Biogeochemistry Commons^™

Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler

Boise State University Theses and Dissertations

Stable isotope analysis has become the method of choice for many studies investigating the paleoecology and paleoclimate of fossil mammal faunas. While organic tissues (collagen, keratins, proteins) persist for < 10⁵ years highly mineralized tooth enamel is resistant to alteration and degradation and faithfully preserves its isotopic composition for millions (> 10⁶) years. Reconstructing past climates from these records relies on both understanding both micro-scale mechanisms of isotope incorporation into individual teeth, and macro-scale changes in isotope compositions over hundreds of thousands or millions of years. In this dissertation I address three questions.

First, how does the geometry and …

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”

Relating Cyanobacteria And Physicochemical Water-Quality Properties In Willow Creek Lake, Nebraska, 2012–14, David L. Rus, Brent M. Hall, Steven A. Thomas

United States Geological Survey: Water Reports and Publications

Document abstract

Cyanobacteria (also referred to as blue-green algae) are naturally present members of phytoplankton assemblages that may detract from beneficial uses of water because some strains produce cyanotoxins that pose health hazards to people and animals. Cyanobacteria populations observed in Willow Creek Lake during 2012 through 2014 were compared to external nutrient loading from the Willow Creek drainage basin and several other physicochemical properties within the lake, including internal nutrient loading. This report is part of a cooperative study between the United States Geological Survey, the Lower Elkhorn Natural Resources District, the Nebraska Department of Environmental Quality, the Nebraska …

Reduced Carbon Use Efficiency And Increased Microbial Turnover With Soil Warming, Jianwei Li, Gangsheng Wang, Melanie A. Mayes, Steven D. Allison, Serita D. Frey, Zheng Shi, Xiao-Ming Hu, Yiqi Luo, Jerry M. Melillo

Faculty Publications

Global soil carbon (C) stocks are expected to decline with warming, and changes in microbial processes are key to this projection. However, warming responses of critical microbial parameters such as carbon use efficiency (CUE) and biomass turnover (rB) are not well understood. Here, we determine these parameters using a probabilistic inversion approach that integrates a microbial-enzyme model with 22 years of carbon cycling measurements at Harvard Forest. We find that increasing temperature reduces CUE but increases rB, and that two decades of soil warming increases the temperature sensitivities of CUE and rB. These temperature sensitivities, which are derived from decades-long …

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.

Clio: An Autonomous Vertical Sampling Vehicle For Global Ocean Biogeochemical Mapping, Michael V. Jakuba, John A. Breier, Daniel Gomez-Ibanez, Kaitlyn Tradd, Mak A. Saito

School of Earth, Environmental, & Marine Sciences Faculty Publications

We report the design, sea trials, and scientific operation of a fast vertical profiling autonomous underwater vehicle, called Clio, designed to cost-effectively improve the understanding of marine microorganism ecosystem dynamics on a global scale by collecting high-volume filter samples autonomously, in contrast to conventional techniques that require a ship’s wire.

Characterizing Diatom Biofilms And Their Influence On The Sand Biogeochemistry Of High Energy Beaches, Logan C. Jarrell

Honors Theses

High energy beaches are among the most dynamic ecological settings on Earth. Compared to mudflats, diatoms of high energy beaches have been more neglected in the literature, particularly true of the intertidal biofilms that form and dissipate with nutrient cycling and light intensity over the tidal cycle. Although short lived, the productivity of these biofilms may be critical to the organic-poor sand. Through sediment coring and subsequent analyses of the uppermost sand of three suspected biofilm stations—non-runnel, runnel crest, and runnel trough—along with seemingly bare sand as a control, this study sought to verify the presence of diatom biofilms and …

Guidelines And Considerations For Designing Field Experiments Simulating Precipitation Extremes In Forest Ecosystems, Heidi Asbjornsen, John L. Campbell, Katie A. Jennings, Matthew A. Vadeboncoeur, Cameron Mcintire, Pamela H. Templer, Richard P. Phillips, Taryn L. Bauerle, Michael C. Dietze, Serita D. Frey, Peter M. Groffman, Rosella Guerrieri, Paul J. Hanson, Eric P. Kelsey, Alan K. Knapp, Nathan G. Mcdowell, Patrick Meir, Kimberly A. Novick, Scott V. Ollinger, Will T. Pockman, Paul G. Schaberg, Stan D. Wullschleger, Melinda D. Smith, Lindsey E. Rustad

