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Full-Text Articles in Entire DC Network
Assessing The Utility Of Imaging Radar For Identifying White Sand Vegetation Structure, Jessica Rosenqvist
Assessing The Utility Of Imaging Radar For Identifying White Sand Vegetation Structure, Jessica Rosenqvist
Dissertations and Theses
White sand vegetation communities are wide spread across South America; found in Peru, Venezuela, Brazilian Amazon and Guyana. They are distributed in patches ranging from <1 km2 to greater than tens of square kilometers and their origins and locations are still not well understood. The communities are related to a variety of factors (soil type, flooding, nutrient content and fire); hence a precise definition for the ecosystem is still not fully defined. Nevertheless, the result of these variations creates a unique environment for endemic plant and animal species to thrive. Furthermore, analysis of these areas has been very scattered and identification of local white sand areas (<1 km2) have not been accomplished. In addition, identification of these locations has currently only used optical satellite imagery (Landsat, MODIS). Hence, in this project, we have attempted to use synthetic aperture radar to create a classification system to locate the white sand vegetation systems. The goal is to be able to apply this method to identify white sand vegetation distribution across South America. The region of focus for this thesis has been in Aracá, a large white sand area located in Brazil in the State of Amazonas. Due to the lack of ground reference data, a classified map by Capurucho et al. (2013), generated using Landsat data, was used as a comparison and reference. JAXA’s ALOS-1 PALSAR (L-band), ESA’s Sentinel-1A (C-band) and NASA’s SRTM sensors were used for land classification. As microwave signals penetrate clouds and haze, the advantage of using sensors with this wavelength allows for an unobstructed coverage of the landscape all year round. Different combinations of polarizations and wavelengths were used during the analysis to try and separate the white sand vegetation from water and terra firme forest. The resulting classification images showed a 30% agreement with the classification map by Capurucho et al. It is important to note, that this number is in fact an agreement percentage as the map used was a classification image and coarse in resolution (due to the lack of reference data). Therefore, this value does not imply a bad classification. Future work will include time-series data, precise ground reference points and data from other sensors such as ALOS-2 PALSAR, to improve the classification accuracy.
Hydrological Drought Analysis For Seven North Georgia Watersheds (1970-2000), Jessica L. Taylor
Hydrological Drought Analysis For Seven North Georgia Watersheds (1970-2000), Jessica L. Taylor
Theses and Dissertations
Drought is a prolonged reduction in precipitation which may result in significant effects on local ecosystems, watersheds, and water sources, with the potential to have negative impacts on human populations. Normalized indexes can be used to characterize drought magnitudes and frequencies using historical data records on temperature, rainfall, snowpack, soil moisture, streamflow, and/or other water supply indicators. This study examined the applicability of two drought indices: Standardized Precipitation Index (SPI) and Streamflow Drought Index (SDI). The SPI and SDI estimate the magnitude of observed rainfall (SPI) and discharge (SDI) deviations from the long-term average.
In this study, SPI and SDI …
Coal Genesis, John J. Renton, Thomas Repine
Coal Genesis, John J. Renton, Thomas Repine
Readings and Notes
Most textbooks classify coal as a sedimentary rock even though it does not fit the definition of a sedimentary rock. While a sedimentary rock is a "rock formed from the products of weathering and erosion", coal forms from the remains of land plants. In fact, coal doesn't even fit the definition of a rock. A rock is defined as "mixture of minerals" and minerals are defined as "natural occurring, solid, inorganic substances ..• " Coal is composed largely (90+%) of organic substances (macerals) which, by definition, are not minerals. If coal must be classified as a rock, because it forms …
Nitrogen Removal And Recycling By Sediments In The Lower Great Miami River, Ohio, Lee A. Slone
Nitrogen Removal And Recycling By Sediments In The Lower Great Miami River, Ohio, Lee A. Slone
Browse all Theses and Dissertations
The Lower Great Miami River (LGMR) has recently experienced algal blooms due to excess nitrogen (N) and phosphorus (P). Some Ohio water treatment plants were ordered to reduce the amount of P that they release into the river, but N also can stimulate eutrophication and algal blooms, either alone or in combination with P. In this study, LGMR sediment N transformations and effects of river impoundments on N cycling were compared with external N loads during different flow conditions to determine the extent to which N is removed or recycled within the system. Sediment nutrient fluxes, sediment N sinks and …
Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk
Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk
Dartmouth Scholarship
Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …
Geographically Isolated Wetlands Are Part Of The Hydrological Landscape, Mark Rains, S. G. Leibowitz, M. J. Cohen, I. F. Creed, H. E. Golden, J. W. Jawitz, P. Kalla, C. R. Lane, M. W. Lang, D. L. Mclaughlin
Geographically Isolated Wetlands Are Part Of The Hydrological Landscape, Mark Rains, S. G. Leibowitz, M. J. Cohen, I. F. Creed, H. E. Golden, J. W. Jawitz, P. Kalla, C. R. Lane, M. W. Lang, D. L. Mclaughlin
School of Geosciences Faculty and Staff Publications
No abstract provided.
