Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 48 of 48

Full-Text Articles in Physical Sciences and Mathematics

Distribution Of Boreal Toad Populations In Relation To Estimated Uv-B Dose In Glacier National Park, Montana, Usa, Blake R. Hossack, Stephen A. Diamond, Paul Stephen Corn Jan 2006

Distribution Of Boreal Toad Populations In Relation To Estimated Uv-B Dose In Glacier National Park, Montana, Usa, Blake R. Hossack, Stephen A. Diamond, Paul Stephen Corn

United States Geological Survey: Staff Publications

A recent increase in ultraviolet B radiation is one hypothesis advanced to explain suspected or documented declines of the boreal toad (Bufo boreas Baird and Girard, 1852) across much of the western USA, where some experiments have shown ambient UV-B can reduce embryo survival. We examined B. boreas occupancy relative to daily UV-B dose at 172 potential breeding sites in Glacier National Park, Montana, to assess whether UV-B limits the distribution of toads. Dose estimates were based on ground-level UV-B data and the effects of elevation, local topographic and vegetative features, and attenuation in the water column. We also …


Divergent Patterns Of Abundance And Age-Class Structure Of Headwater Stream Tadpoles In Burned And Unburned Watersheds, Blake R. Hossack, Paul Stephen Corn, Daniel B. Fagre Jan 2006

Divergent Patterns Of Abundance And Age-Class Structure Of Headwater Stream Tadpoles In Burned And Unburned Watersheds, Blake R. Hossack, Paul Stephen Corn, Daniel B. Fagre

United States Geological Survey: Staff Publications

Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphlls montanlls Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestem Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them bumed in a large wildfire, and were resampled during the 2 years follo\ving the fire. Counts of tadpoles were similar in the 1\\'0 …


Eolian Additions To Late Quaternary Alpine Soils, Indian Peaks Wilderness Area, Colorado Front Range, Daniel R. Muhs, James B. Benedict Jan 2006

Eolian Additions To Late Quaternary Alpine Soils, Indian Peaks Wilderness Area, Colorado Front Range, Daniel R. Muhs, James B. Benedict

United States Geological Survey: Staff Publications

Surface horizons of many alpine soils on Quaternary deposits in high-mountain settings are enriched in silt. The origin of these particles has been debated, particularly in the Rocky Mountain region of North America. The most common explanations are frost shattering of coarser particles and eolian additions from distant sources. We studied soil A horizons on alpine moraines of late-glacial (Satanta Peak) age in the Colorado Front Range. Surface horizons of soils on these moraines are enriched in silt and have a particle size distribution that resembles loess and dust deposits found elsewhere. The compositions of sand and silt fractions of …


The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes Jan 2006

The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes

United States Geological Survey: Staff Publications

Agricultural productivity estimates suggest that the core area of Chaco Canyon could have sustained only a few hundred individuals. Modern analogues of existing Pueblo populations and their domestic habitations with Chaco structures suggest that Chaco at times had a resident population exceeding 2000 people. These data suggest that maize would have had to be imported to feed permanent residents and those visiting Chaco during ritual–political gatherings and those who participated in the accelerated construction and modification of great houses between AD 1030 and 1130. Comparison of strontium-isotope and trace-element ratios of synthetic soil and natural waters from sites within the …


Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott Jan 2006

Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott

United States Geological Survey: Staff Publications

As we write this in early 2005 there are several ESA-related pieces of legislation pending before Congress. Most of the proposed legislation is championed by Republican leaders from western states, who promise to strengthen the use of science or ensure fairer treatment of private landowners. Ir has become a perennial drama on the American political stage: "conservatives" rally to rein in a law that they believe has reached too far and "conservationists" mobilize ro defend the law that they believe offers the best ho pe for protecting biodiversity from relentless economic exploitation. There is much posturing, finger pointing, and, ultimately, …


Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble Jan 2006

Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble

United States Geological Survey: Staff Publications

More than thirty years after its passage, the Endangered Species Act (ESA) of 1973 continues to be a corners tone of U.S. biodiversity policy and among our most powerful environmentallaws. The ESA set the nation's biodiversity conservation policy on a path that emphasized species-based conservation and triggered action only when a species faced imminent extinction. However, promoting recovery has proven more challenging than the original designers of the law anticipated. The number of listed species has mushroomed from 78 in 1973 to 1,267 in 2005, while in that time only 13 species have recovered sufficiently to be removed from the …


Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis Jan 2006

Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis

United States Geological Survey: Staff Publications

The two volumes of The Endangered Species Act at Thirty look backward to evaluate the effectiveness of the act over its first three decades (Wilcove and McMillan 2006; Scott et al. 2006, chap. 2; Goble, this volume; Svancara, this volume; Callicott, this volume; Norton, this volume) and also forward to suggest how it can be used as a cornerstone for conserving biological diversity in increasingly human-dominated landscapes (Davis et al. 2006; Bean 2006). The chapters in part 2 of this volume, for example, appraise the science of the 1990s and 2000s at both the large scale (Lomolino, this volume; Naeem …


Unusual Holocene And Late Pleistocene Carbonate Sedimentation In Bear Lake, Utah And Idaho, Usa, Walter E. Dean, Joseph Rosenbaum, Gary Skipp, Steven Colman, Richard Forester, An Liu, Kathleen R. Simmons, James Bischoff Jan 2006

Unusual Holocene And Late Pleistocene Carbonate Sedimentation In Bear Lake, Utah And Idaho, Usa, Walter E. Dean, Joseph Rosenbaum, Gary Skipp, Steven Colman, Richard Forester, An Liu, Kathleen R. Simmons, James Bischoff

United States Geological Survey: Staff Publications

Bear Lake (Utah–Idaho, USA) has been producing large quantities of carbonate minerals of varying mineralogy for the past 17,000 years. The history of sedimentation in Bear Lake is documented through the study of isotopic ratios of oxygen, carbon, and strontium, percent organic carbon, percent CaCO3, X-ray diffraction mineralogy, HCl-leach inorganic geochemistry, and magnetic properties on samples from three piston cores. Historically, the Bear River, the main source of water for Great Salt Lake, did not enter Bear Lake until it was artificially diverted into the lake at the beginning of the 20th century. However, during the last glacial …


A Continuous 250,000 Yr Record Of Oxygen And Carbon Isotopes In Ostracode And Bulk-Sediment Carbonate From Bear Lake, Utah-Idaho, Walter E. Dean, Jordon Bright, Darrell S. Kaufman, Richard M. Forester Jan 2006

A Continuous 250,000 Yr Record Of Oxygen And Carbon Isotopes In Ostracode And Bulk-Sediment Carbonate From Bear Lake, Utah-Idaho, Walter E. Dean, Jordon Bright, Darrell S. Kaufman, Richard M. Forester

United States Geological Survey: Staff Publications

Oxygen and carbon isotopes from a continuous, 120-m-long, carbonate-rich core from Bear Lake, Utah-Idaho, document dramatic fluctuations in the hydrologic budget of the lake over the last 250,000 yr. Isotopic analyses of bulk sediment samples capture millennialscale variability. Ostracode calcite was analyzed from 78 levels, mainly from the upper half of the core where valves are better preserved, to compare the isotopic value of purely endogenic carbonate with the bulk sediment, which comprises both endogenic and detrital components. The long core exhibits three relatively brief intervals with abundant endogenic aragonite (50±10%) and enriched δ18O and δ13C. …


Alpersite (Mg,Cu)So4•7h2O, A New Mineral Of The Melanterite Group, And Cuprian Pentahydrite: Their Occurrence Within Mine Waste, Ronald C. Peterson, Jane M. Hammarstrom, Robert R. Seal Ii Jan 2006

