The importance of adjusting for trip purpose in regional economic analyses of tourist destinations
J. Loomis, L. Caughlan
2006, Tourism Economics (12) 33-43
This paper investigates the empirical importance of distinguishing visitors and their expenditures by trip purpose when estimating the tourism effects of a national park on a local economy. Accounting for trip purpose is quite important when there are two or more nearby major attractions in the same geographical area. This...
Risk analysis for biological hazards: What we need to know about invasive species
T.J. Stohlgren, J.L. Schnase
2006, Risk Analysis (26) 163-173
Risk analysis for biological invasions is similar to other types of natural and human hazards. For example, risk analysis for chemical spills requires the evaluation of basic information on where a spill occurs; exposure level and toxicity of the chemical agent; knowledge of the physical processes involved in its rate...
A tamarisk habitat suitability map for the continental US
J.T. Morisette, C. S. Jarnevich, A. Ullah, W. Cai, J.A. Pedelty, J.E. Gentle, T.J. Stohlgren, J.L. Schnase
2006, Frontiers in Ecology and the Environment (4) 11-17
This paper presents a national-scale map of habitat suitability for tamarisk (Tamarix spp, salt cedar), a high-priority invasive species. We successfully integrate satellite data and tens of thousands of field sampling points through logistic regression modeling to create a habitat suitability map that is 90% accurate. This interagency effort...
Defining ecosystem flow requirements for the Bill Williams River, Arizona
Patrick B. Shafroth, Vanessa B. Beauchamp, editor(s)
2006, Open-File Report 2006-1314
Alteration of natural river flows resulting from the construction and operation of dams can result in substantial changes to downstream aquatic and bottomland ecosystems and undermine the long-term health of native species and communities (for general review, cf. Ward and Stanford, 1995; Baron and others, 2002; Nilsson and Svedmark, 2002)....
Autumn migration and selection of rock crevices as hibernacula by big brown bats in Colorado
D.J. Neubaum, T. J. O'Shea, K.R. Wilson
2006, Journal of Mammalogy (87) 470-479
Movements, distribution, and roosting requirements of most species of temperate-zone bats in autumn are poorly understood. We conducted the 1st radiotelemetry study of autumn migrations and prehibernation roost selection of bats in western North America. Big brown bats (Eptesicus fuscus, n = 55) in the Poudre River watershed, Colorado, moved...
Sediment and nutrient accumulation within lowland bottomland ecosystems: An example from the Atchafalaya River Basin, Louisiana
C.R. Hupp, G.B. Noe
2006, Conference Paper, Hydrology and Management of Forested Wetlands - Proceeding of the International Conference
Sediment and nutrient deposition, storage, and transformations are important environmental functions of riverine forested wetland ecosystems, yet documentation and interpretation of sedimentation/nutrient processes remain incomplete. Our studies located in the Coastal Plain of southeastern USA, including the Atchafalaya Basin, La. (a distributary of the Mississippi River) serve as example for...
Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario
W.E. Adams Jr., L.W. Kallemeyn, D.W. Willis
2006, Journal of Applied Ichthyology (22) 97-102
Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted...
Recovery of the black-footed ferret: Progress and continuing challenges- Proceedings of the Symposium on the Status of the Black-footed Ferret and Its Habitat, Fort Collins, Colorado, January 28-29, 2004
James E. Roelle, Brian J. Miller, Jerry L. Godbey, Dean E. Biggins, editor(s)
2006, Scientific Investigations Report 2005-5293
The black-footed ferret (Mustela nigripes) is a member of the weasel family (Mustelidae) and is closely related to the Siberian polecat (M. eversmannii) of Asian steppes and the European polecat (M. putorius). Compared to its relatives, the black-footed ferret is an extreme specialist, depending on the prairie dogs (Cynomys spp.)...
