Strontium isotope record of seasonal scale variations in sediment sources and accumulation in low-energy, subtidal areas of the lower Hudson River estuary
J.P. Smith, T.D. Bullen, D.J. Brabander, C.R. Olsen
2009, Chemical Geology (264) 375-384
Strontium isotope (87Sr/86Sr) profiles in sediment cores collected from two subtidal harbor slips in the lower Hudson River estuary in October 2001 exhibit regular patterns of variability with depth. Using additional evidence from sediment Ca/Sr ratios, 137Cs activity and Al, carbonate (CaCO3), and organic carbon (OCsed) concentration profiles, it can...
Landbird migration in the American West: Recent progress and future research directions
J.D. Carlisle, S. K. Skagen, B.E. Kus, Charles van Riper III, K.L. Paxton, J.F. Kelly
2009, The Condor (111) 211-225
Our knowledge of avian behaviors during the nonbreeding period still lags behind that of the breeding season, but the last decade has witnessed a proliferation in research that has yielded significant progress in understanding migration patterns of North American birds. And, although historically the great majority of migration research has...
Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance
W.C. Hockaday, C.A. Masiello, J. T. Randerson, R.J. Smernik, J.A. Baldock, O.A. Chadwick, J.W. Harden
2009, Journal of Geophysical Research G: Biogeosciences (114)
The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric...
Hydrologic and biogeochemical controls of river subsurface solutes under agriculturally enhanced ground water flow
R.A. Wildman Jr., Joseph L. Domagalski, J. G. Hering
2009, Journal of Environmental Quality (38) 1830-1840
The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural...
Cacades: A reliable dissemination protocol for data collection sensor network
Y. Peng, W. Song, R. Huang, M. Xu, B. Shirazi, R. LaHusen, G. Pei
2009, Conference Paper, IEEE Aerospace Conference Proceedings
In this paper, we propose a fast and reliable data dissemination protocol Cascades to disseminate data from the sink(base station) to all or a subset of nodes in a data collection sensor network. Cascades makes use of the parentmonitor-children analogy to ensure reliable dissemination. Each node monitors whether or not...
Evolutionary dynamics of Newcastle disease virus
P.J. Miller, L.M. Kim, Hon S. Ip, C.L. Afonso
2009, Virology (391) 64-72
A comprehensive dataset of NDV genome sequences was evaluated using bioinformatics to characterize the evolutionary forces affecting NDV genomes. Despite evidence of recombination in most genes, only one event in the fusion gene of genotype V viruses produced evolutionarily viable progenies. The codon-associated rate of change for the six NDV...
Estimating avian population size using Bowden's estimator
Duane R. Diefenbach
2009, The Auk (126) 211-217
Avian researchers often uniquely mark birds, and multiple estimators could be used to estimate population size using individually identified birds. However, most estimators of population size require that all sightings of marked birds be uniquely identified, and many assume homogeneous detection probabilities. Bowden's estimator can incorporate sightings of marked birds...
Estimating 3D variation in active-layer thickness beneath arctic streams using ground-penetrating radar
T.R. Brosten, J.H. Bradford, J. P. McNamara, M.N. Gooseff, J.P. Zarnetske, W.B. Bowden, M.E. Johnston
2009, Journal of Hydrology (373) 479-486
We acquired three-dimensional (3D) ground-penetrating radar (GPR) data across three stream sites on the North Slope, AK, in August 2005, to investigate the dependence of thaw depth on channel morphology. Data were migrated with mean velocities derived from multi-offset GPR profiles collected across a stream section within each of the...
Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982-2006
M.A. White, K. M. de Beurs, K. Didan, D.W. Inouye, A.D. Richardson, O.P. Jensen, J. O'Keefe, G. Zhang, R.R. Nemani, Leeuwen W.J.D. van W.J.D., Jesslyn F. Brown, A. de Wit, M. Schaepman, X. Lin, M. Dettinger, A.S. Bailey, J. Kimball, M.D. Schwartz, D. D. Baldocchi, J.T. Lee, W.K. Lauenroth
2009, Global Change Biology (15) 2335-2359
Shifts in the timing of spring phenology are a central feature of global change research. Long-term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns. Satellite remote sensing is instead...
