Effect of imbalanced nutrients and immigration on Prymnesium parvum community dominance and toxicity: Results from in-lake microcosm experiments
R.M. Errera, D. L. Roelke, R.L. Kiesling, B.W. Brooks, J. P. Grover, L. Schwierzke, F. Urena-Boeck, J.W. Baker, J.L. Pinckney
2008, Aquatic Microbial Ecology (52) 33-44
Prymnesium parvum, a haptophyte species, forms harmful blooms, including those that have caused severe fish kills in Texas, USA, over the past 6 yr. We studied P. parvum dynamics using in situ microcosm experiments at Lake Possum Kingdom, Texas, during 3 seasons (fall 2004, winter and spring 2005). Experimental treatments...
Dispersal of Culex quinquefasciatus (Diptera: Culicidae) in a Hawaiian rain forest
D.A. Lapointe
2008, Journal of Medical Entomology (45) 600-609
Introduced mosquito-borne pathogens avian malaria (Plasmodium relictum Grassi and Feletti) and avian pox virus (Avipoxvirus) have been implicated in the past extinctions and declines of Hawaiian avifauna and remain significant obstacles to the recovery and restoration of endemic Hawaiian birds. Effective management of avian disease will require extensive mosquito control...
Linking runoff response to burn severity after a wildfire
J. A. Moody, D.A. Martin, S.L. Haire, D.A. Kinner
2008, Hydrological Processes (22) 2063-2074
Extreme floods often follow wildfire in mountainous watersheds. However, a quantitative relation between the runoff response and burn severity at the watershed scale has not been established. Runoff response was measured as the runoff coefficient C, which is equal to the peak discharge per unit drainage area divided by the...
What was the groundwater quality before mining in a mineralized region? Lessons from the Questa Project
D. Kirk Nordstrom
2008, Geosciences Journal (12) 139-149
The U.S. Geological Survey, in cooperation with the New Mexico Environment Department and supported by Molycorp, Inc (currently Chevron Minerals), has completed a 5-year investigation (2001-2006) to determine the pre-mining ground-water quality at Molycorp's Questa molybdenum mine in northern New Mexico. Current mine-site ground waters are often contaminated with mine-waste...
Changes in the soil C cycle at the arid-hyperarid transition in the Atacama Desert
S.A. Ewing, J. L. Macalady, K. Warren-Rhodes, C.P. McKay, Ronald Amundson
2008, Journal of Geophysical Research G: Biogeosciences (113)
We examined soil organic C (OC) turnover and transport across the rainfall transition from a biotic, arid site to a largely abiotic, hyperarid site. With this transition, OC concentrations decrease, and C cycling slows precipitously, both in surface horizons and below ground. The concentration and isotopic character of soil OC...
Soil morphology of a debris flow chronosequence in a coniferous forest, southern California, USA
J.K. Turk, B.R. Goforth, R.C. Graham, K.J. Kendrick
2008, Geoderma (146) 157-165
Soils on a series of debris flow deposits, ranging from < 1 to 244??years old, were described and sampled in order to investigate the early stages of soil development. The parent material at the site is debris flow regolith, composed mainly of gneiss, the soil moisture regime is xeric, and...
Soil nitrogen accretion along a floodplain terrace chronosequence in northwest Alaska: Influence of the nitrogen-fixing shrub Shepherdia canadensis
Charles Rhoades, Dan Binkley, Hlynur Oskarsson, Robert Stottlemyer
2008, Écoscience (15) 223-230
Nitrogen enters terrestrial ecosystems through multiple pathways during primary succession. We measured accumulation of total soil nitrogen and changes in inorganic nitrogen (N) pools across a 300-y sequence of river terraces in northwest Alaska and assessed the contribution of the nitrogen-fixing shrub Shepherdia canadensis. Our work compared 5 stages of floodplain...
Physical rock properties in and around a conduit zone by well-logging in the Unzen Scientific Drilling Project, Japan
R. Ikeda, T. Kajiwara, K. Omura, S. Hickman
2008, Journal of Volcanology and Geothermal Research (175) 13-19
The objective of the Unzen Scientific Drilling Project (USDP) is not only to reveal the structure and eruption history of the Unzen volcano but also to clarify the ascent and degassing mechanisms of the magma conduit. Conduit drilling (USDP-4) was conducted in 2004, which targeted the magma conduit for the...
