Contingency table analysis of pebble lithology and roundness: A case study of Huangshui River, China and comparison to rivers in the Rocky Mountains, USA
X. Miao, D. A. Lindsey, Z. Lai, Xiuying Liu
2010, Sedimentary Geology (224) 49-53
Contingency table analysis of pebble lithology and roundness is an effective way to identify the source terrane of a drainage basin and to distinguish changes in basin size, piracy, tectonism, and other events. First, the analysis to terrace gravel deposited by the Huangshui River, northeastern Tibet Plateau, China, shows statistically...
Impact of biological soil crusts and desert plants on soil microfaunal community composition
B.J. Darby, D.A. Neher, J. Belnap
2010, Plant and Soil (328) 421-431
Carbon and nitrogen are supplied by a variety of sources in the desert food web; both vascular and non-vascular plants and cyanobacteria supply carbon, and cyanobacteria and plant-associated rhizosphere bacteria are sources of biological nitrogen fixation. The objective of this study was to compare the relative influence of vascular plants...
Estimating length of avian incubation and nestling stages in afrotropical forest birds from interval-censored nest records
T.R. Stanley, W.D. Newmark
2010, The Auk (127) 79-85
In the East Usambara Mountains in northeast Tanzania, research on the effects of forest fragmentation and disturbance on nest survival in understory birds resulted in the accumulation of 1,002 nest records between 2003 and 2008 for 8 poorly studied species. Because information on the length of the incubation and nestling...
Laboratory chalcopyrite oxidation by Acidithiobacillus ferrooxidans: Oxygen and sulfur isotope fractionation
R.S. Thurston, K.W. Mandernack, Wayne C. Shanks III
2010, Chemical Geology (269) 252-261
Laboratory experiments were conducted to simulate chalcopyrite oxidation under anaerobic and aerobic conditions in the absence or presence of the bacterium Acidithiobacillus ferrooxidans. Experiments were carried out with 3 different oxygen isotope values of water (??18OH2O) so that approach to equilibrium or steady-state isotope fractionation for different starting conditions could...
Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise
T.W. Doyle, K. W. Krauss, W.H. Conner, A.S. From
2010, Forest Ecology and Management (259) 770-777
Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest...
Physiological, molecular, and cellular mechanisms of impaired seawater tolerance following exposure of Atlantic salmon, Salmo salar, smolts to acid and aluminum
M.Y. Monette, T. Yada, V. Matey, S. D. McCormick
2010, Aquatic Toxicology (99) 17-32
We examined the physiological, molecular, and cellular mechanisms of impaired ion regulation in Atlantic salmon, Salmo salar, smolts following acute acid and aluminum (Al) exposure. Smolts were exposed to: control (pH 6.5, 3.4??gl-1 Al), acid and low Al (LAl: pH 5.4, 11??gl-1 Al), acid and moderate Al (MAl: pH 5.3,...
The Sudbury impact layer in the paleoproterozoiciron ranges of northern Michigan, USA
W.F. Cannon, K. J. Schulz, J. Wright Horton Jr., David A. King
2010, Geological Society of America Bulletin (122) 50-75
A layer of breccia that contains fragments of impact ejecta has been found at 10 sites in the Paleoproterozoic iron ranges of northern Michigan, in the Lake Superior region of the United States. Radiometric age constraints from events predating and postdating deposition of the breccia are ca. 1875 Ma and...
Measurement and modeling of polychlorinated biphenyl bioaccumulation from sediment for the marine polychaete neanthes arenaceodentata and response to sorbent amendment
E.M.-L. Janssen, Marie Noele Croteau, S. N. Luoma, R.G. Luthy
2010, Environmental Science & Technology (44) 2857-2863
Bioaccumulation rates of polychlorinated biphenyls (PCBs) for the marine polychaete Neanthes arenaceodentata were characterized, including PCB uptake rates from water and sediment, and the effect of sorbent amendment to the sediment on PCB bioavailability, organism growth, and lipid content. Physiological parameters were incorporated into a biodynamic model to predict contaminant...
40Ar/39Ar geochronology and geochemical reconnaissance of the Eocene Lowland Creek volcanic field, west-central Montana
F.O. Dudas, V.O. Ispolatov, S. S. Harlan, L.W. Snee
2010, Journal of Geology (118) 295-304
We report geochronological and geochemical data for the calc-alkalic Lowland Creek volcanic field (LCVF) in westcentral Montana. 40Ar/ 39Ar age determinations show that the LCVF was active from 52.9 to 48.6 Ma, with tuff-forming eruptions at 52.9 ?? 0.14 and 51.8 ?? 0.14 Ma. These dates span the age range...
