
2007, Canadian Journal of Forest Research (37) 11-22
Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this...
Historical trends in creel limits, length-based limits, and season restrictions for black basses in the United States and Canada
C. Paukert, M. McInerny, Ronald Schultz
2007, Fisheries (32) 62-72
We determined for largemouth bass (Micropterus salmoides), smallmouth bass (M. dolomeui), and spotted bass (M. punctulatus) historical trends in state- and province-wide creel limits, length limits, and season closures along with the rationale justifying these regulations. Based on data gathered via mail surveys and the Internet, 55 jurisdictions had state-...
A path-independent integral for the characterization of solute concentration and flux at biofilm detachments
B. Moran, S.S. Kulkarni, H. W. Reeves
2007, International Journal of Fracture (143) 291-300
A path-independent (conservation) integral is developed for the characterization of solute concentration and flux in a biofilm in the vicinity of a detachment or other flux limiting boundary condition. Steady state conditions of solute diffusion are considered and biofilm kinetics are described by an uptake term which can be expressed...
Distinguishing centrarchid genera by use of lateral line scales
N.M. Roberts, C.F. Rabeni, J.S. Stanovick
2007, North American Journal of Fisheries Management (27) 215-219
Predator-prey relations involving fishes are often evaluated using scales remaining in gut contents or feces. While several reliable keys help identify North American freshwater fish scales to the family level, none attempt to separate the family Centrarchidae to the genus level. Centrarchidae is of particular concern in the midwestern United...
Analysis of the sea otter (Enhydra lutris) reproductive tract: A methods manual
Vanessa R. von Biela, Verena A. Gill
2007, Technical Report MMM 2007-002
Reproduction in the female sea otter, Enhydra lutris, was relatively unstudied until Sinha et al. (1966) examined 140 reproductive tracts collected 1955-62 and used their findings to describe sea otter reproductive anatomy and biology. Two years later Sinha and Conaway (1968) published a more detailed paper on the ovary of...
Seismoelectric imaging of shallow targets
S.S. Haines, S.R. Pride, S.L. Klemperer, B. Biondi
2007, Geophysics (72)
We have undertaken a series of controlled field experiments to develop seismoelectric experimental methods for near-surface applications and to improve our understanding of seismoelectric phenomena. In a set of off-line geometry surveys (source separated from the receiver line), we place seismic sources and electrode array receivers on opposite sides of...
Evapotranspiration in a cottonwood (Populus fremontii) restoration plantation estimated by sap flow and remote sensing methods
P. Nagler, A. Jetton, J. Fleming, K. Didan, E. Glenn, J. Erker, K. Morino, J. Milliken, S. Gloss
2007, Agricultural and Forest Meteorology (144) 95-110
Native tree plantations have been proposed for the restoration of wildlife habitat in human-altered riparian corridors of western U.S. rivers. Evapotranspiration (ET) by riparian vegetation is an important, but poorly quantified, term in river water budgets. Native tree restoration plots will potentially increase ET. We used sap flow sensors and...
Comprehensive characterization of atmospheric organic matter in Fresno, California fog water
P. Herckes, J.A. Leenheer, J.L. Collett Jr.
2007, Environmental Science & Technology (41) 393-399
Fogwater collected during winter in Fresno (CA) was characterized by isolating several distinct fractions and characterizing them by infrared and nuclear magnetic resonance (NMR) spectroscopy. More than 80% of the organic matter in the fogwater was recovered and characterized. The most abundant isolated fractions were those comprised of volatile acids...
Platinum group elements and gold in ferromanganese crusts from Afanasiy-Nikitin seamount, equatorial Indian Ocean: Sources and fractionation
V.K. Banakar, J.R. Hein, R.P. Rajani, A.R. Chodankar
2007, Journal of Earth System Science (116) 3-13
The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (r = 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS...
Carbon export and cycling by the Yukon, Tanana, and Porcupine rivers, Alaska, 2001-2005
Robert G. Striegl, Mark M. Dornblaser, George R. Aiken, Kimberly P. Wickland, Peter A. Raymond
2007, Water Resources Research (43)
Loads and yields of dissolved and particulate organic and inorganic carbon (DOC, POC, DIC, PIC) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine rivers (TR, PR) in Alaska during 2001–2005. Total YR carbon export averaged 7.8 Tg C yr−1, 30%...
Gravity and magnetic studies to characterize the geologic framework of the Spring Valley region
Edward A. Mankinen
2007, Book chapter, Regional Tour of the Carbonate System Guidebook
No abstract available....
Response of western mountain ecosystems to climatic variability and change: The Western Mountain Initiative
Nathan L. Stephenson, Dave Peterson, Daniel B. Fagre, Craig D. Allen, Donald McKenzie, Jill Baron, Kelly O’Brian
2007, Mountain Views (1) 4-9
Mountain ecosystems within our national parks and other protected areas provide valuable goods and services such as clean water, biodiversity conservation, and recreational opportunities, but their potential responses to expected climatic changes are inadequately understood. The Western Mountain Initiative (WMI) is a collaboration of scientists whose research focuses on understanding...
A chronology of Late-Pleistocene permafrost events in southern New Jersey, eastern USA
H.M. French, M. Demitroff, S.L. Forman, Wayne L. Newell
2007, Permafrost and Periglacial Processes (18) 49-59
Frost fissures, filled with wind-abraded sand and mineral soil, and numerous small-scale non-diastrophic deformations, occur in the near-surface sediments of the Pine Barrens of southern New Jersey. The fissures are the result of thermal-contraction cracking and indicate the previous existence of either permafrost or seasonally-frozen ground. The deformations reflect thermokarst...
Volcanic arc emplacement onto the southernmost Appalachian Laurentian shelf: Characteristics and constraints
J.F. Tull, C.I. Barineau, P.A. Mueller, J. L. Wooden
2007, Geological Society of America Bulletin (119) 261-274
In the southernmost Appalachians, the Hillabee Greenstone, an Ordovician volcanic arc fragment, lies directly atop the outermost Laurentian Devonian–earliest Mississippian(?) shelf sequence at the structural top of the greenschist facies Talladega belt, the frontal metamorphic allochthon along this orogenic segment. The Hillabee Greenstone...