Alpersite (Mg,Cu)So4•7h2O, A New Mineral Of The Melanterite Group, And Cuprian Pentahydrite: Their Occurrence Within Mine Waste, Ronald C. Peterson, Jane M. Hammarstrom, Robert R. Seal Ii

United States Geological Survey: Staff Publications

Alpersite, Mg0.58 Cu0.37 Zn0.02 Mn0.02 Fe0.01SO4 •7H2 O, a new mineral species with direct relevance to reactions in mine waste, occurs in a mineralogically zoned assemblage in sheltered areas at the abandoned Big Mike mine in central Nevada at a relative humidity of 65% and T = 4 °C. Blue alpersite, which is isostructural with melanterite (FeSO4 •7H2 O), is overlain by a light blue to white layer dominated by pickeringite, alunogen, and epsomite. X-ray diffraction data (MoKα radiation) from a single crystal of alpersite were refined in P21 …


Contact Zone Permeability At Intrusion Boundaries: New Results From Hydraulic Testing And Geophysical Logging In The Newark Rift Basin, New York, Usa, Jurg M. Matter, D. S. Goldberg, Roger H. Morin, M. Stute Jan 2006

Contact Zone Permeability At Intrusion Boundaries: New Results From Hydraulic Testing And Geophysical Logging In The Newark Rift Basin, New York, Usa, Jurg M. Matter, D. S. Goldberg, Roger H. Morin, M. Stute

United States Geological Survey: Staff Publications

Hydraulic tests and geophysical logging performed in the Palisades sill and the underlying sedimentary rocks in the NE part of the Newark Rift Basin, New York, USA, confirm that the particular transmissive zones are localized within the dolerite-sedimentary rock contact zone and within a narrow interval below this contact zone that is characterized by the occurrence of small layers of chilled dolerite. Transmissivity values determined from fluid injection, aquifer testing, and flowmeter measurements generally fall in the range of 8.1E-08 to 9.95E-06 m2/s and correspond to various scales of investigation. The analysis of acoustic and optical BHTV images …


A Method For Mapping Corn Using The Us Geological Survey 1992 National Land Cover Dataset, S. K. Maxwell, J. R. Nuckols, M. H. Ward Jan 2006

A Method For Mapping Corn Using The Us Geological Survey 1992 National Land Cover Dataset, S. K. Maxwell, J. R. Nuckols, M. H. Ward

United States Geological Survey: Staff Publications

Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin’s lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type. Corn requires the highest application of nitrogen fertilizer of crops grown in the Midwest US.We developed a method to refine the US Geological Survey National Land Cover Dataset (NLCD) (including map and original Landsat images) to distinguish corn from other crops. Overall average agreement between the resulting corn and other …


Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway Jan 2006

Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway

United States Geological Survey: Staff Publications

Animals have evolved an impressive array of behavioural traits to avoid depredation. Olfactory camouflage of conspicuous odours is a strategy to avoid depredation that has been implicated only in a few species of birds. Burrowing owls, Athene cunicularia, routinely collect dried manure from mammals and scatter it in their nest chamber, in the tunnel leading to their nest and at the entrance to their nesting burrow. This unusual behaviour was thought to reduce nest depredation by concealing the scent of adults and juveniles, but a recent study suggests that manure functions to attract arthropod prey. However, burrowing owls routinely …


Cougars In Kansas, Charles D. Lee, Alyssa E. Warneke, Mike Houts, Troy R. Livingston, Philip S. Gipson Jan 2006

Cougars In Kansas, Charles D. Lee, Alyssa E. Warneke, Mike Houts, Troy R. Livingston, Philip S. Gipson

United States Geological Survey: Staff Publications

The presence of the cougar (Puma concolor) in the state of Kansas is a controversial issue. Since 1999, 234 cougar sightings have been reported to the Extension Wildlife Specialist at Kansas State University. To those who have reported such sightings, the existence of cougars in Kansas is undeniable. Others, however, question the validity of such sightings as providing evidence of cougars. After surveying other governmental agencies and organizations, we discovered that acceptable identification criteria for rare or unusual felines included things beside sightings: voucher specimens, DNA from hair or scat, tracks, prey carcasses, and photographs or videos. The …