On the formation of the tunnel valleys of the southern Laurentide ice sheet
R. LeB Hooke, C.E. Jennings
2006, Quaternary Science Reviews (25) 1364-1372
Catastrophic releases of meltwater, produced by basal melting and stored for decades in subglacial reservoirs at high pressure, may have been responsible for eroding the broad, deep tunnel valleys that are common along the margins of some lobes of the southern Laurentide ice sheet. We surmise that these releases began...
Water quality of the Crescent River basin, Lake Clark National Park and Preserve, Alaska, 2003-2004
Timothy P. Brabets, Robert T. Ourso
2006, Scientific Investigations Report 2006-5151
The U.S. Geological Survey and the National Park Service conducted a water-quality investigation of the Crescent River Basin in Lake Clark National Park and Preserve from May 2003 through September 2004. The Crescent River Basin was studied because it has a productive sockeye salmon run that is important to the...
Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data
W.F. Waite, L.Y. Gilbert, W.J. Winters, D.H. Mason
2006, Review of Scientific Instruments (77)
Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained...
High REE and Y concentrations in Co-Cu-Au ores of the Blackbird district, Idaho
J. F. Slack
2006, Economic Geology (101) 275-280
Analysis of 11 samples of strata-bound Co-Cu-Au ore from the Blackbird district in Idaho shows previously unknown high concentrations of rare earth elements (REE) and Y, averaging 0.53 wt percent ???REE + Y oxides. Scanning electron microscopy indicates REE and Y residence in monazite, xenotime, and allanite that form complex...
Trends of chlorinated organic contaminants in Great Lakes trout and walleye from 1970-1998
J.P. Hickey, S.A. Batterman, S.M. Chernyak
2006, Archives of Environmental Contamination and Toxicology (50) 97-110
Levels of chlorinated organic contaminants in predator fish have been monitored annually in each of the Great Lakes since the 1970s. This article updates earlier reports with data from 1991 to 1998 for lake trout (Salvelinus namaycush) and (Lake Erie only) walleye (Sander vitreus) to provide a record that now...
Flow resistance dynamics in step‐pool stream channels: 1. Large woody debris and controls on total resistance
Andrew C. Wilcox, Ellen E. Wohl
2006, Water Resources Research (42)
Flow resistance dynamics in step‐pool channels were investigated through physical modeling using a laboratory flume. Variables contributing to flow resistance in step‐pool channels were manipulated in order to measure the effects of various large woody debris (LWD) configurations, steps, grains, discharge, and slope on total flow resistance. This entailed nearly...
Permanent 'phase shifts' or reversible declines in coral cover? Lack of recovery of two coral reefs in St. John, U.S. Virgin Islands
C.S. Rogers, J. Miller
2006, Marine Ecology Progress Series (306) 103-114
Caribbean coral reefs have changed dramatically in the last 3 to 4 decades, with significant loss of coral cover and increases in algae. Here we present trends in benthic cover from 1989 to 2003 at 2 reefs (Lameshur Reef and Newfound Reef) off St. John, US Virgin Islands (USVI). Coral...
Genetic structure of eelgrass Zostera marina meadows in an embayment with restricted water flow
Raquel Muniz-Salazar, Sandra L. Talbot, George K. Sage, David H. Ward, Alejandro Cabello-Pasini
2006, Marine Ecology Progress Series (309) 107-116
Genetic structure of the seagrass Zostera marina in a coastal lagoon with restricted water flow, and with heterogeneous water residence times and oceanographic characteristics, was assessed using 8 polymorphic microsatellite loci. Analyses of genetic differentiation (θ) and Bayesian clustering suggested that the Z. marina population in San Quintin Bay (SQB)...
Common clay and shale
R.L. Virta
2006, Mining Engineering (58) 25-26
At present, 150 companies produce common clay and shale in 41 US states. According to the United States Geological Survey (USGS), domestic production in 2005 reached 24.8 Mt valued at $176 million. In decreasing order by tonnage, the leading producer states include North Carolina, Texas, Alabama, Georgia and Ohio. For...
