Regional patterns in the isotopic composition of natural and anthropogenic nitrate in groundwater, High Plains, U.S.A.
P.B. McMahon, J.K. Böhlke
2006, Environmental Science & Technology (40) 2965-2970
Mobilization of natural nitrate (NO3-) deposits in the subsoil by irrigation water in arid and semiarid regions has the potential to produce large groundwater NO3- concentrations. The use of isotopes to distinguish between natural and anthropogenic NO3- sources in these settings could be complicated by the wide range in δ15N...
Sequence motifs and prokaryotic expression of the reptilian paramyxovirus fusion protein
J. Franke, W.N. Batts, W. Ahne, Gael Kurath, J. R. Winton
2006, Archives of Virology (151) 449-464
Fourteen reptilian paramyxovirus isolates were chosen to represent the known extent of genetic diversity among this novel group of viruses. Selected regions of the fusion (F) gene were sequenced, analyzed and compared. The F gene of all isolates contained conserved motifs homologous to those described for other members of the...
Sample size and the detection of a hump-shaped relationship between biomass and species richness in Mediterranean wetlands
J. L. Espinar
2006, Journal of Vegetation Science (17) 227-232
Questions: What is the observed relationship between biomass and species richness across both spatial and temporal scales in communities of submerged annual macrophytes? Does the number of plots sampled affect detection of hump-shaped pattern? Location: Don??ana National Park, southwestern Spain. Methods: A total of 102 plots were sampled during four...
Palynology and age of some Cretaceous nonmarine deposits in Mongolia and China
D. J. Nichols, M. Matsukawa, M. Ito
2006, Cretaceous Research (27) 241-251
To provide biostratigraphic and paleoecologic data for a major international project studying dinosaur trackways in eastern Asia, samples were collected for palynological analysis from the Choyr Basin of southeastern Mongolia and the Yanji Basin, Jilin Province, northeastern China. Palynologically productive samples from the Choyr Basin are from strata previously identified...
Simulation of solute transport across low-permeability barrier walls
P. T. Harte, Leonard F. Konikow, G.Z. Hornberger
2006, Journal of Contaminant Hydrology (85) 247-270
Low-permeability, non-reactive barrier walls are often used to contain contaminants in an aquifer. Rates of solute transport through such barriers are typically many orders of magnitude slower than rates through the aquifer. Nevertheless, the success of remedial actions may be sensitive to these low rates of transport. Two numerical simulation...
Vascular flora of Izembek National Wildlife Refuge, westernmost Alaska Peninsula, Alaska
Stephen S. Talbot, Sandra Looman Talbot, Wilfred B. Schofield
2006, Rhodora (108) 249-293
The vascular flora of Izembek National Wildlife Refuge (NWR), where few previous collections had been reported, was collected and recorded at sites selected to represent the totality of environmental variation. A total of 349 species (339 native and 10 introduced) was identified. To provide a comparative phytogeographic framework, we analyzed...
Studies on stoneflies (Plecoptera) of Colorado with eastern faunal affinities, including a new state record of the midwestern salmonfly, Pteronarcys pictetii hagen (Plecoptera: Pteronarcyidae)
R.E. Zuellig, B.C. Kondratieff, R.W. Hood
2006, Proceedings of the Entomological Society of Washington (108) 335-340
Pteronarcys pictetii Hagen nymphs were collected and reared from the South Platte River at Julesburg in eastern Colorado. Including P. pictetii, eight species are now known from Colorado that exhibit eastern North American affinities, Paracapnia angulata Hanson, Taeniopteryx burksi Ricker and Ross, Taeniopteryx parvula Banks, Acroneuria abnormis (Newman), Perlesta decipiens...
Petrography and geochemistry of the Middle Devonian coal from Luquan, Yunnan Province, China
S. Dai, D. Han, C. L. Chou
2006, Fuel (85) 456-464
Coals from Luquan, Yunnan Province, China, have high contents of cutinite and microsporinite, with an average of 55 and 33.5 vol%, respectively, (on a mineral-free basis). The coals are classified as cutinitic liptobiolith, sporinite-rich durain, cutinite-rich durain, and sporinitic liptobiolith. These four liptinite-rich coals are often interlayered within the coal...
Spatial and temporal dynamics of microcystin in a Missouri reservoir
J.L. Graham, J.R. Jones, S.B. Jones, T.E. Clevenger
2006, Lake and Reservoir Management (22) 59-68
Environmental factors associated with spatiotemporal variation of microcystin (MC) in Mozingo Lake, a Missouri reservoir, were studied during summer 2001, and annual MC trends were characterized from May 2001-May 2002. MC increased during summer, ranging from 20 to 1220 ng/L. Seasonal patterns in MC corresponded with chlorophyll>35 ??m (Net Chl)...
Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis
Y.-K. Zhang, K. E. Schilling
2006, Journal of Hydrology (319) 328-338
The effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge were studied with water level measurements collected from two monitoring wells over a period of 122 days. The two wells were installed under similar conditions except that one was drilled on the east side of a...
Regional and local species richness in an insular environment: Serpentine plants in California
S. Harrison, H.D. Safford, J.B. Grace, J.H. Viers, K.F. Davies
2006, Ecological Monographs (76) 41-56
We asked how the richness of the specialized (endemic) flora of serpentine rock outcrops in California varies at both the regional and local scales. Our study had two goals: first, to test whether endemic richness is affected by spatial habitat structure (e.g., regional serpentine area, local serpentine outcrop area, regional...
Spectral variability among rocks in visible and near-infrared mustispectral Pancam data collected at Gusev crater: Examinations using spectral mixture analysis and related techniques
W. H. Farrand, J.F. Bell, J. R. Johnson, S. W. Squyres, J. Soderblom, D. W. Ming
2006, Journal of Geophysical Research E: Planets (111)
Visible and near-infrared (VNIR) multispectral observations of rocks made by the Mars Exploration Rover Spirit's Panoramic camera (Pancam) have been analyzed using a spectral mixture analysis (SMA) methodology. Scenes have been examined from the Gusev crater plains into the Columbia Hills. Most scenes on the plains and in the Columbia...
Development of partial rock veneers by root throw in a subalpine setting
W. R. Osterkamp, T.J. Toy, M.T. Lenart
2006, Earth Surface Processes and Landforms (31) 1-14
Rock veneers stabilize hillslope surfaces, occur especially in areas of immature soil, and form through a variety of process sets that includes root throw. Near Westcliffe, Colorado, USA, data were collected from a 20 ?? 500 m transect on the east slope of the Sangre de Cristo Mountains. Ages of...
An introduced predator alters Aleutian Island plant communities by thwarting nutrient subsidies
J.L. Maron, J. A. Estes, D.A. Croll, E.M. Danner, S.C. Elmendorf, S.L. Buckelew
2006, Ecological Monographs (76) 3-24
The ramifying effects of top predators on food webs traditionally have been studied within the framework of trophic cascades. Trophic cascades are compelling because they embody powerful indirect effects of predators on primary production. Although less studied, indirect effects of predators may occur via routes that are not exclusively trophic....
Stress changes along the Sunda trench following the 26 December 2004 Sumatra-Andaman and 28 March 2005 Nias earthquakes
F. F. Pollitz, P. Banerjee, R. Burgmann, M. Hashimoto, N. Choosakul
2006, Geophysical Research Letters (33)
The 26 December 2004 Mw = 9.2 and 28 March 2005 Mw = 8.7 earthquakes on the Sumatra megathrust altered the state of stress over a large region surrounding the earthquakes. We evaluate the stress changes associated with coseismic and postseismic deformation following these two large events, focusing on postseismic...
The allometric relationship between resting metabolic rate and body mass in wild waterfowl (Anatidae) and an application to estimation of winter habitat requirements
M. R. Miller, J. McA Eadie
2006, Condor (108) 166-177
We examined the allometric relationship between resting metabolic rate (RMR; kJ day-1) and body mass (kg) in wild waterfowl (Anatidae) by regressing RMR on body mass using species means from data obtained from published literature (18 sources, 54 measurements, 24 species; all data from captive birds). There was no significant...
Presence and distribution of wastewater-derived pharmaceuticals in soil irrigated with reclaimed water
C.A. Kinney, E. T. Furlong, S.L. Werner, J.D. Cahill
2006, Environmental Toxicology and Chemistry (25) 317-326
Three sites in the Front Range of Colorado, USA, were monitored from May through September 2003 to assess the presence and distribution of pharmaceuticals in soil irrigated with reclaimed water derived from urban wastewater. Soil cores were collected monthly, and 19 pharmaceuticals, all of which were...
Distribution of foraminifera in Pamlico Sound, North Carolina, over the past century
I.J. Abbene, S.J. Culver, D.R. Corbett, M.A. Buzas, L.S. Tully
2006, Journal of Foraminiferal Research (36) 135-151
Foraminiferal and radionuclide data have been used to investigate environmental change that has occurred within Pamlico Sound, North Carolina, over the last century. Environmental conditions were evaluated for three time slices; (1) the modern environment as determined by surficial (0-1 cm) sediments, (2) short-core intervals representing approximately 40 years BP,...
