Distribution, occupancy, and habitat correlates of American martens (Martes americana) in Rocky Mountain National Park, Colorado
R.A. Baldwin, Louis C. Bender
2008, Journal of Mammalogy (89) 419-427
A clear understanding of habitat associations of martens (Martes americana) is necessary to effectively manage and monitor populations. However, this information was lacking for martens in most of their southern range, particularly during the summer season. We studied the distribution and habitat correlates of martens from 2004 to 2006 in...
Distinguishing black carbon from biogenic humic substances in soil clay fractions
D.A. Laird, M.A. Chappell, D.A. Martens, R.L. Wershaw, M. Thompson
2008, Geoderma (143) 115-122
Most models of soil humic substances include a substantial component of aromatic C either as the backbone of humic heteropolymers or as a significant component of supramolecular aggregates of degraded biopolymers. We physically separated coarse (0.2–2.0 μm e.s.d.), medium (0.02–0.2 μm e.s.d.), and fine (> 0.02 μm e.s.d.)...
Seasonal temperature responses to land-use change in the western United States
L.M. Kueppers, M.A. Snyder, L.C. Sloan, D. Cayan, J. Jin, H. Kanamaru, M. Kanamitsu, N.L. Miller, Mary Tyree, H. Du, B. Weare
2008, Global and Planetary Change (60) 250-264
In the western United States, more than 79 000??km2 has been converted to irrigated agriculture and urban areas. These changes have the potential to alter surface temperature by modifying the energy budget at the land-atmosphere interface. This study reports the seasonally varying temperature responses of four regional climate models (RCMs)...
Factors controlling nitrogen release from two forested catchments with contrasting hydrochemical responses
S.F. Christopher, M.J. Mitchell, Michael McHale, E.W. Boyer, Douglas A. Burns, C. Kendall
2008, Hydrological Processes (22) 46-62
Quantifying biogeochemical cycles of nitrogen (N) and the associated fluxes to surface waters remains challenging, given the need to deal with spatial and temporal variability and to characterize complex and heterogeneous landscapes. We focused our study on catchments S14 and S15 located in the Adirondack Mountains...
Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus)
V.K. Stegall, Sean D. Farley, Lorrie D. Rea, K.W. Pitcher, R. O. Rye, C.L. Kester, C. A. Stricker, C.R. Bern
2008, Canadian Journal of Zoology (86) 17-23
Knowledge of diet-tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared ??13C and ??15N of paired serum and vibrissal roots with those of ingested milk (n = 52) from...
Changes in consumption by alewives and lake whitefish after dreissenid mussel invasions in Lakes Michigan and Huron
S.A. Pothoven, C.P. Madenjian
2008, North American Journal of Fisheries Management (28) 308-320
Growth of alewives Alosa pseudoharengus and lake whitefish Coregonus clupeaformis has declined since the arrival and spread of dreissenid mussels in Lakes Michigan and Huron. Alewives are the main forage for the salmonids in Lake Michigan, and lake whitefish are the most important commercial species in both lakes. Bioenergetics modeling...
Small mammals as indicators of short-term and long-term disturbance in mixed prairie
S.A. Leis, David M. Leslie Jr., David M. Engle, J.S. Fehmi
2008, Environmental Monitoring and Assessment (137) 75-84
Disturbance by military maneuvers over short and long time scales may have differential effects on grassland communities. We assessed small mammals as indicators of disturbance by military maneuvers in a mixed prairie in southern Oklahoma USA. We examined sites on two soil series, Foard and Lawton, across a gradient of...
Invertebrate community response to a shifting mosaic of habitat
David M. Engle, S.D. Fuhlendorf, A. Roper, David M. Leslie Jr.
2008, Rangeland Ecology and Management (61) 55-62
Grazing management has focused largely on promoting vegetation homogeneity through uniform distribution of grazing to minimize area in a pasture that is either heavily disturbed or undisturbed. An alternative management model that couples grazing and fire (i.e., patch burning) to promote heterogeneity argues that grazing and fire interact through a...
An exact solution for ideal dam-break floods on steep slopes
C. Ancey, Richard M. Iverson, M. Rentschler, Roger P. Denlinger
2008, Water Resources Research (44)
The shallow‐water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce...
Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China
Y. Zhao, Jiahua Zhang, C. L. Chou, Y. Li, Z. Wang, Y. Ge, C. Zheng
2008, International Journal of Coal Geology (73) 52-62
The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr,...
Effects of grade control structures on the macroinvertebrate assemblage of an agriculturally impacted stream
M.E. Litvan, T.W. Stewart, C.L. Pierce, C.J. Larson
2008, River Research and Applications (24) 218-233
Nearly 400 rock rip-rap grade control structures (hereafter GCS) were recently placed in streams of western Iowa, USA to reduce streambank erosion and protect bridge infrastructure and farmland. In this region, streams are characterized by channelized reaches, highly incised banks and silt and sand substrates that normally support low macroinvertebrate...
Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska
C.J. Schiff, D. S. Kaufman, K.L. Wallace, A. Werner, T.-L. Ku, T.A. Brown
2008, Quaternary Geochronology (3) 56-67
A 5.6-m-long lake sediment core from Bear Lake, Alaska, located 22 km southeast of Redoubt Volcano, contains 67 tephra layers deposited over the last 8750 cal yr, comprising 15% of the total thickness of recovered sediment. Using 12 AMS 14C ages, along with the 137Cs and 210Pb activities of recent...
