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Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles
A. Youngblood, J.B. Grace, J.D. Mciver
2009, Ecological Applications (19) 321-337
Many low‐elevation dry forests of the western United States contain more small trees and fewer large trees, more down woody debris, and less diverse and vigorous understory plant communities compared to conditions under historical fire regimes. These altered structural conditions may contribute to increased probability of unnaturally severe wildfires, susceptibility...
Constraints on deep moonquake focal mechanisms through analyses of tidal stress
R.C. Weber, B.G. Bills, C.L. Johnson
2009, Journal of Geophysical Research E: Planets (114)
[1] A relationship between deep moonquake occurrence and tidal forcing is suggested by the monthly periodicities observed in the occurrence times of events recorded by the Apollo Passive Seismic Experiment. In addition, the typically large S wave to P wave arrival amplitude ratios observed on deep moonquake seismograms are indicative...
Summary of current radiometric calibration coefficients for Landsat MSS, TM, ETM+, and EO-1 ALI sensors
G. Chander, B. L. Markham, D. L. Helder
2009, Remote Sensing of Environment (113) 893-903
This paper provides a summary of the current equations and rescaling factors for converting calibrated Digital Numbers (DNs) to absolute units of at-sensor spectral radiance, Top-Of-Atmosphere (TOA) reflectance, and at-sensor brightness temperature. It tabulates the necessary constants for the Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+),...
Relationship of stream ecological conditions to simulated hydraulic metrics across a gradient of basin urbanization
J. J. Steuer, J. D. Bales, E.M.P. Giddings
2009, Journal of the North American Benthological Society (28) 955-976
The relationships among urbanization, stream hydraulics, and aquatic biology were investigated across a gradient of urbanization in 30 small basins in eastern Wisconsin, USA. Simulation of hydraulic metrics with 1-dimensional unsteady flow models was an effective means for mechanistically coupling the effects of urbanization with stream ecological conditions (i.e., algae,...
Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska
D. Selby, K.D. Kelley, M.W. Hitzman, J. Zieg
2009, Economic Geology (104) 437-444
New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek...
Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth
G.E. Horton, B. H. Letcher, M.M. Bailey, M.T. Kinnison
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 471-483
The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated...
Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2000: A stratified random approach
J. Carter, J.H. Merino, S.L. Merino
2009, Gulf of Mexico Science (27) 1-8
Estimates of submerged aquatic vegetative (SAV) along the U.S. Gulf of Mexico (Gulf) generally focus on seagrasses. In 2000, we attempted a synoptic survey of SAV in the mesohaline (5–20 ppt) zone of estuarine and nearshore areas of the northeastern Gulf. Areas with SAV were identified from existing aerial 1992...
Genetic structure of lake whitefish (Coregonus clupeaformis) in Lake Michigan
J.A. VanDeHey, Brian L. Sloss, Paul J. Peeters, T.M. Sutton
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 382-393
Genetic relationships among lake whitefish (Coregonus clupeaformis) spawning aggregates in Lake Michigan were assessed and used to predict a stock or management unit (MU) model for the resource. We hypothesized that distinct spawning aggregates represented potential MUs and that differences at molecular markers underlie population differentiation. Genetic stock identification using...
Analysis of methods to estimate spring flows in a karst aquifer
N. Sepulveda
2009, Ground Water (47) 337-349
Hydraulically and statistically based methods were analyzed to identify the most reliable method to predict spring flows in a karst aquifer. Measured water levels at nearby observation wells, measured spring pool altitudes, and the distance between observation wells and the spring pool were the parameters used to match measured spring...
Ultra-deep oxidation and exotic copper formation at the late pliocene boyongan and bayugo porphyry copper-gold deposits, surigao, philippines: Geology, mineralogy, paleoaltimetry, and their implications for Geologic, physiographic, and tectonic controls
D.P. Braxton, D. R. Cooke, A.M. Ignacio, R. O. Rye, P.J. Waters
2009, Economic Geology (104) 333-349
The Boyongan and Bayugo porphyry copper-gold deposits are part of an emerging belt of intrusion-centered gold-rich deposits in the Surigao district of northeast Mindanao, Philippines. Exhumation and weathering of these Late Pliocene-age deposits has led to the development of the world's deepest known porphyry oxidation profile at Boyongan (600 m),...
Hydrogeologic structure underlying a recharge pond delineated with shear-wave seismic reflection and cone penetrometer data
S.S. Haines, Adam Pidlisecky, R. Knight
2009, Near Surface Geophysics (7) 329-339
With the goal of improving the understanding of the subsurface structure beneath the Harkins Slough recharge pond in Pajaro Valley, California, USA, we have undertaken a multimodal approach to develop a robust velocity model to yield an accurate seismic reflection section. Our shear-wave reflection section helps us identify and map...
Isotopic variability of mercury in ore, mine-waste calcine, and leachates of mine-waste calcine from areas mined for mercury
S.J. Stetson, J. E. Gray, R. B. Wanty, D.L. Macalady
2009, Environmental Science & Technology (43) 7331-7336
The isotopic composition of mercury (Hg) was determined in cinnabar ore, mine-waste calcine (retorted ore), and leachates obtained from water leaching experiments of calcine from two large Hg mining districts in the U.S. This study is the first to report significant mass-dependent Hg isotopic fractionation between cinnabar ore and resultant...