New evidence for a magmatic influence on the origin of Valles Marineris, Mars
J. M. Dohm, J.-P. Williams, R. C. Anderson, J. Ruiz, P.C. McGuire, G. Komatsu, A.F. Davila, J.C. Ferris, D. Schulze-Makuch, V.R. Baker, W. V. Boynton, A.G. Fairen, T.M. Hare, H. Miyamoto, K. L. Tanaka, S.J. Wheelock
2009, Journal of Volcanology and Geothermal Research (185) 12-27
In this paper, we show that the complex geological evolution of Valles Marineris, Mars, has been highly influenced by the manifestation of magmatism (e.g., possible plume activity). This is based on a diversity of evidence, reported here, for the central part, Melas Chasma, and nearby regions, including uplift, loss of...
Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach
Michael N. Fienen, R. Hunt, D. Krabbenhoft, T. Clemo
2009, Water Resources Research (45)
Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate...
Weathering of the New Albany Shale, Kentucky, USA: I. Weathering zones defined by mineralogy and major-element composition
M.L.W. Tuttle, G. N. Breit
2009, Applied Geochemistry (24) 1549-1564
Comprehensive understanding of chemical and mineralogical changes induced by weathering is valuable information when considering the supply of nutrients and toxic elements from rocks. Here minerals that release and fix major elements during progressive weathering of a bed of Devonian New Albany Shale in eastern Kentucky are documented. Samples were...
Climate alters response of an endemic island plant to removal of invasive herbivores
Mceachern A. Kathryn, D.M. Thomson, K.A. Chess
2009, Ecological Applications (19) 1574-1584
Islands experience higher rates of species extinction than mainland ecosystems, with biological invasions among the leading causes; they also serve as important model systems for testing ideas in basic and applied ecology. Invasive removal programs on islands are conservation efforts that can also be viewed as powerful manipulative experiments, but...
Phylogeny and phylogenetic classification of the antbirds, ovenbirds, woodcreepers, and allies (Aves: Passeriformes: Infraorder Furnariides)
R.G. Moyle, R.T. Chesser, R.T. Brumfield, J.G. Tello, D.J. Marchese, J. Cracraft
2009, Cladistics (25) 386-405
The infraorder Furnariides is a diverse group of suboscine passerine birds comprising a substantial component of the Neotropical avifauna. The included species encompass a broad array of morphologies and behaviours, making them appealing for evolutionary studies, but the size of the group (ca. 600 species) has limited well-sampled higher-level phylogenetic...
Continental-scale patterns in soil geochemistry and mineralogy: results from two transects across the United States and Canada
L. G. Woodruff, W.F. Cannon, D. D. Eberl, D. B. Smith, J.E. Kilburn, J.D. Horton, R. G. Garrett, R.A. Klassen
2009, Applied Geochemistry (24) 1369-1381
In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada (GSC) initiated a pilot study that involved collection of more than 1500 soil samples from 221 sites along two continental transects across Canada and the United States. The pilot study was designed to test and refine protocols...
San Andreas fault geometry at Desert Hot Springs, California, and its effects on earthquake hazards and groundwater
R. D. Catchings, M. J. Rymer, M. R. Goldman, G. Gandhok
2009, Bulletin of the Seismological Society of America (99) 2190-2207
The Mission Creek and Banning faults are two of the principal strands of the San Andreas fault zone in the northern Coachella Valley of southern California. Structural characteristics of the faults affect both regional earthquake hazards and local groundwater resources. We use seismic, gravity, and geological data to characterize the...