Historical And Current Status Of Elk In Kansas, Jonathan M. Conard, Philip S. Gipson, Matt Peek Jan 2006

Historical And Current Status Of Elk In Kansas, Jonathan M. Conard, Philip S. Gipson, Matt Peek

United States Geological Survey: Staff Publications

Elk (Cervus elaphus) historically occurred throughout Kansas but were extirpated from the state around 1890. Free-ranging elk populations were reestablished in Kansas through reintroduction efforts on Cimarron National Grasslands from 1981-1990, and on Fort Riley Military Installation from 1986-1994. Current elk distributions in the state have not been published following these reintroduction efforts. The current and historical distribution of this species in Kansas is described.


Status Of Feral Pigs In Kansas And Nebraska, Philip S. Gipson, Charles D. Lee, Sam Wilson, James R. Thiele, Deke Hobbick Jan 2006

Status Of Feral Pigs In Kansas And Nebraska, Philip S. Gipson, Charles D. Lee, Sam Wilson, James R. Thiele, Deke Hobbick

United States Geological Survey: Staff Publications

Wild pigs have expanded their range markedly during the last 30 years. In Kansas feral pigs from domestic stock were first reported in 1994 on Fort Riley Army Base. During 2005, 2006, and 2007 the occurrence of reproducing wild pigs was confirmed on 18 sites throughout Kansas and 4 sites in Nebraska. One Nebraska population is in a county neighboring Kansas. Estimated numbers of pigs ranged from 8-10 individuals at each of 2 sites in Kansas to more than 30 on each of 3 other sites. The wild pig population in Kansas appears to be changing from 1 predominantly of …


Simulation Of Solute Movement Through Wellbores To Characterize Public Supply Well Contaminant Vulnerability In The High Plains Aquifer, York, Nebraska, Brian R. Clark, Matthew K. Landon, Leon J. Kauffman, George Z. Hornberger Jan 2006

Simulation Of Solute Movement Through Wellbores To Characterize Public Supply Well Contaminant Vulnerability In The High Plains Aquifer, York, Nebraska, Brian R. Clark, Matthew K. Landon, Leon J. Kauffman, George Z. Hornberger

United States Geological Survey: Staff Publications

A ground-water flow and transport model simulating contaminant movement to public supply wells in the High Plains aquifer near York, Nebraska was developed as part of the U.S. Geological Survey National Water-Quality Assessment Program. Water-quality samples were collected from wells screened in unconfined and confined units. Samples collected from a public supply well and selected monitoring wells completed in the confined aquifer have chemistry and age-tracer concentrations consistent with a mix of young water from unconfined recharge areas combined with relatively older confined aquifer water. These results imply that there are preferential flow paths that permit shallow recharge water and …


Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves: Proof Of Concept, Larry V. Benson, E. M. Hattori, H. E. Taylor, S. R. Poulson, E. A. Jolie Jan 2006

Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves: Proof Of Concept, Larry V. Benson, E. M. Hattori, H. E. Taylor, S. R. Poulson, E. A. Jolie

United States Geological Survey: Staff Publications

Isotope and trace-metal analyses were used to determine the origin of plants used to manufacture prehistoric textiles (basketry and matting) from archaeological sites in the western Great Basin. Research focused on strontium (87Sr/86Sr) and oxygen (18O/16O) isotope ratios of willow (Salix sp.) and tule (Schoenoplectus sp.), the dominant raw materials in Great Basin textiles. The oxygen-isotope data indicated that the willow and tule used to produce the textiles were harvested from the banks of rivers or in marshes characterized by flowing water and not from lakes or sinks. The strontium-isotope …