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2017

Biogeochemistry

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Articles 1 - 30 of 54

Full-Text Articles in Physical Sciences and Mathematics

Rethinking Holocene Ecological Relationships Among Caribou, Muskoxen, And Human Hunters On Banks Island, Nwt, Canada: A Stable Isotope Approach, Jordon S. Munizzi Dec 2017

Rethinking Holocene Ecological Relationships Among Caribou, Muskoxen, And Human Hunters On Banks Island, Nwt, Canada: A Stable Isotope Approach, Jordon S. Munizzi

Electronic Thesis and Dissertation Repository

This dissertation explores the ecology of caribou (Rangifer tarandus spp.) and muskoxen (Ovibos moschatus), and its relevance to human hunters on Banks Island, NWT, Canada, over the last 4000 years, primarily through the isotopic analysis of modern and archaeological faunal remains.

First, we establish baseline carbon and nitrogen isotope relationships between modern vegetation and caribou and muskox bone collagen using Bayesian mixing models. The models indicate that dwarf shrub (Salix arctica) does not contribute significantly to bone collagen isotopic compositions in either species, while sedges and yellow lichen (Cetraria tilesii) do. These findings …


Evaluating Potential For Water Quality Decline In Maine Lakes, Kaci N. Fitzgibbon Dec 2017

Evaluating Potential For Water Quality Decline In Maine Lakes, Kaci N. Fitzgibbon

Electronic Theses and Dissertations

Understanding lake vulnerability with respect to eutrophication and loss of water quality is important for sustainability of aquatic ecosystems. This project aims at identifying and quantifying the effects of relevant physiochemical, climate, and watershed characteristics on lake vulnerability in order to develop management decision tools for the Maine Department of Environmental Protection (MEDEP). In a changing chemical and physical environment, using independent variables from each of these categories and then relating them to the summer lake epilimnetic phosphorus (P) concentrations allows for development of models to inform stakeholders of lake vulnerability to eutrophication problems.

We studied 24 lakes covering a …


Phosphate Speleothems In Caves Developed In Iron Ores And Laterites Of The Carajás Mineral Province (Brazil) And A New Occurrence Of Spheniscidite, Alan R.L. Albuquerque, Rômulo S. Angélica, Daniele F. Gonçalves, Simone P.A. Paz Dec 2017

Phosphate Speleothems In Caves Developed In Iron Ores And Laterites Of The Carajás Mineral Province (Brazil) And A New Occurrence Of Spheniscidite, Alan R.L. Albuquerque, Rômulo S. Angélica, Daniele F. Gonçalves, Simone P.A. Paz

International Journal of Speleology

The Carajás Mineral Province has one of the largest concentrations of caves in Brazil, and its iron ore is among the country’s main exports. As a result of iron ore intense extraction, new environmental policies have been implemented. In an attempt to balance economic activity and environmental conservation, an inventory and a relevance-based classification of caves were implemented in 2008 as criteria for environmental licensing of mining ventures. This implementation motivated the present study of phosphate speleothems in Carajás’ caves developed in ferriferous rocks. The objectives of this study are to describe the phosphate minerals and their formation processes based …


Soed Open Course: Seamless Modeling From Creek To Ocean On Unstructured Grids, Y. Joseph Zhang Dec 2017

Soed Open Course: Seamless Modeling From Creek To Ocean On Unstructured Grids, Y. Joseph Zhang

Miscellaneous

This course explains the basic formulations used in the cross-scale SCHISM model, including the recent new developments. Hands-on tutorials will be conducted to familiarize the trainees with the basic tools useful for the modeling system. Although no formal pre-requisites are expected, trainees with prior UG model experience may find it easier to learn. Upon completion the trainees will have acquired basic knowledge on workflow in typical SCHISM simulations and be able to conduct simulations for cross-scale baroclinic processes as found in geophysical fluid dynamics (GFD)

Use Windows Media Player.


