Digital Commons Network^™

The Threat Of The Non-Native Neotropical Rust Puccinia Psidii To Hawaiian Biodiversity And Native Ecosystems: A Case Example Of The Need For Prevention, Lloyd Loope, Janice Uchida, Loyal Mehrhoff

United States Geological Survey: Staff Publications

The threat of invasive species to natural areas presents enormous challenges, but there are opportunities for working toward solutions, often in conjunction with agricultural and forestry perspectives. There is a growing awareness of the danger to botanical biodiversity and conservation from “emerging infectious diseases” that have increased in incidence, geographical distribution, or host range/pathogenicity; have newly evolved characteristics; and/or have been newly discovered (Anderson et al. 2004). There is a heightened concern for forest health due to accelerating worldwide movement of plant pathogens (e.g., with ineffective quarantine measures) that negatively affect both biodiversity and commercial forestry (Wingfield 2003). An important …

Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer

United States Geological Survey: Staff Publications

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L^-1 and MeHg was less than 0.2 ng L^-1. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with …

Influence Of Plankton Mercury Dynamics And Trophic Pathways On Mercury Concentrations Of Top Predator Fish Of A Mining-Impacted Reservoir, A. Robin Stewart, Michael K. Saiki, James S. Kuwabara, Charles N. Alpers, Mark Marvin-Dipasquale, David P. Krabbenhoft

United States Geological Survey: Staff Publications

Physical and biogeochemical characteristics of the aquatic environment that affect growth dynamics of phytoplankton and the zooplankton communities that depend on them may also affect uptake of methylmercury (MeHg) into the pelagic food web of oligotrophic reservoirs. We evaluated changes in the quality and quantity of suspended particulate material, zooplankton taxonomy, and MeHg concentrations coincident with seasonal changes in water storage of a mining-impacted reservoir in northern California, USA. MeHg concentrations in bulk zooplankton increased from 4 ng·g^–1 at low water to 77 ± 6.1 ng·g^–1 at high water and were positively correlated with cladoceran biomass (r = …

Metals Fate And Transport Modelling In Streams And Watersheds: State Of The Science And Usepa Workshop Review, B. S. Caruso, T. J. Cox, R. L. Runkel, M. L. Velleux, K. E. Bencala, D. K. Nordstrom, P. Y. Julien, B. A. Butler, Charles N. Alpers, A. Marion, K. S. Smith

United States Geological Survey: Staff Publications

Metals pollution in surface waters from point and non-point sources (NPS) is a widespread problem in the United States and worldwide (Lofts et al., 2007; USEPA, 2007). In the western United States, metals associated with acid mine drainage (AMD) from hardrock mines in mountainous areas impact aquatic ecosystems and human health (USEPA, 1997a; Caruso and Ward, 1998; Church et al., 2007). Metals fate and transport modelling in streams and watersheds is sometimes needed for assessment and restoration of surface waters, including mining-impacted streams (Runkel and Kimball, 2002; Caruso, 2003; Velleux et al., 2006). The Water Quality Analysis …

Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis …

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …

A New Method Of Synthesizing Black Birnessite Nanoparticles: From Brown To Black Birnessite With Nanostructures, Shizhi Qian, Marcos A. Cheney, Pradip K. Bhowmik, Sang W. Joo, Wensheng Hou, Joseph M. Okoh

Mechanical Engineering Faculty Research

A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7◦C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N2 adsorption (BET) techniques. Wet-aging and lyophilization times are shown to …

An Analysis Of Demographic Disparities Associated With The Proposed U.S.-Mexico Border Fence In Cameron County, Texas, J. Gaines Wilson, Jude A. Benavides, E. Anthony Reisinger, Joseph Lemen, Zachary Hurwitz, Jessica Spangler, Karen Engle

School of Earth, Environmental, & Marine Sciences Faculty Publications

Introduction: The United States Department of Homeland Security (DHS) plans to install a fence along the U.S.-Mexico border by late December 2008. While much attention has been drawn to the environmental, social and political issues surrounding the fence, analysis of demographic data on the populations that will be directly affected has been limited. This paper utilizes geographic information systems (GIS) and U.S. Census Bureau data with the objective of understanding the underlying demographics in areas along the proposed Rio Grande Valley section of the border fence located in Cameron County, Texas.

