Species frequency dynamics in an old-field succession: Effects of disturbance, fertilization and scale
David J. Gibson, Beth A. Middleton, K. Foster, Y. A. K. Honu, E. W. Hoyer, M. Mathis
2005, Journal of Vegetation Science (16) 415-422
Question:Can patterns of species frequency in an old-field be explained within the context of a metapopulation model? Are the patterns observed related to time, spatial scale, disturbance, and nutrient availability?Location:Upland and lowland old-fields in Illinois, USA.Method:Species richness was recorded annually for...
Using cosmogenic nuclides to contrast rates of erosion and sediment yield in a semi-arid, arroyo-dominated landscape, Rio Puerco Basin, New Mexico
P.R. Bierman, J.M. Reuter, M. Pavich, A. C. Gellis, M.W. Caffee, J. Larsen
2005, Earth Surface Processes and Landforms (30) 935-953
Analysis of in-situ-produced 10Be and 26Al in 52 fluvial sediment samples shows that millennial-scale rates of erosion vary widely (7 to 366 m Ma-1) through the lithologically and topographically complex Rio Puerco Basin of northern New Mexico. Using isotopic analysis of both headwater and downstream samples, we determined that the...
Spatial and temporal use of a spawning site in the middle green river by wild and hatchery-reared razorback suckers
T. Modde, Z.H. Bowen, D.C. Kitcheyan
2005, Transactions of the American Fisheries Society (134) 937-944
The population of endangered razorback suckers Xyrauchen texanus in the middle Green River (upper Colorado River basin) has declined during the last 40 years. The apparent cause for this decline is a lack of successful recruitment. This study used radiotelemetry to evaluate the ability of hatchery-reared razorback suckers to locate...
Sources, bioavailability, and photoreactivity of dissolved organic carbon in the Sacramento-San Joaquin River Delta
R. Stepanauskas, M.A. Moran, B.A. Bergamaschi, J.T. Hollibaugh
2005, Biogeochemistry (74) 131-149
We analyzed bioavailability, photoreactivity, fluorescence, and isotopic composition of dissolved organic carbon (DOC) collected at 13 stations in the Sacramento-San Joaquin River Delta during various seasons to estimate the persistence of DOC from diverse shallow water habitat sources. Prospective large-scale wetland restorations in the Delta may change the amount of...
Source mechanism of Vulcanian degassing at Popocatépetl Volcano, Mexico, determined from waveform inversions of very long period signals
Bernard A. Chouet, Phillip B. Dawson, Alejandra Arciniega-Ceballos
2005, Journal of Geophysical Research B: Solid Earth (110) 1-20
The source mechanism of very long period (VLP) signals accompanying volcanic degassing bursts at Popocatépetl is analyzed in the 15–70 s band by minimizing the residual error between data and synthetics calculated for a point source embedded in a homogeneous medium. The waveforms of two eruptions (23 April and 23...
Simulating the evolution of coastal morphology and stratigraphy with a new morphological-behaviour model (GEOMBEST)
D. Stolper, J. H. List, E.R. Thieler
2005, Marine Geology (218) 17-36
A new morphological-behaviour model is used to simulate evolution of coastal morphology associated with cross-shore translations of the shoreface, barrier, and estuary. The model encapsulates qualitative principles drawn from established geological concepts that are parameterized to provide quantitative predictions of morphological change on geological time scales (order 10 3 years),...
Conceptual model of sediment processes in the upper Yuba River watershed, Sierra Nevada, CA
Jennifer A. Curtis, Lorraine E. Flint, Charles N. Alpers, S.M. Yarnell
2005, Geomorphology (68) 149-166
This study examines the development of a conceptual model of sediment processes in the upper Yuba River watershed; and we hypothesize how components of the conceptual model may be spatially distributed using a geographical information system (GIS). The conceptual model illustrates key processes controlling sediment dynamics in the upper Yuba...
New surveys of the Chesapeake Bay impact structure suggest melt pockets and target-structure effect
A. K. Shah, J. Brozena, P. Vogt, D. Daniels, J. Plescia
2005, Geology (33) 417-420
We present high-resolution gravity and magnetic field survey results over the 85-km-diameter Chesapeake Bay impact structure. Whereas a continuous melt sheet is anticipated at a crater this size, shallow-source magnetic field anomalies of ???100 nT instead suggest that impact melt pooled in kilometer-scaled pockets surrounding the base of a central...
