Can nutrients alone shift a sedge meadow towards dominance by the invasive Typha × glauca
Isa Woo, Joy B. Zedler
2002, Wetlands (22) 509-521
Where wetlands receive urban runoff, Typha spp. and other invasive plants often displace the native vegetation. We tested the ability of nutrients (N and P) to increase vegetative growth of T. × glauca(a hybrid of T. latifolia and T. angustifolia). In the greenhouse, 17 treatments revealed that T. × glauca required both N...
Using chemical, hydrologic, and age dating analysis to delineate redox processes and flow paths in the riparian zone of a glacial outwash aquifer‐stream system
Larry J. Puckett, Timothy K. Cowdery, Peter B. McMahon, Lan H. Tornes, Jeffrey D. Stoner
2002, Water Resources Research (38) 9-1-9-20
A combination of chemical and dissolved gas analyses, chlorofluorocarbon age dating, and hydrologic measurements were used to determine the degree to which biogeochemical processes in a riparian wetland were responsible for removing NO3−from groundwaters discharging to the Otter Tail River in west central Minnesota. An analysis of river chemistry and...
Fate and effects of the triazinone herbicide metribuzin in experimental pond mesocosms
J.F. Fairchild, L.C. Sappington
2002, Archives of Environmental Contamination and Toxicology (43) 198-202
Metribuzin is a triazinone herbicide that is widely used for the control of grasses and broad-leaved weeds in soybeans, sugarcane, and numerous other crops. Metribuzin is highly toxic to freshwater macrophytes and algae under laboratory conditions (median plant EC50 = 31 ??g/L; n = 11 species) but has not been...
Adaptive moving mesh methods for simulating one-dimensional groundwater problems with sharp moving fronts
W. Huang, Lingyun Zheng, X. Zhan
2002, International Journal for Numerical Methods in Engineering (54) 1579-1603
Accurate modelling of groundwater flow and transport with sharp moving fronts often involves high computational cost, when a fixed/uniform mesh is used. In this paper, we investigate the modelling of groundwater problems using a particular adaptive mesh method called the moving mesh partial differential equation approach. With this approach, the...
Adaptive inference for distinguishing credible from incredible patterns in nature
Crawford S. Holling, Craig R. Allen
2002, Ecosystems (5) 319-328
Strong inference is a powerful and rapid tool that can be used to identify and explain patterns in molecular biology, cell biology, and physiology. It is effective where causes are single and separable and where discrimination between pairwise alternative hypotheses can be determined experimentally by a simple yes or no...
The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate
L.L. Maughan, E. H. Christiansen, M. G. Best, C. S. Grommé, A.L. Deino, D.G. Tingey
2002, Journal of Volcanology and Geothermal Research (113) 129-157
Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma...
Does bird community structure vary with landscape patchiness? A Chihuahuan Desert perspective
K.J. Gutzwiller, W.C. Barrow Jr.
2002, Oikos (98) 284-298
During the springs of 1995-1997, we studied birds and landscapes at 70 sites in the Chihuahuan Desert to assess relations between bird community structure and landscape patchiness. Within each of two spatial extents (1-kin and 2-km-radius areas centered on each site), we measured the number of patches of individual land-cover...
Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99
M. E. Brigham, D. P. Krabbenhoft, M.L. Olson, J.F. DeWild
2002, Water, Air, & Soil Pollution (138) 61-78
We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early...
Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics
Mark A. Pegg, Clay L. Pierce
2002, River Research and Applications (18) 31-42
Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers...
Physical and chemical effects of grain aggregates on the Palos Verdes margin, southern California
D.E. Drake, R. Eganhouse, W. McArthur
2002, Continental Shelf Research (22) 967-986
Large discharges of wastewater and particulate matter from the outfalls of the Los Angeles County Sanitation Districts onto the Palos Verdes shelf since 1937 have produced an effluent-affected sediment deposit characterized by low bulk density, elevated organic matter content, and a high percentage of fine silt and clay particles relative...
Long-term tritium transport through field-scale compacted soil liner
C. Toupiol, T.W. Willingham, A.J. Valocchi, C.J. Werth, I.G. Krapac, T.D. Stark, D.E. Daniel
2002, Journal of Geotechnical and Geoenvironmental Engineering (128) 640-650
A 13-year study of tritium transport through a field-scale earthen liner was conducted by the Illinois State Geological Survey to determine the long-term performance of compacted soil liners in limiting chemical transport. Two field-sampling procedures (pressure-vacuum lysimeter and core sampling) were used to determine the vertical tritium concentration profiles at...
Components of productivity in black-legged kittiwakes Rissa tridactyla: Response to supplemental feeding
V.A. Gill, Scott A. Hatch
2002, Journal of Avian Biology (33) 113-126
In contrast to the high productivity of black‐legged kittiwakes in Britain, kittiwakes at many colonies in Alaska have failed chronically to reproduce since the mid 1970s. To determine if food is limiting productivity and, if so, at what stages of nesting food shortages are most severe, in 1996 and 1997...
The High Plains Aquifer, USA: Groundwater development and sustainability
K.F. Dennehy, D. W. Litke, P.B. McMahon
2002, Geological Society Special Publication 99-119
The High Plains Aquifer, located in the United States, is one of the largest freshwater aquifers in the world and is threatened by continued decline in water levels and deteriorating water quality. Understanding the physical and cultural features of this area is essential to assessing the factors that affect this...
Material-balance assessment of the New Albany-Chesterian petroleum system of the Illinois basin
M. D. Lewan, M. E. Henry, D.K. Higley, Janet K. Pitman
2002, American Association of Petroleum Geologists Bulletin (86) 745-778
The New Albany-Chesterian petroleum system of the Illinois basin is a well-constrained system from which petroleum charges and losses were quantified through a material-balance assessment. This petroleum system has nearly 90,000 wells penetrating the Chesterian section, a single New Albany Shale source rock accounting for more than 99% of the...