Water quality characterization in some birimian aquifers of the Birim Basin, Ghana
B.-Y. Bruce, S.M. Yidana, Y. Anku, T. Akabzaa, D. Asiedu
2009, KSCE Journal of Civil Engineering (13) 179-187
The objective of this study was to determine the main controls on the hydrochemistry of groundwater in the study area. Mass balance modeling was used simultaneously with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types have been revealed in this...
Response of the everglades ridge and slough landscape to climate variability and 20th-century water management
C.E. Bernhardt, Debra A. Willard
2009, Ecological Applications (19) 1723-1738
The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of...
Biogeochemistry at a wetland sediment-alluvial aquifer interface in a landfill leachate plume
M.M. Lorah, I.M. Cozzarelli, J.K. Böhlke
2009, Journal of Contaminant Hydrology (105) 99-117
The biogeochemistry at the interface between sediments in a seasonally ponded wetland (slough) and an alluvial aquifer contaminated with landfill leachate was investigated to evaluate factors that can effect natural attenuation of landfill leachate contaminants in areas of groundwater/surface-water interaction. The biogeochemistry at the wetland-alluvial aquifer interface differed greatly between...
Climatic implications of reconstructed early - Mid Pliocene equilibrium-line altitudes in the McMurdo Dry Valleys, Antarctica
A.G. Krusic, M.L. Prentice, J. M. Licciardi
2009, Annals of Glaciology (50) 31-36
Early-mid Pliocene moraines in the McMurdo Dry Valleys, Antarctica, are more extensive than the present alpine glaciers in this region, indicating substantial climatic differences between the early-mid Pliocene and the present. To quantify this difference in the glacier-climate regime, we estimated the equilibrium-line altitude (ELA) change since the early-mid Pliocene...
Implications for the dynamic health of a glacier from comparison of conventional and reference-surface balances
W.D. Harrison, L.H. Cox, R. Hock, R.S. March, E.C. Pettit
2009, Annals of Glaciology (50) 25-30
Conventional and reference-surface mass-balance data from Gulkana and Wolverine Glaciers, Alaska, USA, are used to address the questions of how rapidly these glaciers are adjusting (or 'responding') to climate, whether their responses are stable, and whether the glaciers are likely to survive in today's climate. Instability means that a glacier...
Symbiotic regulation of plant growth, development and reproduction
R. J. Rodriguez, D. Carl Freeman, E.D. McArthur, Y.-O. Kim, R. S. Redman
2009, Communitative and Integrative Biology (2) 141-143
The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times...
Using nitrate dual isotopic composition (δ15N and δ18O) as a tool for exploring sources and cycling of nitrate in an estuarine system: Elkhorn Slough, California
Scott D. Wankel, Carol Kendall, Adina Paytan
2009, Journal of Geophysical Research G: Biogeosciences (114)
Nitrate (NO3−) concentrations and dual isotopic composition (δ15N and δ18O) were measured during various seasons and tidal conditions in Elkhorn Slough to evaluate mixing of sources of NO3− within this California estuary. We found the isotopic composition of NO3− was influenced most heavily by mixing of two primary sources with unique isotopic signatures,...
Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup
Shannon S. Badzinski, Paul L. Flint, Kristen B. Gorman, Scott A. Petrie
2009, Environmental Pollution (157) 1886-1893
We collected female greater scaup (Aythya marila) on the Yukon–Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively,...
Sex, season, and time of day interact to affect body temperatures of the Giant Gartersnake
G.D. Wylie, Michael L. Casazza, B.J. Halstead, C.J. Gregory
2009, Journal of Thermal Biology (34) 183-189
1.We examined multiple hypotheses regarding differences in body temperatures of the Giant Gartersnake using temperature-sensitive radio telemetry and an information-theoretic analytical approach.2.Giant Gartersnakes selected body temperatures near 30 ??C, and males and females had similar body temperatures most of the year, except during the midsummer gestation period.3.Seasonal differences in the...
Did the Middlesboro, Kentucky, bolide impact event influence coal rank?
J.C. Hower, S.F. Greb, K.W. Kuehn, C.F. Eble
2009, International Journal of Coal Geology (79) 92-96
The Middlesboro Basin, southeastern Kentucky, occurs on the Cumberland Overthrust Sheet and includes a ca. 5.5-km diameter impact structure. The Lower and Middle Pennsylvanian coal-bearing strata are faulted, with some evidence for shock metamorphism. The event post-dated the latest-Pennsylvanian-early-Permian thrusting and was likely prior to late-Mesozoic entrenchment of drainages. The...
Sediment storage and transport in Pancho Rico Valley during and after the Pleistocene-Holocene transition, Coast Ranges of central California (Monterey County)
A.F. Garcia, S. A. Mahan
2009, Earth Surface Processes and Landforms (34) 1136-1150
Factors influencing sediment transport and storage within the 156??6 km2 drainage basin of Pancho Rico Creek (PRC), and sediment transport from the PRC drainage basin to its c. 11000 km2 mainstem drainage (Salinas River) are investigated. Numeric age estimates are determined by optically stimulated luminescence (OSL) dating on quartz grains...