The effect of mayfly (Hexagenia spp.) burrowing activity on sediment oxygen demand in western Lake Erie
William J. Edwards, Frederick M. Soster, Gerald Matisoff, Donald W. Schloesser
2009, Journal of Great Lakes Research (35) 507-516
Previous studies support the hypothesis that large numbers of infaunal burrow-irrigating organisms in the western basin of Lake Erie may increase significantly the sediment oxygen demand, thus enhancing the rate of hypolimnetic oxygen depletion. We conducted laboratory experiments to quantify burrow oxygen dynamics and increased oxygen demand resulting from burrow...
Evaluation of two spike-and-recovery controls for assessment of extraction efficiency in microbial source tracking studies
D. M. Stoeckel, E.A. Stelzer, L.K. Dick
2009, Water Research (43) 4820-4827
Quantitative PCR (qPCR), applied to complex environmental samples such as water, wastewater, and feces, is susceptible to methodological and sample related biases. In this study, we evaluated two exogenous DNA spike-and-recovery controls as proxies for recovery efficiency of Bacteroidales 16S rDNA gene sequences (AllBac and qHF183) that are used for...
Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni)
Vanessa R. von Biela, V.A. Gill, James L. Bodkin, Jennifer M. Burns
2009, Journal of Mammalogy (90) 1224-1231
Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average...
Global irrigated area map (GIAM), derived from remote sensing, for the end of the last millennium
P.S. Thenkabail, C.M. Biradar, P. Noojipady, V. Dheeravath, Y. Li, M. Velpuri, M. Gumma, O.R.P. Gangalakunta, H. Turral, X. Cai, J. Vithanage, M.A. Schull, R. Dutta
2009, International Journal of Remote Sensing (30) 3679-3733
A Global Irrigated Area Map (GIAM) has been produced for the end of the last millennium using multiple satellite sensor, secondary, Google Earth and groundtruth data. The data included: (a) Advanced Very High Resolution Radiometer (AVHRR) 3-band and Normalized Difference Vegetation Index (NDVI) 10 km monthly time-series for 1997-1999, (b)...
Using LiDAR and quickbird data to model plant production and quantify uncertainties associated with wetland detection and land cover generalizations
B.D. Cook, P.V. Bolstad, E. Naesset, R. Scott Anderson, S. Garrigues, J.T. Morisette, J. Nickeson, K.J. Davis
2009, Remote Sensing of Environment (113) 2366-2379
Spatiotemporal data from satellite remote sensing and surface meteorology networks have made it possible to continuously monitor global plant production, and to identify global trends associated with land cover/use and climate change. Gross primary production (GPP) and net primary production (NPP) are routinely derived from the Moderate Resolution Imaging Spectroradiometer...
Water uptake and nutrient concentrations under a floodplain oak savanna during a non-flood period, lower Cedar River, Iowa
K. E. Schilling, P. Jacobson
2009, Hydrological Processes (23) 3006-3016
Floodplains during non-flood periods are less well documented than when flooding occurs, but non-flood periods offer opportunities to investigate vegetation controls on water and nutrient cycling. In this study, we characterized water uptake and nutrient concentration patterns from 2005 to 2007 under an oak savanna located on the floodplain of...
Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs
Collin A. Eagles-Smith, Joshua T. Ackerman
2009, Environmental Science & Technology (43) 8658-8664
Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small...
Lysimetric evaluation of simplified surface energy balance approach in the Texas high plains
P.H. Gowda, G.B. Senay, 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...
Fluvial fluxes of water, suspended particulate matter, and nutrients and potential impacts on tropical coastal water Biogeochemistry: Oahu, Hawai'i
D.J. Hoover, F.T. MacKenzie
2009, Aquatic Geochemistry (15) 547-570
Baseflow and storm runoff fluxes of water, suspended particulate matter (SPM), and nutrients (N and P) were assessed in conservation, urban, and agricultural streams discharging to coastal waters around the tropical island of Oahu, Hawai'i. Despite unusually low storm frequency and intensity during the study, storms accounted for 8-77% (median...
