Mycorrhizal colonization across hydrologic gradients in restored and reference freshwater wetlands
C.R. Bauer, C.H. Kellogg, S.D. Bridgham, G. A. Lamberti
2003, Wetlands (23) 961-968
Arbuscular mycorrhizae, which are plant root-fungal symbioses, are common associates of vascular plants. Such relationships, however, are thought to be rare in wetland plant roots, although several recent studies suggest that arbuscular mycorrhizae may be important in wetland ecosystems. Our objectives were to determine (1) the level of arbuscular mycorrhizal...
An approach to understanding hydrologic connectivity on the hillslope and the implications for nutrient transport
M. Stieglitz, J. Shaman, J. McNamara, V. Engel, J. Shanley, G.W. Kling
2003, Global Biogeochemical Cycles (17)
Hydrologic processes control much of the export of organic matter and nutrients from the land surface. It is the variability of these hydrologic processes that produces variable patterns of nutrient transport in both space and time. In this paper, we explore how hydrologic “connectivity” potentially affects nutrient transport. Hydrologic connectivity...
Geochemistry of carbonatites of the Tomtor massif
S.M. Kravchenko, G. Czamanske, V.A. Fedorenko
2003, Geochemistry International (41) 545-558
Carbonatites compose sheet bodies in a 300-m sequence of volcanic lamproites, as well as separate large bodies at depths of >250-300 m. An analysis of new high-precision data on concentrations of major, rare, and rare earth elements in carbonatites shows that these rocks were formed during crystallization differentiation of a...
Characterization of petroleum reservoirs in the Eocene Green River Formation, Central Uinta Basin, Utah
C. D. Morgan, S.R. Bereskin
2003, Mountain Geologist (40) 111-127
The oil-productive Eocene Green River Formation in the central Uinta Basin of northeastern Utah is divided into five distinct intervals. In stratigraphically ascending order these are: 1) Uteland Butte, 2) Castle Peak, 3) Travis, 4) Monument Butte, and 5) Beluga. The reservoir in the Uteland Butte interval is mainly lacustrine...
Discharge indices for water quality loads
Richard M. Vogel, Jery R. Stedinger, Richard P. Hooper
2003, Water Resources Research (39) 1-1-1-9
Effective discharge has been used to describe the streamflow level that is responsible for transporting the most sediment over the long term. Careful inspection reveals that this concept may not have been well defined, and different interpretations have led to conflicting representations. Because total load is ultimately the quantity of...
Fire and grazing impacts on plant diversity and alien plant invasions in the southern Sierra Nevada
Jon E. Keeley, Daniel Lubin, C. J. Fotheringham
2003, Ecological Applications (13) 1355-1374
Patterns of native and alien plant diversity in response to disturbance were examined along an elevational gradient in blue oak savanna, chaparral, and coniferous forests. Total species richness, alien species richness, and alien cover declined with elevation, at scales from 1 to 1000 m2. We found no support for the...
Fire and amphibians in North America
D. S. Pilliod, R.B. Bury, E.J. Hyde, C.A. Pearl, P.S. Corn
2003, Forest Ecology and Management (178) 163-181
Information on amphibian responses to fire and fuel reduction practices is critically needed due to potential declines of species and the prevalence of new, more intensive fire management practices in North American forests. The goals of this review are to summarize the known and potential effects of fire and fuels...
Biogeochemical sulphur cycle in an extreme environment - Life beneath a high arctic glacier, Nunavut, Canada
S.E. Grasby, C. C. Allen, T.G. Longazo, J.T. Lisle, Dale W. Griffin, B. Beauchamp
2003, Conference Paper, Journal of Geochemical Exploration
Unique springs discharge from the surface of a high arctic glacier, releasing H2S, and depositing native sulphur, gypsum, and calcite. A rare CaCO3 polymorph, vaterite, is also observed. Physical and chemical conditions of the spring water and surrounding environment, as well as mineralogical and isotopic signatures, argue for biologically mediated...
Hydrothermal diamond-anvil cell: Application to studies of geologic fluids
I.-M. Chou
2003, Acta Petrologica Sinica (19) 213-220
The hydrothermal diamond-anvil cell (HDAC) was designed to simulate the geologic conditions of crustal processes in the presence of water or other fluids. The HDAC has been used to apply external pressure to both synthetic and natural fluid inclusions in quartz to minimize problems caused by stretching or decrepitation of...
Rare-earth elements and Nd and Pb isotopes as source indicators for Labrador Sea clay-size sediments during Heinrich event 2
L. Benson, David Barber, John T. Andrews, Howard E. Taylor, P. Lamothe
2003, Quaternary Science Reviews (22) 881-889
Elemental abundances and Nd and Pb isotope ratios were determined on samples from the carbonate-free, clay-size fractions of sediments from intervals above, within, and below Heinrich event 2 (H-2) in core HU87-9 from the Northwest Labrador Sea slope. In HU87-9, rare-earth element (REE) distributions and elemental concentrations within the H-2...
Lithospheric roots beneath western Laurentia: The geochemical signal in mantle garnets
D. Canil, D.J. Schulze, D. Hall, B. C. Hearn Jr., S.M. Milliken
2003, Canadian Journal of Earth Sciences (40) 1027-1051
This study presents major and trace element data for 243 mantle garnet xenocrysts from six kimberlites in parts of western North America. The geochemical data for the garnet xenocrysts are used to infer the composition, thickness, and tectonothermal affinity of the mantle lithosphere beneath western Laurentia at the time of...
