Effects of hatching time for larval ambystomatid salamanders
M.D. Boone, D.E. Scott, P.H. Niewiarowski
2002, Copeia 511-517
In aquatic communities, the phenology of breeding may influence species interactions. In the early-breeding marbled salamander, Ambystoma opacum, timing of pond filling may determine whether interactions among larvae are competitive or predatory. The objectives of our studies were to determine how time of egg hatching affected size, larval period, and...
Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: Resistance in different U.S. deserts
Jayne Belnap
2002, Journal of Arid Environments (52) 155-165
Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the...
Activity patterns and monitoring numbers of Horned Puffins and Parakeet Auklets
Scott A. Hatch
2002, Waterbirds (25) 348-357
Nearshore counts of birds on the water and time-lapse photography were used to monitor seasonal activity patterns and interannual variation in numbers of Horned Puffins (Fratercula corniculata) and Parakeet Auklets (Aethia psittacula) at the Semidi Islands, Alaska. The best period for over-water counts was mid egg-laying through hatching in auklets...
A test of "Annual resolution" in stalagmites using tree rings
J.L. Betancourt, H. D. Grissino-Mayer, M.W. Salzer, T.W. Swetnam
2002, Quaternary Research (58) 197-199
So-called annual banding has been identified in a number of speleothems in which the number of bands approximates the time interval between successive U-series dates. The apparent annual resolution of speleothem records, however, remains largely untested. Here we statistically compare variations in band thickness from a late Holocene stalagmite in...
Community food webs
Donald L. DeAngelis
Abdel H. El-Shaarawi, Walter W. Piegorsch, editor(s)
2002, Book chapter, Encyclopedia of Environmetrics
Community food webs describe the feeding relationships, or trophic interactions, between the species of an ecological community. Both the structure and dynamics of such webs are the focus of food web research. The topological structures of empirical food webs from many ecosystems have been published on the basis of field...
Fouth World Congress of Herpetology, 3-9 December 2001, Bentota, Sri Lanka
C. Kenneth Dodd Jr., B. Bartholomew
2002, Herpetological Review (33) 3-5
No abstract available....
Sea level response to ENSO along the central California coast: How the 1997-1998 event compares with the historic record
H. F. Ryan, M. Noble
2002, Progress in Oceanography (54) 149-169
Long-term monthly sea level and sea surface temperature (SST) anomalies from central California show that during winter months, positive anomalies are associated with El Niño events and the negative ones with La Niña events. There is no significant impact on monthly mean anomalies associated with Pacific decadal oscillations, although there...
Population differentiation in the red-legged kittiwake (Rissa brevirostris) as revealed by mitochondrial DNA
A. Patirana, S.A. Hatcher, Vicki L. Friesen
2002, Conservation Genetics (3) 335-340
Population decline in red-legged kittiwakes (Rissa brevirostris) over recent decades has necessitated the collection of information on the distribution of genetic variation within and among colonies for implementation of suitable management policies. Here we present a preliminary study of the extent of genetic structuring and gene flow among the three...
Impacts of swine manure pits on groundwater quality
I.G. Krapac, W.S. Dey, William R. Roy, C.A. Smyth, E. Storment, S.L. Sargent, J.D. Steele
2002, Environmental Pollution (120) 475-492
Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the...
Changes during hibernation in different phospholipid and free and esterified cholesterol serum levels in black bears
V. Chauhan, A. Sheikh, A. Chauhan, J. Tsiouris, M. Malik, M. Vaughan
2002, Biochimie (84) 1031-1034
During hibernation, fat is known to be the preferred source of energy. A detailed analysis of different phospholipids, as well as free and esterified cholesterol, was conducted to investigate lipid abnormalities during hibernation. The levels of total phospholipids and total cholesterol in the serum of black bears were found to...
Assessment of undiscovered petroleum resources in Central and South America
Christopher J. Schenk
2002, Conference Paper, World Petroleum Congress Proceedings
The USGS has assessed undiscovered conventional oil and gas resources in 128 selected petroleum provinces of the world. Of these 128 provinces, 23 are in South America, Central America, and the Caribbean area. In the USGS 2000 Assessment, the provinces resulted in mean totals for undiscovered resource of 105 billion...
Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions
Stephanie Prejean, William L. Ellsworth, Mark Zoback, Felix Waldhauser
2002, Journal of Geophysical Research B: Solid Earth (107) ESE 9-1-ESE 9-19
We have determined high-resolution hypocenters for 45,000+ earthquakes that occurred between 1980 and 2000 in the Long Valley caldera area using a double-difference earthquake location algorithm and routinely determined arrival times. The locations reveal numerous discrete fault planes in the southern caldera and adjacent Sierra Nevada block (SNB). Intracaldera faults...
Upper-mantle origin of the Yellowstone hotspot
R.L. Christiansen, G.R. Foulger, J.R. Evans
2002, Geological Society of America Bulletin (114) 1245-1256
Fundamental features of the geology and tectonic setting of the northeast-propagating Yellowstone hotspot are not explained by a simple deep-mantle plume hypothesis and, within that framework, must be attributed to coincidence or be explained by auxiliary hypotheses. These features include the persistence of basaltic magmatism along the hotspot track, the...
The role of the egg jelly coat in protecting Hyla regilla and Bufo canorus embryos from Ultraviolet B radiation during development
L.J. Hansen, D. L. Fabacher, R. Calfee
2002, Environmental Science and Pollution Research (9) 412-416
Background. Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the egg mass jelly...
Generalized extreme gust wind speeds distributions
E. Cheng, C. Yeung
2002, Journal of Wind Engineering and Industrial Aerodynamics (90) 1657-1669
Since summer 1996, the US wind engineers are using the extreme gust (or 3-s gust) as the basic wind speed to quantify the destruction of extreme winds. In order to better understand these destructive wind forces, it is important to know the appropriate representations of these extreme gust wind speeds....
