Biogeochemistry Commons^™

Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford

Theses and Dissertations (Comprehensive)

The Marian Watershed Stewardship Program (MWSP), a community-driven aquatic ecosystem monitoring program, was developed by the Tłı̨chǫ Government to address concerns regarding the cumulative impacts of multiple potential stressors. In particular, the MWSP aims to develop methods that will be effective for detecting potential pollution from the proposed cobalt-gold-copper-bismuth NICO mine within Tłı̨chǫ Lands. In collaboration with the MWSP, paleolimnological methods and geochemical normalization are used to establish pre-mine baselines of lake sediment metals concentrations in the Marian River watershed prior to mine development. This baseline framework can be used to assess for pollution from surficial sediment once ...

Controls On Phosphorus Export From An Agricultural Watershed: Amsden Brook, Fort Fairfield, Maine Usa., Gregory J. Mcdonald

Electronic Theses and Dissertations

This study explores the sources and mechanisms of phosphorus (P) mobilization during base flow within the Amsden Brook watershed, Fort Fairfield, Maine, USA. Amsden Brook is an agriculturally dominated watershed drained by a spring-fed and perennial first- to second-order stream. We characterized the P concentrations within the watershed to investigate connections between soils, stream sediment, surface water, and groundwater. Waters were monitored monthly during the 2017 snow-free period for temperature, pH, dissolved oxygen, conductivity, soluble reactive P (SRP), total P, strong acid anions, strong base cations, dissolved organic carbon (DOC), Al, Fe, and Mn. Phosphorus speciation within soils and sediment ...

Blue Carbon: Methane Emissions From Managed Saline Ponds In The South Bay Salt Pond Restoration Project, San Francisco Bay, Haley J. Miller, Glenn E. Woerndle, Steve Crooks, Jason K. Keller

Biology, Chemistry, and Environmental Sciences Faculty Data Sets

This data set reports net methane (CH₄) emissions from managed saline ponds and a restored salt marsh associated with the South Bay Salt Ponds Restoration Project, San Francisco Bay, CA, USA. Associated biogeochemical and physical data are also reported. Data were collected on five sampling dates over the course of the study: November 2016, January 2017, March 2017, June 2017 and August 2017. Logistics (e.g., weather and road conditions) and nesting birds did not allow us to sample all locations during all sampling events.

Methane emissions were measured using static chambers and biogeochemical data were measured on porewater ...

Investigating Smoke Aerosol Emission Coefficients Using Modis Active Fire And Aerosol Products – A Case Study In The Conus And Indonesia, Xiaoman Lu, Xiaoyang Zhang, Fangjun Li, Mark Cochrane

Global Land Surface Season Data Sets

This data set is in relation to the paper of the same title, which has been submitted to the Journal of Geophysical Research: Biogeosciences.

Instructions for viewing the data in “Readme.txt”

Are The Oxygen Isotope Values Of The Late Cretaceous Western Interior Seaway Different From The Open Ocean?, Camille H. Dwyer, Corinne Myers, Viorel Atudorei

Shared Knowledge Conference

The Western Interior Seaway (WIS) was a North American epicontinental sea that was connected to the open ocean through the passage of the northern Boreal Sea and the southern Tethys Sea from the early Albian (~113 million years ago) to the early Paleogene (~65 million years ago). The WIS began to recced and lost its connection to the southern Tethys Sea in the late Campanian (~72 million years ago). In the early Paleogene, the WIS dried up completely. The oxygen isotopic composition (δ18O) of benthic bivalves was measured from the upper Campanian and lower Maastrichtian (75 million years ago to ...

Groundwater Contamination At Coal Ash Deposit Sites In Kentucky, Brandon Rose

Scholars Week

No abstract provided.

