Do beavers promote the invasion of non-native Tamarix in the Grand Canyon riparian zone
S.G. Mortenson, P.J. Weisberg, B.E. Ralston
2008, Wetlands (28) 666-675
Beavers (Castor canadensis Kuhl) can influence the competitive dynamics of plant species through selective foraging, collection of materials for dam creation, and alteration of hydrologic conditions. In the Grand Canyon National Park, the native Salix gooddingii C.R.Ball (Goodding's willow) and Salix exigua Nutt. (coyote willow) are a staple food of...
Sensitivity of wetland saturated hydraulic heads and water budgets to evapotranspiration
W.B. Shoemaker, S. Huddleston, C.L. Boudreau, A. M. O’Reilly
2008, Wetlands (28) 1040-1047
The sensitivity of wetland saturated hydraulic heads and water budgets to evapotranspiration (ET) was examined using a simplified hydrologic model and eight representations of ET. Estimates of ET that created the most reliable wetland saturated hydraulic heads and water budgets employed vegetation coefficients to correct potential ET, calculated by the...
Significance of detrital zircons in upper Devonian ocean-basin strata of the Sonora allochthon and Lower Permian synorogenic strata of the Mina Mexico foredeep, central Sonora, Mexico
F. G. Poole, G. E. Gehrels, John H. Stewart
2008, Special Paper of the Geological Society of America 121-131
U-Pb isotopic dating of detrital zircons from a conglomeratic barite sandstone in the Sonora allochthon and a calciclastic sandstone in the Mina Mexico foredeep of the Minas de Barita area reveals two main age groups in the Upper Devonian part of the Los Pozos Formation, 1.73-1.65 Ga and 1.44-1.42 Ga;...
Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba
M.E. Reiter, C. W. Boal, D. E. Andersen
2008, Canadian Field-Naturalist (122) 129-137
Distribution, abundance, and habitat relationships of anurans inhabiting subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to experience changes in climate and, in...
Education and training of future wetland scientists and managers
D.A. Wilcox
2008, Wetlands (28) 578-584
Wetland science emerged as a distinct discipline in the 1980s. In response, courses addressing various aspects of wetland science and management were developed by universities, government agencies, and private firms. Professional certification of wetland scientists began in the mid-1990s to provide confirmation of the quality of education and experience of...
Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses
J.R. Knott, M. N. Machette, R.E. Klinger, A.M. Sarna-Wojcicki, J. C. Liddicoat, J. C. Tinsley III, B.T. David, V.M. Ebbs
2008, Conference Paper, Special Paper of the Geological Society of America
During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western...
Canadian groundwater inventory: Regional hydrogeological characterization of the south-central part of the maritimes basin
C. Rivard, Y. Michaud, C. Deblonde, V. Boisvert, C. Carrier, R. H. Morin, T. Calvert, H. Vigneault, D. Conohan, S. Castonguay, R. Lefebvre, A. Rivera, M. Parent
2008, Bulletin of the Geological Survey of Canada 1-96
The Maritimes Groundwater Initiative (MGWI) is a large, integrated, regional hydrogeological study focusing on a representative area of the Maritimes Basin in eastern Canada. The study area covers a land surface of 10 500 km2, of which 9 400 km2 are underlain by sedimentary rocks. This sedimentary bedrock is composed...
Spatial interactions of yarded White-tailed Deer, Odocoileus virginianus
M.E. Nelson, G.A. Sargeant
2008, Canadian Field-Naturalist (122) 221-225
We examined the spatial interactions of nine female White-tailed Deer (Odocoileus virginianus) in two deeryards (winter aggregations) in northeastern Minnesota during February-April 1999. Global positioning system (GPS) collars yielded seven pair-wise comparisons of deer that were located at the same time (???1 minute apart) and mat used overlapping areas. Deer...