Mapping Soil Organic Carbon (Soc) In A Semi-Arid Mountainous Watershed Using Variables From Hyperspectral, Lidar And Traditional Datasets, Ryan Matthew Will Dec 2017

Mapping Soil Organic Carbon (Soc) In A Semi-Arid Mountainous Watershed Using Variables From Hyperspectral, Lidar And Traditional Datasets, Ryan Matthew Will

Boise State University Theses and Dissertations

Quantifying soil organic carbon (SOC) in complex terrain is challenging due to its high spatial variability. Generally, limited discrete observations of SOC data are used to develop spatially distributed maps of SOC by developing quantitative relationships between SOC and available spatially distributed variables. In many ecosystems, remotely sensed information on aboveground vegetation can be used to predict belowground carbon stocks. In this research, we developed maps of SOC across a semi-arid watershed based on discrete field observations and modeling using a suite of variables inclusive of hyperspectral and lidar datasets; these observations provide insights into the controls on soil carbon …


Floodplain Impacts On Water Quality: A Case Study In Southern Louisiana, Emily Delduco Nov 2017

Floodplain Impacts On Water Quality: A Case Study In Southern Louisiana, Emily Delduco

LSU Master's Theses

The quantity and quality of dissolved carbon delivered to coastal margins by rivers is an important component of global carbon cycling. The Atchafalaya River (AR) discharges ~25% of the flow of the Mississippi River (MR) and the total flow of the Red River (RR) into the Gulf of Mexico (GoM) annually while flowing through the largest bottomland swamp in North America. This provides a unique opportunity to study floodplain impacts on dissolved carbon processes in a large river system. The research aimed to: (1) determine DIC and DOC transport and processing by a river swamp basin under varied seasons and …


Assessing The Periodic Groundwater Flow Conditions Of A Perched Aquifer System In The Daniel Boone National Forest, Ethan Sweet Nov 2017

Assessing The Periodic Groundwater Flow Conditions Of A Perched Aquifer System In The Daniel Boone National Forest, Ethan Sweet

Posters-at-the-Capitol

Assessing the Periodic Groundwater Flow Conditions of a Perched Aquifer System in the Daniel Boone National Forest

Ethan Sweet and Jonathan Malzone

Eastern Kentucky University, Department of Geosciences

Natural ephemeral wetlands situated among the ridge-tops in the Daniel Boone National Forest serve as reservoirs that recharge a shallow groundwater system. Unique interactions between surface and groundwater in these isolated systems provide substantial support for the native ecosystem, serving as a breeding ground for amphibians and as source water for vegetation—especially in periods of drought. Currently it is not understood how groundwater could provide regional biodiversity, a drought buffer, or a …


Arctic And North Atlantic Paleo-Environmental Reconstructions From Lake Sediments, Gregory A. De Wet Nov 2017

Arctic And North Atlantic Paleo-Environmental Reconstructions From Lake Sediments, Gregory A. De Wet

Doctoral Dissertations

ABSTRACT

ARCTIC AND NORTH ATLANTIC PALEO-ENVIRONMENTAL RECONSTRUCTIONS FROM LAKE SEDIMENTS MAY 2017 GREGORY A. DE WET, B.Sc., BATES COLLEGE M.Sc., UNIVERSITY OF MASSSCHUSETTS, AMHERST Ph.D., UNIVERSITY OF MASSACHUSETTS, AMHERST Directed by: Drs. Raymond S. Bradley and Isla S. Castañeda There are few fields in the discipline of Earth Science that hold more relevancy in 2017 than studies of earth’s climate. Called the “perfect problem” considering its complexity and magnitude, climate change will continue to be one of the greatest challenges humanity will face in the 21st century. And while numerical models provide valuable information on conditions in the future, …


Mediation Of Eutrophication Of Surface And Subsurface Water From Non-Point Sources: Nutrient Monitoring At Meadowbrook Farm (Madison County, Kentucky), Walter S. Borowski, Jonathan M. Malzone Nov 2017

