Impacts of past climate and sea level change on Everglades wetlands: placing a century of anthropogenic change into a late-Holocene context
Debra A. Willard, C.E. Bernhardt
2011, Climatic Change (107) 59-80
We synthesize existing evidence on the ecological history of the Florida Everglades since its inception ~7 ka (calibrated kiloannum) and evaluate the relative impacts of sea level rise, climate variability, and human alteration of Everglades hydrology on wetland plant communities. Initial freshwater peat accumulation began between 6 and 7 ka...
Biogeochemistry of a temperate forest nitrogen gradient
Steven S. Perakis, Emily R. Sinkhorn
2011, Ecology (92) 1481-1491
Wide natural gradients of soil nitrogen (N) can be used to examine fundamental relationships between plant–soil–microbial N cycling and hydrologic N loss, and to test N-saturation theory as a general framework for understanding ecosystem N dynamics. We characterized plant production, N uptake and return in litterfall, soil gross and net...
Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska
Benjamin M. Jones, G. Grosse, C.D. Arp, M.C. Jones, Anthony K.M. Walter, V.E. Romanovsky
2011, Journal of Geophysical Research: Biogeosciences (116)
Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst...
Comparative mobility of sulfonamides and bromide tracer in three soils
S.T. Kurwadkar, C.D. Adams, Michael T. Meyer, Dana W. Kolpin
2011, Journal of Environmental Management (92) 1874-1881
In animal agriculture, sulfonamides are one of the routinely used groups of antimicrobials for therapeutic and sub-therapeutic purposes. It is observed that, the animals when administered the antimicrobials, often do not completely metabolize them; and excrete the partially metabolized forms into the environment. Due to the continued use of antimicrobials...
Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA
R. W. Healy, T.T. Bartos, C. A. Rice, M.P. McKinley, B. D. Smith
2011, Journal of Hydrology (403) 37-48
The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface...
Hydrogeomorphic processes of thermokarst lakes with grounded-ice and floating-ice regimes on the Arctic coastal plain, Alaska
C.D. Arp, Benjamin M. Jones, F.E. Urban, G. Grosse
2011, Hydrological Processes (25) 2422-2438
Thermokarst lakes cover > 20% of the landscape throughout much of the Alaskan Arctic Coastal Plain (ACP) with shallow lakes freezing solid (grounded ice) and deeper lakes maintaining perennial liquid water (floating ice). Thus, lake depth relative to maximum ice thickness (1·5–2·0 m) represents an important threshold that impacts permafrost,...
Evaluating the effects of future climate change and elevated CO2 on the water use efficiency in terrestrial ecosystems of China
Q. Zhu, H. Jiang, C. Peng, J. Liu, X. Wei, X. Fang, S. Liu, G. Zhou, S. Yu
2011, Ecological Modelling (222) 2414-2429
Water use efficiency (WUE) is an important variable used in climate change and hydrological studies in relation to how it links ecosystem carbon cycles and hydrological cycles together. However, obtaining reliable WUE results based on site-level flux data remains a great challenge when scaling up to larger regional zones. Biophysical,...
Quantification of a greenhouse hydrologic cycle from equatorial to polar latitudes: The mid-Cretaceous water bearer revisited
M.B. Suarez, Luis A. Gonzalez, Greg A. Ludvigson
2011, Palaeogeography, Palaeoclimatology, Palaeoecology (307) 301-312
This study aims to investigate the global hydrologic cycle during the mid-Cretaceous greenhouse by utilizing the oxygen isotopic composition of pedogenic carbonates (calcite and siderite) as proxies for the oxygen isotopic composition of precipitation. The data set builds on the Aptian–Albian sphaerosiderite δ18O data set presented by Ufnar et...
Simulating adsorption of U(VI) under transient groundwater flow and hydrochemistry: Physical versus chemical nonequilibrium model
J. Greskowiak, M.B. Hay, H. Prommer, C. Liu, V.E.A. Post, R. Ma, J.A. Davis, C. Zheng, J.M. Zachara
2011, Water Resources Research (47)
Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface...
Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)'s predictive skill for hurricane-triggered landslides: A case study in Macon County, North Carolina
Z. Liao, Y. Hong, D. Kirschbaum, R.F. Adler, J.J. Gourley, R. Wooten
2011, Natural Hazards (58) 325-339
The key to advancing the predictability of rainfall-triggered landslides is to use physically based slope-stability models that simulate the transient dynamical response of the subsurface moisture to spatiotemporal variability of rainfall in complex terrains. TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis) is a USGS landslide prediction model, coded...
