A new ghost-node method for linking different models and initial investigations of heterogeneity and nonmatching grids
J.E. Dickinson, S.C. James, S. Mehl, M. C. Hill, S. A. Leake, G.A. Zyvoloski, C.C. Faunt, A.-A. Eddebbarh
2007, Advances in Water Resources (30) 1722-1736
A flexible, robust method for linking parent (regional-scale) and child (local-scale) grids of locally refined models that use different numerical methods is developed based on a new, iterative ghost-node method. Tests are presented for two-dimensional and three-dimensional pumped systems that are homogeneous or that have simple heterogeneity. The parent and...
Exploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III
Wolf M. Mooij, Julien Martin, Wiley M. Kitchens, Donald L. DeAngelis
2007, Book chapter, Temporal dimensions of landscape ecology: Wildlife responses to variable resources
The Florida snail kite (Rostrhamus sociabilis) is an endangered raptor that occurs as an isolated population, currently of about 2,000 birds, in the wetlands of southern and central Florida, USA. Its exclusive prey species, the apple snail (Pomacea paludosa) is strongly influenced by seasonal changes in...
Physical criteria for distinguishing sandy tsunami and storm deposits using modern examples
Robert A. Morton, Guy Gelfenbaum, Bruce E. Jaffe
2007, Sedimentary Geology (200) 184-207
Modern subaerial sand beds deposited by major tsunamis and hurricanes were compared at trench, transect, and sub-regional spatial scales to evaluate which attributes are most useful for distinguishing the two types of deposits. Physical criteria that may be diagnostic include: sediment composition,...
Simulated responses of soil organic carbon stock to tillage management scenarios in the Northwest Great Plains
Z. Tan, S. Liu, Z. Li, Thomas R. Loveland
2007, Carbon Balance and Management (2)
BackgroundTillage practices greatly affect carbon (C) stocks in agricultural soils. Quantification of the impacts of tillage on C stocks at a regional scale has been challenging because of the spatial heterogeneity of soil, climate, and management conditions. We evaluated the effects of tillage management on the dynamics of soil organic...
Direct and indirect estimates of natural mortality for Chesapeake Bay blue crab
D.A. Hewitt, D.M. Lambert, J.M. Hoenig, Romuald N. Lipcius, D.B. Bunnell, T.J. Miller
2007, Transactions of the American Fisheries Society (136) 1030-1040
Analyses of the population dynamics of blue crab Callinectes sapidus have been complicated by a lack of estimates of the instantaneous natural mortality rate (M). We developed the first direct estimates of M for this species by solving Baranov's catch equation for M given estimates of annual survival rate and exploitation rate. Annual survival rates were...
A stream sediment geochemical survey of the Ganga River headwaters in the Garhwal Himalaya
P.K. Mukherjee, K.K. Purohit, N.K. Saini, P.P. Khanna, M.S. Rathi, A. E. Grosz
2007, Geochemical Journal (41) 83-95
This study models geochemical and adjunct geologic data to define provinces that are favorable for radioactive-mineral exploration. A multi-element bed-sediment geochemical survey of streams was carried out in the headwaters region of the Ganga River in northern India. Overall median values for uranium and thorium (3.6 and 13.8 ppm; maxima...
Evapotranspiration in a cottonwood (Populus fremontii) restoration plantation estimated by sap flow and remote sensing methods
P. Nagler, A. Jetton, J. Fleming, K. Didan, E. Glenn, J. Erker, K. Morino, J. Milliken, S. Gloss
2007, Agricultural and Forest Meteorology (144) 95-110
Native tree plantations have been proposed for the restoration of wildlife habitat in human-altered riparian corridors of western U.S. rivers. Evapotranspiration (ET) by riparian vegetation is an important, but poorly quantified, term in river water budgets. Native tree restoration plots will potentially increase ET. We used sap flow sensors and...
Seismoelectric imaging of shallow targets
S.S. Haines, S.R. Pride, S.L. Klemperer, B. Biondi
2007, Geophysics (72)
We have undertaken a series of controlled field experiments to develop seismoelectric experimental methods for near-surface applications and to improve our understanding of seismoelectric phenomena. In a set of off-line geometry surveys (source separated from the receiver line), we place seismic sources and electrode array receivers on opposite sides of...
Nitrous oxide fluxes from cultivated areas and rangeland: U.S. High Plains
Edwin P. Weeks, Peter B. McMahon
2007, Vadose Zone Journal (6) 496-510
Concentration profiles of N2O, a greenhouse gas, and the conservative trace gases SF6 and the chlorofluorocarbons CFC-11, CFC-12, CFC-113, and were measured periodically through thick vadose zones at nine sites in the U.S. High Plains. The CFC and SF6 measurements were used to calibrate a one-dimensional gas diffusion model, using...
The application of satellite differential SAR interferometry-derived ground displacements in hydrogeology
D. L. Galloway, J. Hoffmann
2007, Hydrogeology Journal (15) 133-154
The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor, analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the previous decade show how...
Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake
M.J. Olsen, S.F. Bartlett, B.J. Solomon
2007, Earthquake Spectra (23) 95-113
This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data...
Late quaternary temperature record from buried soils of the North American Great Plains
L. Nordt, J. Von Fischer, L. Tieszen
2007, Geology (35) 159-162
We present the first comprehensive late Quaternary record of North American Great Plains temperature by assessing the behavior of the stable isotopic composition (δ13C) of buried soils. After examining the relationship between the δ13C of topsoil organic matter and July temperature from 61 native prairies within a latitudinal range of...
