Statistical modeling of storm-level Kp occurrences
K.J. Remick, Jeffrey J. Love
2006, Geophysical Research Letters (33)
We consider the statistical modeling of the occurrence in time of large Kp magnetic storms as a Poisson process, testing whether or not relatively rare, large Kp events can be considered to arise from a stochastic, sequential, and memoryless process. For a Poisson process, the wait times between successive events...
Fens and floodplains of the temperate zone: Present status, threats, conservation and restoration
R. Van Diggelen, B. Middleton, J. Bakker, A. Grootjans, M. Wassen
2006, Conference Paper, Applied Vegetation Science
This Special Feature focuses on lowland fens and flood plains. In this introduction we discuss the most important mire-related terms, present status, threats and conservation and restoration attempts. Floodplains and especially lowland fens are rare and vulnerable ecosystems. They are highly threatened all over the world because of direct conversion...
Ostracods and facies of the Early and Middle Frasnian at Devils Gate in Nevada: Relationship to the Alamo Event
J.-G. Casier, I. Berra, Ewa Olempska, Charles Sandberg, A. Preat
2006, Acta Palaeontologica Polonica (51) 813-828
In order to document the Alamo Event and to investigate its influence on shallow-marine environments, we undertook a study of ostracods, conodonts, and analysis of the sedimentology of the lower member of the type Devils Gate Limestone, Six major carbonate microfacies (MF1-MF6) ranging from open-marine environments below storm wave base...
Integrated biostratigraphy of foraminifers, radiolarians and conodonts in shallow and deep water Middle Permian (Capitanian) deposits of the "Rader slide", Guadalupe Mountains, West Texas
M.K. Nestell, G.P. Nestell, B. R. Wardlaw, M.J. Sweatt
2006, Stratigraphy (3) 161-194
A diverse assemblage of microfossils is present in a 6m thick sequence of three debris flow deposits interbedded with thin turbidite limestone beds and fine grained siliciclastics exposed above the megaconglomerate in a section (known as the "Rader Slide" in numerous guidebook stops) of the Rader Limestone Member of the...
Interspecific resource partitioning in sympatric ursids
Jerrold L. Belant, Knut Kielland, Erich H. Follmann, Layne G. Adams
2006, Ecological Applications (16) 2333-2343
The fundamental niche of a species is rarely if ever realized because the presence of other species restricts it to a narrower range of ecological conditions. The effects of this narrower range of conditions define how resources are partitioned. Resource partitioning has been inferred but not demonstrated previously for sympatric...
Fabricating data: How substituting values for nondetects can ruin results, and what can be done about it
D.R. Helsel
2006, Chemosphere (65) 2434-2439
The most commonly used method in environmental chemistry to deal with values below detection limits is to substitute a fraction of the detection limit for each nondetect. Two decades of research has shown that this fabrication of values produces poor estimates of statistics, and commonly obscures patterns and trends in...
Attributes of desert tortoise populations at the National Training Center, Central Mojave Desert, California, USA
K.H. Berry, T.Y. Bailey, K.M. Anderson
2006, Journal of Arid Environments (67) 165-191
We sampled 21 study plots for desert tortoises (Gopherus agassizii) at the National Training Center, Fort Irwin, California. Each plot was sampled once between 1997 and 2003 to obtain a snapshot of population attributes, status, and relationships between tortoise densities and human activities. Densities ranged from <1 to 28 tortoises...
Complementary population dynamics of exotic and native Daphnia in North American reservoir communities
J.E. Havel, J.L. Graham
2006, Archiv fur Hydrobiologie (167) 245-264
During its invasion of North America, the exotic Daphnia lumholtzi has rapidly colonized numerous reservoirs, natural lakes, and large rivers. In the current study, we examine the overlap between D. lumholtzi and native Daphnia species through analysis of two data sets: co-occurrence in reservoirs of the south-central United States and...
