Assessment of marine-derived nutrients in the Copper River Delta, Alaska, using natural abundance of the stable isotopes of nitrogen, sulfur, and carbon
Thomas C. Kline, Carol Ann Woody, Mary Anne Bishop, Sean P. Powers, E. Eric Knudsen
2007, American Fisheries Society Symposium (54) 51-60
We performed nitrogen, sulfur, and carbon stable isotope analysis (SIA) on maturing and juvenile anadromous sockeye and coho salmon, and periphyton in two Copper River delta watersheds of Alaska to trace salmonderived nutrients during 2003–2004. Maturing salmon were isotopically enriched relative to alternate freshwater N, S, and C sources as...
Efficiently estimating salmon escapement uncertainty using systematically sampled data
Joel H. Reynolds, Carol Ann Woody, Nancy E. Gove, Lowell F. Fair
2007, American Fisheries Society Symposium (54) 121-129
Fish escapement is generally monitored using nonreplicated systematic sampling designs (e.g., via visual counts from towers or hydroacoustic counts). These sampling designs support a variety of methods for estimating the variance of the total escapement. Unfortunately, all the methods give biased results, with the magnitude of the bias being determined...
Dietary and spatial overlap between sympatric ursids relative to salmon use
Jennifer K. Fortin, Sean D. Farley, Karyn D. Rode, Charles T. Robbins
2007, Ursus (18) 19-29
We hypothesized that there would be minimal dietary overlap between sympatric brown bears (Ursus arctos) and American black bears (U. americanus) relative to salmon (Oncorhynchus spp.) utilization when alternative foods (e.g., fruits) are abundant. To maximize the chance that we would reject this hypothesis, we examined the diets of brown and black...
Fire risk in San Diego County, California: A weighted Bayesian model approach
Crystal A. Kolden, Timothy J. Weigel
2007, California Geographer (47) 42-60
Fire risk models are widely utilized to mitigate wildfire hazards, but models are often based on expert opinions of less understood fire-ignition and spread processes. In this study, we used an empirically derived weights-of-evidence model to assess what factors produce fire ignitions east of San Diego, California. We created and...
Birds of the Rio Grande and other riparian habitats of Western Webb County, Texas
Marc C. Woodin, Mary Kay Skoruppa, Gene W. Blacklock, Graham C. Hickman
2007, Bulletin of the Texas Ornithological Society (40) 67-80
We conducted 164 diurnal morning point counts in 1997 and 89 nocturnal point counts in 1998 along the Rio Grande and at other riparian habitats on remote ranchland in northwestern Webb County. We subsequently conducted 94 diurnal morning and 37 nocturnal point counts in 1999 on public lands along the...
New technologies at the Desert Research Institute make a difference in wildland fire management
Timothy J. Brown, Crystal A. Kolden
2007, Wildland Firefighter (11) 28-32
No abstract available....
Signatures of mountain building: Detrital zircon U/Pb ages from northeast Tibet
Richard O. Lease, Douglas W. Burbank, George E. Gehrels, Zhicai Wang, Daoyang Yuan
2007, Geology (35) 239-242
Although detrital zircon has proven to be a powerful tool for determining provenance, past work has focused primarily on delimiting regional source terranes. Here we explore the limits of spatial resolution and stratigraphic sensitivity of detrital zircon in ascertaining provenance, and we demonstrate its ability to detect source changes for...
Potential ecotoxicological significance of elevated concentrations of strontium in eggshells of passerine birds
Miguel A. Mora, Robert J. Taylor, Bryan L. Brattin
2007, Condor (109) 199-205
We investigated the occurrence and potential ecotoxicological significance of elevated concentrations of strontium (Sr) in eggshells of nine passerine birds from four regions in Arizona. Concentrations of Sr in eggshells ranged from 70 to 1360 µg g−1 dry weight (overall mean = 684 ± 345 SD µg g−1 dw) for the four...
Crustal controls on magmatic-hydrothermal systems: A geophysical comparison of White River, Washington, with Goldfield, Nevada
R.J. Blakely, D. A. John, S. E. Box, B. R. Berger, R.J. Fleck, R. P. Ashley, G.R. Newport, G.R. Heinemeyer
2007, Geosphere (3) 91-107
The White River altered area, Washington, and the Goldfield mining district, Nevada, are nearly contemporaneous Tertiary (ca. 20 Ma) calc-alkaline igneous centers with large exposures of shallow (<1 km depth) magmatic-hydrothermal, acid-sulfate alteration. Goldfield is the largest known high-sulfidation gold deposit in North...