New opportunities for international cooperation in land imaging: The U.S. national land imaging program initiative
T. Stryker
2008, Conference Paper, International Astronautical Federation - 59th International Astronautical Congress 2008, IAC 2008
[No abstract available]...
Endocrine systems in juvenile anadromous and landlocked Atlantic salmon (Salmo salar): Seasonal development and seawater acclimation
Tom O. Nilsen, Lars O.E. Ebbesson, P. Kiilerich, B. Th Bjornsson, Steffen S. Madsen, S. D. McCormick, S.O. Stefansson
2008, General and Comparative Endocrinology (155) 762-772
The present study compares developmental changes in plasma levels of growth hormone (GH), insulin-like growth factor I (IGF-I) and cortisol, and mRNA levels of their receptors and the prolactin receptor (PRLR) in the gill of anadromous and landlocked Atlantic salmon during the spring parr-smolt transformation (smoltification) period and following four...
Joint inversion of fundamental and higher mode Rayleigh waves
Y.-H. Luo, J.-H. Xia, J.-P. Liu, Q.-S. Liu
2008, Chinese Journal of Geophysics (Acta Geophysica Sinica) (51) 242-249
In this paper, we analyze the characteristics of the phase velocity of fundamental and higher mode Rayleigh waves in a six-layer earth model. The results show that fundamental mode is more sensitive to the shear velocities of shallow layers (< 7 m) and concentrated in a very narrow band (around...
Measuring the electrical properties of soil using a calibrated ground-coupled GPR system
C.P. Oden, G.R. Olhoeft, D.L. Wright, M.H. Powers
2008, Conference Paper, Vadose Zone Journal
Traditional methods for estimating vadose zone soil properties using ground penetrating radar (GPR) include measuring travel time, fitting diffraction hyperbolae, and other methods exploiting geometry. Additional processing techniques for estimating soil properties are possible with properly calibrated GPR systems. Such calibration using ground-coupled antennas must account for the effects of...
Assessing bat detectability and occupancy with multiple automated echolocation detectors
P. M. Gorresen, A.C. Miles, C.M. Todd, F.J. Bonaccorso, T.J. Weller
2008, Journal of Mammalogy (89) 11-17
Occupancy analysis and its ability to account for differential detection probabilities is important for studies in which detecting echolocation calls is used as a measure of bat occurrence and activity. We examined the feasibility of remotely acquiring bat encounter histories to estimate detection probability and occupancy. We used echolocation detectors...
Sequestering ADM ethanol plant carbon dioxide
R.J. Finley, D. Riddle
2008, Industrial Bioprocessing (30) 4
Archer Daniels Midland Co. (ADM) and the Illinois State Geological Survey (ISGS) are collaborating on a project in confirming that a rock formation can store carbon dioxide from the plant in its pores. The project aimed to sequester the gas underground permanently to minimize release of the greenhouse gas into...
Relations between nutritional condition and survival of North American elk Cervus elaphus
Louis C. Bender, J.G. Cook, R.C. Cook, P.B. Hall
2008, Wildlife Biology (14) 70-80
We related annual and seasonal survival of four populations of elk Cervus elaphus in the Pacific Northwest, USA, to measures and indices of individual nutritional condition. Among populations, for all mortality (human and non-human causes) sources inclusive, annual survival of adult females was correlated with a rump body condition score...
Winter survival of Eurasian woodcock Scolopax rusticola in central Italy
A. Aradis, M.W. Miller, G. Landucci, P. Ruda, S. Taddei, F. Spina
2008, Wildlife Biology (14) 36-43
The Eurasian woodcock Scolopax rusticola is a popular game bird in much of Europe. However, little is known about its population dynamics. We estimated winter survival of woodcock in a protected area with no hunting in central Italy. We radio-tagged 68 woodcocks with battery-powered radio-transmitters during 2001-2005. Woodcocks were captured...