Methane oxidation in a crude oil contaminated aquifer: Delineation of aerobic reactions at the plume fringes
R.T. Amos, Barbara A. Bekins, Geoffrey N. Delin, Isabelle M. Cozzarelli, D.W. Blowes, J. D. Kirshtein
2011, Journal of Contaminant Hydrology (125) 13-25
High resolution direct-push profiling over short vertical distances was used to investigate CH4 attenuation in a petroleum contaminated aquifer near Bemidji, Minnesota. The contaminant plume was delineated using dissolved gases, redox sensitive components, major ions, carbon isotope ratios in CH4 and CO2, and the presence of methanotrophic bacteria. Sharp redox gradients were observed near the...
Scale-dependent factors affecting North American river otter distribution in the midwest
Mackenzie R. Jeffress, Craig P. Paukert, Joanna B. Whittier, B. K. Sandercock, P. S. Gipson
2011, American Midland Naturalist (166) 177-193
The North American river otter (Lontra canadensis) is recovering from near extirpation throughout much of its range. Although reintroductions, trapping regulations and habitat improvements have led to the reestablishment of river otters in the Midwest, little is known about how their distribution is influenced by local- and landscape-scale habitat....
The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component AM3 of the GFDL global coupled model CM3
L.J. Donner, B.L. Wyman, R.S. Hemler, L.W. Horowitz, Y. Ming, M. Zhao, J.-C. Golaz, P. Ginoux, S.-J. Lin, M.D. Schwarzkopf, J. Austin, G. Alaka, W.F. Cooke, T.L. Delworth, S.M. Freidenreich, C.T. Gordon, S.M. Griffies, I.M. Held, W.J. Hurlin, S.A. Klein, T.R. Knutson, A.R. Langenhorst, H.-C. Lee, Y. Lin, B.I. Magi, S.L. Malyshev, Paul Milly, V. Naik, M.J. Nath, R. Pincus, J.J. Ploshay, V. Ramaswamy, C.J. Seman, E. Shevliakova, J.J. Sirutis, W.F. Stern, R.J. Stouffer, R.J. Wilson, M. Winton, A.T. Wittenberg, F. Zeng
2011, Journal of Climate (24) 3484-3519
The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. The goal of CM3 is to address emerging issues in climate change, including aerosol–cloud interactions, chemistry–climate interactions, and coupling between the troposphere and stratosphere. The model is also...
Long-term patterns and short-term dynamics of stream solutes and suspended sediment in a rapidly weathering tropical watershed
James B. Shanley, W. H. McDowell, Robert F. Stallard
2011, Water Resources Research (47)
The 326 ha Río Icacos watershed in the tropical wet forest of the Luquillo Mountains, northeastern Puerto Rico, is underlain by granodiorite bedrock with weathering rates among the highest in the world. We pooled stream chemistry and total suspended sediment (TSS) data sets from three discrete periods: 1983–1987, 1991–1997, and...
Occurrence of azoxystrobin, propiconazole, and selected other fungicides in US streams, 2005-2006
William A. Battaglin, Mark W. Sandstrom, Kathryn Kuivila, Dana W. Kolpin, Michael T. Meyer
2011, Water, Air, & Soil Pollution (218) 307-322
Fungicides are used to prevent foliar diseases on a wide range of vegetable, field, fruit, and ornamental crops. They are generally more effective as protective rather than curative treatments, and hence tend to be applied before infections take place. Less than 1% of US soybeans were treated with a fungicide...
Estimating trends in alligator populations from nightlight survey data
Ikuko Fujisaki, F.J. Mazzotti, R.M. Dorazio, Kenneth G. Rice, M. Cherkiss, B. Jeffery
2011, Wetlands (31) 147-155
Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends...
Sulfur in the South Florida ecosystem: Distribution, sources, biogeochemistry, impacts, and management for restoration
William H. Orem, C. Gilmour, D. Axelrad, David P. Krabbenhoft, D. Scheidt, P. Kalla, P. McCormick, M. Gabriel, George Aiken
2011, Critical Reviews in Environmental Science and Technology (41) 249-288
Sulfur is broadly recognized as a water quality issue of significance for the freshwater Florida Everglades. Roughly 60% of the remnant Everglades has surface water sulfate concentrations above 1 mg l-1, a restoration performance measure based on present sulfate levels in unenriched areas. Highly enriched marshes in the northern Everglades...
