Estimating watershed level nonagricultural pesticide use from golf courses using geospatial methods
G.A. Fox, G.P. Thelin, G.J. Sabbagh, J.W. Fuchs, I.D. Kelly
2008, Journal of the American Water Resources Association (44) 1363-1372
Limited information exists on pesticide use for nonagricultural purposes, making it difficult to estimate pesticide loadings from nonagricultural sources to surface water and to conduct environmental risk assessments. A method was developed to estimate the amount of pesticide use on recreational turf grasses, specifically golf course turf grasses, for watersheds...
Regional population viability of grassland songbirds: Effects of agricultural management
N.G. Perlut, A.M. Strong, T.M. Donovan, N. J. Buckley
2008, Biological Conservation (141) 3139-3151
Although population declines of grassland songbirds in North America and Europe are well-documented, the effect of local processes on regional population persistence is unclear. To assess population viability of grassland songbirds at a regional scale (???150,000 ha), we quantified Savannah Sparrow Passerculus sandwichensis and Bobolink Dolichonyx oryzivorus annual productivity, adult...
Terrace aggradation during the 1978 flood on Powder River, Montana, USA
J. A. Moody, R.H. Meade
2008, Geomorphology (99) 387-403
Flood processes no longer actively increase the planform area of terraces. Instead, lateral erosion decreases the area. However, infrequent extreme floods continue episodic aggradation of terraces surfaces. We quantify this type of evolution of terraces by an extreme flood in May 1978 on Powder River in southeastern Montana. Within an...
Thermometers and thermobarometers in granitic systems
J. L. Anderson, A. P. Barth, J. L. Wooden, F. Mazdab
Putirka K.D.Tepley III F.J., editor(s)
2008, Reviews in Mineralogy and Geochemistry (69) 121-142
The ability to determine the thermal and barometric history during crystallization and emplacement of granitic plutons has been enhanced by several new calibrations applicable to granitic mineral assemblages. Other existing calibrations for granitic plutons have continued to be popular and fairly robust. Recent advances include the trace element thermometers Ti-in-quartz,...
Sensitivity of the Colorado Plateau to change: Climate, ecosystems, and society
S. Schwinning, J. Belnap, David R. Bowling, J.R. Ehleringer
2008, Ecology and Society (13)
The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multidecadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado...
Sympatric Masticophis flagellum and Coluber constrictor select vertebrate prey at different levels of taxonomy
B.J. Halstead, H.R. Mushinsky, E.D. McCoy
2008, Copeia 897-908
Masticophis flagellum (Coachwhip) and Coluber constrictor (Eastern Racer) are widespread North American snakes with similar foraging modes and habits. Little is known about the selection of prey by either species, and despite their apparently similar foraging habits, comparative studies of the foraging ecology of sympatric M. flagellum and C. constrictor...
Late Pleistocene and Early Holocene lake-level fluctuations in the Lahontan Basin, Nevada: Implications for the distribution of archaeological sites
K.D. Adams, Thomas Goebel, K. Graf, G.M. Smith, A.J. Camp, R.W. Briggs, D. Rhode
2008, Geoarchaeology (23) 608-643
The Great Basin of the western U.S. contains a rich record of late Pleistocene and Holocene lake-level fluctuations as well as an extensive record of human occupation during the same time frame. We compare spatial-temporal relationships between these records in the Lahontan basin to consider whether lake-level fluctuations across the...
Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States
C.T. Green, L.J. Puckett, J.K. Böhlke, B.A. Bekins, S.P. Phillips, L. J. Kauffman, J. M. Denver, H.M. Johnson
2008, Journal of Environmental Quality (37) 994-1009
The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin...
Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming
B.A. Lipinski, J.I. Sams, B. D. Smith, W. Harbert
2008, Geophysics (73)
Production of methane from thick, extensive coal beds in the Powder River Basin of Wyoming has created water management issues. Since development began in 1997, more than 650 billion liters of water have been produced from approximately 22,000 wells. Infiltration impoundments are used widely to dispose of by-product water from...