Historical and simulated ecosystem carbon dynamics in Ghana: Land use, management, and climate
Z. Tan, L.L. Tieszen, E. Tachie-Obeng, S. Liu, A.M. Dieye
2009, Biogeosciences (6) 45-58
We used the General Ensemble biogeochemical Modeling System (GEMS) to simulate responses of natural and managed ecosystems to changes in land use and land cover, management, and climate for a forest/savanna transitional zone in central Ghana. Model results show that deforestation for crop production during the 20th century resulted in...
Tsunamis and splay fault dynamics
J. Wendt, D. D. Oglesby, E.L. Geist
2009, Geophysical Research Letters (36)
The geometry of a fault system can have significant effects on tsunami generation, but most tsunami models to date have not investigated the dynamic processes that determine which path rupture will take in a complex fault system. To gain insight into this problem, we use the 3D finite element method...
Design of smart sensing components for volcano monitoring
M. Xu, W.-Z. Song, R. Huang, Y. Peng, B. Shirazi, R. LaHusen, A. Kiely, N. Peterson, A. Ma, L. Anusuya-Rangappa, M. Miceli, D. McBride
2009, Pervasive and Mobile Computing (5) 639-653
In a volcano monitoring application, various geophysical and geochemical sensors generate continuous high-fidelity data, and there is a compelling need for real-time raw data for volcano eruption prediction research. It requires the network to support network synchronized sampling, online configurable sensing and situation awareness, which pose significant challenges on sensing...
Net Loss of CaCO3 from a subtropical calcifying community due to seawater acidification: Mesocosm-scale experimental evidence
A.J. Andersson, I. B. Kuffner, F.T. MacKenzie, P. L. Jokiel, K. S. Rodgers, A. Tan
2009, Biogeosciences (6) 1811-1823
Acidification of seawater owing to oceanic uptake of atmospheric CO 2 originating from human activities such as burning of fossil fuels and land-use changes has raised serious concerns regarding its adverse effects on corals and calcifying communities. Here we demonstrate a net loss of calcium carbonate (CaCO3) material as a...
Comparison of humus and till as prospecting material in areas of thick overburden and multiple ice-flow events: An example from northeastern New Brunswick
Bruce E. Broster, M.L. Dickson, M.A. Parkhill
2009, Journal of Geochemical Exploration (103) 115-132
Thirty-nine elements in humus and till matrix were compared at 109 sites overlying Ag-As-Cu-Mo-Pb-Zn mineralized occurrences in northeastern New Brunswick to assess humus for anomaly identification. Humus element concentrations were not consistently correlative with maximum or minimum concentrations found in the underlying till or bedrock. The humus demonstrated significantly higher...
Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?
K. W. Krauss, T.W. Doyle, R.J. Howard
2009, Environmental and Experimental Botany (67) 118-126
Plant populations may adapt to environmental conditions over time by developing genetically based morphological or physiological characteristics. For tidal freshwater forested wetlands, we hypothesized that the conditions under which trees developed led to ecotypic difference in response of progeny to hydroperiod. Specifically, we looked for evidence of ecotypic adaptation for...
Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution
Andrew J. Long, L.D. Putnam
2009, Journal of Hydrology (376) 579-588
Convolution modeling is useful for investigating the temporal distribution of groundwater age based on environmental tracers. The framework of a quasi-transient convolution model that is applicable to two-domain flow in karst aquifers is presented. The model was designed to provide an acceptable level of statistical confidence in parameter estimates when...
Contemporaneous deposition of phyllosilicates and sulfates: Using Australian acidic saline lake deposits to describe geochemical variability on Mars
A.M. Baldridge, S.J. Hook, J.K. Crowley, G.M. Marion, J.S. Kargel, J.L. Michalski, B.J. Thomson, Filho C.R. de Souza, N.T. Bridges, A.J. Brown
2009, Geophysical Research Letters (36)
Studies of the origin of the Martian sulfate and phyllosilicate deposits have led to the hypothesis that there was a marked, global-scale change in the Mars environment from circum-neutral pH aqueous alteration in the Noachian to an acidic evaporitic system in the late Noachian to Hesperian. However, terrestrial studies suggest...
