Growth and survival of Escherichia coli and enterococci populations in the macro-alga Cladophora (Chlorophyta)
M.N. Byappanahalli, D.A. Shively, M.B. Nevers, M.J. Sadowsky, R.L. Whitman
2003, FEMS Microbiology Ecology (46) 203-211
The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro...
Influences of upland and riparian land use patterns on stream biotic integrity
C.D. Snyder, J.A. Young, R. Villella, D. P. Lemarie
2003, Landscape Ecology (18) 647-664
We explored land use, fish assemblage structure, and stream habitat associations in 20 catchments in Opequon Creek watershed, West Virginia. The purpose was to determine the relative importance of urban and agriculture land use on stream biotic integrity, and to evaluate the spatial scale (i.e., whole-catchment vs riparian buffer) at...
Aeolian processes in Proctor Crater on Mars: Sedimentary history as analyzed from multiple data sets
L.K. Fenton, J. L. Bandfield, A. W. Ward
2003, Journal of Geophysical Research E: Planets (108) 3-1
Proctor Crater is a 150 km diameter crater in Noachis Terra, within the southern highlands of Mars. The analysis leading to the sedimentary history incorporates several data sets including imagery, elevation, composition, and thermal inertia, mostly from the Mars Global Surveyor mission. The resulting stratigraphy reveals that the sedimentary history...
Plant community patterns in unburned and burned blackbrush (Coleogyne ramosissima) shrublands in the Mojave Desert
Matthew L. Brooks, John R. Matchett
2003, Western North American Naturalist (63) 283-298
The blackbrush vegetation type is dominated by Coleogyne ramossisima, which is thought to preclude the coexistence of many other plant species. Fire can remove blackbrush cover and possibly increase plant species richness and evenness. Fire also may increase the frequency and cover of alien annual grasses, thereby intensifying landscape flammability....
Atmospheric deposition maps for the Rocky Mountains
L. Nanus, K. Campbell, G.P. Ingersoll, D. W. Clow, M.A. Mast
2003, Atmospheric Environment (37) 4881-4892
Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the...
Fire and invasive plants in California ecosystems
Jon E. Keeley
2003, Fire Management Today (63) 18-19
Groundwater level changes in a deep well in response to a magma intrusion event on Kilauea Volcano, Hawai'i
S. Hurwitz, M.J.S. Johnston
2003, Geophysical Research Letters (30)
On May 21, 2001, an abrupt inflation of Kilauea Volcano's summit induced a rapid and large increase in compressional strain, with a maximum of 2 ??strain recorded by a borehole dilatometer. Water level (pressure) simultaneously dropped by 6 cm. This mode of water level change (drop) is in contrast to...
A 16,000 14C yr B.P. packrat midden series from the USA-Mexico Borderlands
C.A. Holmgren, M.C. Penalba, K.A. Rylander, J.L. Betancourt
2003, Quaternary Research (60) 319-329
A new packrat midden chronology from Playas Valley, southwestern New Mexico, is the first installment of an ongoing effort to reconstruct paleovegetation and paleoclimate in the U.S.A.-Mexico Borderlands. Playas Valley and neighboring basins supported pluvial lakes during full and/or late glacial times. Plant macrofossil and pollen assemblages from nine middens...
The typological approach to submarine groundwater discharge (SGD)
H. Bokuniewicz, R. Buddemeier, B. Maxwell, C. Smith
2003, Biogeochemistry (66) 145-158
Coastal zone managers need to factor submarine groundwater discharge (SGD) in their integration. SGD provides a pathway for the transfer of freshwater, and its dissolved chemical burden, from the land to the coastal ocean. SGD reduces salinities and provides nutrients to specialized coastal habitats. It also can be a pollutant...
Web-based data delivery services in support of disaster-relief applications
Brenda K. Jones, Ron R. Risty, M. Buswell
2003, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
The U.S. Geological Survey Earth Resources Observation Systems Data Center responds to emergencies in support of various government agencies for human-induced and natural disasters. This response consists of satellite tasking and acquisitions, satellite image registrations, disaster-extent maps analysis and creation, base image provision and support, Web-based mapping services for product...
Percolation induced heat transfer in deep unsaturated zones
N. Lu, G.D. LeCain
2003, Journal of Geotechnical and Geoenvironmental Engineering (129) 1040-1053
Subsurface temperature data from a borehole located in a desert wash were measured and used to delineate the conductive and advective heat transfer regimes, and to estimate the percolation quantity associated with the 1997-1998 El Ni??no precipitation. In an arid environment, conductive heat transfer dominates the variation of shallow subsurface...
Interactions of bullfrog tadpole predators and an insecticide: Predation release and facilitation
M.D. Boone, R. D. Semlitsch
2003, Oecologia (137) 610-616
The effect of a contaminant on a community may not be easily predicted, given that complex changes in food resources and predator-prey dynamics may result. The objectives of our study were to determine the interactive effects of the insecticide carbaryl and predators on body size, development, survival, and activity of...
Vertical velocity variance in the mixed layer from radar wind profilers
K. Eng, R.L. Coulter, W. Brutsaert
2003, Journal of Hydrologic Engineering (8) 301-307
Vertical velocity variance data were derived from remotely sensed mixed layer turbulence measurements at the Atmospheric Boundary Layer Experiments (ABLE) facility in Butler County, Kansas. These measurements and associated data were provided by a collection of instruments that included two 915 MHz wind profilers, two radio acoustic sounding systems, and...