Synthesis of isotopically modified ZnO nanoparticles and their potential as nanotoxicity tracers
A.D. Dybowska, Marie Noele Croteau, S.K. Misra, D. Berhanu, Samuel N. Luoma, P. Christian, P. O'Brien, E. Valsami-Jones
2011, Environmental Pollution (159) 266-273
Understanding the behavior of engineered nanoparticles in the environment and within organisms is perhaps the biggest obstacle to the safe development of nanotechnologies. Reliable tracing is a particular issue for nanoparticles such as ZnO, because Zn is an essential element and a common pollutant thus present at elevated background concentrations. We synthesized isotopically...
Understanding the role of fog in forest hydrology: Stable isotopes as tools for determining input and partitioning of cloud water in montane forests
Martha A. Scholl, W. Eugster, R. Burkard
2011, Hydrological Processes (25) 353-366
Understanding the hydrology of tropical montane cloud forests (TMCF) has become essential as deforestation of mountain areas proceeds at an increased rate worldwide. Passive and active cloud‐water collectors, throughfall and stemflow collectors, visibility or droplet size measurements, and micrometeorological sensors are typically used to measure the fog water inputs to...
Secular trends in storm-level geomagnetic activity
J.J. Love
2011, Annales Geophysicae (29) 251-262
Analysis is made of K-index data from groups of ground-based geomagnetic observatories in Germany, Britain, and Australia, 1868.0–2009.0, solar cycles 11–23. Methods include nonparametric measures of trends and statistical significance used by the hydrological and climatological research communities. Among the three observatory groups, German K data systematically record the highest disturbance levels,...
Influence of changing water sources and mineral chemistry on the everglades ecosystem
Paul V. McCormick, Judson Harvey, Eric Crawford
2011, Critical Reviews in Environmental Science and Technology (41) 28-63
Human influences during the previous century increased mineral inputs to the Florida Everglades by changing the sources and chemistry of surface inflows. Biogeochemical responses to this enrichment include changes in the availability of key limiting nutrients such as P, the potential for increased turnover of nutrient pools due to accelerated...
Dissolved organic matter in the Florida everglades: Implications for ecosystem restoration
G. R. Aiken, C.C. Gilmour, D. P. Krabbenhoft, W. Orem
2011, Critical Reviews in Environmental Science and Technology (41) 217-248
Dissolved organic matter (DOM) in the Florida Everglades controls a number of environmental processes important for ecosystem function including the absorption of light, mineral dissolution/precipitation, transport of hydrophobic compounds (e.g., pesticides), and the transport and reactivity of metals, such as mercury. Proposed attempts to return the Everglades to more natural...
Canopy water balance of windward and leeward Hawaiian cloud forests on Haleakalā, Maui, Hawai'i
Thomas W. Giambelluca, John K. DeLay, Michael A. Nullet, Martha A. Scholl, Stephen B. Gingerich
2011, Hydrological Processes (25) 438-447
The contribution of intercepted cloud water to precipitation at windward and leeward cloud forest sites on the slopes of Haleakalā, Maui was assessed using two approaches. Canopy water balance estimates based on meteorological monitoring were compared with interpretations of fog screen measurements collected over a 2-year period at each location....
Ammonium in thermal waters of Yellowstone National Park: Processes affecting speciation and isotope fractionation
J.M. Holloway, D. Kirk Nordstrom, J.K. Böhlke, R. Blaine McCleskey, J.W. Ball
2011, Geochimica et Cosmochimica Acta (75) 4611-4636
Dissolved inorganic nitrogen, largely in reduced form (NH4(T)≈NH4(aq)++NH3(aq)o), has been documented in thermal waters throughout Yellowstone National Park, with concentrations ranging from a few micromolar along the Firehole River to millimolar concentrations at Washburn Hot Springs. Indirect evidence from rock nitrogen analyses and previous work on organic compounds associated with...
Climatic controls on the snowmelt hydrology of the northern Rocky Mountains
Gregory T. Pederson, S.T. Gray, T. Ault, W. Marsh, Daniel B. Fagre, A.G. Bunn, C.A. Woodhouse, L.J. Graumlich
2011, Journal of Climate (24) 1666-1687
The northern Rocky Mountains (NRMs) are a critical headwaters region with the majority of water resources originating from mountain snowpack. Observations showing declines in western U.S. snowpack have implications for water resources and biophysical processes in high-mountain environments. This study investigates oceanic and atmospheric controls underlying changes in timing, variability,...