Mediation Of Eutrophication Of Surface And Subsurface Water From Non-Point Sources: Nutrient Monitoring At Meadowbrook Farm (Madison County, Kentucky), Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Non-point sources from various human activities such as farming have replaced industrial point sources as contributors of many contaminants in surface and subsurface waters of the United States. Eastern Kentucky University’s Meadowbrook Farm (720 acres, ~2.9 km2; Madison County, Kentucky) is a teaching facility dedicated to improving farming techniques and discovering best practices for farm operations that include minimizing environmental impacts. Agricultural activities on the Farm contribute nutrients to the Muddy Creek (Kentucky River) watershed that promote eutrophication and degrade water quality. Farm management already uses protocols to mediate drainage of dissolved nitrogen off the Farm, but also …


Nutrient Contamination From Non-Point Sources: Dissolved Nitrate And Ammonium In Surface And Subsurface Waters At Eku Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Hunter R. Evans, Walter S. Borowski, Jonathan M. Malzone Nov 2017

Nutrient Contamination From Non-Point Sources: Dissolved Nitrate And Ammonium In Surface And Subsurface Waters At Eku Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Hunter R. Evans, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities often contaminate watersheds with excess nutrients leading to poor water quality and eutrophication. We assayed dissolved nutrient levels in surface and subsurface waters of Eastern Kentucky University’s Meadowbrook Farm in order to assess levels of dissolved nutrients leaving its farmland and draining into the Muddy Creek watershed. The Farm raises both crops and livestock so that nutrient sources include fertilizer and manure. We sampled springs, runoff, and subsurface pipe drainage as well as Muddy Creek on six days from May to August 2016 under a variety of weather conditions. Using established, standard colorimetric methods, we measured nitrate (NO …


Nutrient Contamination From Non-Point Sources: Dissolved Phosphate In Surface And Subsurface Waters At Eku Meadowbrook Farm, Madison County, Kentucky, Hunter R. Evans, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone Nov 2017

Nutrient Contamination From Non-Point Sources: Dissolved Phosphate In Surface And Subsurface Waters At Eku Meadowbrook Farm, Madison County, Kentucky, Hunter R. Evans, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Farms are non-point sources for nutrient contaminants that drain into watersheds and contribute to eutrophication and other environmental problems. Eastern Kentucky University’s Meadowbrook Farm raises both crops and livestock, causing dissolved phosphorus in the form of orthophosphate (PO43-) from fertilizer and animal manure to enter surface and subsurface waters, eventually flowing into Muddy Creek, a tributary of the Kentucky River.

We sampled surface water, springs, and water from French drains that emanate from the farm, and also sampled Muddy Creek waters from May through August 2016. Typically, 1 to 2 days after sampling, we colorimetrically measured dissolved …


Patterns Of Nutrient Export For A Typical Non-Point Source, Meadowbrook Farm, Madison County, Kentucky, James Scott Winter, Walter S. Borowski, Jonathan M. Malzone Nov 2017

Patterns Of Nutrient Export For A Typical Non-Point Source, Meadowbrook Farm, Madison County, Kentucky, James Scott Winter, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Excess nutrients are found in watersheds originating from active farmland often causing poor water quality and eutrophication in natural waters. Use of fertilizer and animal husbandry can contaminate both surface water and groundwater. Eastern Kentucky University’s Meadowbrook Farm raises crops and livestock and is typical of farms that contribute excess nutrient contaminants to watersheds as non-point sources. An instrumented weir is positioned within a key sub-watershed of the Farm that empties into Muddy Creek, a tributary of the Kentucky River. This drainage is the largest outlet from the Farm that is representative of the Farm’s collective activities.

