Holocene vegetation and fire regimes in subalpine and mixed conifer forests, southern Rocky Mountains, USA
R. Scott Anderson, Craig D. Allen, J.L. Toney, R.B. Jass, A.N. Bair
2008, International Journal of Wildland Fire (17) 96-114
Our understanding of the present forest structure of western North America hinges on our ability to determine antecedent forest conditions. Sedimentary records from lakes and bogs in the southern Rocky Mountains of Colorado and New Mexico provide information on the relationships between climate and vegetation change, and fire history since...
Quantitative estimation of bioclimatic parameters from presence/absence vegetation data in North America by the modern analog technique
R.S. Thompson, K. H. Anderson, P. J. Bartlein
2008, Quaternary Science Reviews (27) 1234-1254
The method of modern analogs is widely used to obtain estimates of past climatic conditions from paleobiological assemblages, and despite its frequent use, this method involved so-far untested assumptions. We applied four analog approaches to a continental-scale set of bioclimatic and plant-distribution presence/absence data for North America to assess how...
Where temperate meets tropical: Multi-factorial effects of elevated CO2, nitrogen enrichment, and competition on a mangrove-salt marsh community
K.L. McKee, J.E. Rooth
2008, Global Change Biology (14) 971-984
Our understanding of how elevated CO2 and interactions with other factors will affect coastal plant communities is limited. Such information is particularly needed for transitional communities where major vegetation types converge. Tropical mangroves (Avicennia germinans) intergrade with temperate salt marshes (Spartina alterniflora) in the northern Gulf of Mexico, and this transitional...
Evaluation of Landsat-7 SLC-off image products for forest change detection
Michael A. Wulder, Stephanie M. Ortlepp, Joanne C. White, Susan Maxwell
2008, Canadian Journal of Remote Sensing (34) 93-99
Since July 2003, Landsat-7 ETM+ has been operating without the scan line corrector (SLC), which compensates for the forward motion of the satellite in the imagery acquired. Data collected in SLC-off mode have gaps in a systematic wedge-shaped pattern outside of the central 22 km swath of the imagery; however,...
Mercury and organic carbon dynamics during runoff episodes from a northeastern USA watershed
P. F. Schuster, J. B. Shanley, M. Marvin-DiPasquale, M.M. Reddy, G. R. Aiken, D.A. Roth, Howard E. Taylor, D. P. Krabbenhoft, J.F. DeWild
2008, Water, Air, & Soil Pollution (187) 89-108
Mercury and organic carbon concentrations vary dynamically in streamwater at the Sleepers River Research Watershed in Vermont, USA. Total mercury (THg) concentrations ranged from 0.53 to 93.8 ng/L during a 3-year period of study. The highest mercury (Hg) concentrations occurred slightly before peak flows and were associated with the highest...
Storm-driven sediment transport in Massachusetts Bay
J.C. Warner, B. Butman, P.S. Dalyander
2008, Continental Shelf Research (28) 257-282
Massachusetts Bay is a semi-enclosed embayment in the western Gulf of Maine about 50 km wide and 100 km long. Bottom sediment resuspension is controlled predominately by storm-induced surface waves and transport by the tidal- and wind-driven circulation. Because the Bay is open to the northeast, winds from the northeast...
Trends of pesticides and nitrate in ground water of the Central Columbia Plateau, Washington, 1993-2003
L. Frans
2008, Conference Paper, Journal of Environmental Quality
Pesticide and nitrate data for ground water sampled in the Central Columbia Plateau, Washington, between 1993 and 2003 by the U.S. Geological Survey National Water-Quality Assessment Program were evaluated for trends in concentration. A total of 72 wells were sampled in 1993-1995 and again in 2002-2003 in three well networks...
Sprint swimming performance of wild bull trout (Salvelinus confluentus)
M.G. Mesa, J. Phelps, L.K. Weiland
2008, Northwest Science (82) 1-6
We conducted laboratory experiments to determine the sprint swimming performance of wild juvenile and adult bull trout Salvelinus confluentus. Sprint swimming speeds were estimated using high-speed digital video analysis. Thirty two bull trout were tested in sizes ranging from about 10 to 31 cm. Of these, 14 fish showed at...
Precision of descriptors for percent marrow fat content for White-tailed Deer, Odocoileus viriginianus
L.D. Mech
2008, Canadian Field-Naturalist (122) 273-273
Based on 168 records of both verbal descriptors of White-tailed Deer (Odocoileus virginianus) femur-marrow fat and percentage of fat measured later, "gelatinous" served well to distinguish fat 56%....
MODIS and SeaWIFS on-orbit lunar calibration
Jielun Sun, R.E. Eplee Jr., X. Xiong, T. Stone, G. Meister, C.R. McClain
2008, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
The Moon plays an important role in the radiometric stability monitoring of the NASA Earth Observing System's (EOS) remote sensors. The MODIS and SeaWIFS are two of the key instruments for NASA's EOS missions. The MODIS Protoflight Model (PFM) on-board the Terra spacecraft and the MODIS Flight Model 1 (FM1)...
Decadal-scale changes of nitrate in ground water of the United States, 1988-2004
Michael G. Rupert
2008, Journal of Environmental Quality (37) S240-S248
This study evaluated decadal-scale changes of nitrate concentrations in groundwater samples collected by the USGS National Water-Quality Assessment Program from 495 wells in 24 well networks across the USA in predominantly agricultural areas. Each well network was sampled once during 1988-1995 and resampled once during 2000-2004. Statistical tests of decadal-scale...