The geohydrologic setting of Yucca Mountain, Nevada
J. S. Stuckless, W. W. Dudley
2002, Applied Geochemistry (17) 659-682
This paper provides a geologic and hydrologic framework of the Yucca Mountain region for the geochemical papers in this volume. The regional geologic units, which range in age from late Precambrian through Holocene, are briefly described. Yucca Mountain is composed of dominantly pyroclastic units that range in age from 11.4...
Effect of growth conditions and staining procedure upon the subsurface transport and attachment behaviors of a groundwater protist
R.W. Harvey, N. Mayberry, N.E. Kinner, D.W. Metge, F. Novarino
2002, Applied and Environmental Microbiology (68) 1872-1881
The transport and attachment behaviors of Spumella guttula (Kent), a nanoflagellate (protist) found in contaminated and uncontaminated aquifer sediments in Cape Cod, Mass., were assessed in flowthrough and static columns and in a field injection-and-recovery transport experiment involving an array of multilevel samplers. Transport of S. guttula harvested from low-nutrient...
VOCs, pesticides, nitrate, and their mixtures in groundwater used for drinking water in the United States
P. J. Squillace, J. C. Scott, M.J. Moran, B. T. Nolan, D.W. Kolpin
2002, Environmental Science & Technology (36) 1923-1930
Samples of untreated groundwater from 1255 domestic drinking-water wells and 242 public supply wells were analyzed as part of the National Water-Quality Assessment Program of the U.S. Geological Survey between 1992 and 1999. Wells were sampled to define the regional quality of the groundwater resource and, thus, were distributed geographically...
A comparative assessment of genetic diversity among differently-aged populations of Spartina alterniflora on restored versus natural wetlands
S.E. Travis, C.E. Proffitt, R.C. Lowenfeld, T.W. Mitchell
2002, Restoration Ecology (10) 37-42
We collected naturally recolonizing Spartina alterniflora (smooth cord grass) from each of three restored sites and one undisturbed reference site in southwestern Louisiana to assess the impact of wetland restoration on genetic diversity. We used amplified fragment length polymorphisms (AFLPs) to produce 94 polymorphic genetic markers, which were used to...
Possible importance of algal toxins in the Salton Sea, California
Kristen M. Reifel, M. P. McCoy, Tonie E. Rocke, M. A. Tiffany, S. H. Hurlbert, D. J. Faulkner
2002, Hydrobiologia (473) 275-292
In response to wildlife mortality including unexplained eared grebe (Podiceps nigricollis) die-off events in 1992 and 1994 and other mortality events including large fish kills, a survey was conducted for the presence of algal toxins in the Salton Sea. Goals of this survey were to determine if and...
Rare earth element variations resulting from inversion of pigeonite and subsolidus reequilibration in lunar ferroan anorthosites
O.B. James, C. Floss, J. J. McGee
2002, Geochimica et Cosmochimica Acta (66) 1269-1284
We present results of a secondary ion mass spectrometry study of the rare earth elements (REEs) in the minerals of two samples of lunar ferroan anorthosite, and the results are applicable to studies of REEs in all igneous rocks, no matter what their planet of origin. Our pyroxene analyses are used to determine solid-solid REE distribution coefficients (D = CREE in...
Problems in evaluating regional and local trends in temperature: An example from eastern Colorado, USA
R.A. Pielke Sr., T. Stohlgren, L. Schell, W. Parton, N. Doesken, K. Redmond, J. Moeny, T. McKee, T.G.F. Kittel
2002, International Journal of Climatology (22) 421-434
We evaluated long-term trends in average maximum and minimum temperatures, threshold temperatures, and growing season in eastern Colorado, USA, to explore the potential shortcomings of many climate-change studies that either: (1) generalize regional patterns from single stations, single seasons, or a few parameters over short duration from averaging dissimilar stations:...
Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model
R.L. Runkel, B. A. Kimball
2002, Environmental Science & Technology (36) 1093-1101
A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions....
A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates
P.A. Maurice, M.J. Pullin, S.E. Cabaniss, Q. Zhou, K. Namjesnik-Dejanovic, G. R. Aiken
2002, Water Research (36) 2357-2371
This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the...
Eros: Shape, topography, and slope processes
P.C. Thomas, J. Joseph, B. Carcich, J. Veverka, B.E. Clark, J.F. Bell III, A.W. Byrd, R. Chomko, M. Robinson, S. Murchie, L. Prockter, A. Cheng, N. Izenberg, M. Malin, C. Chapman, L.A. McFadden, Randolph L. Kirk, M. Gaffey, P. G. Lucey
2002, Icarus (155) 18-37
Stereogrammetric measurement of the shape of Eros using images obtained by NEAR's Multispectral Imager provides a survey of the major topographic features and slope processes on this asteroid. This curved asteroid has radii ranging from 3.1 to 17.7 km and a volume of 2535±20 km3. The center of figure is...
Controls on facies and sequence stratigraphy of an upper Miocene carbonate ramp and platform, Melilla basin, NE Morocco
Kevin J. Cunningham, Luke S. Collins
2002, Sedimentary Geology (146) 285-304
Upwelling of cool seawater, paleoceanographic circulation, paleoclimate, local tectonics and relative sea-level change controlled the lithofacies and sequence stratigraphy of a carbonate ramp and overlying platform that are part of a temporally well constrained carbonate complex in the Melilla basin, northeastern Morocco. At Melilla, from oldest to youngest, a third-order...