We measured flow …


Soil Carbon Cycling Proxies: Understanding Their Critical Role In Predicting Climate Change Feedbacks, Vanessa L. Bailey, Ben Bond-Lamberty, Kristen M. Deangelis, A. Stuart Grandy, Christine V. Hawkes, Kate Heckman, Kate Lajtha, Richard P. Phillips, Benjamin N. Sulman, Katherine E. O. Todd-Brown, Matthew D. Wallenstein Oct 2017

Soil Carbon Cycling Proxies: Understanding Their Critical Role In Predicting Climate Change Feedbacks, Vanessa L. Bailey, Ben Bond-Lamberty, Kristen M. Deangelis, A. Stuart Grandy, Christine V. Hawkes, Kate Heckman, Kate Lajtha, Richard P. Phillips, Benjamin N. Sulman, Katherine E. O. Todd-Brown, Matthew D. Wallenstein

Faculty Publications

The complexity of processes and interactions that drive soil C dynamics necessitate the use of proxy variables to represent soil characteristics that cannot be directly measured (correlative proxies), or that aggregate information about multiple soil characteristics into one variable (integrative proxies). These proxies have proven useful for understanding the soil C cycle, which is highly variable in both space and time, and are now being used to make predictions of the fate and persistence of C under future climate scenarios. However, the C pools and processes that proxies represent must be thoughtfully considered in order to minimize uncertainties in empirical …


Linking Mining Wastewater Discharge To Methylmercury Production In A Sub-Arctic Peatland, Lauren E. Twible Sep 2017

Linking Mining Wastewater Discharge To Methylmercury Production In A Sub-Arctic Peatland, Lauren E. Twible

Electronic Thesis and Dissertation Repository

It is well established that the addition of sulphate (SO42-) to peatlands increases methylmercury (MeHg) concentrations in pore waters via microbial methylation. Less information exists about the effects of different concentrations and sources of SO42- loading on MeHg production in remote, non- SO42- impacted regions like Canada’s north, where increased SO42- loadings come not from the atmosphere, but often from mining waste water and rock tailings. A three year field study (two years of loading; one year of recovery) examined the effects of simulated wastewater (containing 27.2 mg/L SO42- …


Facilitate Visualization And Distribution Of Nasa's Environmental Science Data Through Open Standards And Open Source Software For Geospatial, Yaxing Wei, Zhaoying (Angie) Wei, Suresh Santhanavannan Sep 2017

Facilitate Visualization And Distribution Of Nasa's Environmental Science Data Through Open Standards And Open Source Software For Geospatial, Yaxing Wei, Zhaoying (Angie) Wei, Suresh Santhanavannan

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

This paper introduces the utilization of open standards and open source software for visualization and distribution of geospatial environmental science data at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC). The ORNL DAAC is one of the NASA Earth Observing System Data and Information System (EOSDIS) data centers. A big challenge for the ORNL DAAC (https://daac.ornl.gov) is to efficiently manage over a thousand heterogeneous environmental data, collected through field campaigns, aircraft/satellite observations, and model simulations. ORNL DAAC also has to provide tools to easily find, visualize, and access the heterogeneous data. To address this challenge, the ORNL …


Fungal Community Homogenization, Shift In Dominant Trophic Guild, And Appearance Of Novel Taxa With Biotic Invasion, Mark A. Anthony, Serita D. Frey, Kristina A. Stinson Sep 2017

Fungal Community Homogenization, Shift In Dominant Trophic Guild, And Appearance Of Novel Taxa With Biotic Invasion, Mark A. Anthony, Serita D. Frey, Kristina A. Stinson

Faculty Publications

Invasion by non-native plants may fundamentally restructure the soil fungal community. The invasive plant, Alliaria petiolata, produces secondary compounds suppressive to mycorrhizal fungi and may therefore be expected to have generally negative effects on other components of the fungal community. Here, we compared fungal biomass, diversity, community composition, and the relative abundance of fungal trophic guilds, along with edaphic properties of soils collected from uninvaded and invaded plots across six temperate forests. Invaded plots were differentiated from uninvaded plots by lower variation in fungal community composition (beta diversity) and soil properties, higher fungal richness and community evenness (alpha diversity), and …


East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen Sep 2017

East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen

Earth and Environmental Sciences Faculty Publications

Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in deep water within the lake are controlled by feedbacks between climate and hinterland forest composition. Particle-size patterns are also best explained by vegetation, through feedbacks with lake levels, wildfires, and erosion. We develop a new source-to-sink framework that links lacustrine sedimentation to hinterland vegetation in tropical …


Nitrogen And Carbon Isotopic Dynamics Of Subarctic Soils And Plants In Southern Yukon Territory And Its Implications For Paleoecological And Paleodietary Studies, Farnoush Tahmesabi, Fred J. Longstaffe, Grant Zazula, Bruce Bennett Aug 2017

Nitrogen And Carbon Isotopic Dynamics Of Subarctic Soils And Plants In Southern Yukon Territory And Its Implications For Paleoecological And Paleodietary Studies, Farnoush Tahmesabi, Fred J. Longstaffe, Grant Zazula, Bruce Bennett

Earth Sciences Publications

We examine here the carbon and nitrogen isotopic compositions of bulk soils (8 topsoil and 7 subsoils, including two soil profiles) and five different plant parts of 79 C3 plants from two main functional groups: herbs and shrubs/subshrubs, from 18 different locations in grasslands of southern Yukon Territory, Canada (eastern shoreline of Kluane Lake and Whitehorse area). The Kluane Lake region in particular has been identified previously as an analogue for Late Pleistocene eastern Beringia. All topsoils have higher average total nitrogen δ15N and organic carbon δ13C than plants from the same sites with a …


Genetic And Biological Studies On Solanum Plants: Insights Into The Leaf Wax Alkane Paleoclimate Proxy, Amanda Lorraine Dorothy Bender Aug 2017

Genetic And Biological Studies On Solanum Plants: Insights Into The Leaf Wax Alkane Paleoclimate Proxy, Amanda Lorraine Dorothy Bender

Arts & Sciences Electronic Theses and Dissertations

The hydrogen isotopic composition (δ2H) of precipitation records fluxes of water in the hydrological cycle, and can reflect climatic variables such as temperature and humidity. Leaf wax n-alkanes can record δ2H of precipitation; consequently, n-alkanes extracted from sedimentary archives are commonly used as proxies for paleoenvironmental reconstruction. However, the utility of the leaf wax paleoclimate proxy is modulated by uncertainty about how physiological processes affect hydrogen isotopic compositions during alkane biosynthesis. This work aims to improve our understanding of the leaf wax paleoclimate proxy by examining biological and environmental sources of variability on cuticular leaf waxes. We used Solanum (tomato) …


Methylmercury Production In Two Northern Fen Peatlands, Mikhail J. Mack Jul 2017

Methylmercury Production In Two Northern Fen Peatlands, Mikhail J. Mack

Electronic Thesis and Dissertation Repository

Northern peatlands provide conditions favourable for sulphate reducing bacteria, microorganisms responsible for producing methylmercury, an aquatic pollutant. An expected climate driven shift from moss- to sedge-dominance may alter mercury biogeochemistry. Observations from a moss-dominated poor fen and sedge-dominated intermediate fen were used to compare methylmercury to assess if contrasting plant communities, nutrients status and/or hydrologic regime control production. Chapter 2 compared porewater methylmercury and ancillary chemistry across two Northern Ontario fens. The lower water table, greater dissolved organic carbon, and lower pH in the poor fen resulted in 3.1 times greater methylmercury. Chapter 3, riparian zones in intermediate fen were …


Changes In Substrate Availability Drive Carbon Cycle Response To Chronic Warming, Grace Pold, A. Stuart Grandy, Jerry M. Melillo, Kristen M. Deangelis Jul 2017

Changes In Substrate Availability Drive Carbon Cycle Response To Chronic Warming, Grace Pold, A. Stuart Grandy, Jerry M. Melillo, Kristen M. Deangelis

Faculty Publications

As earth's climate continues to warm, it is important to understand how the capacity of terrestrial ecosystems to retain carbon (C) will be affected. We combined measurements of microbial activity with the concentration, quality, and physical accessibility of soil carbon to microorganisms to evaluate the mechanisms by which more than two decades of experimental warming has altered the carbon cycle in a Northeast US temperate deciduous forest. We found that concentrations of soil organic matter were reduced in both the organic and mineral soil horizons. The molecular composition of the carbon was altered in the mineral soil with significant reductions …