On developing thermal cave detection techniques for earth, the moon and mars
J. Judson Wynne, Timothy N. Titus, Guillermo Chong Diaz
2008, Earth and Planetary Science Letters (272) 240-250
The purpose of this study is to (1) demonstrate the viability of detecting terrestrial caves at thermal-infrared wavelengths, (2) improve our understanding of terrestrial cave thermal behavior, (3) identify times of day when cave openings have the maximum thermal contrast with the surrounding surface regolith, and (4) further our understanding...
Stress changes from the 2008 Wenchuan earthquake and increased hazard in the Sichuan basin
T. Parsons, C. Ji, E. Kirby
2008, Nature (454) 509-510
On 12 May 2008, the devastating magnitude 7.9 (Wenchuan) earthquake struck the eastern edge of the Tibetan plateau, collapsing buildings and killing thousands in major cities aligned along the western Sichuan basin in China. After such a large-magnitude earthquake, rearrangement of stresses in the crust commonly leads to subsequent damaging...
Compositional stratigraphy of clay-bearing layered deposits at Mawrth Vallis, Mars
J.J. Wray, B.L. Ehlmann, S. W. Squyres, J.F. Mustard, Randolph L. Kirk
2008, Geophysical Research Letters (35)
Phyllosilicates have previously been detected in layered outcrops in and around the Martian outflow channel Mawrth Vallis. CRISM spectra of these outcrops exhibit features diagnostic of kaolinite, montmorillonite, and Fe/Mg-rich smectites, along with crystalline ferric oxide minerals such as hematite. These minerals occur in distinct stratigraphic horizons, implying changing environmental...
Magnetic monitoring of earth and space
Jeffrey J. Love
2008, Physics Today (61) 31-37
For centuries, navigators of the world’s oceans have been familiar with an effect of Earth’s magnetic field: It imparts a directional preference to the needle of a compass. Although in some settings magnetic orientation remains important, the modern science of geomagnetismhas emerged from its romantic nautical origins and developed into a subject of great depth and...
Multi-proxy evidence for Late Pleistocene-Holocene climatic and environmental changes in Lop-Nur, Xinjiang, Northwest China
C. Luo, D. Yang, Z. Peng, Z. Zhang, L. Weiguo, J. He, C. Zhou
2008, Chinese Journal of Geochemistry (27) 257-264
A 10.35-m-long sediment core from the Luobei depression in Lop-Nur, Xinjiang, Northwest China, provides detailed information about environmental changes during the Late Pleistocene. The samples taken every 5 cm of the core were analyzed for 10 environmental proxies, including magnetic susceptibility, granularity, chroma, carbonate and loss on ignition (LOI), and...
A 2650-year-long record of environmental change from northern Yellowstone National Park based on a comparison of multiple proxy data
C. Whitlock, W. Dean, J. Rosenbaum, L. Stevens, S. Fritz, B. Bracht, M. Power
2008, Quaternary International (188) 126-138
Geochemical, stable-isotope, pollen, charcoal, and diatom records were analyzed at high-resolution in cores obtained from Crevice Lake, a varved-sediment lake in northern Yellowstone National Park. The objective was to reconstruct the ecohydrologic, vegetation, and fire history of the watershed for the last 2650 years to better understand past climate variations...
Overgrowth of fungi (endolithic hypermycosis) associated with multifocal to diffuse distinct amorphous dark discoloration of corals in the Indo-Pacific
Thierry M. Work, G.S. Aeby, F.G. Stanton, D. Fenner
2008, Coral Reefs (27) 663-663
Coral disease surveys in American Samoa and Hawai‘i revealed colonies with a distinct dark discoloration affecting 20–60% of the colony surface (Fig. 1a). In some cases, tissue loss with algal infiltration was present within discolored areas. On microscopy, these lesions had marked overgrowth of the coral skeleton and...
Permeameter data verify new turbulence process for MODFLOW
Eve L. Kuniansky, Keith J. Halford, W. Barclay Shoemaker
2008, Ground Water (46) 768-771
A sample of Key Largo Limestone from southern Florida exhibited turbulent flow behavior along three orthogonal axes as reported in recently published permeameter experiments. The limestone sample was a cube measuring 0.2 m on edge. The published nonlinear relation between hydraulic gradient and discharge was simulated using the turbulent flow...
