Quantifying tolerance indicator values for common stream fish species of the United States
M. R. Meador, D.M. Carlisle
2007, Ecological Indicators (7) 329-338
The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of...
Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin
K.A. Kincare
2007, Journal of Paleolimnology (37) 383-394
The water level of the Lake Michigan basin is currently 177 m above sea level. Around 9,800 14C years B.P., the lake level in the Lake Michigan basin had dropped to its lowest level in prehistory, about 70 m above sea level. This low level (Lake Chippewa) had profound effects...
Large-scale causes of variation in the serpentine vegetation of California
J.B. Grace, H.D. Safford, S. Harrison
2007, Conference Paper, Plant and Soil
Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this...
Self-gravity wake structures in Saturn's a ring revealed by Cassini vims
M.M. Hedman, P. D. Nicholson, H. Salo, B.D. Wallis, B. J. Buratti, K. H. Baines, R. H. Brown, R. N. Clark
2007, Astronomical Journal (133) 2624-2629
During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti (Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented...
Paleovalley fills: Trunk vs. tributary
E.P. Kvale, A.W. Archer
2007, American Association of Petroleum Geologists Bulletin (91) 809-821
A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills....
Early vegetation development on an exposed reservoir: Implications for dam removal
G.T. Auble, P.B. Shafroth, M. L. Scott, J. E. Roelle
2007, Environmental Management (39) 806-818
The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical...
Compositional zoning of the Bishop Tuff
W. Hildreth, C. J. N. Wilson
2007, Journal of Petrology (48) 951-999
Compositional data for >400 pumice clasts, organized according to eruptive sequence, crystal content, and texture, provide new perspectives on eruption and pre-eruptive evolution of the >600 km3 of zoned rhyolitic magma ejected as the Bishop Tuff during formation of Long Valley caldera. Proportions and compositions of different pumice types are given for...
Utility of R0 as a predictor of disease invasion in structured populations
Paul C. Cross, Philip L. Johnson, James O. Lloyd-Smith, Wayne M. Getz
2007, Journal of the Royal Society Interface (4) 315-324
Early theoretical work on disease invasion typically assumed large and well-mixed host populations. Many human and wildlife systems, however, have small groups with limited movement among groups. In these situations, the basic reproductive number, R0, is likely to be a poor predictor of a disease pandemic because it typically does not...
Modeling the influence of river discharge on salt intrusion and residual circulation in Danshuei River estuary, Taiwan
W.-C. Liu, W.-B. Chen, R. T. Cheng, M.-H. Hsu, A.Y. Kuo
2007, Continental Shelf Research (27) 900-921
A 3-D, time-dependent, baroclinic, hydrodynamic and salinity model was implemented and applied to the Danshuei River estuarine system and the adjacent coastal sea in Taiwan. The model forcing functions consist of tidal elevations along the open boundaries and freshwater inflows from the main stream and major tributaries in the Danshuei...
Species-area curves indicate the importance of habitats' contributions to regional biodiversity
G.W. Chong, T.J. Stohlgren
2007, Ecological Indicators (7) 387-395
We examined species-area curves, species composition and similarity (Jaccard's coefficients), and species richness in 17 vegetation types to develop a composite index of a vegetation type's contribution to regional species richness. We collected data from 1 to 1000 m2 scales in 147 nested plots in Rocky Mountain National Park, Colorado,...
Invasive plants and their ecological strategies: Prediction and explanation of woody plant invasion in New England
P.M. Herron, C.T. Martine, A.M. Latimer, S. A. Leicht-Young
2007, Diversity and Distributions (13) 633-644
Effective management of introduced species requires the early identification of species that pose a significant threat of becoming invasive. To better understand the invasive ecology of species in New England, USA, we compiled a character data set with which to compare non-native species that are known invaders to non-native species...
An evaluation of freshwater mussel toxicity data in the derivation of water quality guidance and standards for copper
F.A. March, F.J. Dwyer, T. Augspurger, C.G. Ingersoll, N. Wang, C.A. Mebane
2007, Environmental Toxicology and Chemistry (26) 2066-2074
The state of Oklahoma has designated several areas as freshwater mussel sanctuaries in an attempt to provide freshwater mussel species a degree of protection and to facilitate their reproduction. We evaluated the protection afforded freshwater mussels by the U.S. Environmental Protection Agency (U.S. EPA) hardness-based 1996 ambient copper water quality...
Variation in the establishment of a non-native annual grass influences competitive interactions with Mojave Desert perennials
L.A. DeFalco, G.C.J. Fernandez, R.S. Nowak
2007, Biological Invasions (9) 293-307
Competition between native and non-native species can change the composition and structure of plant communities, but in deserts, the highly variable timing of resource availability also influences non-native plant establishment, thus modulating their impacts on native species. In a field experiment, we varied densities of the non-native annual grass Bromus...
Geomorphic and sedimentologic evidence for the separation of Lake Superior from Lake Michigan and Huron
J.W. Johnston, T.A. Thompson, D.A. Wilcox, S.J. Baedke
2007, Journal of Paleolimnology (37) 349-364
A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from...
Multiple-species analysis of point count data: A more parsimonious modelling framework
M.W. Alldredge, K. H. Pollock, T.R. Simons, S.A. Shriner
2007, Journal of Applied Ecology (44) 281-290
1. Although population surveys often provide information on multiple species, these data are rarely analysed within a multiple-species framework despite the potential for more efficient estimation of population parameters. 2. We have developed a multiple-species modelling framework that uses similarities in capture/detection processes among species to model multiple species data...