Linking Organic Matter Dynamics To Management, Restoration, And Climate In The Florida Everglades, Peter Regier Jun 2017

Linking Organic Matter Dynamics To Management, Restoration, And Climate In The Florida Everglades, Peter Regier

FIU Electronic Theses and Dissertations

The Florida Everglades is a massive and highly managed subtropical wetland ecosystem, strongly influenced by anthropogenic control of freshwater distribution and highly susceptible to a changing climate, including rising sea-level and changes in temperature and rainfall. Shifting hydrologic regimes impact ecosystem function and biogeochemistry, which in turn control the sources, fate, and transport of organic matter. As a master environmental variable, it is essential to understand how organic matter dynamics will respond to changes in the balance between freshwater and saltwater associated with landscape-scale Everglades restoration efforts and climate change. The research comprising this dissertation improves current understanding of the …


Influence Of Common Bean (Phaseolus Vulgaris) Grown In Elevated Co2 On Apatite Dissolution, Brian Matthew Morra May 2017

Influence Of Common Bean (Phaseolus Vulgaris) Grown In Elevated Co2 On Apatite Dissolution, Brian Matthew Morra

Electronic Theses and Dissertations

Elevated concentrations of atmospheric CO2 brought about by human activity creates changes in plant morphology, growth rate and exudate production. Our study sought to understand the effect of these changes on soil mineral weathering using plants grown under two conditions, ambient CO2 (400ppm) and elevated CO2 (1000ppm). Phaseolus vulgaris (common beans) were grown in flow-through microcosms consisting of a mixture of quartz and apatite sands. Plant growth was sustained by a nutrient solution devoid of calcium (Ca) and phosphorous (P). Using Atomic Adsorption Spectroscopy and colorimetry, Ca and P content of the leachate and plant tissue served …


Revealing The Current Relationship Between Stream Acidification And Fish Species Richness: What Is The Status After Two Decades Of Recovery?, Patrick A. Harmon May 2017

Revealing The Current Relationship Between Stream Acidification And Fish Species Richness: What Is The Status After Two Decades Of Recovery?, Patrick A. Harmon

Masters Theses, 2010-2019

Prior to limitations placed on atmospheric emission of sulfur dioxide, Shenandoah National Park streams were heavily impacted by acid deposition. Acidification of these streams resulted in a depletion of acid neutralizing capacity (ANC) and a loss of fish species diversity. Differences in bedrock composition of park watersheds produce variation in stream response to acidification such that siliciclastic watersheds provide the lowest ANC, basaltic-carbonate watersheds provide the highest ANC, and granitic watersheds provide an intermediate ANC. Previous results by Bulger et al. (1995) indicated a significant relationship between ANC and fish species richness in thirteen park streams, such that low ANC …


Summer Precipitation Occurrence Effect On Two Passerine Species In Thule, Greenland, Sara E. Baugh May 2017

Summer Precipitation Occurrence Effect On Two Passerine Species In Thule, Greenland, Sara E. Baugh

Celebration of Learning

Climate change is occurring at a faster rate in the Arctic than the rest of the globe, causing temperature rises at twice the rate of the global average and increased summer precipitation in the form of rain. These precipitation events are predicted to affect migratory bird species that breed throughout the Arctic. Increased occurrence of heavy rainstorms indirectly affect bird populations by impacting distribution and abundance of food supply, and directly by increasing mortality rates of juveniles. Studies conducted on bird species throughout the low Arctic regions; have shown that it is not the total precipitation of a breeding season …


The Effects Of Urbanization On Nitrogen Processing In Urban Streams, Peter Francissen, Dr. Kevin Geedey, Dr. Michael Reisner May 2017

The Effects Of Urbanization On Nitrogen Processing In Urban Streams, Peter Francissen, Dr. Kevin Geedey, Dr. Michael Reisner