Disturbance frequency and community structure in a twenty-five year intervention study
J.C. Trexler, W.F. Loftus, S. Perry
2005, Oecologia (145) 140-152
Models of community regulation commonly incorporate gradients of disturbance inversely related to the role of biotic interactions in regulating intermediate trophic levels. Higher trophic-level organisms are predicted to be more strongly limited by intermediate levels of disturbance than are the organisms they consume. We used a manipulation of the frequency...
The evolution of vertebrate Toll-like receptors
J.C. Roach, G. Glusman, L. Rowen, A. Kaur, M. K. Purcell, K.D. Smith, L.E. Hood, A. Aderem
2005, Proceedings of the National Academy of Sciences of the United States of America (102) 9577-9582
The complete sequences of Takifugu Toll-like receptor (TLR) loci and gene predictions from many draft genomes enable comprehensive molecular phylogenetic analysis. Strong selective pressure for recognition of and response to pathogen-associated molecular patterns has maintained a largely unchanging TLR recognition in all vertebrates. There are six major families of vertebrate...
Heat as a tracer to estimate dissolved organic carbon flux from a restored wetland
K.R. Burow, J. Constantz, R. Fujii
2005, Ground Water (43) 545-556
Heat was used as a natural tracer to characterize shallow ground water flow beneath a complex wetland system. Hydrogeologic data were combined with measured vertical temperature profiles to constrain a series of two‐dimensional, transient simulations of ground water flow and heat transport using the model code...
Suburban wildlife: Lessons, challenges, and opportunities
S. DeStefano, R.D. Deblinger, C. Miller
2005, Urban Ecosystems (8) 131-137
The United States, as well as most developed and many developing nations worldwide, is becoming increasingly urban and suburban.Although urban, suburban, and commercial development account for less than one percent to just over 20% of land use among states, 50-90% of the residents of those states can be classified as...
Acute and chronic toxicity of lead in water and diet to the amphipod Hyalella azteca
J.M. Besser, W. G. Brumbaugh, E.L. Brunson, C.G. Ingersoll
2005, Environmental Toxicology and Chemistry (24) 1807-1815
We evaluated the influence of waterborne and dietary lead (Pb) exposure on the acute and chronic toxicity of Pb to the amphipod Hyalella azteca. Test solutions were generated by a modified diluter with an extended (24‐h) equilibration period. Acute (96‐h) toxicity of Pb varied with water hardness...
Estimation of regional material yield from coastal landslides based on historical digital terrain modelling
C.J. Hapke
2005, Earth Surface Processes and Landforms (30) 679-697
High-resolution historical (1942) and recent (1994) digital terrain models were derived from aerial photographs along the Big Sur coastline in central California to measure the long-term volume of material that enters the nearshore environment. During the 52-year measurement time period, an average of 21 000 ?? 3100 m3 km-1 a-1...
Transmission of atmospherically derived trace elements through an undeveloped, forested Maryland watershed
J.R. Scudlark, Karen C. Rice, Kathryn M. Conko, Owen P. Bricker, T.M. Church
2005, Water, Air, & Soil Pollution (163) 53-79
The transmission of atmospherically derived trace elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) was evaluated in a small, undeveloped, forested watershed located in north-central Maryland. Atmospheric input was determined for wet-only and vegetative throughfall components. Annual throughfall fluxes were significantly enriched over incident...
Analysis of vegetation distribution in Interior Alaska and sensitivity to climate change using a logistic regression approach
M.P. Calef, A. D. McGuire, H.E. Epstein, T.S. Rupp, H.H. Shugart
2005, Journal of Biogeography (32) 863-878
Aim: To understand drivers of vegetation type distribution and sensitivity to climate change. Location: Interior Alaska. Methods: A logistic regression model was developed that predicts the potential equilibrium distribution of four major vegetation types: tundra, deciduous forest, black spruce forest and white spruce forest based on elevation, aspect, slope, drainage...