Sapflow and water use of freshwater wetland trees exposed to saltwater incursion in a tidally influenced South Carolina watershed
K. W. Krauss, J.A. Duberstein
2010, Canadian Journal of Forest Research (40) 525-535
Sea-level rise and anthropogenic activity promote salinity incursion into many tidal freshwater forested wetlands. Interestingly, individual trees can persist for decades after salt impact. To understand why, we documented sapflow (Js), reduction in Js with sapwood depth, and water use (F) of baldcypress (Taxodium distichum (L.) Rich.) trees undergoing exposure...
Effects of prior detections on estimates of detection probability, abundance, and occupancy
Jason D. Riddle, Rua S. Mordecai, Kenneth H. Pollock, Theodore R. Simons
2010, The Auk (127) 94-99
Survey methods that account for detection probability often require repeated detections of individual birds or repeated visits to a site to conduct Counts or collect presence-absence data. Initial encounters with individual species or individuals of a species could influence detection probabilities for subsequent encounters. For example, observers may be more...
Development of a macrophyte-based index of biotic integrity for Minnesota lakes
M.W. Beck, L.K. Hatch, B. Vondracek, R.D. Valley
2010, Ecological Indicators (10) 968-979
Traditional approaches for managing aquatic resources have often failed to account for effects of anthropogenic disturbances on biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective assessment method to integrate ecological, functional, and structural aspects...
Effects of topographic position and geology on shaking damage to residential wood-framed structures during the 2003 San Simeon earthquake, western San Luis obispo county, California
T.P. McCrink, C.J. Wills, C.R. Real, M.W. Manson
2010, Earthquake Spectra (26) 779-802
A statistical evaluation of shaking damage to wood-framed houses caused by the 2003 M6.5 San Simeon earthquake indicates that both the rate and severity of damage, independent of structure type, are significantly greater on hilltops compared to hill slopes when underlain by Cretaceous or Tertiary sedimentary rocks. This increase in...
Inherent Limitations of Hydraulic Tomography
Geoffrey C. Bohling, J.J. Butler
2010, Ground Water (48) 809-824
We offer a cautionary note in response to an increasing level of enthusiasm regarding high-resolution aquifer characterization with hydraulic tomography. We use synthetic examples based on two recent field experiments to demonstrate that a high degree of nonuniqueness remains in estimates of hydraulic parameter fields even when those estimates are...
Marine effect of introduced salmonids: Prey consumption by exotic steelhead and anadromous brown trout in the Patagonian Continental Shelf
J. Ciancio, D.A. Beauchamp, M. Pascual
2010, Limnology and Oceanography (55) 2181-2192
On the basis of stable isotope analysis, we estimated the marine diet of the most abundant anadromous salmonid species in Patagonian Atlantic basins. The results were coupled with bioenergetic and population models to estimate the consumption of food by salmonids and was compared with that by seabirds, the most abundant...
Effects of coalbed natural gas development on fish assemblages in tributary streams of the Powder and Tongue rivers
W.N. Davis, R.G. Bramblett, A.V. Zale
2010, Freshwater Biology (55) 2612-2625
1. Extraction of coalbed natural gas (CBNG) often results in disposal of large quantities of CBNG product water, which may affect aquatic ecosystems. We evaluated the effects of CBNG development on fish assemblages in tributary streams of the Powder and Tongue rivers. We used treatment and control, impact versus reference...
Radiocarbon dating of small terrestrial gastropod shells in North America
J.S. Pigati, J.A. Rech, J.C. Nekola
2010, Quaternary Geochronology (5) 519-532
Fossil shells of small terrestrial gastropods are commonly preserved in wetland, alluvial, loess, and glacial deposits, as well as in sediments at many archeological sites. These shells are composed largely of aragonite (CaCO3) and potentially could be used for radiocarbon dating, but they must meet two criteria before their 14C...
SHRIMP U-Pb dating of recurrent Cryogenian and Late Cambrian-Early Ordovician alkalic magmatism in central Idaho: Implications for Rodinian rift tectonics
K. Lund, J. N. Aleinikoff, K. V. Evans, E. A. duBray, E.H. deWitt, D.M. Unruh
2010, Geological Society of America Bulletin (122) 430-453
Composite alkalic plutonic suites and tuffaceous diamictite, although discontinuously exposed across central Idaho in roof pendants and inliers within the Idaho batholith and Challis volcanic-plutonic complex, define the >200-km-long northwest-aligned Big Creek-Beaverhead belt. Sensitive highresolution ion microprobe (SHRIMP) U-Pb zircon dates on these igneous rocks provide direct evidence for the...
