Physical Sciences and Mathematics Commons^™

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

Saturating Growth Rate Against Phosphorus Concentration Explained By Macromolecular Allocation, Gabrielle Armin, Jongsun Kim, Keisuke Inomura

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed, yet the mechanisms behind the relationship remain elusive. Here, we use a mechanistic model of phytoplankton and show that the saturating relationship between growth rate and phosphorous concentration can be interpreted by intracellular macromolecular allocation. At low nutrient levels, the diffusive nutrient transport linearly increases with the phosphorous concentration, while the internal phosphorous requirement increases with the growth rate, leading to a non-linear increase in the growth rate with phosphorous. This increased phosphorous requirement is due to the increased allocation to biosynthetic and photosynthetic molecules. …

Effects Of Excessive Soil Phosphorus Accumulation On Loblolly Pine (Pinus Taeda L.) Seedlings, Hannah C. Bays

Electronic Theses and Dissertations

Many landowners in East Texas apply poultry litter to pastures as a source of nitrogen (N) for forage crops. After many years of repeated poultry litter application, soils can accumulate extremely high extractable phosphorus (P) concentrations, sometimes over 1000 mg kg^-1 of plant available P. Landowners report the conversion of these pastures to loblolly pine (Pinus taeda L.) plantations is often problematic, with poor seedling survival and abnormal tree growth. This study was conducted to assess the effects of excessive soil phosphorus on loblolly pine seedlings. An outdoor pot study was conducted using bare root seedlings and triple …

Nutrient And Sediment Dynamics Change Following A Major Flood Event On A Large, Grassland River, M. Chen, M. Guenther, J. Corman

School of Natural Resources: Faculty Publications

No abstract provided.

Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Phytoplankton account for about a half of photosynthesis in the world, making them a key player in the ecological and biogeochemical systems. One of the key traits of phytoplankton is their growth rate because it indicates their productivity and affects their competitive capability. The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed yet the mechanisms behind the relationship remain elusive. Here we use a mechanistic model and metadata of phytoplankton to show that the saturating relationship between growth rate and nitrate concentration can be interpreted by intracellular macromolecular allocation. At low nitrate levels, the …

Influence Of Recycled Water Irrigation On Triticale Nutrient Absorption, Xiaona Li, Juying Wu, Ruiwen Zheng, Honglu Liu, Wenyong Wu

IGC Proceedings (1997-2023)

No abstract provided.

Under-Ice Phytoplankton Blooms: Shedding Light On The "Invisible" Part Of Arctic Primary Production, Mathieu Ardyna, C. J. Mundy, Nicolas Mayot, Lisa C. Matthes, Laurent Oziel, Christopher Horvat, Eva Leu, Philipp Assmy, Victoria Hill, Patricia A. Matrai, Matthew Gale, Igor A. Melnikov, Kevin R. Arrigo

OES Faculty Publications

The growth of phytoplankton at high latitudes was generally thought to begin in open waters of the marginal ice zone once the highly reflective sea ice retreats in spring, solar elevation increases, and surface waters become stratified by the addition of sea-ice melt water. In fact, virtually all recent large-scale estimates of primary production in the Arctic Ocean (AO) assume that phytoplankton production in the water column under sea ice is negligible. However, over the past two decades, an emerging literature showing significant under-ice phytoplankton production on a pan-Arctic scale has challenged our paradigms of Arctic phytoplankton ecology and phenology. …

What Is The Limiting Nutrient In Winter In Urban Reservoirs? A Case Study., Precious Nyabami

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The importance of reservoirs in widely acknowledged by urban population, yet little is understood scientifically about their ability to process nutrients deposited into them in winter. Nutrients in waste water, lawns and construction runoff are deposited into reservoirs and several ecosystem services are lost which leads to what several researchers call “the urban syndrome”. Some studies have been done on the winter limnology of lakes, yet little is understood about the same process in reservoirs. To fill this missing knowledge gap, a study on one of Nebraska’s lakes (Holmes’ lake) was done. In this study, we simulated how phosphorus, nitrogen …

Impacts Of Human Recreation On Nutrient Availability And Periphyton Abundance On The Niobrara River, Matthew Chen, Jessica Corman, Sydney Kimnach, Kayla Vondracek

