Populations dynamics of red brome (Bromus madritensis subsp. Rubens): Times for concern, opportunities for management
L. F. Salo
2004, Journal of Arid Environments (57) 291-296
Red brome is a Mediterranean winter annual grass that has invaded south-western USA deserts. Unlike native annuals, it does not maintain a soil seed bank, but exhibits early and uniform germination. Above-average winter precipitation in these regions allows red brome to reach high density and biomass. These are time for...
Enhanced gas-phase transport in a deep unsaturated zone, Amargosa Desert (U.S.A.)
Michelle Ann Walvoord, David A. Stonestrom
Karel Kovar, Z. Hrkal, J. Bruthans, editor(s)
2004, Conference Paper, International conference on finite element models, MODFLOW, and more: Solving groundwater problems
No abstract available....
Effects of distance from cattle water developments on grassland birds
A.L. Fontaine, P.L. Kennedy, Douglas H. Johnson
2004, Journal of Range Management (57) 238-242
Many North American grassland bird populations appear to be declining, which may be due to changes in grazing regimes on their breeding areas. Establishment of water developments and confining cattle (Bos taurus L.) to small pastures often minimizes spatial heterogeneity of cattle forage consumption, which may lead to uniformity in...
Nutritional condition of Northern Yellowstone Elk
R.C. Cook, J.G. Cook, L.D. Mech
2004, Journal of Mammalogy (85) 714-722
We estimated nutritional condition for 96 female northern Yellowstone elk (Cervus elaphus nelsoni) during mid- to late winter 2000, 2001, and 2002. Neither year nor capture location significantly influenced any measure of condition (body fat, body mass, and longissimus dorsi thickness; P ≥ 0.14). Overall, age = 8.9 years ± 0.4 SE, body...
The wetland continuum: A conceptual framework for interpreting biological studies
N.H. Euliss Jr., J. W. LaBaugh, L.H. Fredrickson, D.M. Mushet, Murray K. Laubhan, G.A. Swanson, T. C. Winter, D.O. Rosenberry, R.D. Nelson
2004, Wetlands (24) 448-458
We describe a conceptual model, the wetland continuum, which allows wetland managers, scientists, and ecologists to consider simultaneously the influence of climate and hydrologic setting on wetland biological communities. Although multidimensional, the wetland continuum is most easily represented as a two-dimensional gradient, with ground water and atmospheric water constituting the...
Small mammals in montane wet meadow habitat at Grays Lake, Idaho
J. E. Austin, W.H. Pyle
2004, Northwest Science (78) 225-233
Cervid forage utilization in noncommercially thinned ponderosa pine forests
M.C. Gibbs, J.A. Jenks, C.S. Deperno, B.F. Sowell, Kurt J. Jenkins
2004, Journal of Range Management (57) 435-441
To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22...
Habitat selection by tundra swans on Northern Alaska breeding grounds
Susan L. Earnst, T. Rothe
2004, Waterbirds (27) 224-233
Habitat selection by the Tundra Swan (Cygnus columbianus columbianus) was evaluated on the Colville River Delta prior to oil field development (1982-1989). Tundra Swan territories comprised a lake, used for refuge and foraging, and terrestrial habitats and ponds near the lake's perimeter used for foraging and nesting. Tundra swan sightings...
Ice processes affect habitat use and movements of adult cutthroat trout and brook trout in a Wyoming foothills stream
J.W. Lindstrom, W.A. Hubert
2004, North American Journal of Fisheries Management (24) 1341-1352
Habitat use and movements of 25 adult cutthroat trout Oncorhynchus clarkii and 25 adult brook trout Salvelinus fontinalis from fall through winter 2002-2003 were assessed by means of radiotelemetry in a 7-km reach of a Rocky Mountains foothills stream. Temporal dynamics of winter habitat conditions were evaluated by regularly measuring...