Synergistic Effects Of Climate Change And Grazing On Net Primary Production Of Mongolian Grasslands, Shree R. S. Dangal, Hanqin Tian, Chaoqun Lu, Shufen Pan, Neil Pederson, Amy Hessl
Synergistic Effects Of Climate Change And Grazing On Net Primary Production Of Mongolian Grasslands, Shree R. S. Dangal, Hanqin Tian, Chaoqun Lu, Shufen Pan, Neil Pederson, Amy Hessl
Faculty & Staff Scholarship
In arid and semi-arid regions, grassland degradation has become a major environmental and economic problem, but little information is available on the response of grassland productivity to both climate change and grazing intensity. By developing a grazing module in a process-based ecosystem model, the dynamic land ecosystem model (DLEM), we explore the roles of climate change, elevated CO2, and varying grazing intensities in affecting aboveground net primary productivity (ANPP) across different grassland sites in Mongolia. Our results show that both growing season precipitation totals and average temperature exert important controls on annual ANPP across six sites over a precipitation gradient, …
Modeled Inflow Validation & Nutrient Loading Estimation In Two Subwatersheds Of The Lower Laguna Madre, Hudson R. Deyoe, Warren Pulich, Nelun Fernando
Modeled Inflow Validation & Nutrient Loading Estimation In Two Subwatersheds Of The Lower Laguna Madre, Hudson R. Deyoe, Warren Pulich, Nelun Fernando
School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)
University of Texas Rio Grande Valley will characterize nutrient loading rates into the Lower Laguna Madre for subwatersheds by monitoring stream flow and water quality (particularly total nitrogen and phosphorus). This information will be used to evaluate Texas Rainfall-Runoff model performance in estimating ungaged inflows and to establish a relationship between ungaged inflows and nutrient loading regimes to the Lower Laguna Madre. View on Map
Utilization Of Satellite-Derived Salinity For Enso Studies And Climate Indices, Caroline Mary Corbett
Utilization Of Satellite-Derived Salinity For Enso Studies And Climate Indices, Caroline Mary Corbett
Theses and Dissertations
Conventionally, El Niño-Southern Oscillation (ENSO) is studied using sea surface temperature (SST) observations in the central and eastern equatorial Pacific Ocean. Recently, sea surface salinity (SSS) in the equatorial Pacific has been studied in relation to the phases of ENSO. Previously, SSS was observed in the equatorial Pacific using the Tropical Ocean Global Atmosphere (TOGA) / Tropical Atmosphere Ocean (TOA), the Argo float network, and Oceanic General Circulation Models (OGCM). The launch of NASA’s Aquarius Salinity Mission and ESA’s Soil Moisture Ocean Salinity (SMOS) opened a new era in which high resolution global near real-time SSS observations are readily available. …
Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman
Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman
Cal Poly Humboldt theses and projects
The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current land-use. Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. …
Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest
Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest
Cal Poly Humboldt theses and projects
Soil carbon (C) affects the active gases in the atmosphere, nutrient cycling, and diversity of flora and fauna. Soil organic matter (SOM) is partially comprised of C, and a widely-accepted ratio of 0.58 organic carbon (OC) to organic matter (OM) is used to measure soil C on a landscape scale. However, this ratio varies according to vegetation, depth, hydrology, and may lead to miscalculations of soil C and SOM estimates. Soil C and SOM are inherently complex and it is not completely understood which environmental factors have the most influence in their formation, which occurs on a time scale of …
Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones
Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones
Graduate Student Theses, Dissertations, & Professional Papers
This dissertation describes the estimation, error quantification, and incorporation of land surface information from microwave satellite remote sensing for modeling global ecosystem land-atmosphere net CO2 exchange. Retrieval algorithms were developed for estimating soil moisture, surface water, surface temperature, and vegetation phenology from microwave imagery timeseries. Soil moisture retrievals were merged with model-based soil moisture estimates and incorporated into a light-use efficiency model for vegetation productivity coupled to a soil decomposition model. Results, including state and uncertainty estimates, were evaluated with a global eddy covariance flux tower network and other independent global model- and remote-sensing based products.
Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman
Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman
Theses and Dissertations (Comprehensive)
Peat-accumulating wetlands are ecosystems whose rate of photosynthetic production of organic matter is greater than that of its decomposition, resulting in a build up of soil organic matter that may take centuries to fully decompose. Carbon (C) stocks within these ecosystems are a function of inputs from photosynthesis, and losses from heterotrophic decomposition. Due to the short growing season and overall cold climate of boreal and tundra regions, C has been accumulating within these landscapes, mostly in soil organic matter, since the last glaciation. Climate change, predicted to result in rising temperatures and increased precipitation, has begun to degrade the …
The Effects Of Blended Learning On Critical Thinking In A High School Earth Science Class, Renee Nicole Borglum
The Effects Of Blended Learning On Critical Thinking In A High School Earth Science Class, Renee Nicole Borglum
Dissertations and Theses @ UNI
This study analyzed the effects of differing levels of technology use in a high school Earth Science class on student performance on the Classroom Test of Scientific Reasoning (CTSR). Blended learning manipulates the combination of hands-on activities, classroom discussions, online discussions, interactive simulations and a variety of assessments that engage, instruct and assess student learning. Critical thinking is the set of skills and dispositions that foster problem solving, reasoning ability and selfregulation. The increasing use of technology in the classroom and fluctuation of content standards prompted this research. The results have implications for the classroom teacher of a wide range …
Integrated Geophysical Approach Using Electrical Resistivity Tomography And Multichannel Analysis Of Surface Wave In Assessing Wilson Spring Development, Ibrahim E. Ahmed
Integrated Geophysical Approach Using Electrical Resistivity Tomography And Multichannel Analysis Of Surface Wave In Assessing Wilson Spring Development, Ibrahim E. Ahmed
Doctoral Dissertations
"This research investigated fractured zones leading to preferential flow paths of Wilson Spring. In this context, electrical resistivity tomography (ERT) data and multi-channel analyses of surface waves (MASW) data were acquired at studied site with the purpose of mapping a variable depth to top of bedrock and geological structures.
Interpretation of the boreholes, MASW, and ERT data indicated that a depth to top of rock does vary significantly at the studied site due to many solution-widened fractures. Multiple near-vertical solution-widened fractures were mapped in the studied site based on the interpretation of the ERT data. The mapped solution-widened fractures appear …
Palynological Studies Of Holocene Lake Sediments In The Missouri Ozarks, Robert D. Haselwander
Palynological Studies Of Holocene Lake Sediments In The Missouri Ozarks, Robert D. Haselwander
Doctoral Dissertations
"Five small lakes in southeast Missouri (Frisco, Pine Forest, and Bray Area lakes [Phelps County], and Cypress and Blue ponds [Bollinger County]) were cored for paleolimnological studies. Cores were evaluated for their sedimentology, palynology, and geochemistry. In two of these lakes (Bray Area and Pine Forest lakes) the planktonic algae were also studied in the water column, along with ecological parameters. Algae in the sediments were compared to algae in the water to understand the resistance of different species to decay, and a suggested methodology for this work is described. Reconstructions of the past environments around each lake were created …
Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton
Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton
OES Faculty Publications
The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits …
Beyond Just Sea-Level Rise: Considering Macroclimatic Drivers Within Coastal Wetland Vulnerability Assessments To Climate Change, Michael J. Osland, Nicholas M. Enwright, Richard H. Day, Christopher A. Gabler, Camille L. Stagg, James B. Grace
Beyond Just Sea-Level Rise: Considering Macroclimatic Drivers Within Coastal Wetland Vulnerability Assessments To Climate Change, Michael J. Osland, Nicholas M. Enwright, Richard H. Day, Christopher A. Gabler, Camille L. Stagg, James B. Grace
School of Earth, Environmental, & Marine Sciences Faculty Publications
Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate change-related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would …
An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble
An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble
OES Faculty Publications
In principle, tandem mass spectrometry can be used to detect and quantify the peptides present in a microbiome sample, enabling functional and taxonomic insight into microbiome metabolic activity. However, the phylogenetic diversity constituting a particular microbiome is often unknown, and many of the organisms present may not have assembled genomes. In ocean microbiome samples, with particularly diverse and uncultured bacterial communities, it is difficult to construct protein databases that contain the bulk of the peptides in the sample without losing detection sensitivity due to the overwhelming number of candidate peptides for each tandem mass spectrum. We describe a method for …