Sulfur (34S/32S) Isotope Composition Of Gypsum And Implications For Deep Cave Formation On The Nullarbor Plain, Australia, Matej Lipar, Mateja Ferk, Sonja Lojen, Milo Barham

International Journal of Speleology

Large deep caves with little relation to surface topography are distinctive karst features on the Nullarbor Plain of Australia. The presence of gypsum deposits and chemoautotrophic bacteria within the caves have been suggested as evidence for cave formation and (or) enlargement via sulfuric acid speleogenesis. To test this hypothesis, the stable sulfur isotope compositions (δ³⁴S) of both cave gypsum and surface gypsum were measured. Analyses yielded relatively high, positive δ³⁴S values from both cave gypsum and surface gypsum, arguing against gypsum genesis via microbial chemoautotrophy, and more broadly, sulfuric acid speleogenesis. Instead, the gypsum is interpreted ...

High-Dimensional Isotope Relationships, Yuyang He

LSU Doctoral Dissertations

High-dimensional isotope relationships describes the relationships of two or more element or position-specific (PS) elements in the same molecule or ion. It provides us more powerful tools to study reaction mechanisms and dynamics. Chapter 1 is about dual or multiple stable isotope relationship on δ-δ (or δ'-δ') space. While temporal data sampled from a closed-system can be treated by a Rayleigh Distillation Model (RDM), spatial data should be treated by a Reaction-Transport Model (RTM). Here we compare the results of a closed-system RDM to a RTM for systems with diffusional mass transfer by simulating the trajectories on nitrate's ...

Geotraces And Beyond: Studies Of Trace Elements In Coastal And Open Ocean Waters With An Emphasis On The Effects Of Oxygen Depletion And Hydrothermal Plumes, Peng Ho

Dissertations

We investigated various dissolved trace element (dTE) distributions in two distinct areas: the coastal northern Gulf of Mexico and the eastern tropical Pacific Ocean.

A multi-year (2007‒2011) chemical time series of eight stations in the western Mississippi Sound (MS) and northwestern Mississippi Bight (MB) was undertaken to examine the factors affecting chemical distributions in this dynamic region. Key findings include the frequent development of bottom water hypoxia in MB during late spring-summer, the likely contribution of submarine groundwater discharge (SGD) to the material flows, and observation of effects of episodic events including tropical storms and the opening of the ...

Nitrogen Cycling During A Period Of Environmental Change, Kaizad Patel

Electronic Theses and Dissertations

Natural and anthropogenic disturbances have altered the N cycle on the regional to global scale. Although numerous studies have examined the effects of chronic atmospheric N deposition on ecosystem processes, less is known about intra-annual variability of these processes, or how these responses might be altered under conditions of changing climate. The work described in this dissertation focuses on the effects of a changing chemical and physical climate, particularly terrestrial N processes (a) during Maine’s changing winters, and (b) in response to chronic elevated N additions.

Subnivean winter soil processes were examined at the Dwight B. DeMerritt Forest (DBDF ...

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim ...

Low Temperature Hydrogen Production And Habitability Of A Hyperalkaline Serpentinite Aquifer In The Samail Ophiolite, Hannah Marie Miller

Geological Sciences Graduate Theses & Dissertations

Continental serpentinizing systems, such as the Samail Ophiolite in Oman, are excellent locations to study low-temperature water/rock reactions leading hydrogen production. Hydrogen is a strong electron donor that, along with electron acceptors such as CO₂ or SO₄^2-, can sustain microbial life. I performed experimental and analytical work with partially serpentinized peridotite from Oman to determine that Fe(II)-bearing brucite is a key reactive mineral leading to hydrogen production. At 100°C and fluid compositions similar to those found in shallow serpentinizing aquifers, we experimentally observed the destabilization of Fe(II)-brucite to produce hydrogen and ...

Assessing The Reliability Of The Benthic Mg/Ca–Temperature Proxy: A Uvigerina Core-Top Study From New Zealand, Cassandre R. Stirpe

Electronic Theses and Dissertations

Sediment cores from New Zealand’s Bay of Plenty and the Chatham Rise in the Southwest Pacific were sampled to establish a regional Mg/Ca–temperature calibration for the benthic foraminifer Uvigerina peregrina. Comparison of foraminiferal Mg/Ca from core-top sediments to local bottom water temperatures reveals a Mg/Ca–temperature relationship broadly consistent with previously published calibrations. In addition to bottom water temperatures, other environmental parameters are examined for possible influence on the Mg/Ca of foraminiferal calcite. Elderfield et al. (2006) proposed that such parameters may exert an influence at colder temperatures, particularly below temperatures of ~3oC (e ...