Accumulation of PCB congeners in nestling tree swallows (Tachycineta bicolor) on the Hudson River, New York
Kathy R. Echols, Donald E. Tillitt, John W. Nichols, Anne L. Secord, John P. McCarty
2004, Environmental Science & Technology (38) 6240-6246
Tree swallows (Tachycineta bicolor) were used as a sentinel species to monitor the contamination and bioavailability of polychlorinated biphenyls (PCBs) in the Hudson River watershed. Several tree swallow nest box colonies around and downstream from Hudson Falls, NY, were studied. Tree swallow eggs, adults, and 5-, 10-, and 15-day-old nestlings...
WTAQ - A computer program for aquifer-test analysis of confined and unconfined aquifers
P. M. Barlow, A.F. Moench
2004, Conference Paper, Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
Computer program WTAQ was developed to implement a Laplace-transform analytical solution for axial-symmetric flow to a partially penetrating, finite-diameter well in a homogeneous and anisotropic unconfined (water-table) aquifer. The solution accounts for wellbore storage and skin effects at the pumped well, delayed response at an observation well, and delayed or...
Environment, agriculture, and settlement patterns in a marginal Polynesian landscape
P.V. Kirch, A.S. Hartshorn, O.A. Chadwick, P.M. Vitousek, D. R. Sherrod, J. Coil, L. Holm, W.D. Sharp
2004, Proceedings of the National Academy of Sciences of the United States of America (101) 9936-9941
Beginning ca. A.D. 1400, Polynesian farmers established permanent settlements along the arid southern flank of Haleakala Volcano, Maui, Hawaiian Islands; peak population density (43-57 persons per km2) was achieved by A.D. 1700-1800, and it was followed by the devastating effects of European contact. This settlement, based on dryland agriculture with...
Predicting maternal body burdens of organochlorine pesticides from eggs and evidence of maternal transfer in Alligator mississippiensis
R.H. Rauschenberger, M. S. Sepulveda, J.J. Wiebe, N.J. Szabo, T. S. Gross
2004, Environmental Toxicology and Chemistry (23) 2906-2915
Few data exist regarding maternal-embryonal transfer of organochlorine pesticides (OCPs) in reptiles. The objective of the present study was to evaluate maternal transfer of OCPs in American alligators (Alligator mississippiensis) from low-, intermediate-, and high-OCP-exposure sites. Overall, total OCP burdens ranged from less than 0.8 ppb in blood to more...
The effects of macroinvertebrate taxonomic resolution in large landscape bioassessments: An example from the Mid-Atlantic Highlands, U.S.A.
I.R. Waite, A.T. Herlihy, D. P. Larsen, N.S. Urquhart, D.J. Klemm
2004, Freshwater Biology (49) 474-489
1. During late spring 1993-1995, the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) sampled 490 wadeable streams in the mid-Atlantic Highlands (MAH) of the U.S. for a variety of physical, chemical and biological indicators of environmental condition. We used the resulting data set to evaluate the importance...
Use of remote sensing techniques to determine the effects of grazing on vegetation cover and dune elevation at assateague island national seashore: Impact of horses
G. H. De Stoppelaire, T.W. Gillespie, J. C. Brock, G.A. Tobin
2004, Environmental Management (34) 642-649
The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and...
Effects of multiple routes of cadmium exposure on the hibernation success of the American toad (Bufo americanus)
S.M. James, E. E. Little, R. D. Semlitsch
2004, Archives of Environmental Contamination and Toxicology (46) 518-527
The effects of multiple routes of cadmium exposure on juvenile American toads (Bufo americanus) were evaluated using environmentally relevant concentrations. During or after exposure, toads were individually hibernated for 172 days at approximately 4°C. The following experiments were conducted: (1) dermal exposure (hibernation in soil contaminated with up to 120...
Chemistry of burning the forest floor during the FROSTFIRE experimental burn, interior Alaska, 1999
J.W. Harden, J. C. Neff, D. V. Sandberg, M.R. Turetsky, R. Ottmar, G. Gleixner, T. L. Fries, K.L. Manies
2004, Global Biogeochemical Cycles (18)
Wildfires represent one of the most common disturbances in boreal regions, and have the potential to reduce C, N, and Hg stocks in soils while contributing to atmospheric emissions. Organic soil layers of the forest floor were sampled before and after the FROSTFIRE experimental burn in interior Alaska, and were...