Numerical modeling of higher order magnetic moments in UXO discrimination
V. Sanchez, L. Yaoguo, M.N. Nabighian, D.L. Wright
2008, IEEE Transactions on Geoscience and Remote Sensing (46) 2568-2583
The surface magnetic anomaly observed in unexploded ordnance (UXO) clearance is mainly dipolar, and consequently, the dipole is the only magnetic moment regularly recovered in UXO discrimination. The dipole moment contains information about the intensity of magnetization but lacks information about the shape of the target. In contrast, higher order...
Ocean wavenumber estimation from wave-resolving time series imagery
N.G. Plant, K. T. Holland, M.C. Haller
2008, IEEE Transactions on Geoscience and Remote Sensing (46) 2644-2658
We review several approaches that have been used to estimate ocean surface gravity wavenumbers from wave-resolving remotely sensed image sequences. Two fundamentally different approaches that utilize these data exist. A power spectral density approach identifies wavenumbers where image intensity variance is maximized. Alternatively, a cross-spectral correlation approach identifies wavenumbers where...
Effects of weather on survival in populations of boreal toads in Colorado
R. D. Scherer, E. Muths, B.A. Lambert
2008, Journal of Herpetology (42) 508-517
Understanding the relationships between animal population demography and the abiotic and biotic elements of the environments in which they live is a central objective in population ecology. For example, correlations between weather variables and the probability of survival in populations of temperate zone amphibians may be broadly applicable to several...
Patch-reef morphology as a proxy for Holocene sea-level variability, Northern Florida Keys, USA
J. C. Brock, M. Palaseanu-Lovejoy, C. W. Wright, A. Nayegandhi
2008, Coral Reefs (27) 555-568
A portion of the northern Florida Keys reef tract was mapped with the NASA Experimental Advanced Airborne Research Lidar (EAARL) and the morphology of patch reefs was related to variations in Holocene sea level. Following creation of a lidar digital elevation model (DEM), geospatial analyses delineated morphologic attributes of 1,034...
Use of complex hydraulic variables to predict the distribution and density of unionids in a side channel of the Upper Mississippi River
J. J. Steuer, T.J. Newton, S. J. Zigler
2008, Hydrobiologia (610) 67-82
Previous attempts to predict the importance of abiotic and biotic factors to unionids in large rivers have been largely unsuccessful. Many simple physical habitat descriptors (e.g., current velocity, substrate particle size, and water depth) have limited ability to predict unionid density. However, more recent studies have found that complex hydraulic...
Associations of multi-decadal sea-surface temperature variability with US drought
G.J. McCabe, J.L. Betancourt, S.T. Gray, M.A. Palecki, H.G. Hidalgo
2008, Quaternary International (188) 31-40
Recent research suggests a link between drought occurrence in the conterminous United States (US) and sea surface temperature (SST) variability in both the tropical Pacific and North Atlantic Oceans on decadal to multidecadal (D2M) time scales. Results show that the Atlantic Multidecadal Oscillation (AMO) is the most consistent indicator of...
A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States - II) Untreated drinking water sources
M. J. Focazio, D.W. Kolpin, K.K. Barnes, E. T. Furlong, M. T. Meyer, S.D. Zaugg, L. B. Barber, M.E. Thurman
2008, Science of the Total Environment (402) 201-216
Numerous studies have shown that a variety of manufactured and natural organic compounds such as pharmaceuticals, steroids, surfactants, flame retardants, fragrances, plasticizers and other chemicals often associated with wastewaters have been detected in the vicinity of municipal wastewater discharges and livestock agricultural facilities. To provide new data and insights about...
Host mating system and the spread of a disease-resistant allele in a population
D.L. DeAngelis, Jennifer M. Koslow, J. Jiang, S. Ruan
2008, Theoretical Population Biology (74) 191-198
The model presented here modifies a susceptible-infected (SI) host-pathogen model to determine the influence of mating system on the outcome of a host-pathogen interaction. Both deterministic and stochastic (individual-based) versions of the model were used. This model considers the potential consequences of varying mating systems on the rate of spread...
The arctic water resource vulnerability index: An integrated assessment tool for community resilience and vulnerability with respect to freshwater
L. Alessa, A. Kliskey, R. Lammers, C. Arp, D. White, L. Hinzman, R. Busey
2008, Environmental Management (42) 523-541
People in the Arctic face uncertainty in their daily lives as they contend with environmental changes at a range of scales from local to global. Freshwater is a critical resource to people, and although water resource indicators have been developed that operate from regional to global scales and for midlatitude...