Estimating hydraulic properties using a moving-model approach and multiple aquifer tests
K. J. Halford, D. Yobbi
2006, Ground Water (44) 284-291
A new method was developed for characterizing geohydrologic columns that extended >600 m deep at sites with as many as six discrete aquifers. This method was applied at 12 sites within the Southwest Florida Water Management District. Sites typically were equipped with multiple production wells, one for each aquifer and...
Changes in the timing of winter-spring streamflows in eastern North America, 1913-2002
G.A. Hodgkins, R. W. Dudley
2006, Geophysical Research Letters (33)
Changes in the timing and magnitude of winter-spring streamflows were analyzed for gaging stations in eastern North America north of 41?? north latitude during various periods through 2002. Approximately 32 percent of stations north of 44?? have significantly earlier flows over the 50, 60, 70, and 90 year periods; 64...
Estimating the size of fish consumed by double-crested cormorants: Considerations for better understanding cormorant-fish interactions
James H. Johnson, Robert M. Ross, James E. McKenna, Graham E. Lewis
2006, Journal of Great Lakes Research (32) 91-101
We measured 926 smallmouth bass (Micropterus dolomieu), 6,935 yellow perch (Perca flavescens), 6,416 rock bass (Ambloplites rupestris), and 4,852 pumpkinseed (Lepomis gibbosus) otoliths recovered from double-crested cormorant (Phalacrocorax auritus) pellets to determine the sizes (total lengths) of these fish consumed by cormorants. Otoliths were recovered from cormorant pellets collected from...
Sediment yield and runoff frequency of small drainage basins in the Mojave Desert, U.S.A
Peter G. Griffiths, R. Hereford, R. H. Webb
2006, Geomorphology (74) 232-244
Sediment yield from small arid basins, particularly in the Mojave Desert, is largely unknown owing to the ephemeral nature of these fluvial systems and long recurrence interval of flow events. We examined 27 reservoirs in the northern and eastern Mojave Desert that trapped...
Flood lavas on Earth, Io and Mars
Laszlo P. Keszthelyi, Stephen Self, Thorvaldur Thordarson
2006, Journal of the Geological Society (163) 253-264
Flood lavas are major geological features on all the major rocky planetary bodies. They provide important insight into the dynamics and chemistry of the interior of these bodies. On the Earth, they appear to be associated with major and mass extinction events. It is therefore not surprising that there has...
Trend analysis of time-series phenology of North America derived from satellite data
B. C. Reed
2006, GIScience and Remote Sensing (43) 24-38
Remote sensing information has been used in studies of the seasonal dynamics (phenology) of the land surface since the 1980s. While our understanding of remote sensing phenology is still in development, it is regarded as a key to understanding land-surface processes over large areas. Phenologic metrics, including start of season,...
Recognizing the Albian-Cenomanian (OAE1d) sequence boundary using plant carbon isotopes: Dakota Formation, Western Interior Basin, USA
D.R. Grocke, Greg A. Ludvigson, B.L. Witzke, S.A. Robinson, R. M. Joeckel, David F. Ufnar, R.L. Ravn
2006, Geology (34) 193-196
Analysis of bulk sedimentary organic matter and charcoal from an Albian-Cenomanian fluvial-estuarine succession (Dakota Formation) at Rose Creek Pit (RCP), Nebraska, reveals a negative excursion of ???3???, in late Albian strata. Overlying Cenomanian strata have ??13C values of -24???, to -23???, that are similar to pre-excursion values. The absence of...
Evaluation of a lake whitefish bioenergetics model
Charles P. Madenjian, Daniel V. O’Connor, Steven A. Pothoven, Philip J. Schneeberger, Richard R. Rediske, James P. O'Keefe, Roger A. Bergstedt, Ray L. Argyle, Stephen B. Brandt
2006, Transactions of the American Fisheries Society (135) 61-75
We evaluated the Wisconsin bioenergetics model for lake whitefish Coregonus clupeaformis in the laboratory and in the field. For the laboratory evaluation, lake whitefish were fed rainbow smelt Osmerus mordax in four laboratory tanks during a 133-d experiment. Based on a comparison of bioenergetics model predictions of lake whitefish food...