Assessing Shoreline Change And Vegetation Cover Adjacent To Back-Barrier Shoreline Stabilization Structures In Georgia Estuaries, Katherine R. Wakefield
Assessing Shoreline Change And Vegetation Cover Adjacent To Back-Barrier Shoreline Stabilization Structures In Georgia Estuaries, Katherine R. Wakefield
College of Graduate Studies: Theses & Dissertations
Anthropogenic stabilization of erosional shorelines by hard-armoring structures is used for protection of property, especially if buildings, historical monuments, cultural resources, or other infrastructure are present. The post-installation effects of shoreline stabilization structures on adjacent shorelines in the back-barrier marshes of coastal Georgia are a concern, and interest in living shorelines as erosion control devices has increased because of their use of natural materials and vegetation. AMBUR shoreline analysis software was used to calculate pre-and post-installation shoreline change rates of shorelines adjacent to riprap and bulkhead structures. There was no significant difference between the post-installation shoreline change rates of the …
Application Of Uranium And Strontium Isotopes As Salinity And Paleo-Environmental Conditions Tracers:Insight From The Rio Grande River And Pedogenic Carbonates In Drylands Soils Of Southwest, Usa., Syprose Nyachoti
Open Access Theses & Dissertations
South New Mexico and west Texas regions of the northern Chihuahua Desert are characteristic of low annual rainfall and high potential evapotranspiration rates. Soils in these arid and semi-arid regions are abundant of pedogenic carbonates of various stages of development. Both surface and ground water resource in the area have high salt content; the Rio Grande river, which flows through the region is known for its high salinity downstream. Due to increasing population in cities of the region thus high food demand, irrigation activities along the river valley have enhanced crop productivity. High evapotranspiration rates and intense saline flood irrigation …
Marine Ecoregion And Deepwater Horizon Oil Spill Affect Recruitment And Population Structure Of A Salt Marsh Snail, Steven C. Pennings, Scott Zengel, Jacob Oehrig, Merryl Alber, T. Dale Bishop, Donald R. Deis, Donna Devlin, A. Randall Hughes, John J. Hutchens, Jr., Whitney M. Kiehn, Caroline R. Mcfarlin, Clay L. Montague, Sean P. Powers, C. Edward Proffitt, Nicholle Rutherford, Camille L. Stagg, Keith Walters
Marine Ecoregion And Deepwater Horizon Oil Spill Affect Recruitment And Population Structure Of A Salt Marsh Snail, Steven C. Pennings, Scott Zengel, Jacob Oehrig, Merryl Alber, T. Dale Bishop, Donald R. Deis, Donna Devlin, A. Randall Hughes, John J. Hutchens, Jr., Whitney M. Kiehn, Caroline R. Mcfarlin, Clay L. Montague, Sean P. Powers, C. Edward Proffitt, Nicholle Rutherford, Camille L. Stagg, Keith Walters
University Faculty and Staff Publications
Marine species with planktonic larvae often have high spatial and temporal variation in recruitment that leads to subsequent variation in the ecology of benthic adults. Using a combination of published and unpublished data, we compared the population structure of the salt marsh snail, Littoraria irrorata, between the South Atlantic Bight and the Gulf Coast of the United States to infer geographic differences in recruitment and to test the hypothesis that the Deepwater Horizon oil spill led to widespread recruitment failure of L. irrorata in Louisiana in 2010. Size-frequency distributions in both ecoregions were bimodal, with troughs in the distributions consistent …
A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman
A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman
School of Natural Resources: Dissertations, Theses, and Student Research
The Nebraska Sandhills are the largest sand dune system in the Western Hemisphere, and are unique because they remain relatively undisturbed from row crop agriculture. Research in the past two decades demonstrated that the Sandhills are dynamic on millennial timescales, switching between stabilized, vegetated states to non-vegetated, mobilized states. The Sandhills are currently stabilized, but understanding how ecological processes are altered as sand dunes transition from stabilized to mobilized states, provides insight into the thresholds, stability, and resilience of this grassland ecosystem. My research investigated the impacts of vegetation disturbances on ecological processes and the sand dune surface stability. For …
Response Of Fishes To Restoration Projects In Bayou St. John Located Within The City Of New Orleans, Louisiana, Including Hydrological Characterization And Hydrodynamic Modelling, Patrick W. Smith
LSU New Orleans Theses and Dissertations