Structure and earthquake offsets on the San Andreas fault at the Wrightwood, California paleoseismic site
R. J. Weldon, T. E. Fumal, T. J. Powers, S.K. Pezzopane, K.M. Scharer, John C. Hamilton
2002, Bulletin of the Seismological Society of America (92) 2704-2725
Thirty-eight trenches and natural exposures across the San Andreas fault zone, four km northwest of Wrightwood, California, reveal the structure and stratigraphy of this paleoseismic site. A 25-m-thick stratigraphic section of late Holocene peat, debris flows, and fluvial sediments have accumulated syntectonically and are deformed in a complicated flower, or...
Application of classification-tree methods to identify nitrate sources in ground water
T.B. Spruill, W.J. Showers, S. S. Howe
2002, Conference Paper, Journal of Environmental Quality
A study was conducted to determine if nitrate sources in ground water (fertilizer on crops, fertilizer on golf courses, irrigation spray from hog (Sus scrofa) wastes, and leachate from poultry litter and septic systems) could be classified with 80% or greater success. Two statistical classification-tree models were devised from 48...
A new population of Aleutian shield fern (Polystichum aleuticum C. Christens.) on Adak Island, Alaska
Sandra L. Talbot, Stephen S. Talbot
2002, American Fern Journal (92) 288-293
We report and describe a new population of the endangered Aleutian shield fern (Polystichum aleuticum C. Christens.) discovered on Mount Reed, Adak Island, Alaska. The new population is located at a lower elevation than the other known populations, placing the species' known elevational range between 338 m and 525 m....
Vegetation and climate controls on potential CO2, DOC and DON production in northern latitude soils
J. C. Neff, D.U. Hooper
2002, Global Change Biology (8) 872-884
Climatic change may influence decomposition dynamics in arctic and boreal ecosystems, affecting both atmospheric CO2 levels, and the flux of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) to aquatic systems. In this study, we investigated landscape-scale controls on potential production of these compounds using a one-year laboratory incubation...
Comparison of methods for nutrient measurement in calcareous soils: Ion-exchange resin bag, capsule, membrane, and chemical extractions
S. K. Sherrod, J. Belnap, M. E. Miller
2002, Soil Science (167) 666-679
Four methods for measuring quantities of 12 plant-available nutrients were compared using three sandy soils in a series of three experiments. Three of the methods use different ion-exchange resin forms—bags, capsules, and membranes—and the fourth was conventional chemical extraction. The first experiment compared nutrient extraction data from a medium of...
Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources
Paul F. Schuster, David P. Krabbenhoft, David L. Naftz, L. DeWayne Cecil, Mark L. Olson, John F. DeWild, David D. Susong, Jaromy R. Green, Michael L. Abbott
2002, Environmental Science & Technology (36) 2303-2310
Mercury (Hg) contamination of aquatic ecosystems and subsequent methylmercury bioaccumulation are significant environmental problems of global extent. At regional to global scales, the primary mechanism of Hg contamination is atmospheric Hg transport. Thus, a better understanding of the long-term history of atmospheric Hg cycling and quantification of the sources is...
American white pelican soaring flight times and altitudes relative to changes in thermal depth and intensity
H.D. Shannon, G.S. Young, M. Yates, Mark R. Fuller, W. Seegar
2002, The Condor (104) 679-683
We compared American White Pelican (Pelecanus erythrorhynchos) soaring flight times and altitudes to model-produced estimates of thermal depth and intensity. These data showed that pelican soaring flight was confined to the thermal layer, and that the vertical extent of the soaring flight envelope increased with increases in thermal depth. Pelicans...
Anaerobic methane oxidation in a landfill-leachate plume
Ethan L. Grossman, Luis A. Cifuentes, Isabelle M. Cozzarelli
2002, Environmental Science & Technology (36) 2436-2442
The alluvial aquifer adjacent to Norman Landfill, OK, provides an excellent natural laboratory for the study of anaerobic processes impacting landfill-leachate contaminated aquifers. We collected groundwaters from a transect of seven multilevel wells ranging in depth from 1.3 to 11 m that were oriented parallel to the flow path. The...
Carbon dioxide emission rate of Kīlauea Volcano: Implications for primary magma and the summit reservoir
T.M. Gerlach, K.A. McGee, T. Elias, A. J. Sutton, M.P. Doukas
2002, Journal of Geophysical Research B: Solid Earth (107) ECV 3-1-ECV 3-15
We report a CO2 emission rate of 8500 metric tons per day (t d−1) for the summit of Kīlauea Volcano, several times larger than previous estimates. It is based on three sets of measurements over 4 years of synchronous SO2 emission rates and volcanic CO2/SO2concentration ratios for the summit correlation spectrometer (COSPEC)...
Satellite imagery characterizes local animal reservoir populations of Sin Nombre virus in the southwestern United States
Gregory E. Glass, Terry L. Yates, Joshua B. Fine, Timothy M. Shields, John B. Kendall, Andrew G. Hope, Cheryl A. Parmenter, C.J. Peters, Thomas G. Ksiazek, Chung-Sheng Li, Jonathan A. Patz, James N. Mills
2002, Proceedings of the National Academy of Sciences of the United States of America (99) 16817-16822
The relationship between the risk of hantaviral pulmonary syndrome (HPS), as estimated from satellite imagery, and local rodent populations was examined. HPS risk, predicted before rodent sampling, was highly associated with the abundance of Peromyscus maniculatus, the reservoir of Sin Nombre virus (SNV). P. maniculatus were common in high-risk sites,...