Risk-targeted versus current seismic design maps for the conterminous United States
Nicolas Luco, Bruce R. Ellingwood, Ronald O. Hamburger, John D. Hooper, Jeffrey K. Kimball, Charles A. Kircher
2007, Conference Paper, SEAOC 2007 Convention Proceedings
The probabilistic portions of the seismic design maps in the NEHRP Provisions (FEMA, 2003/2000/1997), and in the International Building Code (ICC, 2006/2003/2000) and ASCE Standard 7-05 (ASCE, 2005a), provide ground motion values from the USGS that have a 2% probability of being exceeded in 50 years. Under the assumption that...
Determinants of elephant distribution at Nazinga Game Ranch, Burkina Faso
Jonathan A. Jenks, Robert W. Klaver, Zeno W. Wicks III
2007, Pachyderm (42) 70-80
We used seasonal ground total counts and remote sensing and GIS technology to relate elephant (Loxodonta africana africana) distribution at Nazinga Game Ranch to environmental and anthropogenic factors. Variables used in analyses were normalized difference vegetation index, elevation, stream density, density of poaching and human illegal activities, distance to dams,...
Three distinct clades of cultured heterocystous cyanobacteria constitute the dominant N2-fixing members of biological soil crusts of the Colorado Plateau, USA
C.M. Yeager, J. L. Kornosky, R.E. Morgan, E.C. Cain, F. Garcia-Pichel, D.C. Housman, J. Belnap, C.R. Kuske
2007, FEMS Microbiology Ecology (60) 85-97
The identity of the numerically dominant N2-fixing bacteria in biological soil crusts of the Colorado Plateau region and two outlying areas was determined using multiple approaches, to link the environmental diversity of nifH gene sequences to cultured bacterial isolates from the regions. Of the nifH sequence-types detected in soil crusts...
The Northern end of the Dead Sea Basin: Geometry from reflection seismic evidence
A. S. Al-Zoubi, T. Heinrichs, I. Qabbani, Uri S. ten Brink
2007, Tectonophysics (434) 55-69
Recently released reflection seismic lines from the Eastern side of the Jordan River north of the Dead Sea were interpreted by using borehole data and incorporated with the previously published seismic lines of the eastern side of the Jordan River. For the first time, the lines from the eastern side...
Nitrate dynamics within the Pajaro River, a nutrient-rich, losing stream
C.R. Ruehl, A.T. Fisher, Huertos M. Los, Scott D. Wankel, C.G. Wheat, Carol Kendall, C.E. Hatch, C. Shennan
2007, Journal of the North American Benthological Society (26) 191-206
The major ion chemistry of water from an 11.42-km reach of the Pajaro River, a losing stream in central coastal California, shows a consistent pattern of higher concentrations during the 2nd (dry) half of the water year. Most solutes are conserved during flow along the reach, but [NO3−] decreases by...
Seismic velocity structure and seismotectonics of the eastern San Francisco Bay region, California
J.L. Hardebeck, A.J. Michael, T.M. Brocher
2007, Bulletin of the Seismological Society of America (97) 826-842
The Hayward Fault System is considered the most likely fault system in the San Francisco Bay Area, California, to produce a major earthquake in the next 30 years. To better understand this fault system, we use microseismicity to study its structure and kinematics. We present a new 3D seismic-velocity model...
Temporal and spatial variability in stable isotope compositions of a freshwater mussel: Implications for biomonitoring and ecological studies
L. Gustafson, W. Showers, T. Kwak, J. Levine, M. Stoskopf
2007, Oecologia (152) 140-150
Stable isotopes can be used to elucidate ecological relationships in community and trophic studies. Findings are calibrated against baselines, e.g. from a producer or primary consumer, assumed to act as a reference to the isotopic context created by spatio-temporal attributes such as geography, climate, nutrient, and energy sources. The ability...
