Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams
M. R. Meador, D.M. Carlisle, J.F. Coles
2008, Ecological Indicators (8) 718-728
Identification of stressors related to biological impairment is critical to biological assessments. We applied nationally derived tolerance indicator values for four water-quality variables to fish and benthic macroinvertebrate assemblages at 29 sites along an urban gradient in New England. Tolerance indicator values (TIVs), as biologically based predictors of water-quality variables,...
Non-spore forming eubacteria isolated at an altitude of 20,000 m in Earth's atmosphere: extended incubation periods needed for culture-based assays
Dale W. Griffin
2008, Aerobiologia (24) 19-25
On 13 August 2004, an atmospheric sample was collected at an altitude of 20,000 m along a west to east transect over the continental United States by NASA’s Stratospheric and Cosmic Dust Program. This sample was then shipped to the US Geological Survey’s Global Desert Dust program for microbiological analyses....
Reproductive ecology of Actinonaias ligamentina (Bivalvia:Unionidae) in a regulated river
K.R. Moles, J.B. Layzer
2008, Journal of the North American Benthological Society (27) 212-222
Factors affecting the reproductive success of freshwater mussels in lotic systems are poorly understood. Gravidity, fecundity, and fertilization success of Actinonaias ligamentina were examined at 4 sites along a 63-km reach of the Green River immediately below the Green River Dam, Kentucky. No gravid females were collected at the site...
Impact effects and regional tectonic insights: Backstripping the Chesapeake Bay impact structure
T. Hayden, M. Kominz, David S. Powars, Lucy E. Edwards, K.G. Miller, J.V. Browning, A.A. Kulpecz
2008, Geology (36) 327-330
The Chesapeake Bay impact structure is a ca. 35.4 Ma crater located on the eastern seaboard of North America. Deposition returned to normal shortly after impact, resulting in a unique record of both impact-related and subsequent passive margin sedimentation. We use backstripping to show that the impact strongly affected sedimentation...
A rapid method for hydraulic profiling in unconsolidated formations
P. Dietrich, J.J. Butler Jr., K. Faiss
2008, Ground Water (46) 323-328
Information on vertical variations in hydraulic conductivity (K) can often shed much light on how a contaminant will move in the subsurface. The direct-push injection logger has been developed to rapidly obtain such information in shallow unconsolidated settings. This small-diameter tool consists of a short screen located just behind a...
A quantitative evaluation of the iron-sulfur world and its relevance to life's origins
D.S. Ross
2008, Conference Paper, Astrobiology
The significance of Wa??chtersha??user's iron-sulfur world to the origin of life and the limits to its notional autocatalytic cycles are examined in kinetic simulations of the chain polymerization sequence primitive materials ??? amino acids ??? oligomers The simulations were run for the formation of all oligomers up to the 20-mer...
Effect of hydrological conditions on nitrous oxide, methane, and carbon dioxide dynamics in a bottomland hardwood forest and its implication for soil carbon sequestration
K. Yu, S.P. Faulkner, M.J. Baldwin
2008, Global Change Biology (14) 798-812
This study was conducted at three locations in a bottomland hardwood forest with a distinct elevation and hydrological gradient: ridge (high, dry), transition, and swamp (low, wet). At each location, concentrations of soil greenhouse gases (N2O, CH4, and CO2), their fluxes to the atmosphere, and soil redox potential (Eh) were...
Soil nutrient-landscape relationships in a lowland tropical rainforest in Panama
F.K. Barthold, R.F. Stallard, H. Elsenbeer
2008, Forest Ecology and Management (255) 1135-1148
Soils play a crucial role in biogeochemical cycles as spatially distributed sources and sinks of nutrients. Any spatial patterns depend on soil forming processes, our understanding of which is still limited, especially in regards to tropical rainforests. The objective of our study was to investigate the effects of landscape properties,...
Translocation and early post-release demography of endangered Laysan teal
M.H. Reynolds, N.E. Seavy, M.S. Vekasy, J.L. Klavitter, L.P. Laniawe
2008, Animal Conservation (11) 160-168
In an attempt to reduce the high extinction risk inherent to small island populations, we translocated wild Laysan teal Anas laysanensis to a portion of its presumed prehistoric range. Most avian translocations lack the strategic post-release monitoring needed to assess early population establishment or failure. Therefore, we monitored the survival...