Celebration of Learning

Urban stream syndrome is described as the deterioration of stream health in an urbanized watershed and is associated with the loss of ecosystem services, which in turn degrades downstream environments. One key symptom of the urban stream syndrome is reduced processing of inorganic nitrogen. Previous research suggests that as urbanization increases and water quality decreases, the uptake length (Sw) of inorganic N increases. This indicates that the stream is increasing the export of N downstream compared to in situ incorporation of N into the ecosystem. We measured uptake length (Sw) of NO3, using a pulse addition method, along 9 different …


Biogeochemical Characteristics Of Organic Matter In A Karst Groundwater System, Teresa Lynn Brown May 2017

Biogeochemical Characteristics Of Organic Matter In A Karst Groundwater System, Teresa Lynn Brown

Doctoral Dissertations

Development of regional groundwater carbon budgets hinges on the ability to quantify and monitor biogeochemical processes controlled by microbial recycling of natural dissolved organic matter (DOM) in carbon-limited (oligotrophic) areas. DOM is the major reservoir of organic carbon in aquatic ecosystems. However, isolation and characterization of DOM in oligotrophic freshwater systems has been limited by operational protocols and instrumentation. The goals of this research were to investigate the seasonal dynamics of microbially-driven organic matter degradation in a karst groundwater system influenced by surface water, and to identify analytical tools and biomarkers to measure long-term hydro-ecological trends in the Appalachian region. …


Factors Controlling Diffusive Co2 Production And Transport In The Cedarburg Bog, Saukville, Wisconsin, Emily Kay Joynt May 2017

Factors Controlling Diffusive Co2 Production And Transport In The Cedarburg Bog, Saukville, Wisconsin, Emily Kay Joynt

Theses and Dissertations

Wetlands are vital components of the carbon cycle, containing an estimated 20-30% of the global soil carbon reservoir. The Cedarburg Bog of southeastern Wisconsin boasts a myriad of wetland habitats including the southernmost string bog found in North America. Soil carbon dioxide (CO2) behavior in these systems is the response of multiple interdependent variables that are, collectively, not well understood. Many studies have measured and modeled soil CO2 flux (soil respiration) based on isolated, intermittent measurements that do not account for the full range of soil CO2 flux intensity. In the Cedarburg Bog, high-resolution measurements of soil CO2 flux were …


Influence Of Algae On Soil Saturated Hydraulic Conductivity: An In Situ Treatment Option For Reducing Infiltration Beneath Unlined Algae Cultivation Ponds, Molly Brianne Pattullo May 2017

Influence Of Algae On Soil Saturated Hydraulic Conductivity: An In Situ Treatment Option For Reducing Infiltration Beneath Unlined Algae Cultivation Ponds, Molly Brianne Pattullo

Masters Theses

Commercial production of algal biofuels is currently limited by high capital costs, including the cost of installation and maintenance of plastic pond liners, which mitigate seepage of cultivation fluids and control the release of salts and nutrients into the subsurface beneath outdoor algae cultivation ponds. However, studies of animal waste settling lagoons show that underlying soils ranging from sands to clay loams can exhibit reduced hydraulic conductivity within days to weeks after construction, reducing the need for plastic liners. The mechanisms of the hydraulic conductivity reductions, or “soil sealing”, are physical rearrangement of soil particles, buildup of fines, and the …


Influence Of Environmental Conditions And Inundation History On Bacterial Diversity Of Salt Marsh Soils In Southern Louisiana, Brandon M. Bagley May 2017

Influence Of Environmental Conditions And Inundation History On Bacterial Diversity Of Salt Marsh Soils In Southern Louisiana, Brandon M. Bagley

Masters Theses

Diversity patterns and controls on bacterial community composition were investigated from coastal salt marsh soils in southern Louisiana (USA) from 2012 – 2014. These salt marshes are part of an extensive coastal landscape that is experiencing land loss due to subsidence, sea-level rise, and anthropogenic activities, including from the impacts of the Deepwater Horizon oil spill in 2010. Prior to the oil spill, microbiology research focused predominately on biogeochemical roles and not on taxonomic representation in the soils or on understanding the significance of taxonomic diversity at the microbial level to marsh food webs or ecosystem dynamics. The purpose of …