Microparasite assemblages of conspecific shrew populations in Southern California
J. Laakkonen, Robert N. Fisher, T. J. Case
2003, Journal of Parasitology (89) 1153-1158
The microparasite component communities of 2 species of shrews, Notiosorex crawfordi and Sorex ornatus, were investigated for the first time in 2 isolated and 3 continuous landscapes in southern California. With microscopical examination, a total of 6 parasite species was found in N. crawfordi and 8 species in S. ornatus....
Modeling radium and radon transport through soil and vegetation
J.A. Kozak, H. W. Reeves, B.A. Lewis
2003, Journal of Contaminant Hydrology (66) 179-200
A one-dimensional flow and transport model was developed to describe the movement of two fluid phases, gas and water, within a porous medium and the transport of 226Ra and 222Rn within and between these two phases. Included in this model is the vegetative uptake of water and aqueous 226Ra and...
Status of Alabama shad and skipjack herring in Gulf of Mexico drainages
M.F. Mettee, P. E. O’Neil
2003, American Fisheries Society Symposium (2003) 157-170
Gulf of Mexico drainages are inhabited by two alosine species, the anadromous Alabama shad Alosa alabamae and the skipjack herring A. chrysochloris. Although their distributions are reasonably well documented, the life history and ecology of both species has been incompletely investigated. Infrequent literature references suggest populations of both species have...
Direct assessment of groundwater vulnerability from single observations of multiple contaminants
Fred Worrall, Dana W. Kolpin
2003, Water Resources Research (39) 2-1-2-8
Groundwater vulnerability is a central concept in pollution risk assessment, yet its estimation has been largely a matter of expert judgment. This work applies a method for the direct calculation of vulnerability from monitoring well observations of pesticide concentrations. The method has two major advantages: it is independent of the...
Improving ground-penetrating radar data in sedimentary rocks using deterministic deconvolution
J. Xia, E. K. Franseen, R. D. Miller, T.V. Weis, A.P. Byrnes
2003, Journal of Applied Geophysics (54) 15-33
Resolution is key to confidently identifying unique geologic features using ground-penetrating radar (GPR) data. Source wavelet "ringing" (related to bandwidth) in a GPR section limits resolution because of wavelet interference, and can smear reflections in time and/or space. The resultant potential for misinterpretation limits the usefulness of GPR. Deconvolution offers...
Advection, pelagic food webs and the biogeography of seabirds in Beringia
John F. Piatt, Alan M. Springer
2003, Marine Ornithology: Journal of Seabird Research and Conservation (31) 141-154
Despite its great distance from productive shelf-edge habitat, the inner shelf area of the Bering Sea, from St. Lawrence Island to the Bering Strait, supports a surprisingly large number (>5 million) of seabirds during summer, mostly small plantivorous auklets (65%) and large piscivorous murres (19%) and kittiwakes (5%). This paradox...
The influence of water depth and flow regime on phytoplankton biomass and community structure in a shallow, lowland river
H.V. Leland
2003, Conference Paper, Hydrobiologia
The taxonomic composition and biomass of phytoplankton in the San Joaquin River, California, were examined in relation to water depth, flow regime, and water chemistry. Without substantial tributary inflow, maintenance demands exceeded algal production during summer and autumn in this eutrophic, 'lowland type' river due to light-limiting conditions for algal...
How should environmental stress affect the population dynamics of disease?
Kevin D. Lafferty, Robert D. Holt
2003, Ecology Letters (6) 654-664
We modelled how stress affects the population dynamics of infectious disease. We were specifically concerned with stress that increased susceptibility of uninfected hosts when exposed to infection. If such stresses also reduced resources, fecundity and/or survivorship, there was a reduction in the host carrying capacity. This lowered the contact between...
Radiogenic helium in shallow groundwater within a clay till, southwestern Ontario
Amy L. Sheldon, D. Kip Solomon, Robert J. Poreda, Andrew Hunt
2003, Water Resources Research (39)
Profiles of 4He in pore water were measured in clay aquitards in SW Ontario. The 4He distributions are consistent with groundwater velocities that are <6 mm yr−1, and thus diffusion is the dominant transport mechanism for 4He. Modeling indicates that the effective diffusion coefficient for 4He is 6.3 ± 1.6 × 10−6 cm2 s−1. Furthermore, the...
A genetic survey of Salvinia minima in the southern United States
Paul T. Madeira, Colette C. Jacono, Phil Tipping, Thai K. Van, Ted D. Center
2003, Aquatic Botany (76) 127-139
No abstract available....
Fracture network of the Ferron Sandstone Member of the Mancos Shale, east-central Utah, USA
S. M. Condon
2003, International Journal of Coal Geology (56) 111-139
The fracture network at the outcrop of the Ferron Sandstone Member of the Mancos Shale was studied to gain an understanding of the tectonic history of the region and to contribute data to studies of gas and water transmissivity related to the occurrence and production of coal-bed methane. About 1900...
Relating species abundance distributions to species-area curves in two Mediterranean-type shrublands
Jon E. Keeley
2003, Diversity and Distributions (9) 253-259
Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species-area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species-area relationships and different species abundance patterns. The species-area relationship in Australian heathlands...