Crustal structure across the Altyn Tagh Range at the northern margin of the Tibetan Plateau and tectonic implications
J. Zhao, Walter D. Mooney, X. Zhang, Z. Li, Z. Jin, N. Okaya
2006, Earth and Planetary Science Letters (241) 804-814
We present new seismic refraction/wide-angle-reflection data across the Altyn Tagh Range and its adjacent basins. We find that the crustal velocity structure, and by inference, the composition of the crust changes abruptly beneath the Cherchen fault, i.e., ∼100 km north of the northern...
Estimating hydraulic properties using a moving-model approach and multiple aquifer tests
K. J. Halford, D. Yobbi
2006, Ground Water (44) 284-291
A new method was developed for characterizing geohydrologic columns that extended >600 m deep at sites with as many as six discrete aquifers. This method was applied at 12 sites within the Southwest Florida Water Management District. Sites typically were equipped with multiple production wells, one for each aquifer and...
Constraints on the mechanism of long-term, steady subsidence at Medicine Lake volcano, northern California, from GPS, leveling, and InSAR
Michael P. Poland, Roland Burgmann, Daniel Dzurisin, Michael Lisowski, Timothy Masterlark, Susan Owen, Jonathan Fink
2006, Journal of Volcanology and Geothermal Research (150) 55-78
Leveling surveys across Medicine Lake volcano (MLV) have documented subsidence that is centered on the summit caldera and decays symmetrically on the flanks of the edifice. Possible mechanisms for this deformation include fluid withdrawal from a subsurface reservoir, cooling/crystallization of subsurface magma, loading by the...
Characterization and petrologic interpretation of olivine-rich basalts at Gusev Crater, Mars
H.Y. McSween, M.B. Wyatt, Ralf Gellert, J.F. Bell, R.V. Morris, Kenneth E. Herkenhoff, L.S. Crumpler, K.A. Milam, K.R. Stockstill, L.L. Tornabene, R. E. Arvidson, P. Bartlett, D. Blaney, N.A. Cabrol, P. R. Christensen, B.C. Clark, J.A. Crisp, D.J. Des Marais, T. Economou, J.D. Farmer, W. Farrand, A. Ghosh, M. Golombek, S. Gorevan, R. Greeley, V.E. Hamilton, J. R. Johnson, B.L. Joliff, G. Klingelhofer, A.T. Knudson, S. McLennan, D. Ming, J.E. Moersch, R. Rieder, S. W. Ruff, C. Schroder, P.A. de Souza, S. W. Squyres, H. Wanke, A. Wang, A. Yen, J. Zipfel
2006, Journal of Geophysical Research E: Planets (111)
Rocks on the floor of Gusev crater are basalts of uniform composition and mineralogy. Olivine, the only mineral to have been identified or inferred from data by all instruments on the Spirit rover, is especially abundant in these rocks. These picritic basalts are similar in many respects to certain Martian...
Trace element geochemistry and surface water chemistry of the Bon Air coal, Franklin County, Cumberland Plateau, southeast Tennessee
S.A. Shaver, J.C. Hower, C.F. Eble, E.D. McLamb, K. Kuers
2006, International Journal of Coal Geology (67) 47-78
Mean contents of trace elements and ash in channel, bench-column, and dump samples of the abandoned Bon Air coal (Lower Pennsylvanian) in Franklin County, Tennessee are similar to Appalachian COALQUAL mean values, but are slightly lower for As, Fe, Hg, Mn, Na, Th, and U, and slightly higher for ash,...
Partitioning evapotranspiration in sparsely vegetated rangeland using a portable chamber
David I. Stannard, Mark A. Weltz
2006, Water Resources Research (42)
A portable chamber was used to separate evapotranspiration (ET) from a sparse, mixed‐species shrub canopy in southeastern Arizona, United States, into vegetation and soil components. Chamber measurements were made of ET from the five dominant species, and from bare soil, on 3 days during the monsoon season when the soil surface was...
Analysis of environmental variation in a Great Plains reservoir using principal components analysis and geographic information systems
J.M. Long, W.L. Fisher
2006, Lake and Reservoir Management (22) 132-140
We present a method for spatial interpretation of environmental variation in a reservoir that integrates principal components analysis (PCA) of environmental data with geographic information systems (GIS). To illustrate our method, we used data from a Great Plains reservoir (Skiatook Lake, Oklahoma) with longitudinal variation in physicochemical conditions. We measured...