Seasonal movements, winter range use, and migratory connectivity of the Black Oystercatcher
M. Johnson, P. Clarkson, M.I. Goldstein, S. M. Haig, Richard B. Lanctot, D.F. Tessler, D. Zwiefelhofer
2010, Condor (112) 731-743
The Black Oystercatcher (Haematopus bachmani) is an intertidal obligate along North America's Pacific coast and a species of high conservation concern (population size 8900-11 000 individuals). Understanding birds' movements and space use throughout the annual cycle has become paramount in the face of changing environmental conditions, and intertidal species may...
Neotectonics and paleoseismology of the Limón and pedro miguel faults in Panamá: earthquake hazard to the Panamá canal
Thomas Rockwell, Edon Gath, Tania Gonzalez, Chris Madden, Danielle Verdugo, Caitlin Lippincott, Tim Dawson, Lewis A. Owen, Markus Fuchs, Ana Cadena, Pat Williams, Elise Weldon, Pastora Franceschi
2010, Bulletin of the Seismological Society of America (100) 3097-3129
We present new geologic, tectonic geomorphic, and geochronologic data on the slip rate, timing, and size of past surface ruptures for the right-lateral Lim??n and Pedro Miguel faults in central Panam??. These faults are part of a system of conjugate faults that accommodate the internal deformation of Panam?? resulting from...
Redwoods, restoration, and implications for carbon budgets
Mary Ann Madej
2010, Geomorphology (116) 264-273
The coast redwoods (Sequoia sempervirens) of California have several unique characteristics that influence interactions between vegetation and geomorphic processes. Case studies, using a combination of in-channel wood surveys and an air photo inventory of landslides, illustrate current conditions in a redwood-dominated watershed undergoing restoration work, and the influence of wood...
Detrital zircon evidence for progressive underthrusting in Franciscan metagraywackes, west-central California
C.A. Snow, J. Wakabayashi, W. G. Ernst, J. L. Wooden
2010, Geological Society of America Bulletin (122) 282-291
We present new U/Pb ages for detrital zircons separated from six quartzose metagraywackes collected from different Franciscan Complex imbricate nappes around San Francisco Bay. All six rocks contain a broad spread of Late Jurassic-Cretaceous grains originating from the Klamath-Sierra Nevada volcanic-plutonic arc. Units young structurally downward, consistent with models of...
Paleobiogeography, high-resolution stratigraphy, and the future of Paleozoic biostratigraphy: Fine-scale diachroneity of the Wenlock (Silurian) conodont Kockelella walliseri
Bradley D. Cramer, Mark A. Kleffner, Carlton E. Brett, P.I. McLaughlin, Lennart Jeppsson, Axel Munnecke, Christian Samtleben
2010, Palaeogeography, Palaeoclimatology, Palaeoecology (294) 232-241
The Wenlock Epoch of the Silurian Period has become one of the chronostratigraphically best-constrained intervals of the Paleozoic. The integration of multiple chronostratigraphic tools, such as conodont and graptolite biostratigraphy, sequence stratigraphy, and ??13Ccarb chemostratigraphy, has greatly improved global chronostratigraphic correlation and portions of the Wenlock can now be correlated...
Estimating soil turnover rate from tree uprooting during hurricanes in Puerto Rico
M.T. Lenart, D.A. Falk, F.N. Scatena, W. R. Osterkamp
2010, Forest Ecology and Management (259) 1076-1084
Soil turnover by tree uprooting in primary and secondary forests on the island of Puerto Rico was measured in 42 study plots in the months immediately after the passage of a Category 3 hurricane. Trunk basal area explained 61% of the variability of mound volume and 53% of the variability...
Post-collisional magmatism in the central East African Orogen: The Maevarano Suite of north Madagascar
K. M. Goodenough, Ronald J. Thomas, B. De Waele, R. M. Key, D. I. Schofield, W. Bauer, R. D. Tucker, J. M. Rafahatelo, M. Rabarimanana, A.V. Ralison, T. Randriamananjara
2010, LITHOS (116) 18-34
Late tectonic, post-collisional granite suites are a feature of many parts of the Late Neoproterozoic to Cambrian East African Orogen (EAO), where they are generally attributed to late extensional collapse of the orogen, accompanied by high heat flow and asthenospheric uprise. The Maevarano Suite comprises voluminous plutons which were emplaced...