Quantifying the impacts of restoration on coastal waterways is crucial to understanding their effectiveness. Here, I look at the impacts of multiple restoration projects on urban waterways within the city limits of New Orleans, LA, with an emphasis on the response of fishes. First I report the effects of two projects designed to improve exchange down estuary on the hydrologic characteristics of Bayou St. John (BSJ). Within BSJ, flow is dominated by subtidal wind driven processes. Removal of an outdated flood control structure did not appear to alter exchange in BSJ, but removal combined with sector gate openings did. I …
Coarse Bedload Routing And Dispersion Through Tributary Confluences, Kurt Imhoff, Andrew C. Wilcox
Coarse Bedload Routing And Dispersion Through Tributary Confluences, Kurt Imhoff, Andrew C. Wilcox
Geosciences Faculty Publications
Sediment routing fundamentally influences channel morphology and propagation of disturbances. However, the transport and storage of bedload particles in headwater channel confluences, which may be significant nodes of the channel network in terms of sediment routing, morphology, and habitat, is poorly understood. To characterize routing processes through confluences of headwater channels, we investigate how sediment routing patterns through headwater confluences compare to those described in low-gradient gravel bed river systems, and how confluences affect the dispersive behavior of coarse bedload particles compared to non-confluence reaches. We address these questions with a field tracer experiment using passive-integrated transponder and radio-frequency identification …
Iodp Expedition 347baltic Sea Basin Paleoenvironment And Biosphere, Thomas Andrén, Bo Barker Jørgensen, Carol Cotterill, Sophie Green, Elinor Andrén, Jeanine L. Ash, Thorsten Bauersachs, Barry Cragg, Anne-Sophie Fanget, Annick Fehr, Wojciech Granoszewski, JerOen Groeneveld, Dalton S. Hardisty, Emilio Herrero-Bervera, Outi Hyttinen, Jørn Bo Jensen, Sean Johnson, Michael Kenzler, Aarno Kotilainen, Ulrich Kotthoff, Ian Pg Marshall, E. Martin, S. Obrochta, Sandra Passchier, Nadine B. Quintana Krupinski, Natascha Riedinger, Caroline Slomp, Ian Snowball, Anna Stepanova, Sarah Strano
Iodp Expedition 347baltic Sea Basin Paleoenvironment And Biosphere, Thomas Andrén, Bo Barker Jørgensen, Carol Cotterill, Sophie Green, Elinor Andrén, Jeanine L. Ash, Thorsten Bauersachs, Barry Cragg, Anne-Sophie Fanget, Annick Fehr, Wojciech Granoszewski, JerOen Groeneveld, Dalton S. Hardisty, Emilio Herrero-Bervera, Outi Hyttinen, Jørn Bo Jensen, Sean Johnson, Michael Kenzler, Aarno Kotilainen, Ulrich Kotthoff, Ian Pg Marshall, E. Martin, S. Obrochta, Sandra Passchier, Nadine B. Quintana Krupinski, Natascha Riedinger, Caroline Slomp, Ian Snowball, Anna Stepanova, Sarah Strano
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The Integrated Ocean Drilling Program (IODP) expedition 347 cored sediments from different settings of the Baltic Sea covering the last glacial-interglacial cycle. The main aim was to study the geological development of the Baltic Sea in relation to the extreme climate variability of the region with changing ice cover and major shifts in temperature, salinity, and biological communities. Using the Greatship Manisha as a European Consortium for Ocean Research Drilling (ECORD) mission-specific platform, we recovered 1.6 km of core from nine sites of which four were additionally cored for microbiology. The sites covered the gateway to the North Sea and …
Mobile Mud Dynamics In The East China Sea Elucidated Using 210pb, 137cs, 7be, And 234th As Tracers, Jinlong Wang, Jinzhou Du, Mark Baskaran, Jing Zhang
Mobile Mud Dynamics In The East China Sea Elucidated Using 210pb, 137cs, 7be, And 234th As Tracers, Jinlong Wang, Jinzhou Du, Mark Baskaran, Jing Zhang
Environmental Science and Geology Faculty Research Publications
“Mobile mud” (MM), which has fine grain size distribution (>90% clay + silt, and <5% sand) and high porosity (≥0.50), plays an important role in the biogeochemical cycles in the estuarine areas and the inshore shelf. A suite of MM samples from the coastal area of the East China Sea (ECS) was collected in spring and summer of 2011 to observe their spatial and temporal distribution, grain size, and radionuclides concentrations. The MM thickness ranged from 0.5 to 11 cm (average: 2.2 cm (May) and 3.9 cm (August)). The thick mud layer is mainly distributed along the coast, with an area of 2.2 × 104 km2 in May and 1.5 × 104 km2 in August, with corresponding masses of 8.8 × 108 and 7.8 × 108 t, respectively. The estimated masses of MM are considerably larger than the annual sediment discharge mass of the Changjiang River. The distribution of 137Cs inventories in MM indicates that 137Cs can be effectively utilized as a transport tracer of MM in the river‐dominated estuaries and coastal areas. The higher inventories of 7Be in MM in the river mouth in spring are attributed to higher depositional flux and higher sediment discharge. The ratio of the MM inventory of 234Thex/production in the overlying water column of >2.5 in south inshore indicates that the sediment focusing resulted in the increased mass flux. The residence time of MM is estimated as 3–6 years both by mass balance of MM and 210Pbex in MM.