Lagoonal reef accretion and holocene sea-level history from three atolls in the Cook Islands, Central South Pacific
S.C. Gray, J.R. Hein
2005, Journal of Coastal Research (21) 253-264
Radiocarbon ages of corals from cores collected at nine drill sites in the lagoons of three atolls (Pukapuka, Rakahanga, Aitutaki, Cook Islands) provide a history of lagoon sedimentation in response to Holocene sea-level rise and stabilization. Holocene lagoonal reefs were established between 8700 and 7800 years B.P. on 130,000-200,000 year-old...
The role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion
P.D. Krushelnycky, S.M. Joe, A.C. Medeiros, C.C. Daehler, L.L. Loope
2005, Diversity and Distributions (11) 319-331
Analysis of long-term patterns of invasion can reveal the importance of abiotic factors in influencing invasion dynamics, and can help predict future patterns of spread. In the case of the invasive Argentine ant (Linepithema humile), most prior studies have investigated this species' limitations in hot and dry climates. However, spatial...
Willingness to pay for non angler recreation at the lower Snake River reservoirs
J.R. McKean, D. Johnson, R.G. Taylor, Richard L. Johnson
2005, Journal of Leisure Research (37) 178-194
This study applied the travel cost method to estimate demand for non angler recreation at the impounded Snake River in eastern Washington. Net value per person per recreation trip is estimated for the full non angler sample and separately for camping, boating, water-skiing, and swimming/picnicking. Certain recreation activities would be...
Incorporating seepage losses into the unsteady streamflow equations for simulating intermittent flow along mountain front streams
R.G. Niswonger, David E. Prudic, G. Pohll, J. Constantz
2005, Water Resources Research (41) 1-16
Seepage losses along numerous mountain front streams that discharge intermittently onto alluvial fans and piedmont alluvial plains are an important source of groundwater in the Basin and Range Province of the Western United States. Determining the distribution of seepage loss along mountain front streams is important when assessing groundwater resources...
Karst database development in Minnesota: Design and data assembly
Y. Gao, E.C. Alexander Jr., R.G. Tipping
2005, Environmental Geology (47) 1072-1082
The Karst Feature Database (KFD) of Minnesota is a relational GIS-based Database Management System (DBMS). Previous karst feature datasets used inconsistent attributes to describe karst features in different areas of Minnesota. Existing metadata were modified and standardized to represent a comprehensive metadata for all the karst features in Minnesota. Microsoft...
Baseline models of trace elements in major aquifers of the United States
L. Lee, D. Helsel
2005, Applied Geochemistry (20) 1560-1570
Trace-element concentrations in baseline samples from a survey of aquifers used as potable-water supplies in the United States are summarized using methods appropriate for data with multiple detection limits. The resulting statistical distribution models are used to develop summary statistics and estimate probabilities of exceeding water-quality standards. The models are...
Effects of urban development in the Puget Lowland, Washington, on interannual streamflow patterns: Consequences for channel form and streambed disturbance
Christopher P. Konrad, Derek B. Booth, Stephen J. Burges
2005, Water Resources Research (41)
Recovery and protection of streams in urban areas depend on a comprehensive understanding of how human activities affect stream ecosystems. The hydrologic effects of urban development and the consequences for stream channel form and streambed stability were examined in 16 streams in the Puget Lowland, Washington, using three streamflow metrics...
A spatial model of potential jaguar habitat in Arizona
J.R. Hatten, A. Averill-Murray, W.E. van Pelt
2005, Journal of Wildlife Management (69) 1024-1033
The jaguar (Panthera onca) is an endangered species that occasionally visits the southwestern United States from Mexico. The number of jaguar sightings per decade has declined over the last 100 years in Arizona, USA, raising conservation concerns for the species at a local and national level. In 1997, state, federal,...
DUCKS: Low cost thermal monitoring units for near-vent deployment
A. Harris, D. Pirie, K. Horton, H. Garbeil, E. Pilger, H. Ramm, R. Hoblitt, C. Thornber, M. Ripepe, E. Marchetti, P. Poggi
2005, Journal of Volcanology and Geothermal Research (143) 335-360
During 1999 we designed and tested a thermal monitoring system to provide a cheap, robust, modular, real-time system capable of surviving the hostile conditions encountered proximal to active volcanic vents. In November 2000 the first system was deployed at Pu'u...
