Local versus landscape-scale effects of savanna trees on grasses
Corinna Riginos, James B. Grace, David J. Augustine, Truman P. Young
2009, Journal of Ecology (97) 1337-1345
1. Savanna ecosystems – defined by the coexistence of trees and grasses – cover more than one‐fifth the world’s land surface and harbour most of the world’s rangelands, livestock and large mammal diversity. Savanna trees can have a variety of effects on grasses, with consequences for the wild and domestic...
Effects of Groundwater Development on Uranium: Central Valley, California, USA
Bryant C. Jurgens, Miranda S. Fram, Kenneth Belitz, Karen R. Burow, Matthew K. Landon
2009, Ground Water (48) 913-928
Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in...
Sexing sirenians: Validation of visual and molecular sex determination in both wild dugongs (Dugong dugon) and Florida manatees (Trichechus manatus latirostris)
J. Lanyon, H. Sneath, J. Ovenden, D. Broderick, Robert K. Bonde
2009, Aquatic Mammals (35) 187-192
Sexing wild marine mammals that show little to no sexual dimorphism is challenging. For sirenians that are difficult to catch or approach closely, molecular sexing from tissue biopsies offers an alternative method to visual discrimination. This paper reports the results of a field study to validate the use of two...
Potential Inundation due to Rising Sea Levels in the San Francisco Bay Region
Noah Knowles
2009, Report
An increase in the rate of sea level rise is one of the primary impacts of projected global climate change. To assess potential inundation associated with a continued acceleration of sea level rise, the highest resolution elevation data available were assembled from various sources and mosaicked to cover the land...
Geochemical Evolution of Great Salt Lake, Utah, USA
Blair F. Jones, David L. Naftz, Ronald J. Spencer, Charles G. Oviatt
2009, Aquatic Geochemistry (15) 95-121
"The Great Salt Lake (GSL) of Utah, USA, is the largest saline lake in North America, and its brines are some of the most concentrated anywhere in the world. The lake occupies a closed basin system whose chemistry reflects solute inputs from the weathering of a diverse suite of rocks in its drainage...
Hatch Timing Variations Among Reservoir Gizzard Shad Populations: Implications for Stocked Sander spp. Fingerlings
Richard D. Zweifela, David B. Bunnell, Mary T. Bremiganc, R. Scott Hale
2009, North American Journal of Fisheries Management (29) 488-494
Growth and survival of stocked Sander spp. fingerlings can be influenced by timing of stocking in relation to the peak in density of larval gizzard shad Dorosoma cepedianum. However, coordinating stockings to coincide with peaks in gizzard shad density is difficult due to temporal variation in spawn timing among reservoirs....
Declining global per capita agricultural production and warming oceans threaten food security
Christopher C. Funk, Molly E. Brown
2009, Food Security (1) 271-289
Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security...
Predicting organic floc transport dynamics in shallow aquatic ecosystems: Insights from the field, the laboratory, and numerical modeling
Judson W. Harvey, Gregory B. Noe, Laurel G. Larsen, John P. Crimaldi
2009, Water Resources Research (45)
Transport of particulate organic material can impact watershed sediment and nutrient budgets and can alter the geomorphologic evolution of shallow aquatic environments. Prediction of organic aggregate (“floc”) transport in these environments requires knowledge of how hydraulics and biota affect the entrainment, settling, and aggregation of particles. This study evaluated the...
Importance of light, temperature, zooplankton, and fish in predicting the nighttime vertical distribution of Mysis diluviana
Brent Boscarino, Lars G. Rudstam, S.A. Ellenberger, Robert O’Gorman
2009, Aquatic Biology (5) 263-279
The opossum shrimp Mysis diluviana (formerly M. relicta) performs large amplitude diel vertical migrations in Lake Ontario and its nighttime distribution is influenced by temperature, light and the distribution of its predators and prey. At one location in southeastern Lake Ontario, we measured the vertical distribution of mysids, mysid predators (i.e. planktivorous fishes)...
Organochlorine pesticides residue in lakes of Khorezm, Uzbekistan
Michael R. Rosen, Bakhriddin Nishonov, Dilorom Fayzieva, L. Saito, J. Lamers
2009, Book, 10th International HCH and pesticide forum book of papers: how many obsolete pesticides have been disposed of 8 years after signature of Stockholm Convention
The Khorezm province in northwest Uzbekistan is a productive agricultural area within the Aral Sea Basin that produces cotton, rice and wheat. Various organochlorine pesticides were widely used for cotton production before Uzbekistan's independence in 1991. In Khorezm, small lakes have formed in natural depressions that receive inputs mostly from...
Sensitivity of the carbon cycle in the Arctic to climate change
A. David McGuire, Leif G. Anderson, Torben R. Christensen, Scott Dallimore, Laodong Guo, Daniel J. Hayes, Martin Heimann, T.D. Lorenson, Robie W. Macdonald, Nigel Roulet
2009, Ecological Monographs (79) 523-555
The recent warming in the Arctic is affecting a broad spectrum of physical, ecological, and human/cultural systems that may be irreversible on century time scales and have the potential to cause rapid changes in the earth system. The response of the carbon cycle of the Arctic to changes in climate...
Geochemistry of inorganic nitrogen in waters released from coal-bed natural gas production wells in the Powder River Basin, Wyoming
Richard L. Smith, Deborah A. Repert, Charles P. Hart
2009, Environmental Science & Technology (43) 2348-2354
Water originating from coal-bed natural gas (CBNG) production wells typically contains ammonium and is often disposed via discharge to ephemeral channels. A study conducted in the Powder River Basin, Wyoming, documented downstream changes in CBNG water composition, emphasizing nitrogen-cycling processes and the fate of ammonium. Dissolved ammonium concentrations from 19...