Martian mud volcanism: Terrestrial analogs and implications for formational scenarios
James A. Skinner, A. Mazzini
2009, Marine and Petroleum Geology (26) 1866-1878
The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that equivalent Martian processes likely required discrete sedimentary depocenters,...
Enantiomer fractions of chlordane components in sediment from U.S. Geological Survey sites in lakes and rivers
E.M. Ulrich, W.T. Foreman, P. C. Van Metre, J.T. Wilson, S.A. Rounds
2009, Science of the Total Environment (407) 5884-5893
Spatial, temporal, and sediment-type trends in enantiomer signatures were evaluated for cis- and trans-chlordane (CC, TC) in archived core, suspended, and surficial-sediment samples from six lake, reservoir, and river sites across the United States. The enantiomer fractions (EFs) measured in these samples are in good agreement with those reported for sediment, soil,...
A new numerical method for calculating extrema of received power for polarimetric SAR
Y. Zhang, Jiahua Zhang, Z. Lu, W. Gong
2009, IEEE Geoscience and Remote Sensing Letters (6) 666-670
A numerical method called cross-step iteration is proposed to calculate the maximal/minimal received power for polarized imagery based on a target's Kennaugh matrix. This method is much more efficient than the systematic method, which searches for the extrema of received power by varying the polarization ellipse angles of receiving and...
Impediments to predicting site response: Seismic property estimation and modeling simplifications
E.M. Thompson, L.G. Baise, R. E. Kayen, B.B. Guzina
2009, Bulletin of the Seismological Society of America (99) 2927-2949
We compare estimates of the empirical transfer function (ETF) to the plane SH-wave theoretical transfer function (TTF) within a laterally constant medium for invasive and noninvasive estimates of the seismic shear-wave slownesses at 13 Kiban-Kyoshin network stations throughout Japan. The difference between the ETF and either of the TTFs is...
The relative importance of disturbance and exotic-plant abundance in California coastal sage scrub
G.M. Fleming, J.E. Diffendorfer, P.H. Zedler
2009, Ecological Applications (19) 2210-2227
Many ecosystems of conservation concern require some level of disturbance to sustain their species composition and ecological function. However, inappropriate disturbance regimes could favor invasion or expansion of exotic species. In southern California coastal sage scrub (CSS) fire is a natural disturbance, but because of human influence, frequencies may now...
Timing of breeding and reproductive performance in murres and kittiwakes reflect mismatched seasonal prey dynamics
M.T. Shultz, John F. Piatt, A.M.A. Harding, Arthur B. Kettle, Thomas I. van Pelt
2009, Marine Ecology Progress Series (393) 247-258
Seabirds are thought to time breeding to match the seasonal peak of food availability with peak chick energetic demands, but warming ocean temperatures have altered the timing of spring events, creating the potential for mismatches. The resilience of seabird populations to climate change depends on their ability to anticipate changes...
Response to critique by lucas et al. (2009) of paper by Fassett (2009) documenting Paleocene dinosaurs in the San Juan Basin
J.E. Fassett
2009, Palaeontologia Electronica (12)
In this issue of Palaeontologia Electronica Lucas, et al. (2009) question the validity f the Fassett (2009) paper that presented evidence for Paleocene dinosaurs in the San Juan Basin of New Mexico and Colorado. Their challenges focus primarily on the lithostratigraphy, palynology, and paleomagnetism of the dinosaur-bearing Ojo Alamo Sandstone,...
Freshwaters in the public eye: Understanding the role of images and media in aquatic conservation
J.B. Monroe, C. V. Baxter, J. D. Olden, P. L. Angermeier
2009, Fisheries (34) 581-585
[No abstract available]...