The role of deposits in tsunami risk assessment
B. Jaffe
2008, Conference Paper, Solutions to Coastal Disasters Congress 2008: Tsunamis - Proceedings of the Solutions to Coastal Disasters Congress 2008: Tsunamis
An incomplete catalogue of tsunamis in the written record hinders tsunami risk assessment. Tsunami deposits, hard evidence of tsunami, can be used to extend the written record. The two primary factors in tsunami risk, tsunami frequency and magnitude, can be addressed through field and modeling studies of tsunami deposits. Recent...
Processes of coastal bluff erosion in weakly lithified sands, Pacifica, California, USA
B.D. Collins, N. Sitar
2008, Geomorphology (97) 483-501
Coastal bluff erosion and landsliding are currently the major geomorphic processes sculpting much of the marine terrace dominated coastline of northern California. In this study, we identify the spatial and temporal processes responsible for erosion and landsliding in an area of weakly lithified sand coastal bluffs located south of San...
Modeling unobserved sources of heterogeneity in animal abundance using a Dirichlet process prior
R.M. Dorazio, B. Mukherjee, L. Zhang, M. Ghosh, H.L. Jelks, F. Jordan
2008, Biometrics (64) 635-644
In surveys of natural populations of animals, a sampling protocol is often spatially replicated to collect a representative sample of the population. In these surveys, differences in abundance of animals among sample locations may induce spatial heterogeneity in the counts associated with a particular sampling protocol. For some species, the...
In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer
R.A. Gebrekristos, A.M. Shapiro, B.H. Usher
2008, Hydrogeology Journal (16) 629-639
An in situ method of estimating the effective diffusion coefficient for a chemical constituent that diffuses into the primary porosity of a rock is developed by abruptly changing the concentration of the dissolved constituent in a borehole in contact with the rock matrix and monitoring the time-varying concentration. The...
Geomorphic evidence for former lobate debris aprons at low latitudes on Mars: Indicators of the Martian paleoclimate
E. Hauber, S. Van Gasselt, M. G. Chapman, G. Neukum
2008, Journal of Geophysical Research E: Planets (113)
Circumferential depressions enclosing mesas and plateaus in the northern Kasei Valles and in the Tartarus Colles regions of Mars are interpreted as indicators of the former extent of lobate debris aprons, thought to be mixtures of ice and elastic particles. These former lobate debris aprons existed about 1 Ga ago...
Dietary biomagnification of organochlorine contaminants in Alaskan polar bears
T.W. Bentzen, Erich H. Follmann, Steven C. Amstrup, G.S. York, M. J. Wooller, D.C.G. Muir, T. M. O'Hara
2008, Canadian Journal of Zoology (86) 177-191
Concentrations of organochlorine contaminants in the adipose tissue of polar bears (Ursus maritimus Phipps, 1774) vary throughout the Arctic. The range in concentrations has not been explained fully by bear age, sex, condition, location, or reproductive status. Dietary pathways expose polar bears to a variety of contaminant profiles and concentrations....
Influences of calcium availability and tree species on Ca isotope fractionation in soil and vegetation
B.D. Page, T.D. Bullen, M.J. Mitchell
2008, Biogeochemistry (88) 1-13
The calcium (Ca) isotope system is potentially of great use for understanding biogeochemical processes at multiple scales in forest ecosystems, yet remains largely unexplored for this purpose. In order to further our understanding of Ca behavior in forests, we examined two nearly adjacent hardwood-dominated catchments with differing soil Ca concentrations,...
The annual migration cycle of emperor geese in western Alaska
Jerry W. Hupp, Joel A. Schmutz, Craig R. Ely
2008, Arctic (61) 23-34
Most emperor geese (Chen canagica) nest in a narrow coastal region of the Yukon-Kuskokwim Delta (YKD) in western Alaska, but their winter distribution extends more than 3000 km from Kodiak Island, Alaska, to the Commander Islands, Russia. We marked 53 adult female emperor geese with satellite transmitters on the YKD...