Fix success and accuracy of GPS radio collars in old-growth temperate coniferous forests
Kimberly A. Sager-Fradkin, Kurt J. Jenkins, Robert L. Hoffman, P. Happe, J. Beecham, R.G. Wright
2007, Journal of Wildlife Management (71) 1298-1308
Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared...
Identifying sources of nitrogen to Hanalei Bay, Kauai, utilizing the nitrogen isotope signature of macroalgae
E. Derse, K.L. Knee, Scott D. Wankel, Carol Kendall, Carl J. Berg Jr., A. Paytan
2007, Environmental Science & Technology (41) 5217-5223
Sewage effluent, storm runoff, discharge from polluted rivers, and inputs of groundwater have all been suggested as potential sources of land derived nutrients into Hanalei Bay, Kauai. We determined the nitrogen isotopic signatures (δ15N) of different nitrate sources to Hanalei Bay...
Population growth of Yellowstone grizzly bears: Uncertainty and future monitoring
R.B. Harris, Gary C. White, C.C. Schwartz, M.A. Haroldson
2007, Ursus (18) 168-178
Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem of the US Rocky Mountains have recently increased in numbers, but remain vulnerable due to isolation from other populations and predicted reductions in favored food resources. Harris et al. (2006) projected how this population might fare in the future under alternative...
Genetic investigation of natural hybridization between rainbow and coastal cutthroat trout in the copper River Delta, Alaska
I. Williams, G.H. Reeves, S.L. Graziano, J.L. Nielsen
2007, Transactions of the American Fisheries Society (136) 926-942
Molecular genetic methods were used to quantify natural hybridization between rainbow trout Oncorhynchus mykiss or steelhead (anadromous rainbow trout) and coastal cutthroat trout O. clarkii clarkii collected in the Copper River delta, Southeast Alaska. Eleven locations were sampled to determine the extent of hybridization and the distribution of hybrids. Four diagnostic nuclear microsatellite loci...
Welcome to the National Wetlands Research Center Library: Not Just Another Library-A Special Library
Linda Broussard
2007, Fact Sheet 2007-3028
Libraries are grouped into four major types: public, school, academic, and special. The U.S. Geological Survey's (USGS) National Wetlands Research Center (NWRC) library is classified as a special library because it is sponsored by the Federal government, and the collections focus on a specific subject. The NWRC library is the...
Two new genera of Lumbriculidae (Annelida, Clitellata) from North Carolina, USA
S.V. Fend, D. R. Lenat
2007, Zootaxa 1-22
Recent benthic macroinvertebrate collections from North Carolina contained many undescribed oligochaete taxa, mostly belonging to the family Lumbriculidae. Three of the new species had arrangements of spermathecae and atria previously unreported for the family, and were assigned to new two genera. Pilaridrilus is distinguished by the location of spermathecal pores...
Vegetation classification, mapping, and monitoring at Voyageurs National Park, Minnesota: An application of the U.S. National Vegetation Classification
D. Faber-Langendoen, N. Aaseng, K. Hop, M. Lew-Smith, J. Drake
2007, Applied Vegetation Science (10) 361-374
Question: How can the U.S. National Vegetation Classification (USNVC) serve as an effective tool for classifying and mapping vegetation, and inform assessments and monitoring? Location: Voyageurs National Park, northern Minnesota, U.S.A and environs. The park contains 54 243 ha of terrestrial habitat in the sub-boreal region of North America. Methods:...
Upper-crustal structure beneath the strait of Georgia, Southwest British Columbia
R.K. Dash, G.D. Spence, M. Riedel, R.D. Hyndman, T.M. Brocher
2007, Geophysical Journal International (170) 800-812
We present a new three-dimensional (3-D) P-wave velocity model for the upper-crustal structure beneath the Strait of Georgia, southwestern British Columbia based on non-linear tomographic inversion of wide-angle seismic refraction data. Our study, part of the Georgia Basin Geohazards Initiative (GBGI) is primarily aimed at mapping the depth of the...
The impact of agricultural soil erosion on the global carbon cycle
Kristof Van Oost, T.A. Quine, G. Govers, S. De Gryze, J. Six, J.W. Harden, J.C. Ritchie, G.W. McCarty, G. Heckrath, C. Kosmas, J.V. Giraldez, J.R. Marques Da Silva, R. Merckx
2007, Science (318) 626-629
Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year–1 to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink...