Pore-water chemistry from the ICDP-USGS coer hole in the Chesapeake Bay impact structure--Implications for paleohydrology, microbial habitat, and water resources
Ward E. Sanford, Mary A. Voytek, David S. Powars, Blair F. Jones, Isabelle M. Cozzarelli, Robert P. Eganhouse, Charles S. Cockell
2009, Special Paper of the Geological Society of America (458) 867-890
We investigated the groundwater system of the Chesapeake Bay impact structure by analyzing the pore-water chemistry in cores taken from a 1766-m-deep drill hole 10 km north of Cape Charles, Virginia. Pore water was extracted using high-speed centrifuges from over 100 cores sampled from a 1300 m section of...
Desert Dust Storm Microbiology: Issues in Planetary Health
Dale W. Griffin
2009, Book chapter, Yearbook of Science and Technology
Distinct freshwater and seawater isoforms of Na+/K+-ATPase in gill chloride cells of Atlantic salmon
Stephen D. McCormick, A.M. Regish, A.K. Christensen
2009, Journal of Experimental Biology (212) 3994-4001
Gill Na(+)/K(+)-ATPase (NKA) in teleost fishes is involved in ion regulation in both freshwater and seawater. We have developed and validated rabbit polyclonal antibodies specific to the NKA alpha1a and alpha1b protein isoforms of Atlantic salmon (Salmo salar Linnaeus), and used western blots and immunohistochemistry to characterize their size, abundance...
Transport of tritium contamination to the atmosphere in an arid environment
C. Amanda Garcia, Brian J. Andraski, Michael J. Johnson, David A. Stonestrom, Robert L. Michel, C.A. Cooper, S.W. Wheatcraft
2009, Vadose Zone Journal (8) 450-461
Soil–plant–atmosphere interactions strongly influence water movement in desert unsaturated zones, but little is known about how such interactions affect atmospheric release of subsurface water-borne contaminants. This 2-yr study, performed at the U.S. Geological Survey's Amargosa Desert Research Site in southern Nevada, quantified the magnitude and spatiotemporal variability of tritium (3H)...
Lysimetric Evaluation of Simplified Surface Energy Balance Approach in the Texas High Plains
Gabriel B. Senay, P.H. Gowda, T.A. Howell, T.H. Marek
2009, Applied Engineering in Agriculture (25) 665-669
Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surface Energy Balance (SSEB) is...
Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the Potomac River
Micah Kieffer
2009, Journal of Applied Ichthyology (25) 34-38
We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: a saltwater/freshwater reach at river km (rkm) 63-141 was the...
Earth imagery for the masses—TerraLook delivers free satellite imagery for monitoring change
Eugene A. Fosnight
2009, Earth Imaging Journal (4) 32-36
Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer
P.B. Hatzinger, John Karl Bohlke, N.C. Sturchio, B. Gu, L.J. Heraty, R.C. Borden
2009, Environmental Chemistry (6) 44-52
An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for...
Multi-scale measurements and modeling of denitrification in streams with varying flow and nitrate concentration in the upper Mississippi River basin, USA
J.K. Bohlke, Ronald C. Antweiler, Judson W. Harvey, Andrew E. Laursen, Lesley K. Smith, Richard L. Smith, Mary A. Voytek
2009, Biogeochemistry (93) 117-141
Denitrification is an important net sink for NO3− in streams, but direct measurements are limited and in situ controlling factors are not well known. We measured denitrification at multiple scales over a range of flow conditions and NO3− concentrations in streams draining agricultural land in the upper Mississippi River basin....
Geomorphology and river dynamics of the lower Copper River, Alaska
Timothy P. Brabets, Jeffrey S. Conaway
2009, Scientific Investigations Report 2009-5257
Located in south-central Alaska, the Copper River drains an area of more than 24,000 square miles. The average annual flow of the river near its mouth is 63,600 cubic feet per second, but is highly variable between winter and summer. In the winter, flow averages approximately 11,700 cubic feet per...
A simple technique for continuous measurement of time-variable gas transfer in surface waters
Craig R. Tobias, John Karl Bohlke, Judson W. Harvey, Eurybiades Busenberg
2009, Limnology and Oceanography: Methods (7) 185-195
Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the...
Estimated land-surface subsidence in Harris County, Texas, 1915-17 to 2001
Mark C. Kasmarek, Robert K. Gabrysch, Michaela R. Johnson
2009, Scientific Investigations Map 3097
Land-surface subsidence, or land subsidence, in Harris County, Texas, which encompasses much of the Houston area, has been occurring for decades. Land subsidence has increased the frequency and extent of flooding, damaged buildings and transportation infrastructure, and caused adverse environmental effects. The primary cause of land subsidence in the Houston...
2008 Spawning Cisco Investigations in the Canadian Waters of Lake Superior
Daniel L. Yule, Peter A. Addison, Lori M. Evrard, Ken I. Cullis, Gary A. Cholwek
2009, Report
The Great Lakes Science Center of the United States Geological Survey (USGS) is working cooperatively with the Ontario Ministry of Natural Resources (OMNR) on a threeyear study to develop standard procedures for acoustic and midwater trawl (AC-MT) assessments of spawning cisco Coregonus artedi that the OMNR can carry forward as...