Mountaintop island age determines species richness of boreal mammals in the American Southwest
J.K. Frey, M.A. Bogan, Terry L. Yates
2007, Ecography (30) 231-240
Models that describe the mechanisms responsible for insular patterns of species richness include the equilibrium theory of island biogeography and the nonequilibrium vicariance model. The relative importance of dispersal or vicariance in structuring insular distribution patterns can be inferred from these models. Predictions of the alternative models were tested for...
Arsenic attenuation by oxidized aquifer sediments in Bangladesh
Kenneth G. Stollenwerk, George N. Breit, Alan H. Welch, James C. Yount, John W. Whitney, Andrea L. Foster, M.N. Uddin, R.K. Majumder, N. Ahmed
2007, Science of the Total Environment (379) 133-150
Recognition of arsenic (As) contamination of shallow fluvio-deltaic aquifers in the Bengal Basin has resulted in increasing exploitation of groundwater from deeper aquifers that generally contain low concentrations of dissolved As. Pumping-induced infiltration of high-As groundwater could eventually cause As concentrations in these aquifers to increase. This study investigates the...
Ammonia causes decreased brain monoamines in fathead minnows (Pimephales promelas)
Patrick J. Ronan, Mark P. Gaikowski, Steven J. Hamilton, Kevin J. Buhl, Cliff H. Summers
2007, Brain Research (1147) 184-191
Hyperammonemia, arising from variety of disorders, leads to severe neurological dysfunction. The mechanisms of ammonia toxicity in brain are not completely understood. This study investigated the effects of ammonia on monoaminergic systems in brains of fathead minnows (Pimephales promelas). Fish serve as a good model system to investigate hyperammonemic effects...
Chromosome painting among Proboscidea, Hyracoidea and Sirenia: Support for Paenungulata (Afrotheria, Mammalia) but not Tethytheria
A.T. Pardini, P. C. M. O’Brien, B. Fu, R. K. Bonde, F.F.B. Elder, M. A. Ferguson-Smith, F. Yang, T.J. Robinson
2007, Proceedings of the Royal Society B: Biological Sciences (274) 1333-1340
Despite marked improvements in the interpretation of systematic relationships within Eutheria, particular nodes, including Paenungulata (Hyracoidea, Sirenia and Proboscidea), remain ambiguous. The combination of a rapid radiation, a deep divergence and an extensive morphological diversification has resulted in a limited phylogenetic signal confounding resolution within this clade both at the...
Year-class formation of upper St. Lawrence River northern pike
B.M. Smith, J.M. Farrell, H.B. Underwood, S.J. Smith
2007, North American Journal of Fisheries Management (27) 481-491
Variables associated with year-class formation in upper St. Lawrence River northern pike Esox lucius were examined to explore population trends. A partial least-squares (PLS) regression model (PLS 1) was used to relate a year-class strength index (YCSI; 1974-1997) to explanatory variables associated with spawning and nursery areas (seasonal water level...
MT+, integrating magnetotellurics to determine earth structure, physical state, and processes
P. A. Bedrosian
2007, Conference Paper, Surveys in Geophysics
As one of the few deep-earth imaging techniques, magnetotellurics provides information on both the structure and physical state of the crust and upper mantle. Magnetotellurics is sensitive to electrical conductivity, which varies within the earth by many orders of magnitude and is modified by a range of earth processes. As...
Estimating hydraulic properties of volcanic aquifers using constant-rate and variable-rate aquifer tests
K. Rotzoll, A. I. El-Kadi, S. B. Gingerich
2007, Journal of the American Water Resources Association (43) 334-345
In recent years the ground-water demand of the population of the island of Maui, Hawaii, has significantly increased. To ensure prudent management of the ground-water resources, an improved understanding of ground-water flow systems is needed. At present, large-scale estimations of aquifer properties are lacking for Maui. Seven analytical methods using...
Nutrients stimulate leaf breakdown rates and detritivore biomass: Bottom-up effects via heterotrophic pathways
J.L. Greenwood, A.D. Rosemond, J.B. Wallace, W. F. Cross, H.S. Weyers
2007, Oecologia (151) 637-649
Most nutrient enrichment studies in aquatic systems have focused on autotrophic food webs in systems where primary producers dominate the resource base. We tested the heterotrophic response to long-term nutrient enrichment in a forested, headwater stream. Our study design consisted of 2 years of pretreatment data in a reference and...
Using a bioenergetic model to assess growth reduction from catch-and-release fishing and hooking injury in rainbow trout, Oncorhynchus mykiss
Julie M. Meka, F.J. Margraf
2007, Fisheries Management and Ecology (14) 131-139
A bioenergetic model was used to predict the potential effects of feeding cessation caused by catch-and-release capture and a reduction in feeding efficiency from hooking injuries on rainbow trout, Oncorhynchus mykiss (Walbaum), growth in southwest Alaska, USA. Simulations indicated that a 1-day feeding cessation for a rainbow trout captured one to two...
Effect of horseshoe crab spawning density on nest disturbance and exhumation of eggs: A simulation study
D. R. Smith
2007, Estuaries and Coasts (30) 287-295
Because the Delaware Bay horseshoe crab (Limulus polyphemus) population is managed to provide for dependent species, such as migratory shorebirds, there is a need to understand the process of egg exhumation and to predict eggs available to foraging shorebirds. A simple spatial model was used to simulate horseshoe crab spawning...