Faculty Publications

Precipitation regimes are changing in response to climate change, yet understanding of how forest ecosystems respond to extreme droughts and pluvials remains incomplete. As future precipitation extremes will likely fall outside the range of historical variability, precipitation manipulation experiments (PMEs) are critical to advancing knowledge about potential ecosystem responses. However, few PMEs have been conducted in forests compared to short-statured ecosystems, and forest PMEs have unique design requirements and constraints. Moreover, past forest PMEs have lacked coordination, limiting cross-site comparisons. Here, we review and synthesize approaches, challenges, and opportunities for conducting PMEs in forests, with the goal of guiding design …

Cover Crops May Cause Winter Warming In Snow-Covered Regions, Danica L. Lombardozzi, Gordon B. Bonan

Faculty Publications

Cover crops, grown between cash crops when soil is fallow, are a management strategy that may help mitigate climate change. The biogeochemical effects of cover crops are well documented, as they provide numerous localized benefits to farmers. We test potential biogeophysical climate impacts of idealized cover crop scenarios by assuming that cover crops are planted offseason in all crop regions throughout North America. Our results suggest that planting cover crops increases wintertime temperature up to 3 °C in central North America by decreasing albedo in regions with variable snowpack. Cover crops with higher leaf area indices increase temperature more by …

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 …

Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham

Dissertations, Theses, and Capstone Projects

Coastal megacities deposit significant amounts of carbon (C), nitrogen (N) and other pollutants into surrounding waters. These inputs, including wastewater and surface water runoff, may affect estuarine and adjacent wetland biogeochemical cycles, microbial production and ultimately greenhouse gas (GHG) efflux. In many megacities pollutant loading is typically greatest after periods of precipitation when the volume of wastewater and storm water runoff exceeds local sanitation capacity, resulting in the discharge of raw sewage into adjacent waters. These combined sewage overflow (CSO) events have received considerable attention primarily due to their potential impact on human health and eutrophication. However, whether these events …

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 δ'^{18 …}

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 Bonnet …

Responses Of Non-Native Earthworms To Experimental Eradication Of Garlic Mustard And Implications For Native Vegetation, Kristina A. Stinson, Serita D. Frey, M. R. Jackson, E. Coates-Connor, Mark A. Anthony, K. Martinez

Faculty Publications

Recent studies in invasion biology suggest that positive feedback among two or more introduced organisms facilitate establishment within a new range and drive changes in native plant communities. Here, we experimentally tested for relationships between native plants and two non-native organisms invading forest habitats in North America: garlic mustard (Alliaria petiolata, Brassicaceae) and earthworms. In two forested sites, we compared understory vegetation and earthworm biomass in plots where garlic mustard was removed for three years, plots without garlic mustard invasion, and plots invaded by garlic mustard that was not removed. Earthworm biomass was highest in the plots with garlic mustard, …

Litter Identity Affects Assimilation Of Carbon And Nitrogen By A Shredding Caddisfly, Adam C. Siders, Zacchaeus G. Compson, Bruce A. Hungate, Paul Dijkstra, George W. Koch, Adam S. Wymore, A. Stuart Grandy, Jane C. Marks

Faculty Publications

Ecologists often equate litter quality with decomposition rate. In soil and sediments, litter that is rapidly decomposed by microbes often has low concentrations of tannin and lignin and low C:N ratios. Do these same traits also favor element transfer to higher trophic levels in streams, where many insects depend on litter as their primary food source? We test the hypothesis that slow decomposition rates promote element transfer from litter to insects, whereas rapid decomposition favors microbes. We measured carbon and nitrogen fluxes from four plant species to a leaf-shredding caddisfly using isotopically labeled litter. Caddisflies assimilated a higher percentage of …

Mainland Southeast Asia In The Longue Durée: A Zooarchaeological Test Of The "Broad Spectrum Revolution" In Northern Thailand, Cyler Norman Conrad