Tamarix as habitat for birds: Implications for riparian restoration in the Southwestern United States
M. K. Sogge, S.J. Sferra, E. H. Paxton
2008, Restoration Ecology (16) 146-154
Exotic vegetation has become a major habitat component in many ecosystems around the world, sometimes dramatically changing the vegetation community structure and composition. In the southwestern United States, riparian ecosystems are undergoing major changes in part due to the establishment and spread of the exotic Tamarix (saltcedar, tamarisk). There are...
Comparisons of shear-wave slowness in the Santa Clara Valley, California using blind interpretations of data from invasive and noninvasive methods
D.M. Boore, M.W. Asten
2008, Bulletin of the Seismological Society of America (98) 1983-2003
Many groups contributed to a blind interpretation exercise for the determination of shear-wave slowness beneath the Santa Clara Valley. The methods included invasive methods in deep boreholes as well as noninvasive methods using active and passive sources, at six sites within the valley (with most investigations being conducted at a...
Home range and movements of feral cats on Mauna Kea, Hawai'i
Dan M. Goltz, S.C. Hess, K.W. Brinck, P.C. Banko, R.M. Danner
2008, Pacific Conservation Biology (14) 177-184
Feral cats Felis catus in dry subalpine woodland of Mauna Kea, Hawai?i, live in low density and exhibit some of the largest reported home ranges in the literature. While 95% fixed kernel home range estimates for three females averaged 772 ha, four males averaged 1 418 ha, and one male...
(U-Th)/He dating of kimberlites-A case study from north-eastern Kansas
T.J. Blackburn, D.F. Stockli, R. W. Carlson, P. Berendsen
2008, Earth and Planetary Science Letters (275) 111-120
Dating kimberlite intrusive rocks by radiogenic isotope geochronology often is a difficult task, complicated by both the lack of dateable minerals within kimberlite as well as significant sample alteration that can degrade samples and alter parent-daughter ratios. This study presents a new geochronologic tool for timing the emplacement of kimberlites...
Northeast storms ranked by wind stress and wave-generated bottom stress observed in Massachusetts Bay, 1990-2006
B. Butman, C. R. Sherwood, P.S. Dalyander
2008, Continental Shelf Research (28) 1231-1245
Along the coast of the northeastern United States, strong winds blowing from the northeast are often associated with storms called northeasters, coastal storms that strongly influence weather. In addition to effects caused by wind stress, the sea floor is affected by bottom stress associated with these storms. Bottom stress caused...
Infinite slope stability under steady unsaturated seepage conditions
Ning Lu, Jonathan W. Godt
2008, Water Resources Research (44)
We present a generalized framework for the stability of infinite slopes under steady unsaturated seepage conditions. The analytical framework allows the water table to be located at any depth below the ground surface and variation of soil suction and moisture content above the water table under steady infiltration conditions. The...
Western juniper and ponderosa pine ecotonal climate-growth relationships across landscape gradients in southern Oregon
K.C. Knutson, D.A. Pyke
2008, Canadian Journal of Forest Research (38) 3021-3032
Forecasts of climate change for the Pacific northwestern United States predict warmer temperatures, increased winter precipitation, and drier summers. Prediction of forest growth responses to these climate fluctuations requires identification of climatic variables limiting tree growth, particularly at limits of free species distributions. We addressed this problem at the pine-woodland...
Fecal indicator bacteria and Salmonella in ponds managed as bird habitat, San Francisco Bay, California, USA
G.G. Shellenbarger, N.D. Athearn, John Y. Takekawa, A.B. Boehm
2008, Water Research (42) 2921-2930
Throughout the world, coastal resource managers are encouraging the restoration of previously modified coastal habitats back into wetlands and managed ponds for their ecosystem value. Because many coastal wetlands are adjacent to urban centers and waters used for human recreation, it is important to understand how wildlife can affect water...