UCARE Research Products

In freshwater ecosystems, eutrophication can create many problems. Excess nutrients, like nitrogen or phosphorus, promote algal or cyanobacterial growth. This growth also leads to increased organic matter production and decomposition, a process that can reduce oxygen concentration in the water. When this happens, species diversity declines, transparency of the water declines, and anoxia may lead to fish kills . Of particular concern is the possibility of cyanobacteria blooms that create compounds toxic for humans. Many of the waters across Nebraska receive excessive nutrients from human activities, largely related to agriculture (Dickey 1982). However, there is one river, the Niobrara River, …

Guide To Urban Gardening In Winooski Valley, Vermont, Grace Claire O'Neil

Graduate College Dissertations and Theses

Urban gardens have become a growing interest in the Burlington, Vermont area. As interest grows, soil management, amendment, and health are integral to garden productivity. A baseline of soil health for the Burlington Area Community Gardens was created. Explored hypotheses include how nutrient concentrations changed over time (2011 to 2018) in till and no-till scenarios.

Ten sites in the Winooski Valley area were soil sampled in the Fall of 2018, along with eight sites in the Chittenden County vicinity in the Spring of 2019 for comparison. Using the Modified Morgan’s Universal Extraction Solution, soil nutrients such as phosphorus (P), potassium …

The Impact Of Eddies On Nutrient Supply, Diatom Biomass And Carbon Export In The Northern South China Sea, Yung-Yen Shih, Chin-Chang Hung, Sing-How Tuo, Huan-Jie Shao, Chun Hoe Chow, Francois L.L. Muller, Yuan-Hong Cai

OES Faculty Publications

We have investigated the effect of eddies (cold and warm eddies, CEs and WEs) on the nutrient supply to the euphotic zone and the organic carbon export from the euphotic zone to deeper parts of the water column in the northern South China Sea. Besides basic hydrographic and biogeochemical parameters, the flux of particulate organic carbon (POC), a critical index of the strength of the oceanic biological pump, was also measured at several locations within two CEs and one WE using floating sediment traps deployed below the euphotic zone. The POC flux associated with the CEs (85 ± 55 mg-C …

Effects Of Detritivores On Nutrient Dynamics And Corn Biomass In Mesocosms, Josephine Lindsey-Robbins, Angélica Vázquez-Ortega, Kevin Mccluney, Shannon Pelini

School of Earth, Environment and Society Faculty Publications

(1) Background: Strategies aimed at managing freshwater eutrophication should be based on practices that consider cropland invertebrates, climatic change, and soil nutrient cycling. Specifically, detritivores play a crucial role in the biogeochemical processes of soil through their consumptive and burrowing activities. Here, we evaluated the effectiveness of increasing detritivore abundance as a strategy for nutrient management under varied rainfall. (2) Methods: We manipulated soil macroinvertebrate abundance and rainfall amount in an agricultural mesocosms. We then measured the phosphorus, nitrogen, and carbon levels within the soil, corn, invertebrates, and soil solution. (3) Results: Increasing detritivore abundance in our soil significantly increased …

The Effects Of Citric Acid On Ph And Nutrient Uptake In Wheatgrass (Triticum Aestivum), Cristina Tusei

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Temporal Changes Of Nutrients Within The Lower Grand River Watershed And Selected Sites, Weston Scott Duley

Masters Theses

"This report presents the results of a study carried out in collaboration with the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources (MDNR) to estimate total nitrogen (TN) and total phosphorus (TP) at five USGS monitoring sites within Lower Grand River Watershed (LGRW) and two monitoring sites on the Missouri River. The objective of this study was to quantify temporal changes in TN and TP concentrations and compare those to best management practices (BMPs).

In this study, the approach to the analysis of long-term surface water-quality data by using Weighted Regressions on Time, Discharge and Seasons models …

Vitamin D: Controversy Cancer And Beyond, Cristian J. Rosales, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Vitamins are an essential part to wellbeing. This was not something always known however, as the Germ theory was the accepted thesis of the 18th century. It was found that certain accessory factors helped mitigate and even cure these diseases such as beriberi, scurvy, and rickets. Accessory factors, later coined vitamins by Casimir Funk, are an essential constituent of the human diet. Vitamin D is technically not a vitamin but functions as a steroid hormone whose most well-known purpose is calcification of the human skeleton. This helps prevent osteomalacia in adults and rickets, a serious problem in children due to …

Extending Observations Further: Using Historic Biogeochemical Data To Understand Trends In Puget Sound, Ben Larson, Stephanie Jaeger, Wendy Eash-Loucks, Kimberle Stark, Bruce Nairn