Data and Methods: Demographic measures of income, education, …

Nutrient And Carbon Dynamics In The Chesapeake Bay Outflow Plume And Their Effect On The Coastal Ocean Environment, Katherine C. Filippino

OES Theses and Dissertations

Seasonally resolved nutrient and carbon fluxes from estuaries to the coastal ocean are poorly constrained. Nutrient and carbon cycling in highly productive regions like the Chesapeake Bay outflow plume and surrounding coastal environments greatly affect our global understanding of carbon cycling. The overall questions for the research described in this dissertation stem from the need to close global carbon budgets, and obtain a fundamental understanding of nutrient dynamics in a coastal region heavily influenced by seasonality and human impacts.

Within the framework of physical characteristics of the outflow plume and through the characterization of nutrient concentrations, primary productivity rates, and …

Groundwater Contamination In Caves: Four Case Studies In Spain, Monserrat Jiménez-Sánchez, Heather Stoll, Iñaki Vadillo, Manolo López-Chicano, María Domínguez-Cuesta, Wenceslao Martín-Rosales, Mónica Meléndez-Asensio

International Journal of Speleology

Groundwater quality was monitored in four Spanish caves using concentrations of nitrate, potassium, phosphorus and in some cases total organic carbon. Three of the caves are located in NW Spain and contain prehistoric cave paintings and hence have special conservation interest. Of these, two are open show caves (Tito Bustillo and Pindal Caves), while the other one (Herrerías Cave) is not managed for tours and is partially closed off to public access. The fourth cave (Las Maravillas Cave) is located in SW Spain and is opened to the public because of its geological features and natural beauty. In this paper, …

An Investigation Of Meromixis In Cave Pools, Lechuguilla Cave, New Mexico, David B. Levy

International Journal of Speleology

Chemical characteristics of permanent stratification in cave pools (meromixis) may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically < 1 mg L^-1), biogenic meromixis resulting in O₂(g)-depleted subsurface waters is not expected. Four pools at various depths below ground surface (0 m) were studied: (1) …

The Role Of The Epikarst In Karst And Cave Hydrogeology: A Review, Paul W. Williams

International Journal of Speleology

The epikarst (also known as the subcutaneous zone) comprises highly weathered carbonate bedrock immediately beneath the surface or beneath the soil (when present) or exposed at the surface. Porosity and permeability are higher near the surface than at depth, consequently after recharge percolating rainwater is detained near the base of the epikarst, the detention ponding producing an epikarstic aquifer. Such an aquifer is found only where the uppermost part of the vadose zone is very weathered compared to the bedrock at depth. Sometimes this contrast in porosity and permeability does not occur either because the epikarst has been scraped off …

Monitoring Climatological, Hydrological And Geochemical Parameters In The Père Noël Cave (Belgium): Implication For The Interpretation Of Speleothem Isotopic And Geochemical Time-Series, Sophie Verheyden, Dominique Genty, Guy Deflandre, Yves Quinif, Eduard Keppens

International Journal of Speleology

Père Noël cave climatology (air and water temperature, P_CO2), hydrology (drip rate, conductivity) and geochemistry of water and calcite deposits (δ¹⁸O, δ¹³C, Mg/Ca and Sr/Ca) where studied to better interpret stable isotopic and trace element variations of speleothems. Results of an automated monitoring station and of manual sampling between 1991 and 1998 have demonstrated the highly seasonal signal of drip rate, its control by water excess and rainfall, and, at a shorter scale to air pressure changes. The modern calcite deposit study suggests a relationship between cave calcite isotopic composition (δ¹⁸O and …