Elevation Promotes Long-Term Survival Of Pinus Elliottii Var. Densa, A Foundation Species Of The Endangered Pine Rockland Ecosystem In The Florida Keys, Grant L. Harley, Justin T. Maxwell, George T. Raber
Elevation Promotes Long-Term Survival Of Pinus Elliottii Var. Densa, A Foundation Species Of The Endangered Pine Rockland Ecosystem In The Florida Keys, Grant L. Harley, Justin T. Maxwell, George T. Raber
Faculty Publications
The pine rockland community in southern Florida, which supports numerous state- and federally listed flora and fauna species, is considered endangered. Without its foundation species, Pinus elliottii var. densa, habitat and species diversity are lost to tropical hardwood hammock. Here, we investigate the landscape factors that contribute to the long-term persistence of pine rocklands on the 2 islands that contain the largest remaining habitat in the Florida Keys: Big Pine Key and No Name Key. Plot-level biophysical data and island-scale remotely sensed vegetation data were collected from pine rockland savannas and examined with multi-dimensional analysis. On both islands, vegetation …
Characterization Of The Constituent Mineral Components Of North African Surface Dust Samples Utilizing Computer Controlled Scanning Electron Microscopy (Ccsem), Zakariah Edward Sabatka
Characterization Of The Constituent Mineral Components Of North African Surface Dust Samples Utilizing Computer Controlled Scanning Electron Microscopy (Ccsem), Zakariah Edward Sabatka
Earth & Environmental Sciences Theses - Archive
Analysis of the constituent mineral components of surface dusts/soils from Chad-Niger region, North Africa, was undertaken by computer controlled scanning electron microscopy (CCSEM) to determine if differences in composition could be used for source attribution to distinguish windblown material from different contributing source areas. A total of 11 surficial samples were selected for analysis by computer controlled scanning electron microscopy (CCSEM). These samples were from two different geographic locations in the Chad-Niger region. CCSEM analysis generates data on individual dust particles that includes: particle size, shape, and chemical composition. This type of particle characterization used a Scanning Electron Microscope (SEM) …
Mycorrhizal Roots In A Temperate Forest Take Up Organic Nitrogen From 13c- And 15n-Labeled Organic Matter, Matthew A. Vadeboncoeur, Andrew P. Ouimette, Erik A. Hobbie
Mycorrhizal Roots In A Temperate Forest Take Up Organic Nitrogen From 13c- And 15n-Labeled Organic Matter, Matthew A. Vadeboncoeur, Andrew P. Ouimette, Erik A. Hobbie
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Background and Aims
The importance of the uptake of nitrogen in organic form by plants and mycorrhizal fungi has been demonstrated in various ecosystems including temperate forests. However, in previous experiments, isotopically labeled amino acids were often added to soils in concentrations that may be higher than those normally available to roots and mycorrhizal hyphae in situ, and these high concentrations could contribute to exaggerated uptake.
Methods
We used an experimental approach in which we added 13C-labeled and 15N-labeled whole cells to root-ingrowth cores, allowing proteolytic enzymes to release labeled organic nitrogen at a natural rate, as …