A simplified approach for monitoring hydrophobic organic contaminants associated with suspended sediment: Methodology and applications
B.J. Mahler, P. C. Van Metre
2003, Archives of Environmental Contamination and Toxicology (44) 288-297
Hydrophobic organic contaminants, although frequently detected in bed sediment and in aquatic biota, are rarely detected in whole-water samples, complicating determination of their occurrence, load, and source. A better approach for the investigation of hydrophobic organic contaminants is the direct analysis of sediment in suspension, but procedures for doing so...
The sedimentary record of climatic and anthropogenic influence on the Patuxent estuary and Chesapeake Bay ecosystems
T. M. Cronin, C.D. Vann
2003, Estuaries (26) 196-209
Ecological and paleoecological studies from the Patuxent River mouth reveal dynamic variations in benthic ostracode assemblages over the past 600 years due to climatic and anthropogenic factors. Prior to the late 20th century, centennial-scale changes in species dominance were influenced by climatic and hydrological factors that primarily affected salinity and...
Paleozoic and Mesozoic silica-rich seawater: Evidence from hematitic chert (jasper) deposits
Tor Grenne, J. F. Slack
2003, Geology (31) 319-322
Laterally extensive beds of highly siliceous, hematitic chert (jasper) are associated with many volcanogenic massive sulfide (VMS) deposits of Late Cambrian to Early Cretaceous age, yet are unknown in analogous younger (including modern) settings. Textural studies suggest that VMS-related jaspers in the Ordovician Løkken ophiolite of Norway were originally deposited...
Application of adaptive cluster sampling to low-density populations of freshwater mussels
D. R. Smith, R.F. Villella, D. P. Lemarie
2003, Environmental and Ecological Statistics (10) 7-15
Freshwater mussels appear to be promising candidates for adaptive cluster sampling because they are benthic macroinvertebrates that cluster spatially and are frequently found at low densities. We applied adaptive cluster sampling to estimate density of freshwater mussels at 24 sites along the Cacapon River, WV, where a preliminary timed search...
Early neogene history of the central American arc from Bocas del Toro, western Panama
Anthony G. Coates, Marie-Pierre Aubry, William A. Berggren, Laurel S. Collins, Michael J. Kunk
2003, Geological Society of America Bulletin (115) 271-287
A newly discovered sequence of lower to middle Miocene rocks from the eastern Bocas del Toro archipelago, western Panama, reveals the timing and environment of the earliest stages in the rise of the Isthmus of Panama in this region. Two new formations, the Punta Alegre Formation (lower Miocene, Aquitanian to...
Mineral resource of the month: platinum-group metals
Henry Hilliard
2003, Geotimes (2003)
The precious metals commonly referred to as platinum-group metals (PGM) include iridium, osmium, palladium, platinum, rhodium and ruthenium. PGM are among the rarest of elements, and their market values — particularly for palladium, platinum and rhodium — are the highest of all precious metals....
Comprehensive water quality of the Boulder Creek Watershed, Colorado, during high-flow and low-flow conditions, 2000
Sheila F. Murphy, Philip L. Verplanck, Larry B. Barber, editor(s)
2003, Water-Resources Investigations Report 03-4045
Executive SummaryThe Boulder Creek Watershed, Colorado, is 1160 square kilometers in area and ranges in elevation from 1480 to 4120 meters above sea level. Streamflow originates primarily as snowmelt near the Continental Divide, and thus discharge varies seasonally and annually (Chapter 1). Most of the water in Boulder Creek is...
A Framework for Long-term Ecological Monitoring in Olympic National Park: Prototype for the Coniferous Forest Biome
Kurt Jenkins, Andrea Woodward, Ed Schreiner
2003, Information and Technology Report 2003-0006
This report is the result of a five-year collaboration between scientists of the U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Olympic Field Station, and the natural resources staff of Olympic National Park to develop a comprehensive strategy for monitoring natural resources of Olympic National Park. Olympic National Park...
Chapter C: Hydrothermal Enrichment of Gallium in Zones of Advanced Argillic Alteration-Examples from the Paradise Peak and McDermitt Ore Deposits, Nevada
James J. Rytuba, David A. John, Andrea Foster, Steven D. Ludington, Boris Kotlyar
2003, Bulletin 2209-C
Gallium is produced as a byproduct from bauxite and zinc sulfide ores and rarely from primary Ga ores. High Ga contents (>60 ppm) can occur in zones of advanced argillic alteration consisting of alunite+kaolinite+quartz associated with quartz-alunite (high sulfidation Au-Ag) deposits. In a magmatic-hydrothermal environment, the zones of advanced argillic...
Consumption of fungal sporocarps by Yellowstone grizzly bears
David J. Mattson, Shannon Podruzny, Mark A. Haroldson
2002, Ursus (13) 95-103
Sign of grizzly bears (Ursus arctos horribilis) consuming fungal sporocarps (mushrooms and truffles) was observed on 68 occasions during a study of radiomarked bears in the Yellowstone region, 1977–96. Sporocarps also were detected in 96 grizzly bear feces. Most fungi consumedby Yellowstone's grizzlybearsweremembersofthe Boletaceae(Suillus spp.), Russulaceae (Russula spp. and...
Effects of management practices on wetland birds: Black tern
Amy L. Zimmerman, Jill A. Dechant, Douglas A. Johnson, Christopher M. Goldade, Brent E. Jamison, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Effects of management practices on wetland birds: Yellow Rail
Christopher M. Goldade, Jill A. Dechant, Douglas H. Johnson, Amy L. Zimmerman, Brent E. Jamison, James O. Church, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Effects of management practices on wetland birds: Virginia rail
Amy L. Zimmerman, Jill A. Dechant, Brent E. Jamison, Douglas H. Johnson, Christopher M. Goldade, James O. Church, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Effects of management practices on wetland birds: American Avocet
Jill A. Dechant, Amy L. Zimmerman, Douglas H. Johnson, Christopher M. Goldade, Brent E. Jamison, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