Geomorphic effects of large debris flows and flash floods, northern Venezuela, 1999
M. C. Larsen, G. F. Wieczorek
2006, Zeitschrift fur Geomorphologie, Supplementband (145) 147-175
A rare, high-magnitude storm in northern Venezuela in December 1999 triggered debris flows and flash floods, and caused one of the worst natural disasters in the recorded history of the Americas. Some 15,000 people were killed. The debris flows and floods inundated coastal communities on alluvial fans at the mouths...
Biodiversity management of fens and fen meadows by grazing, cutting and burning
B.A. Middleton, B. Holsten, R. Van Diggelen
2006, Conference Paper, Applied Vegetation Science
Question: Can the biodiversity of fens in Europe and North America be maintained through the use of grazing (especially cattle grazing), fire, and/or cutting? Location: European and North American fens. Methods: This paper is a review of the literature on the effects of grazing, fire and cutting on fens, to...
The rocks of Gusev Crater as viewed by the Mini-TES instrument
S. W. Ruff, P. R. Christensen, D.L. Blaney, W. H. Farrand, J. R. Johnson, J.R. Michalski, J.E. Moersch, S.P. Wright, S. W. Squyres
2006, Journal of Geophysical Research E: Planets (111)
The Miniature Thermal Emission Spectrometer (Mini-TES) on board the Mars Exploration Rover Spirit is part of a payload designed to investigate whether a lake once existed in Gusev Crater. Mini-TES has observed hundreds of rocks along the rover's traverse into the Columbia Hills, yielding information on their distribution, bulk mineralogy,...
Automatic alignment of vector data and orthoimagery for the national map
C.A. Knoblock, C. Shahabi, C.-C. Chen, E.L. Usery
2006, Conference Paper, ACM International Conference Proceeding Series
A general problem in combining road vector data with orthoimagery from different sources is that they rarely align. There are a variety of causes to this problem, but the most common one is that the latest products are collected with higher accuracy and improved processing techniques. In previous work, we...
Testing of stack-unit/aquifer sensitivity analysis using contaminant plume distribution in the subsurface of Savannah River Site, South Carolina, USA
J.M. Rine, J.M. Shafer, E. Covington, R. C. Berg
2006, Hydrogeology Journal (14) 1620-1634
Published information on the correlation and field-testing of the technique of stack-unit/aquifer sensitivity mapping with documented subsurface contaminant plumes is rare. The inherent characteristic of stack-unit mapping, which makes it a superior technique to other analyses that amalgamate data, is the ability to deconstruct the sensitivity analysis on a unit-by-unit...
Pelagic seabird surveys in the Tuamotu and Gambier Archipelagos, French Polynesia
Eric A. Vanderwerf, Ray J. Pierce, Verena A. Gill, Graham Wragg, Philippe Raust, T. Lee Tibbitts
2006, Marine Ornithology: Journal of Seabird Research and Conservation (34) 65-70
We conducted pelagic seabird surveys in the Gambier and Tuamotu Archipelagos in the southeastern Pacific Ocean totaling 40 hours during 7-27 March 2003 and 22.5 hours during 22-27 July 2001. We used a 300-m-wide strip transect to estimate seabird density, and we estimated relative abundance of birds at all distances....
Predicting minimum habitat characteristics for the Indiana bat in the Champlain Valley
K.S. Watrous, T.M. Donovan, R.M. Mickey, S.R. Darling, A.C. Hicks, S. L. Von Oettingen
2006, Journal of Wildlife Management (70) 1228-1237
Predicting potential habitat across a landscape for rare species is extremely challenging. However, partitioned Mahalanobis D2 methods avoid pitfalls commonly encountered when surveying rare species by using data collected only at known species locations. Minimum habitat requirements are then determined by examining a principal components analysis to find consistent habitat...
Influence of potentially confounding factors on sea urchin porewater toxicity tests
R.S. Carr, J.M. Biedenbach, M. Nipper
2006, Archives of Environmental Contamination and Toxicology (51) 573-579
The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH,...