Rainbow trout (Oncorhynchus mykiss) invasion and the spread of hybridization with native westslope cutthroat trout (Oncorhynchus clarkii lewisi)
M.C. Boyer, C.C. Muhlfeld, F.W. Allendorf
2008, Canadian Journal of Fisheries and Aquatic Sciences (65) 658-669
We analyzed 13 microsatellite loci to estimate gene flow among westslope cutthroat trout, Oncorhynchus clarkii lewisi, populations and determine the invasion pattern of hybrids between native O. c. lewisi and introduced rainbow trout, Oncorhynchus mykiss, in streams of the upper Flathead River system, Montana (USA) and British Columbia (Canada). Fourteen...
Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado
V.G. deWolfe, P.M. Santi, J. Ey, J.E. Gartner
2008, Geomorphology (96) 366-377
To reduce the hazards from debris flows in drainage basins burned by wildfire, erosion control measures such as construction of check dams, installation of log erosion barriers (LEBs), and spreading of straw mulch and seed are common practice. After the 2002 Missionary Ridge Fire in southwest Colorado, these measures were...
Natural radionuclide mobility and its influence on U-Th-Pb dating of secondary minerals from the unsaturated zone at Yucca Mountain, Nevada
L.A. Neymark, Y. V. Amelin
2008, Geochimica et Cosmochimica Acta (72) 2067-2089
Extreme U and Pb isotope variations produced by disequilibrium in decay chains of 238U and 232Th are found in calcite, opal/chalcedony, and Mn-oxides occurring as secondary mineral coatings in the unsaturated zone at Yucca Mountain, Nevada. These very slowly growing minerals (mm my-1) contain excess 206Pb and 208Pb formed from...
Spectroscopy, morphometry, and photoclinometry of Titan's dunefields from Cassini/VIMS
J. W. Barnes, R. H. Brown, L. Soderblom, Christophe Sotin, S. Le Mouelic, S. Rodriguez, R. Jaumann, R.A. Beyer, B. J. Buratti, K. Pitman, K. H. Baines, R. Clark, P. Nicholson
2008, Icarus (195) 400-414
Fine-resolution (500 m/pixel) Cassini Visual and Infrared Mapping Spectrometer (VIMS) T20 observations of Titan resolve that moon's sand dunes. The spectral variability in some dune regions shows that there are sand-free interdune areas, wherein VIMS spectra reveal the exposed dune substrate. The interdunes from T20 are, variously, materials that correspond...
Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States
C.T. Green, L.H. Fisher, B.A. Bekins
2008, Journal of Environmental Quality (37) 1073-1085
The main physical and chemical controls on nitrogen (N) fluxes between the root zone and the water table were determined for agricultural sites in California, Indiana, Maryland, Nebraska, and Washington from 2004 to 2005. Sites included irrigated and nonirrigated fields; soil textures ranging from clay to sand; crops including corn,...
Biogeochemical and ecological impacts of livestock grazing in semi-arid southeastern Utah, USA
D. P. Fernandez, J. C. Neff, R. L. Reynolds
2008, Journal of Arid Environments (72) 777-791
Relatively few studies have examined the ecological and biogeochemical effects of livestock grazing in southeastern Utah. In this study, we evaluated how grazing has affected soil organic carbon and nitrogen to a depth of 50 cm in grasslands located in relict and actively-grazed sites in the Canyonlands physiographic section of...
Fluvial channels on Titan: Initial Cassini RADAR observations
R. D. Lorenz, R.M. Lopes, F. Paganelli, J. I. Lunine, Randolph L. Kirk, K. L. Mitchell, Laurence A. Soderblom, E. R. Stofan, G. Ori, M. Myers, H. Miyamoto, J. Radebaugh, B. Stiles, S. D. Wall, C. A. Wood
2008, Planetary and Space Science (56) 1132-1144
Cassini radar images show a variety of fluvial channels on Titan's surface, often several hundreds of kilometers in length. Some (predominantly at low- and mid-latitude) are radar-bright and braided, resembling desert washes where fines have been removed by energetic surface liquid flow, presumably from methane rainstorms. Others (predominantly at high...
Identifying habitat sinks: A case study of Cooper's hawks in an urban environment
R.W. Mannan, R.J. Steidl, C. W. Boal
2008, Urban Ecosystems (11) 141-148
We studied a population of Cooper's hawks (Accipiter cooperii) in Tucson, Arizona from 1994 to 2005. High rates of mortality of nestlings from an urban-related disease prompted speculation that the area represented an ecological trap and habitat sink for Cooper's hawks. In this paper, we used estimates of survival and...