Carbon Dioxide Concentration In Air Within The Nerja Cave (Malaga, Andalusia, Spain), Cristina Liñán, Iñaki Vadillo, Francisco Carrasco

International Journal of Speleology

From 2001 to 2005 the CO₂ concentration of the air in the interior and exterior of the Nerja Cave was studied and its relation with the air temperature and visitor number. The average annual CO₂ concentration outside of the cave is 320 ppmv, whilst inside, the mean concentration increases to 525 ppmv during autumn and winter, and in the order of 750 ppmv during spring and summer. The temporal variation of CO₂ content in the air of the cave is strongly influenced by its degree of natural ventilation which is, in turn, determined by the difference between …

Dwelling, Walking, Serving: Organic Preservation Along The Camino De Santiago Pilgrimage Landscape, Mercedes Chamberlain Quesada-Embid

Antioch University Dissertations & Theses

This study is an exploration of the people and the landscape of the well-known Camino de Santiago pilgrimage route. Although there are many routes that make up the entirety of the pilgrimage, this research is specifically focused on the landscape of the Camino Francés, or French Route, in northern Spain. The path has been written about in many ways and for a myriad of reasons since it became affiliated with the Christian tradition in the early ninth century. This research, however, is different. By way of an environmental history and hermeneutic approach, an investigation of the interrelated and overlapping human …

Dactyls Reveal Evolutionary Patterns In Decapod Crustaceans, Jeffrey Guy Agnew

LSU Doctoral Dissertations

Because of their high preservation potential and uses in foraging and defense, decapod crustacean dactyls (movable fingers of claws) are potentially excellent test subjects for an ongoing debate concerning the relative importance of top-down (predators) and bottom-up (prey) controls on morphologic diversification and evolution. The utility of dactyls for inferring evolutionary patterns were evaluated using living and subfossil xanthoid crabs sampled from the southeast U.S. Atlantic and Gulf of Mexico coasts, and were used to: (1) distinguish the roles of selection and constraint on dactyl morphology through allometric and shape comparisons in the context of the crab’s phylogenetic relationships and …

Hydrologic Response To Extreme Warm And Cold Summers In The Mcmurdo Dry Valleys, East Antarctica, Peter T. Doran, Christopher P. Mckay, Andrew G. Fountain, Thomas H. Nylen, Diane M. Mcknight, Chris Jaros, John E. Barrett

Geography Faculty Publications and Presentations

The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- …

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Progress Report, Period Ending: December 31, 2007, Margaret N. Rees

Limnological Studies

• The limnologist position has been announced.
• Project 1: Review of the draft Boulder Basin Adaptive Management Plan is underway.
• Project 2: Development of a white paper expressing the joint needs of the entities involved in Water 2025 projects is being coordinated.
• Project 3: A bibliographic reference spreadsheet organizing literature citations related to quagga and zebra mussel research has been completed.
• Project 4: A comprehensive literature search of Lake Mead limnology is well underway; an Access database has been designed to organize reference citations; and a special collections library at UNLV is being established to house original rare documents and other …

An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro

Tanzania Journal of Science

Pitfall trapping is the traditional method for sampling carabid beetles and other grounddwelling invertebrates. Tests were carried out in the Udzungwa Mountains National Park between March 1999 and July 2000. Results indicated that pitfall traps were less efficient compared to manual searching methods, both in terms of relative abundance and species richness of carabid beetles. The results are discussed in the context of biodiversity inventories in theEastern Arc Mountains.

Science Plan For Potential 2008 Experimental High Flow At Glen Canyon Dam, Grand Canyon Monitoring And Research Center

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

Imaging Thermal Stratigraphy In Freshwater Lakes Using Georadar, John H. Bradford, Cody R. Johnson, Troy Brosten, James P. Mcnamara, Michael N. Gooseff

CGISS Publications and Presentations

Thermal stratification exerts significant control over biogeochemical processing in freshwater lakes. Thus, the temporal and spatial distribution of the thermal structure is an important component in understanding lake ecosystems. We present the first reported observations of lake thermal stratification from surface based georadar measurements acquired over two small freshwater lakes. This method is very useful because it can provide rapid acquisition of 2D or 3D lotic stratification.