Anthropology ETDs

In northern Thailand, previous zooarchaeological research suggests that hunter-gatherers consumed a broad diversity of animal resources during the Pleistocene-Holocene transition and afterwards (Gorman 1971a). This is a pattern characteristic of Kent Flannery’s (1969) “broad spectrum revolution” hypothesis. Based primarily on presence and absence evidence, faunal assemblages in northern Thailand typically include species of mammals, reptiles, birds, fish and shellfish, suggesting that prehistoric foragers consumed a wide range of taxa within this mainland Southeast Asian tropical environment. Although zooarchaeological analyses commonly identify this pattern within prehistoric cave and rockshelter sites, past investigations have 1) not attempted to formally test Flannery’s hypothesis, …

Minerals In The Rhizosphere: Overlooked Mediators Of Soil Nitrogen Availability To Plants And Microbes, Andrea Jilling, Marco Keiluweit, Alexandra R. Contosta, Serita D. Frey, Joshua Schimel, Jorg Schnecker, Richard G. Smith, Lisa Tiemann, A. Stuart Grandy

Faculty Publications

Despite decades of research progress, ecologists are still debating which pools and fluxes provide nitrogen (N) to plants and soil microbes across different ecosystems. Depolymerization of soil organic N is recognized as the rate-limiting step in the production of bioavailable N, and it is generally assumed that detrital N is the main source. However, in many mineral soils, detrital polymers constitute a minor fraction of total soil organic N. The majority of organic N is associated with clay-sized particles where physicochemical interactions may limit the accessibility of N-containing compounds. Although mineral-associated organic matter (MAOM) has historically been considered a critical, …

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 …

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, using multiple linear …

Geochemical Dynamics And Nitrous Oxide Release From The Hyporheic Zone Of Streams, Annika Marie Quick

Boise State University Theses and Dissertations

The hyporheic zones of streams and rivers, consisting of the sediments beneath and immediately adjacent to the stream channel, are an important site of geochemical processing. Due to the difficulty of measuring these geochemical processes in the hyporheic zone in situ with meaningful spatial and temporal resolution, we conducted multiple column and large-scale flume experiments to model 1D and 2D hyporheic flow paths and observed important geochemical reactions, including the production and consumption of nitrous oxide (N₂O). N₂O is a significant greenhouse gas, but the controls on its emissions from streams are poorly constrained. We describe …

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

Graduate 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 at …

Building Up Biogeography: Pattern To Process, William D. Pearse, A. Marcia Barbosa, Susanne A. Fritz, Sally A. Keith, Luke J. Harmon, John Harte, Daniele Silvestro, Xiao Xiao, T. Jonathan Davies

Ecology Center Publications

Linking pattern to process across spatial and temporal scales has been a key goal of the field of biogeography. In January 2017, the 8th biennial conference of the International Biogeography Society sponsored a symposium on Building up biogeography—process to pattern that aimed to review progress towards this goal. Here we present a summary of the symposium, in which we identified promising areas of current research and suggested future research directions. We focus on (1) emerging types of data such as behavioral observations and ancient DNA, (2) how to better incorporate historical data (such as fossils) to move beyond what we …

An Assessment Of Atmospheric And Meteorological Factors Regulating Red Sea Phytoplankton Growth, Wenzhao Li, Hesham El-Askary, Mohamed A. Qurban, Emmanouil Proestakis, Michael J. Garay, Olga V. Kalishnikova, Vassilis Amiridis, Antonis Gkikas, Eleni Marinou, Thomas Piechota, K. P. Manikandan

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study considers the various factors that regulate nutrients supply in the Red Sea. Multi-sensor observation and reanalysis datasets are used to examine the relationships among dust deposition, sea surface temperature (SST), and wind speed, as they may contribute to anomalous phytoplankton blooms, through time-series and correlation analyses. A positive correlation was found at 0–3 months lag between chlorophyll-a (Chl-a) anomalies and dust anomalies over the Red Sea regions. Dust deposition process was further examined with dust aerosols’ vertical distribution using satellite lidar data. Conversely, a negative correlation was found at 0–3 months lag between SST anomalies …

Importance Considered Organic Versus Inorganic Source Of Carbon To Lakes For Calculating Net Effect On Landscape C Budgets, Weiqi Lu, Shilu Wang, Kevin M. Yeager, Fang Liu, Qiangsheng Huang, Yuxue Yang, Peng Xiang, Yingchun Lü, Chong-Qiang Liu