Studies on geological background and source of fluorine in drinking water in the North China Plate fluorosis areas
K. Luo, F. Feng, H. Li, C. L. Chou, Z. Feng, D. Yunshe
2008, Toxicological and Environmental Chemistry (90) 237-246
Endemic fluorosis in northern China is usually produced by high fluorine (F) content in drinking water. Thirty-one samples of drinking waters, mainly well waters and nearly 200 samples of rocks, loess, and coal were analyzed for F content using the combustion hydrolysis-fluoride-ion selective electrode (ISE) method. The geologic cross sections...
Landsat continuity: Issues and opportunities for land cover monitoring
M.A. Wulder, Joanne C. White, S.N. Goward, J. G. Masek, J. R. Irons, M. Herold, W.B. Cohen, Thomas R. Loveland, C. E. Woodcock
2008, Remote Sensing of Environment (112) 955-969
Initiated in 1972, the Landsat program has provided a continuous record of earth observation for 35 years. The assemblage of Landsat spatial, spectral, and temporal resolutions, over a reasonably sized image extent, results in imagery that can be processed to represent land cover over large areas with an amount of spatial...
Middle UV to near-IR spectrum of electron-excited SO2
J.M. Ajello, A. Aguilar, R.S. Mangina, G.K. James, P. Geissler, L. Trafton
2008, Journal of Geophysical Research E: Planets (113)
We investigated the electron impact–induced fluorescence spectrum of SO2 to provide excitation cross sections for modeling Io's emission spectrum and analyzing Cassini Imaging Science Subsystem observations. The electron-excited middle-ultraviolet visible optical near-infrared (VOIR) emission spectrum of SO2 gas was generated in the laboratory and studied from 2000 to 11,000 Å at a...
Simulated natural hydrologic regime of an intermountain playa conservation site
J.S. Sanderson, N.B. Kotliar, D.A. Steingraeber, C. Browne
2008, Wetlands (28) 363-377
An intermountain playa wetland preserve in Colorado's San Luis Valley was studied to assess how its current hydrologic function compares to its natural hydrologic regime. Current hydrologic conditions were quantified, and on-site effects of off-site water use were assessed. A water-budget model was developed to simulate an unaltered (i.e., natural)...
The effects of water-level fluctuations on vegetation in a Lake Huron wetland
D.A. Wilcox, S. J. Nichols
2008, Wetlands (28) 487-501
The diversity and resultant habitat value of wetland plant communities in the Laurentian Great Lake's are dependent on water-level fluctuations of varying frequency and amplitude. Conceptual models have described the response of vegetation to alternating high and low lake levels, but few quantitative studies have documented the changes that occur....
Evolution of the Mazatzal province and the timing of the Mazatzal orogeny: Insights from U-Pb geochronology and geochemistry of igneous and metasedimentary rocks in southern New Mexico
J.M. Amato, A.O. Boullion, A.M. Serna, A.E. Sanders, G. L. Farmer, G. E. Gehrels, J. L. Wooden
2008, Geological Society of America Bulletin (120) 328-346
New U-Pb zircon ages, geochemistry, and Nd isotopic data are presented from three localities in the Paleoproterozoic Mazatzal province of southern New Mexico, United States. These data help in understanding the source regions and tectonic setting of magmatism from 1680 to 1620 Ma, the timing of the Mazatzal orogeny, the...
Stress tolerance in plants via habitat-adapted symbiosis
R. J. Rodriguez, J. Henson, E. Van Volkenburgh, M. Hoy, L. Wright, F. Beckwith, Y.-O. Kim, R. S. Redman
2008, ISME Journal (2) 404-416
We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal...
Atmospherically deposited PBDEs, pesticides, PCBs, and PAHs in western U.S. National Park fish: Concentrations and consumption guidelines
L.K. Ackerman, A.R. Schwindt, S.L.M. Simonich, D.C. Koch, T.F. Blett, C.B. Schreck, M.L. Kent, D.H. Landers
2008, Environmental Science & Technology (42) 2334-2341
Concentrations of polybrominated diphenyl ethers (PBDEs), pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons were measured in 136 fish from 14 remote lakes in 8 western U.S. National Parks/Preserves between 2003 and 2005 and compared to human and wildlife contaminant health thresholds. A sensitive (median detection limit, -18 pg/g wet...