Reply to comment by T. N. Narasimhan on “A method to estimate groundwater depletion from confining layers”
Christopher E. Neuzil, Leonard F. Konikow
2008, Water Resources Research (44)
We thank T. N. Narasimhan for his comment on our paper [Konikow and Neuzil, 2007] and for extending the discussion with a historical perspective, additional examples, and some considerations we did not discuss, including implications for water management. We support and agree with the thrust of his comments....
Monitoring programs to assess reintroduction efforts: A critical component in recovery
E. Muths, V. Dreitz
2008, Animal Biodiversity and Conservation (31) 47-56
Reintroduction is a powerful tool in our conservation toolbox. However, the necessary follow-up, i.e. long-term monitoring, is not commonplace and if instituted may lack rigor. We contend that valid monitoring is possible, even with sparse data. We present a means to monitor based on demographic data and a projection model...
L5 TM radiometric recalibration procedure using the internal calibration trends from the NLAPS trending database
G. Chander, Md. O. Haque, E. Micijevic, J. A. Barsi
2008, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
From the Landsat program's inception in 1972 to the present, the earth science user community has benefited from a historical record of remotely sensed data. The multispectral data from the Landsat 5 (L5) Thematic Mapper (TM) sensor provide the backbone for this extensive archive. Historically, the radiometric calibration procedure for...
Radiometric cross-calibration of the Terra MODIS and Landsat 7 ETM+ using an invariant desert site
T. Choi, A. Angal, G. Chander, X. Xiong
2008, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
A methodology for long-term radiometric cross-calibration between the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) sensors was developed. The approach involves calibration of near-simultaneous surface observations between 2000 and 2007. Fifty-seven cloud-free image pairs were carefully selected over the Libyan desert for...
Validation of exposure time for discharge measurements made with two bottom-tracking acoustic doppler current profilers
J. A. Czuba, K. Oberg
2008, Conference Paper, Proceedings of the IEEE working conference on current measurement technology
Previous work by Oberg and Mueller of the U.S. Geological Survey in 2007 concluded that exposure time (total time spent sampling the flow) is a critical factor in reducing measurement uncertainty. In a subsequent paper, Oberg and Mueller validated these conclusions using one set of data to show that the...
Key elements of regional seismic velocity models for long period ground motion simulations
T.M. Brocher
2008, Journal of Seismology (12) 217-221
Regional 3-D seismic velocity models used for broadband strong motion simulations must include compressional-wave velocity (Vp), shear-wave velocity (Vs), intrinsic attenuation (Qp, Qs), and density. Vs and Qs are the most important of these parameters because the strongest ground motions are generated chiefly by shear- and surface-wave arrivals. Because Vp...
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
2008, Geochemical Journal (42) 93-118
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986,...
Temporal trends in nitrate and selected pesticides in mid-atlantic ground water
L.M. Debrewer, S.W. Ator, J. M. Denver
2008, Conference Paper, Journal of Environmental Quality
Evaluating long-term temporal trends in regional ground-water quality is complicated by variable hydrogeologic conditions and typically slow flow, and such trends have rarely been directly measured. Ground-water samples were collected over near-decadal and annual intervals from unconfined aquifers in agricultural areas of the Mid-Atlantic region, including fractured carbonate rocks in...
Carbonate precipitation by the thermophilic archaeon Archaeoglobus fulgidus: A model of carbon flow for an ancient microorganism
L. L. Robbins, K. A. Van Cleave, P. Ostrom
2008, Biogeosciences Discussions (5) 3409-3432
Microbial carbonate precipitation experiments were conducted using the archaeon bacteria Archaeoglobus fulgidus to determine chemical and isotopic fractionation of organic and inorganic carbon into mineral phases. Carbonate precipitation was induced in two different experiments using A. fulgidus to determine the relative abundance of organically derived carbon incorporated into carbonate minerals...
Tales from a distant swamp: Petrological and paleobotanical clues for the origin of the sand coal lithotype (Mississippian, Valley Fields, Virginia)
J.C. Hower, J.M.K. O’Keefe, C.F. Eble
2008, International Journal of Coal Geology (75) 119-126
Tournasian (Mississippian) Price Formation semianthracites (Rmax = 2.40%) in the Valley Fields of southwestern Virginia contain a lithotype described in an early-20th-century report as a "sand" coal. The Center for Applied Energy Research inherited a collection of coals containing sand coal specimens, making it possible to study the lithotype from...
The release of dissolved actinium to the ocean: A global comparison of different end-members
W. Geibert, M. Charette, G. Kim, W.S. Moore, J. Street, M. Young, A. Paytan
2008, Marine Chemistry (109) 409-420
The measurement of short-lived 223Ra often involves a second measurement for supported activities, which represents 227Ac in the sample. Here we exploit this fact, presenting a set of 284 values on the oceanic distribution of 227Ac, which was collected when analyzing water samples for short-lived radium isotopes by the radium...
Wildfire effects on water temperature and selection of breeding sites by the Boreal Toad (Bufo boreas) in seasonal wetlands
B. R. Hossack, P.S. Corn
2008, Herpetological Conservation and Biology (3) 46-54
Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature,...
Turning population trend monitoring into active conservation: Can we save the cascades frog (Rang cascadae) in the Lassen Region of California?
G. M. Fellers, K.L. Pope, J.E. Stead, M.S. Koo, W.H. Welsh Jr.
2008, Herpetological Conservation and Biology (3) 28-39
Monitoring the distribution, population size, and trends of declining species is necessary to evaluate their vulnerability to extinction. It is the responsibility of scientists to alert management professionals of the need for preemptive action if a species approaches imminent, regional extirpation. This is the case with Rana cascadae (Cascades Frog)...
Nutrient availability affects pigment production but not growth in lichens of biological soil crusts
M. A. Bowker, G.W. Koch, J. Belnap, N.C. Johnson
2008, Soil Biology and Biochemistry (40) 2819-2826
Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn...