Seismoelectric data processing for surface surveys of shallow targets
S.S. Haines, A. Guitton, B. Biondi
2007, Geophysics (72)
The utility of the seismoelectric method relies on the development of methods to extract the signal of interest from background and source-generated coherent noise that may be several orders-of-magnitude stronger. We compare data processing approaches to develop a sequence of preprocessing and signal/noise separation and to quantify the noise level...
Body size mediated coexistence of consumers competing for resources in space
A. Basset, D.L. Angelis
2007, Oikos (116) 1363-1377
Body size is a major phenotypic trait of individuals that commonly differentiates co-occurring species. We analyzed inter-specific competitive interactions between a large consumer and smaller competitors, whose energetics, selection and giving-up behaviour on identical resource patches scaled with individual body size. The aim was to investigate whether pure metabolic constraints...
Factors influencing ground-water recharge in the eastern United States
B. T. Nolan, R. W. Healy, P.E. Taber, K. Perkins, K.J. Hitt, D.M. Wolock
2007, Journal of Hydrology (332) 187-205
Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1...
Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer
Douglas B. Kent, J.A. Wilkie, J.A. Davis
2007, Water Resources Research (43)
[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of...
The effects of acidic mine drainage from historical mines in the Animas River watershed, San Juan County, Colorado—What is being done and what can be done to improve water quality?
Stanley E. Church, Robert J. Owen, Paul Von Guerard, Philip L. Verplanck, Briant A. Kimball, Douglas B. Yager
2007, Book chapter, Understanding and responding to hazardous substances at mine sites in the western United States
Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas...
Carbon export and cycling by the Yukon, Tanana, and Porcupine rivers, Alaska, 2001-2005
Robert G. Striegl, Mark M. Dornblaser, George R. Aiken, Kimberly P. Wickland, Peter A. Raymond
2007, Water Resources Research (43)
Loads and yields of dissolved and particulate organic and inorganic carbon (DOC, POC, DIC, PIC) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine rivers (TR, PR) in Alaska during 2001–2005. Total YR carbon export averaged 7.8 Tg C yr−1, 30%...
Tectonic uplift, threshold hillslopes, and denudation rates in a developing mountain range
S.A. Binnie, W.M. Phillips, M.A. Summerfield, L.K. Fifield
2007, Geology (35) 743-746
Studies across a broad range of drainage basins have established a positive correlation between mean slope gradient and denudation rates. It has been suggested, however, that this relationship breaks down for catchments where slopes are at their threshold angle of stability because, in such cases, denudation is controlled by the...
Quantitative PCR detection of Batrachochytrium dendrobatidis DNA from sediments and water
Julie D. Kirshtein, Chauncey W. Anderson, J.S. Wood, Joyce E. Longcore, Mary A. Voytek
2007, Diseases of Aquatic Organisms (77) 11-15
The fungal pathogen Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease implicated in amphibian declines on 5 continents. Polymerase chain reaction (PCR) primer sets exist with which amphibians can be tested for this disease, and advances in sampling techniques allow non-invasive testing of animals. We developed filtering and PCR based quantitative...
Alternative community structures in a kelp-urchin community: A qualitative modeling approach
G. Montano-Moctezuma, H.W. Li, P.A. Rossignol
2007, Ecological Modelling (205) 343-354
Shifts in interaction patterns within a community may result from periodic disturbances and climate. The question arises as to the extent and significance of these shifting patterns. Using a novel approach to link qualitative mathematical models and field data, namely using the inverse matrix to identify the community matrix, we...
Relationships between reef fish communities and remotely sensed rugosity measurements in Biscayne National Park, Florida, USA
Ilsa B. Kuffner, John Brock, Rikki Grober-Dunsmore, Victor E. Bonito, T. Donald Hickey, C. Wayne Wright
2007, Environmental Biology of Fishes (78) 71-82
The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying...
Brown-headed cowbird, Molothrus ater, parasitism and abundance in the northern Great Plains
L.D. Igl, Douglas H. Johnson
2007, Canadian Field-Naturalist (121) 239-255
The Brown-headed Cowbird (Molothrus ater) reaches its highest abundance in the northern Great Plains, but much of our understanding of cowbird ecology and host-parasite interactions comes from areas outside of this region. We examine cowbird brood parasitism and densities during two studies of breeding birds in the northern Great Plains...
Effects of flow diversions on water and habitat quality: Examples from California's highly manipulated Sacramento–San Joaquin Delta
Nancy E. Monsen, James E. Cloern, Jon R. Burau
2007, San Francisco Estuary and Watershed Science (5)
We use selected monitoring data to illustrate how localized water diversions from seasonal barriers, gate operations, and export pumps alter water quality across the Sacramento-San Joaquin Delta (California). Dynamics of water-quality variability are complex because the Delta is a mixing zone of water from the Sacramento and San Joaquin Rivers,...
Climate matching as a tool for predicting potential North American spread of Brown Treesnakes
Gordon H. Rodda, Robert N. Reed, Catherine S. Jarnevich
G.W. Witmer, W. C. Pitt, K.A. Fagerstone, editor(s)
2007, Conference Paper, Managing Vertebrate Invasive Species – Proceedings of a Symposium
Climate matching identifies extralimital destinations that could be colonized by a potential invasive species on the basis of similarity to climates found in the species’ native range. Climate is a proxy for the factors that determine whether a population will reproduce enough to offset mortality. Previous climate matching models (e.g.,...