Record high Wolf, Canis lupus, pack density
L.D. Mech, S. Tracy
2004, Canadian Field-Naturalist (118) 127-129
This report documents a year-around Wolf (Canis lupus) density of 18.2/100 km2 and a summer density of 30.8/100 km2, in a northeastern Minnesota Wolf pack. The previous record was a summer density of 14.1/100 km2, for a Wolf pack on Vancouver Island, British Columbia, Canada....
Response of desert biological soil crusts to alterations in precipitation frequency
J. Belnap, S. L. Phillips, M. E. Miller
2004, Oecologia (141) 306-316
Biological soil crusts, a community of cyanobacteria, lichens, and mosses that live on the soil surface, occur in deserts throughout the world. They are a critical component of desert ecosystems, as they are important contributors to soil fertility and stability. Future climate scenarios predict alteration of the timing and amount...
Uranium adsorption on weathered schist - Intercomparison of modeling approaches
T.E. Payne, J.A. Davis, M. Ochs, M. Olin, C.J. Tweed
2004, Radiochimica Acta (92) 651-661
Experimental data for uranium adsorption on a complex weathered rock were simulated by twelve modelling teams from eight countries using surface complexation (SC) models. This intercomparison was part of an international project to evaluate the present capabilities and limitations of SC models in representing sorption by geologic materials. The models...
Application of near real-time radial semblance to locate the shallow magmatic conduit at Kilauea Volcano, Hawaii
P. Dawson, D. Whilldin, B. Chouet
2004, Geophysical Research Letters (31)
Radial Semblance is applied to broadband seismic network data to provide source locations of Very-Long-Period (VLP) seismic energy in near real time. With an efficient algorithm and adequate network coverage, accurate source locations of VLP energy are derived to quickly locate the shallow magmatic conduit system at Kilauea Volcano, Hawaii....
Origin of placer laurite from Borneo: Se and As contents, and S isotopic compositions
K.H. Hattori, L.J. Cabri, B. Johanson, M. L. Zientek
2004, Mineralogical Magazine (68) 353-368
We examined grains of the platinum-group mineral, laurite (RuS2), from the type locality, Pontyn River, Tanah Laut, Borneo, and from the Tambanio River, southeast Borneo. The grains show a variety of morphologies, including euhedral grains with conchoidal fractures and pits, and spherical grains with no crystal faces, probably because of...
A guided inquiry approach to learning the geology of the U.S
M.L. Leech, D. G. Howell, A.E. Egger
2004, Journal of Geoscience Education (52) 368-373
A guided inquiry exercise has been developed to help teach the geology of the U.S. This exercise is intended for use early in the school term when undergraduate students have little background knowledge of geology. Before beginning, students should be introduced to rock types and have a basic understanding of...
Facilitating fish passage at ultra low head dams: An alternative to dam removal
M. Odeh
2004, Conference Paper, Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001
Ecosystem sustainability and returning the biological integrity to rivers continue to change the landscape of fish passage technology. Installing a conventional fishways has a limited degree of success in accommodating fish passage needs. Recently, the option of total dam removal has been gaining momentum among resource managers, conservationists, and even...
Nitrite toxicity of Litopenaeus vannamei in water containing low concentrations of sea salt or mixed salts
A. Sowers, S.P. Young, J. Jeffery Isely, C.L. Browdy, J.R. Tomasso Jr.
2004, Journal of the World Aquaculture Society (35) 445-451
The uptake, depuration and toxicity of environmental nitrite was characterized in Litopenaeus vannamei exposed in water containing low concentrations of artificial sea salt or mixed salts. In 2 g/L artificial sea salts, nitrite was concentrated in the hemolymph in a dose-dependent and rapid manner (steady-state in about 2 d). When...