Changes In Soil Microbial Functioning In Coastal Wetlands Exposed To Environmental Stressors And Subsidies, Shelby M. Servais

FIU Electronic Theses and Dissertations

Environmental perturbations are ubiquitous features of ecosystems and shape ecological structure and function. Climate change will alter the intensity and frequency of disturbances and expose ecosystems to novel combinations of useful inputs (subsidies) and harmful inputs (stressors). Coastal wetlands are particularly vulnerable to changing environmental conditions and are increasingly exposed to effects of interacting subsidies and stressors. In particular, the Florida Coastal Everglades, which has experienced accelerated change due to a history of water management practices, is vulnerable to new disturbances associated with climate change. The low-lying Florida Everglades faces multiple disturbances from storm surge, nutrient enrichment, and sea-level rise ...

Environmental Dynamics Of Dissolved Organic Matter And Dissolved Black Carbon In Fluvial Systems: Effects Of Biogeochemistry And Land Use, J. Alan Roebuck Jr.

FIU Electronic Theses and Dissertations

Black carbon (BC) is an organic residue formed primarily from biomass burning (e.g., wildfires) and fossil fuel combustion. Until recently, it was understood that BC was highly recalcitrant and stabilized in soils over millennial scales. However, a fraction of the material can be solubilized and transported in fluvial systems as dissolved BC (DBC), which represents on average 10% of the global export of dissolved organic carbon (DOC) from rivers to coastal systems. The composition of DBC controls its reactivity, and it has been linked with a variety of in-stream processes that induce both carbon sequestration and evasion of CO₂ ...

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape ...

Carbon Dynamics In Tropical Lake Malawi, Maxon Ngochera

Theses and Dissertations

Large lakes of the world play a vital role in the global carbon cycle as they act both as conduits and sinks of terrestrially and atmospherically derived carbon. Lake Malawi, lying at the extreme southernmost end of the East African Rift Valley is one of the largest, deepest and most ancient of the African Great Lakes. In this study, the spatial and seasonal variation of direct measurements of air and water pCO2 were taken for a period of one annual cycle using a vessel of opportunity along the north-south axis of Lake Malawi. These data, together with limnological and meteorological ...

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein ...

Applications Of Reservoir Limnology Theory And Steady-State Modeling To Eutrophication Management In Beaver Lake, Arkansas, Matthew Rich

Theses and Dissertations

Reservoir limnology theory predicts that phytoplankton biomass (PB) is greatest in riverine-transition zones and least in lacustrine zones leading to an inverse pattern in water clarity. These theoretical patterns were utilized to create a statistical model of chlorophyll-a (Chl-a), an indicator of PB, and Secchi transparency (ST), an indicator of Chl-a, in Beaver Lake, Arkansas, a 12,800-ha reservoir, in order to hindcast historical conditions. Sampling for Chl-a, ST, and photic depth occurred semimonthly at 12 locations along a 78-km transect from the river inflow to the dam during the 2015 growing season. The ratio of Chl-a and ST measured ...

Recent Climate Warming Drives Ecological Change In A Remote High-Arctic Lake, Lineke Woelders, Jan Lenaerts, Kimberley Hagemans, Keechy Akkerman, Thomas B. Van Hoof, Wim Z. Hoek

University Libraries Open Access Fund Supported Publications

The high Arctic is the fastest warming region on Earth, evidenced by extreme near-surface temperature increase in non-summer seasons, recent rapid sea ice decline and permafrost melting since the early 1990’s. Understanding the impact of climate change on the sensitive Arctic ecosystem to climate change has so far been hampered by the lack of time-constrained, high-resolution records and by implicit climate data analyses. Here, we show evidence of sharp growth in freshwater green algae as well as distinct diatom assemblage changes since ~1995, retrieved from a high-Arctic (80 °N) lake sediment record on Barentsøya (Svalbard). The proxy record approaches ...