Sediment storage and severity of contamination in a shallow reservoir affected by historical lead and zinc mining
K. E. Juracek
2008, Environmental Geology (54) 1447-1463
A combination of sediment-thickness measurement and bottom-sediment coring was used to investigate sediment storage and severity of contamination in Empire Lake (Kansas), a shallow reservoir affected by historical Pb and Zn mining. Cd, Pb, and Zn concentrations in the contaminated bottom sediment typically exceeded baseline concentrations by at least an...
Isotope geochemistry of mercury in source rocks, mineral deposits and spring deposits of the California Coast Ranges, USA
C.N. Smith, S.E. Kesler, J.D. Blum, J. J. Rytuba
2008, Earth and Planetary Science Letters (269) 398-406
We present here the first study of the isotopic composition of mercury in rocks, ore deposits, and active spring deposits from the California Coast Ranges, a part of Earth's crust with unusually extensive evidence of mercury mobility and enrichment. The Franciscan Complex and Great Valley Sequence, which form the bedrock...
Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsills siliquoidea)
N. Wang, R.J. Erickson, C.G. Ingersoll, C.D. Ivey, E.L. Brunson, T. Augspurger, M.C. Barnhart
2008, Environmental Toxicology and Chemistry (27) 1141-1146
The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at...
Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA
J. A. Izbicki, J.W. Ball, T.D. Bullen, S. J. Sutley
2008, Applied Geochemistry (23) 1325-1352
Chromium(VI) concentrations in excess of the California Maximum Contaminant Level (MCL) of 50 μg/L occur naturally in alkaline, oxic ground-water in alluvial aquifers in the western Mojave Desert, southern California. The highest concentrations were measured in aquifers eroded from mafic rock, but Cr(VI)...
Occurrence and fate of pesticides in four contrasting agricultural settings in the United States
G. V. Steele, H.M. Johnson, Mark W. Sandstrom, P. D. Capel, J.E. Barbash
2008, Journal of Environmental Quality (37) 1116-1132
Occurrence and fate of 45 pesticides and 40 pesticide degradates were investigated in four contrasting agricultural settings—in Maryland, Nebraska, California, and Washington. Primary crops included corn at all sites, soybeans in Maryland, orchards in California and Washington, and vineyards in Washington. Pesticides and pesticide degradates detected in water samples from...
Greenland ice sheet surface temperature, melt and mass loss: 2000-06
D.K. Hall, R.S. Williams Jr., S.B. Luthcke, N.E. DiGirolamo
2008, Journal of Glaciology (54) 81-93
A daily time series of 'clear-sky' surface temperature has been compiled of the Greenland ice sheet (GIS) using 1 km resolution moderate-resolution imaging spectroradiometer (MODIS) land-surface temperature (LST) maps from 2000 to 2006. We also used mass-concentration data from the Gravity Recovery and Climate Experiment (GRACE) to study mass change...
Longitudinal gradients along a reservoir cascade
L.E. Miranda, M.D. Habrat, S. Miyazono
2008, Transactions of the American Fisheries Society (137) 1851-1865
Reservoirs have traditionally been regarded as spatially independent entities rather than as longitudinal segments of a river system that are connected upstream and downstream to the river and other reservoirs. This view has frustrated advancement in reservoir science by impeding adequate organization of available information and by hindering interchanges with...
Nutrient availability affects pigment production but not growth in lichens of biological soil crusts
M. A. Bowker, G.W. Koch, J. Belnap, N.C. Johnson
2008, Soil Biology and Biochemistry (40) 2819-2826
Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn...
Remote sensing and GIS approach for water-well site selection, southwest Iran
K. Rangzan, A. Charchi, E. Abshirini, J. Dinger
2008, Environmental & Engineering Geoscience (14) 315-326
The Pabdeh-Lali Anticline of northern Khuzestan province is located in southwestern Iran and occupies 790 km2. This structure is situated in the Zagros folded belt. As a result of well-developed karst systems in the anticlinal axis, the water supply potential is high and is drained by many peripheral springs. However,...