Nesting habitat of the Tule Greater White-fronted Goose Anser albifrons elgasi
R.V. Densmore, Craig R. Ely, K.S. Bollinger, S. Kratzer, Mark S. Udevitz, D.J. Fehringer, T.C. Rothe
2006, Wildfowl (56) 37-51
This paper presents the first information on the availability and use of nesting habitat by the rare Tule Greater White-fronted Goose Anser albifrons elgasi. The breeding range was sampled by marking geese with radio transmitters on wintering and moulting areas, and tracking them to nest sites in Alaska. Nesting habitat...
A new probabilistic seismic hazard assessment for greater Tokyo
R.S. Stein, S. Toda, T. Parsons, E. Grunewald, R. Blong, S. Sparks, H. Shah, J. Kennedy
2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (364) 1965-1988
Tokyo and its outlying cities are home to one-quarter of Japan's 127 million people. Highly destructive earthquakes struck the capital in 1703, 1855 and 1923, the last of which took 105 000 lives. Fuelled by greater Tokyo's rich seismological record, but challenged by its magnificent complexity, our joint Japanese-US group...
Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico
L. Zambrano, E. Vazquez-Dominguez, D. Garcia-Bedoya, W.F. Loftus, J.C. Trexler
2006, Ichthyological Exploration of Freshwaters (17) 193-206
We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western...
Geology, geochronology, and geochemistry of basaltic flows of the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra, central New Mexico
F. Maldonado, J. R. Budahn, L. Peters, D.M. Unruh
2006, Canadian Journal of Earth Sciences (43) 1251-1268
The geochronology, geochemistry, and isotopic compositions of basaltic flows erupted from the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra volcanic centres in central New Mexico indicate that each of these lavas had unique origins and that the predominant mantle involved in their production was an ocean-island...
Proximate and landscape factors influence grassland bird distributions
M.A. Cunningham, Douglas H. Johnson
2006, Ecological Applications (16) 1062-1075
Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and...
Impact of eutrophication on shallow marine benthic foraminifers over the last 150 years in Osaka Bay, Japan
Akira Tsujimoto, Ritsuo Nomura, Moriaki Yasuhara, Hideo Yamazaki, Shusaku Yoshikawa
2006, Marine Micropaleontology (60) 258-268
High-resolution foraminiferal analysis was conducted on a short sediment core from the inner part of Osaka Bay, Japan. Changes in foraminiferal assemblages were associated with eutrophication, bottom water hypoxia, and changes in red tide-causing algae. Before the 1920s, the calcareous species Ammonia beccarii, and the agglutinated species Eggerella advena and...
Survey design for detecting rare freshwater mussels
D. R. Smith
2006, Journal of the North American Benthological Society (25) 701-711
A common objective when surveying freshwater mussels is to detect the presence of rare populations. In certain situations, such as when endangered or threatened species are potentially in the area of a proposed impact, the survey should be designed to ensure a high probability of detecting species presence. Linking survey...
Relevance of cryptic fishes in biodiversity assessments: A case study at Buck Island Reef National Monument, St. Croix
W. F. Smith-Vaniz, H.L. Jelks, L.A. Rocha
2006, Bulletin of Marine Science (79) 17-48
Because cryptic fishes are difficult to accurately survey, they are undersampled components of coral reef habitats, and their ecological roles have been generally ignored. Fifty-eight enclosed stations were sampled in shoreline, nearshore reef, lagoon, backreef, forereef, and bank/shelf habitats with an ichthyocide (rotenone) at Buck Island Reef National Monument, St....
Mineral of the month: tin
James F. Carlin Jr.
2005, Geotimes (2005)
Tin was one of the first metals discovered by humans and, like most metals, tin is rarely used by itself. Most tin is used as a protective coating or as an alloy with other metals in a diverse range of commercial and defense applications....