The role of shear and tensile failure in dynamically triggered landslides
T.L. Gipprich, R.K. Snieder, R.W. Jibson, W. Kimman
2008, Geophysical Journal International (172) 770-778
Dynamic stresses generated by earthquakes can trigger landslides. Current methods of landslide analysis such as pseudo-static analysis and Newmark's method focus on the effects of earthquake accelerations on the landslide mass to characterize dynamic landslide behaviour. One limitation of these methods is their use Mohr-Coulomb failure criteria, which only accounts...
Thermal and energetic constraints on ectotherm abundance: A global test using lizards
L.B. Buckley, G.H. Rodda, W. Jetz
2008, Ecology (89) 48-55
Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population...
Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain
R.L. Bentzen, A.N. Powell, R.S. Suydam
2008, Journal of Wildlife Management (72) 1781-1789
King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2...
Mesozoic non-marine petroleum source rocks determined by palynomorphs in the Tarim Basin, Xinjiang, northwestern China
D.-X. Jiang, Y.-D. Wang, E. I. Robbins, J. Wei, N. Tian
2008, Geological Magazine (145) 868-885
The Tarim Basin in Northwest China hosts petroleum reservoirs of Cambrian, Ordovician, Carboniferous, Triassic, Jurassic, Cretaceous and Tertiary ages. The sedimentary thickness in the basin reaches about 15 km and with an area of 560000 km2, the basin is expected to contain giant oil and gas fields. It is therefore...
Modeling variability and trends in pesticide concentrations in streams
A. V. Vecchia, Jeffrey D. Martin, R. J. Gilliom
2008, Journal of the American Water Resources Association (44) 1308-1324
A parametric regression model was developed for assessing the variability and long-term trends in pesticide concentrations in streams. The dependent variable is the logarithm of pesticide concentration and the explanatory variables are a seasonal wave, which represents the seasonal variability of concentration in response to seasonal application rates; a streamflow...
SAGE celebrates 25 years of learning geophysics by doing geophysics
G.R. Jiracek, W.S. Baldridge, A.J. Sussman, S. Biehler, L.W. Braile, J.F. Ferguson, B.E. Gilpin, D.K. McPhee, L. Pellerin
2008, Leading Edge (Tulsa, OK) (27) 1340-1344
The increasing world demand and record-high costs for energy and mineral resources, along with the attendant environmental and climate concerns, have escalated the need for trained geophysicists to unprecedented levels. This is not only a national need; it's a critical global need. As Earth scientists and educators we must seriously...
Clarification and changes in Permian stratigraphic nomenclature in Kansas
R.S. Sawin, E. K. Franseen, R.R. West, Greg A. Ludvigson, W.L. Watney
2008, Current Research in Earth Sciences (254) 1-3
This paper outlines Permian nomenclature changes to Zeller (1968) that have been adopted by the Kansas Geological Survey. The Permian System/ Period, Cisuralian Series/Epoch, and Asselian Stage/Age are established at the base of the Bennett Shale Member of the Red Eagle Limestone. Series/epoch names Wolfcampian, Leonardian, and Guadalupian are retained...
Are hotspots of evolutionary potential adequately protected in southern California?
Amy G. Vandergast, A.J. Bohonak, S.A. Hathaway, J. Boys, Robert N. Fisher
2008, Biological Conservation (141) 1648-1664
Reserves are often designed to protect rare habitats, or "typical" exemplars of ecoregions and geomorphic provinces. This approach focuses on current patterns of organismal and ecosystem-level biodiversity, but typically ignores the evolutionary processes that control the gain and loss of biodiversity at these and other levels (e.g., genetic, ecological). In...
Sunlight, season, snowmelt, storm, and source affect E. coli populations in an artificially ponded stream
R.L. Whitman, K. Przybyla-Kelly, D.A. Shively, M.B. Nevers, M.N. Byappanahalli
2008, Science of the Total Environment (390) 448-455
Reducing fecal indicator bacteria, such as Escherichia coli (E. coli), in streams is important for many downstream areas. E. coli concentrations within streams may be reduced by intervening ponds or wetlands through a number of physical and biological means. A section of Dunes Creek, a small coastal stream of southern...
A comparative analysis of simulated and observed landslide locations triggered by Hurricane Camille in Nelson County, Virginia
M.M. Morrissey, G. F. Wieczorek, B. A. Morgan
2008, Hydrological Processes (22) 524-531
In 1969, Nelson County, Virginia received up to 71 cm of rain within 12 h starting at 7 p.m. on August 19. The total rainfall from the storm exceeded the 1000-year return period in the region. Several thousands of landslides were induced by rainfall associated with Hurricane Camille causing fatalities...
HiRISE observations of fractured mounds: Possible Martian pingos
Colin M. Dundas, Michael T. Mellon, Alfred S. McEwen, Alexandra Lefort, Laszlo P. Keszthelyi, Nicolas Thomas
2008, Geophysical Research Letters (35)
Early images from the High Resolution Imaging Science Experiment (HiRISE) camera have revealed small fractured mounds in the Martian mid‐latitudes. HiRISE resolves fractures on the mound surfaces, indicating uplift, and shows that the mound surface material resembles that of the surrounding landscape. Analysis of Mars Orbiter Camera (MOC) images shows...
A biodynamic understanding of dietborne metal uptake by a freshwater invertebrate
M.-N. Croteau, S. N. Luoma
2008, Environmental Science & Technology (42) 1801-1806
Aquatic organisms accumulate metals from dissolved and particulate phases. Dietborne metal uptake likely prevails in nature, but the physiological processes governing metal bioaccumulation from diet are not fully understood. We characterize dietborne copper, cadmium, and nickel uptake by a freshwater gastropod (Lymnaea stagnalis) both in terms of biodynamics and membrane...
Revisiting the 1872 Owens Valley, California, Earthquake
S. E. Hough, K. Hutton
2008, Conference Paper, Bulletin of the Seismological Society of America
The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of...