Earth and Environmental Sciences Faculty Publications

Lakes and reservoirs transform, emit, and bury carbon that is exported from land and are thus significant components of terrestrial carbon budgets. Their significance is often assessed by integrating these water bodies into terrestrial primary production. However, the transfer of inorganic carbon (IC) is likely a sticking point for these integrations because IC is not part of net ecosystem production. Here we integrated carbon evasion and organic carbon (OC) burial in a lake in the context of inorganic and OC cycling in a karst catchment from a system perspective. The lake emitted carbon dioxide (CO₂) and buried OC …

Investigation Of Omnivorous Trophic Position In The Drilling Gastropod, Urosalpinx Cinerea, Using Stable Isotope Analysis, Molly E. Karnes, Michelle M. Casey

Scholars Week

Drill-holes found in the fossil record are an important tool to study ecological patterns of the past. It is therefore important to gain a better understanding of the role of extant drilling snails in modern ecosystems. Although traditionally considered a predator, trophic position of 3.0, specimens of the muricid Urosalpinx cinerea from Long Island Sound revealed trophic positions between 2.3 and 2.5, suggestive of an omnivorous diet. This study addresses the generality of this result by examining a U. cinerea population from Wilmington, North Carolina. Preliminary whole body, soft tissue stable isotope analysis of nitrogen and carbon was conducted on …

Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner

OES Faculty Publications

To assess phytoplankton nutritional status in seasonally oligotrophic waters of the southern Mid-Atlantic Bight, and the potential for rain to stimulate primary production in this region during summer, shipboard bioassay experiments were performed using natural seawater and phytoplankton collected north and south of the Gulf Stream. Bioassay treatments comprised iron, nitrate, iron + nitrate, iron + nitrate + phosphate, and rainwater. Phytoplankton growth was inferred from changes in chlorophyll a, inorganic nitrogen, and carbon-13 uptake, relative to unamended control treatments. Results indicated the greatest growth stimulation by iron + nitrate + phosphate, intermediate growth stimulation by rainwater, modest growth …

Biogeochemical Cycling Of Selenium In The Arctic Ocean, Kyle M. Mcquiggan

OES Theses and Dissertations

Changes in the global climate may have a pronounced effect on the biogeochemical cycling of trace elements like selenium (Se) in the Arctic Ocean. This study described the first quantitative examination of the biogeochemical cycle of selenium in the Amerasian Basin, providing the baseline from which future changes can be identified. Aerosol, dissolved and particulate water samples were collected for Se determinations during the U.S. GEOTRACES GN01 Arctic expedition that sampled the two parts of the Amerasian Basin in 2015: The Makarov Basin on the way to the North Pole and the Canada Basin on the return trip to Dutch …

An Analytical Framework For The Steady State Impact Of Carbonate Compensation On Atmospheric Co2, Anne Willem Omta

Faculty Scholarship

The deep-ocean carbonate ion concentration impacts the fraction of the marine calcium carbonate production that is buried in sediments. This gives rise to the carbonate compensation feedback, which is thought to restore the deep-ocean carbonate ion concentration on multimillennial timescales. We formulate an analytical framework to investigate the impact of carbonate compensation under various changes in the carbon cycle relevant for anthropogenic change and glacial cycles. Using this framework, we show that carbonate compensation amplifies by 15–20% changes in atmospheric CO2resulting from a redistribution of carbon between the atmosphere and ocean (e.g., due to changes in temperature, salinity, or nutrient …

Carbon Budget Of Tidal Wetlands, Estuaries, And Shelf Waters Of Eastern North America, R. G. Najjar, M. Herrmann, R. Alexander, D. J. Burdige, D. Butman, W.-J. Cai, E. A. Canuel, R. F. Chen, M. A. M. Friedrichs, M. R. Mulholland

OES Faculty Publications

Carbon cycling in the coastal zone affects global carbon budgets and is critical for understanding the urgent issues of hypoxia, acidification, and tidal wetland loss. However, there are no regional carbon budgets spanning the three main ecosystems in coastal waters: tidal wetlands, estuaries, and shelf waters. Here we construct such a budget for eastern North America using historical data, empirical models, remote sensing algorithms, and process‐based models. Considering the net fluxes of total carbon at the domain boundaries, 59 ± 12% (± 2 standard errors) of the carbon entering is from rivers and 41 ± 12% is from the atmosphere, …