Evidence for an Alleghanian (Early Carboniferous to Late Permian) tectonothermal event in the New Jersey Coastal Plain basement from 40Ar/39Ar biotite data, geochemistry and gravity modeling
T.J. Maguire, R.A. Volkert, C. C. Swisher III, R. E. Sheridan
2009, Journal of Geodynamics (48) 23-36
40Ar/39Ar dating of biotite from felsic orthogneiss recovered from the -3890-foot level of the Island Beach State Park (IBSP) well beneath the outer New Jersey Coastal Plain was accomplished using CO2 laser incremental-heating techniques. Over 75% of the Ar released from the incremental-heating experiment form a well-behaved plateau with a...
High-quality unsaturated zone hydraulic property data for hydrologic applications
Kimberlie Perkins, John R. Nimmo
2009, Water Resources Research (45)
In hydrologic studies, especially those using dynamic unsaturated zone moisture modeling, calculations based on property transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values has become increasingly common with the use of neural networks....
A method to assess longitudinal riverine connectivity in tropical streams dominated by migratory biota
K.E. Crook, C. M. Pringle, Mary C. Freeman
2009, Aquatic Conservation: Marine and Freshwater Ecosystems (19) 714-723
1. One way in which dams affect ecosystem function is by altering the distribution and abundance of aquatic species. 2. Previous studies indicate that migratory shrimps have significant effects on ecosystem processes in Puerto Rican streams, but are vulnerable to impediments to upstream or downstream passage, such as dams and...
Moderate rates of late Quaternary slip along the northwestern margin of the Basin and Range Province, Surprise Valley fault, northeastern California
Stephen F. Personius, Anthony J. Crone, Michael N. Machette, Shannon Mahan, David J. Lidke
2009, Journal of Geophysical Research B: Solid Earth (114)
The 86-km-long Surprise Valley normal fault forms part of the active northwestern margin of the Basin and Range province in northeastern California. We use trench mapping and radiocarbon, luminescence, and tephra dating to estimate displacements and timing of the past five surface-rupturing earthquakes on the central part of the fault...
Influence of trees in the landscape on parasitism rates of grassland passerine nests in Southeastern North Dakota
Pamela J. Pietz, Deborah A. Buhl, Jill A. Shaffer, Maiken Winter, Douglas H. Johnson
2009, Condor (111) 36-42
Woody vegetation has been linked to increased rates of Brown-headed Cowbird (Molothrus ater) parasitism for some grassland hosts. In northern North Dakota, however, studies reported that parasitism of grassland passerine nests was lower in landscapes with trees than in those without trees. We looked for evidence of this pattern elsewhere,...
LANDFIRE: A nationally consistent vegetation, wildland fire, and fuel assessment
Matthew G. Rollins
2009, International Journal of Wildland Fire (18) 235-249
LANDFIRE is a 5-year, multipartner project producing consistent and comprehensive maps and data describing vegetation, wildland fuel, fire regimes and ecological departure from historical conditions across the United States. It is a shared project between the wildland fire management and research and development programs of the US Department of Agriculture...
Examining the influence of heterogeneous porosity fields on conservative solute transport
B.X. Hu, M.M. Meerschaert, W. Barrash, D.W. Hyndman, C. He, X. Li, Laodong Guo
2009, Journal of Contaminant Hydrology (108) 77-88
It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of...
Tectonic evolution of the Salton Sea inferred from seismic reflection data
D.S. Brothers, N. W. Driscoll, G.M. Kent, A.J. Harding, J.M. Babcock, R. L. Baskin
2009, Nature Geoscience (2) 581-584
Oblique extension across strike-slip faults causes subsidence and leads to the formation of pull-apart basins such as the Salton Sea in southern California. The formation of these basins has generally been studied using laboratory experiments or numerical models. Here we combine seismic reflection data and geological observations from the Salton...
Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado
R.A. Baldwin, Louis C. Bender
2009, Canadian Journal of Zoology (87) 1000-1008
We used scat analysis to determine diets and relative nutritional values of diets for black bears (Ursus americanus Pallas, 1780) in Rocky Mountain National Park, Colorado, from 2003 to 2006, and compared foods consumed and nutritional components to identify important sources of fecal gross energy (GE), crude fat (CF), and...