Biogeochemical Evolution Of Cryoconite Holes On Canada Glacier, Taylor Valley, Antarctica, Elizabeth A. Bagshaw, Martyn Tranter, Andrew G. Fountain, Kathleen A. Welch, Hassan J. Basagic, W. Berry Lyons

Geography Faculty Publications and Presentations

The cryoconite holes of the McMurdo Dry Valleys are simple, closed biogeochemical systems involving water, ice, mineral and organic debris, which serve as ecosystems for consortia of microorganisms. This study is the first to document the seasonal and annual chemical evolution of solutes in cryoconite holes. Samples of glacier ice, frozen cryoconite holes and those containing water were collected during the austral summer of 2005–2006. The isolation age was calculated from the excess Cl‾ in the holes, and varied from 0 to 5 years (a), consistent with the last hot summer when the cryoconite holes were open to the atmosphere. …

Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn

United States Geological Survey: Staff Publications

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area …

Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific …

Sustainability Of Western Kentucky University: An Examination Of Campus Environmental Policies, Performance And Potential For Change, Christian Ryan-Downing

Masters Theses & Specialist Projects

Institutions of higher learning are in a pivotal position to address the environmental problems that global society faces now, but response to this challenge requires transformation in priorities and practices. Recognizing the impacts that universities have on the environment and the social and economic costs associated with these impacts, institutions of higher learning are changing policies and management to become more sustainable. Sustainability is defined by the World Commission on Environment and Development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs" (1987). To evaluate the environmental impacts …

Hunting For Hydrothermal Vents Along The Galápagos Spreading Center, Rachel M. Haymon, Edward T. Baker, Joseph A. Resing, Scott M. White, Ken C. Macdonald

Faculty Publications

No abstract provided.

Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise

United States Geological Survey: Staff Publications

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic Wshes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 >m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid Wsh Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the …

Relationship Between Vegetation Biophysical Properties And Surface Temperature Using Multisensor Satellite Data, Seungbum Hong, Venkataraman Lakshmi, Eric Small

Faculty Publications

Vegetation is an important factor in global climatic variability and plays a key role in the complexinteractions between the land surface and the atmosphere. This study focuses on the spatial and temporalvariability of vegetation and its relationship with land–atmosphere interactions. The authors have analyzedthe vegetation water content (VegWC) from the Advanced Microwave Scanning Radiometer for EOS(AMSR-E), the leaf area index (LAI), the normalized difference vegetation index (NDVI), the land surfacetemperature (Ts), and the Moderate Resolution Imaging Spectroradiometer (MODIS). Three regions,which have climatically differing characteristics, have been selected: the North America Monsoon System(NAMS) region, the Southern Great Plains (SGP) region, and …

Saprolegniaceae Identified On Amphibian Eggs Throughout The Pacific Northwest, Usa, By Internal Transcribed Spacer Sequences And Phylogenetic Analysis, Jill E. Petrisko, Christopher A. Pearl, David S. Pilliod, Peter P. Sheridan, Charles F. Williams, Charles R. Peterson, R. Bruce Bury

United States Geological Survey: Staff Publications

We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlya and Leptolegnia. Our phylogeny grouped S. semihypogyna with Achlya rather than with the Saprolegnia reference …

Quaternary Glaciation And Hydrologic Variation In The South American Tropics As Reconstructed From The Lake Titicaca Drilling Project, Sherilyn C. Fritz, Paul A. Baker, Geoffrey O. Seltzer, Ashley Ballantyne, Pedro Tapia, Hai Cheng, R. Lawrence Edwards

Department of Earth and Atmospheric Sciences: Faculty Publications

A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative …