Estimating biomass of submersed vegetation using a simple rake sampling technique
K.P. Kenow, J.E. Lyon, R. K. Hines, A. Elfessi
2007, Hydrobiologia (575) 447-454
We evaluated the use of a simple rake sampling technique for predicting the biomass of submersed aquatic vegetation. Vegetation sampled from impounded areas of the Mississippi River using a rake sampling technique, was compared with vegetation harvested from 0.33-m2 quadrats. The resulting data were used to model the relationship between...
Net emissions of CH4 and CO2 in Alaska: Implications for the region's greenhouse gas budget
Q. Zhuang, J. M. Melillo, A. D. McGuire, D. W. Kicklighter, R.G. Prinn, P.A. Steudler, B.S. Felzer, S. Hu
2007, Ecological Applications (17) 203-212
We used a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to study the net methane (CH4) fluxes between Alaskan ecosystems and the atmosphere. We estimated that the current net emissions of CH4 (emissions minus consumption) from Alaskan soils are ???3 Tg CH 4/yr. Wet tundra ecosystems are responsible for 75%...
Global impacts of conversions from natural to agricultural ecosystems on water resources: Quantity versus quality
Bridget R. Scanlon, Ian Jolly, Marios Sophocleous, Lu Zhang
2007, Water Resources Research (43)
Past land use changes have greatly impacted global water resources, with often opposing effects on water quantity and quality. Increases in rain‐fed cropland (460%) and pastureland (560%) during the past 300 years from forest and grasslands decreased evapotranspiration and increased recharge (two orders of magnitude) and streamflow (one order of...
SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England
R. P. Wintsch, J. N. Aleinikoff, G. J. Walsh, Wallace A. Bothner, A. M. Hussey, C.M. Fanning
2007, American Journal of Science (307) 119-167
U-Pb ages of detrital, metamorphic, and magmatic zircon and metamorphic monazite and titanite provide evidence for the ages of deposition and metamorphism of metasedimentary rocks from the Merrimack and Putnam-Nashoba terranes of eastern New England. Rocks from these terranes are interpreted here as having been deposited in the middle Paleozoic...
North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada
W. Park, David C. Douglas, Thomas C. Shirley
2007, Limnology and Oceanography (52) 248-256
We propose and evaluate the hypothesis that Dungeness crab (Cancer magister) larvae from the northwestern coast of the United States and Canada can be transported northward to southeastern Alaska. Larvae collected in southeastern Alaska during May and June 1997–2004 had abundances and stages that varied seasonally, interannually, and spatially. An...
Solar forcing of Gulf of California climate during the past 2000 yr suggested by diatoms and silicoflagellates
John A. Barron, David Bukry
2007, Marine Micropaleontology (62) 115-139
High-resolution records of the past 2000 yr are compared in a north–south transect (28° N to 24° N) of three cores from the eastern slopes of the Guaymas, Carmen, and Pescadero Basins of the Gulf of California (hereafter referred to as the “Gulf”). Evenly-spaced samples from the varved sediments in each...
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...
Multibeam observations of mine burial near Clearwater, FL, including comparisons to predictions of wave-induced burial
M.L. Wolfson, D. F. Naar, P.A. Howd, S. D. Locker, B.T. Donahue, Carl T. Friedrichs, A.C. Trembanis, M. D. Richardson, T.F. Wever
2007, IEEE Journal of Oceanic Engineering (32) 103-118
A Kongsberg Simrad EM 3000 multibeam sonar (Kongsberg Simrad, Kongsberg, Norway) was used to conduct a set of six repeat high-resolution bathymetric surveys west of Indian Rocks Beach (IRB), just to the south of Clearwater, FL, between January and March 2003, to observe in situ scour and burial of instrumented...
Spatial correlation of shear-wave velocity in the San Francisco Bay Area sediments
E.M. Thompson, L.G. Baise, R. E. Kayen
2007, Soil Dynamics and Earthquake Engineering (27) 144-152
Ground motions recorded within sedimentary basins are variable over short distances. One important cause of the variability is that local soil properties are variable at all scales. Regional hazard maps developed for predicting site effects are generally derived from maps of surficial...
Vertical spatial sensitivity and exploration depth of low-induction-number electromagnetic-induction instruments
J.B. Callegary, T.P.A. Ferre, R.W. Groom
2007, Vadose Zone Journal (6) 158-167
Vertical spatial sensitivity and effective depth of exploration (d e) of low-induction-number (LIN) instruments over a layered soil were evaluated using a complete numerical solution to Maxwell's equations. Previous studies using approximate mathematical solutions predicted a vertical spatial sensitivity for instruments operating under LIN conditions that, for a given transmitter-receiver...
Trace analysis of trimethoprim and sulfonamide, macrolide, quinolone, and tetracycline antibiotics in chlorinated drinking water using liquid chromatography electrospray tandem mass spectrometry
Z. Ye, H.S. Weinberg, M. T. Meyer
2007, Analytical Chemistry (79) 1135-1144
A multirun analytical method has been developed and validated for trace determination of 24 antibiotics including 7 sulfonamides, 3 macrolides, 7 quinolones, 6 tetracyclines, and trimethoprim in chlorine-disinfected drinking water using a single solid-phase extraction method coupled to liquid chromatography with positive electrospray tandem mass spectrometry detection. The analytes were...
Ecological linkages between headwaters and downstream ecosystems: Transport of organic matter, invertebrates, and wood down headwater channels
M.S. Wipfli, J.S. Richardson, R.J. Naiman
2007, Journal of the American Water Resources Association (43) 72-85
Headwater streams make up a large proportion of the total length and watershed area of fluvial networks, and are partially characterized by the large volume of organic matter (large wood, detritus, and dissolved organic matter) and invertebrate inputs from the riparian forest, relative to stream size. Much of those inputs...
Evaluation of the status of anurans on a refuge in suburban Maryland
S.M. Brander, J. Andrew Royle, M. Eames
2007, Journal of Herpetology (41) 52-60
Because many anurans have well-defined breeding seasons and male anurans produce loud advertisement calls, surveys of these breeding choruses are believed to provide a dependable means of monitoring population trends. The Patuxent Research Refuge initiated such a calling survey in the spring of 1997, which uses volunteers to collect anuran...
Nesting and foraging behavior of red-winged blackbirds in stormwater wetlands
D. W. Sparling, J. Eisemann, W. Kuenzel
2007, Urban Ecosystems (10) 1-15
Stormwater wetlands are a common part of urban and suburban landscapes. These constructed wetlands provide first-order treatment of effluent from roads, parking lots, lawns and other surfaces. They also provide habitat for wetland-associated birds. Thus, there is a concern that birds may be attracted to potentially toxic habitats. This study...
Influences of wildfire and channel reorganization on spatial and temporal variation in stream temperature and the distribution of fish and amphibians
J. B. Dunham, A.E. Rosenberger, C.H. Luce, B.E. Rieman
2007, Ecosystems (10) 335-346
Wildfire can influence a variety of stream ecosystem properties. We studied stream temperatures in relation to wildfire in small streams in the Boise River Basin, located in central Idaho, USA. To examine the spatio-temporal aspects of temperature in relation to wildfire, we employed three approaches: a pre-post fire comparison of...
Effects of sea-level rise on ground water flow in a coastal aquifer system
John P. Masterson, S. P. Garabedian
2007, Ground Water (45) 209-217
The effects of sea-level rise on the depth to the fresh water/salt water interface were simulated by using a density-dependent, three-dimensional numerical ground water flow model for a simplified hypothetical fresh water lens that is similar to shallow, coastal aquifers found along the Atlantic coast of the United States. Simulations...
Cytherellid species (Ostracoda) and their significance to the Late Quaternary events in the Santos Basin, Brazil
C.T. Bergue, J.C. Coimbra, T. M. Cronin
2007, Senckenbergiana Maritima (37) 5-12
Four autochthonous cytherellid species (Cytherella serratula (BRADY, 1880), C. hermargentina WHATLEY et al. 1998, C. pleistocenica sp. nov. and C. santosensis sp. nov.) have been identified from two offshore cores (44 samples) within the Santos Basin. The distribution of these ostracodes is controlled by local hydrological conditions such as the...
Mangrove recruitment after forest disturbance is facilitated by herbaceous species in the Caribbean
K.L. McKee, J.E. Rooth, Ilka C. Feller
2007, Ecological Applications (17) 1678-1693
Plant communities along tropical coastlines are often affected by natural and human disturbances, but little is known about factors influencing recovery. We focused on mangrove forests, which are among the most threatened ecosystems globally, to examine how facilitation by herbaceous vegetation might improve forest restoration after disturbance. We specifically investigated...
A chronology of Late-Pleistocene permafrost events in southern New Jersey, eastern USA
H.M. French, M. Demitroff, S.L. Forman, Wayne L. Newell
2007, Permafrost and Periglacial Processes (18) 49-59
Frost fissures, filled with wind-abraded sand and mineral soil, and numerous small-scale non-diastrophic deformations, occur in the near-surface sediments of the Pine Barrens of southern New Jersey. The fissures are the result of thermal-contraction cracking and indicate the previous existence of either permafrost or seasonally-frozen ground. The deformations reflect thermokarst...
Prediction of lethal/effective concentration/dose in the presence of multiple auxiliary covariates and components of variance
S. Gutreuter, M.A. Boogaard
2007, Environmental Toxicology and Chemistry (26) 1978-1986
Predictors of the percentile lethal/effective concentration/dose are commonly used measures of efficacy and toxicity. Typically such quantal-response predictors (e.g., the exposure required to kill 50% of some population) are estimated from simple bioassays wherein organisms are exposed to a gradient of several concentrations of a single agent. The toxicity of...
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%...
Development of a soil conservation standard and guidelines for OHV recreation management in California
T.L. Bedrossian, S.D. Reynolds
2007, Environmental & Engineering Geoscience (13) 241-253
In 2004, the California State Parks (CSP) agency contracted with the California Geological Survey (CGS) to update the 1991 Soil Conservation Guide-lines/Standards for Off-Highway Vehicle (OHV) Recreation Management. Per state legislation, the 1991 standards were updated to establish a generic and measurable standard at least sufficient to allow restoration of...
Investigations of adult Lost River, shortnose, and Klamath largescale suckers in Upper Klamath Lake and its tributaries, Oregon. Annual report 2005
P.M. Barry, B.S. Hayes, A.C. Scott, C.D. Luton, E.C. Janney
2007, Report
n/a...
Shorebird roost-site selection at two temporal scales: Is human disturbance a factor?
K. A. Peters, David L. Otis
2007, Journal of Applied Ecology (44) 196-209
1. Roost-site selection in shorebirds is governed by ambient factors, including environmental conditions and human disturbance. Determination of the extent to which these factors affect roost use and the associated implications for shorebird habitat protection is important for conservation strategies and informed management of human recreational use of these habitats....
Assessing exotic plant species invasions and associated soil characteristics: A case study in eastern Rocky Mountain National Park, Colorado, USA, using the pixel nested plot design
M. A. Kalkhan, E.J. Stafford, P.J. Woodly, T.J. Stohlgren
2007, Applied Soil Ecology (35) 622-634
Rocky Mountain National Park (RMNP), Colorado, USA, contains a diversity of plant species. However, many exotic plant species have become established, potentially impacting the structure and function of native plant communities. Our goal was to quantify patterns of exotic plant species in relation to native plant species, soil characteristics, and...