Salish Sea Ecosystem Conference

Fluctuations in Puget Sound water quality reflect a combination of natural variability and anthropogenic influence. Predictions of how future changes will unfold requires an understanding of the complex interplay between these factors. Recent and ongoing measurement of water quality parameters allow a thorough assessment of variability over short time scales, but understanding changes over longer (e.g., decadal) timescales is critical for forecasting future changes. Examining long term trends requires the use of historical data, however, measurements that pre-date modern monitoring programs can be scarce, and the detection limits are often higher than newer analytical techniques. Here, we will consider several …

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 …

Nutrient Contamination From An Agricultural Non-Point Source And Its Mitigation: A Case Study Of Eku Meadowbrook Farm, Madison County, Kentucky, Walter S. Borowski, Reid E. Buskirk, James Scott Winter, Jonathan Malzone Dr.

EKU Faculty and Staff Scholarship

Non-point sources are now responsible for most nutrient contamination in surface water and groundwater, leading to eutrophication and decreased water quality. Because of fertilizer use and animal husbandry, agricultural areas are prime sources for nutrient contamination. Consequently, it is advisable to mitigate entry of nutrients into watersheds from agricultural runoff and groundwater flow. Eastern Kentucky University (EKU) Meadowbrook Farm (Madison County, Kentucky) seeks to decrease its export of nutrients to Muddy Creek, which is tributary of the Kentucky River. To demonstrate the efficacy of any sequestration strategies, nutrient export must be measured both before and after sequestration efforts are implemented. …

Nutrient Export From A Proximal Intermittent Stream Draining Eku Meadowbrook Farm, Madison County, Kentucky, James Scott Winter, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities contribute significant amounts of nutrients that contaminate surface and subsurface water. Eastern Kentucky University (EKU) Meadowbrook Farm (Madison County, Kentucky) seeks to decrease its export of nutrients to Muddy Creek using sequestration techniques. The first step in the overall process is to determine nutrient export at present, before sequestration efforts take place. Here we estimate the export of phosphate, nitrate, and ammonium during Tropical Storm Cindy (July 22 to 24, 2017) from a proximal, intermittent stream, named the BRC. This stream drains a representative portion the Farm, receiving water from a dairy complex, pasture, and cropland.

To estimate …

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

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

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 (PO₄^3-) 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

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 …

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

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 (PO₄^3-) 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 …

Limiting Nutrient Contaminants From Agricultural Non-Point Sources: Nutrient Monitoring At Eku’S Meadowbrook Farm, Madison County, Kentucky, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Sources of contamination to U.S. waterways have largely shifted from industrial, point sources to agricultural and other non-point sources associated with common human activities. EKU’s Meadowbrook Farm explores best-practices in agriculture and animal husbandry that not only act to increase the efficiency of farm operations, but also to limit environmental effects such as the eutrophification of its neighboring watershed.

We recently started a collaboration with the Farm and the EKU Department of Agriculture, which are developing methods to sequester phosphorus and thus limit nutrient export to the adjacent Muddy Creek watershed. Our task is to quantify the amount of phosphorus …

Modelling Of Dreissenid Mussel Impacts On Lake Michigan, Chunqi Shen

Theses and Dissertations

Invasive dreissenid mussel appear to have profoundly altered Great Lakes food webs and nutrient cycles during the past several decades. Recent declines of phytoplankton were supposed to be highly related with the increase of mussel population. These phytoplankton declines were further found to be coincident with declines in the abundance of planktivorous fish. In addition, the resurgence of Cladophora in Great lakes was estimated to be associated with the high density colonization of mussels. More light is available at lake bottom due to the mussels’ graze effect. The mussels further promote Cladophora growth by fertilizing it with nutrient-rich excrement. And …

Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick

OES Faculty Publications

Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, …

Temporal And Spatial Nutrient Trends Of The Lower Boise River, Southwest Idaho, Brian M. Yelen

Boise State University Theses and Dissertations

Elevated nutrients, orthophosphate and nitrate, in the Lower Boise River (LBR) in southwest Idaho may be attributed to contamination from agriculture runoff draining into tributaries and/or waste water treatment plants (WWTP). To better understand the sources and associated spatial and temporal dynamics of nutrient loading to the LBR, a series of high resolution synoptic sampling events were conducted. Six separate synoptic sampling events were conducted along approximately 65 miles, from upstream near the city of Boise to the confluence with the Snake River, seasonally from July 2012 to October 2013 with a sampling increment of approximately 0.5 miles. The samples …

Nutrient Movements Through Ruminant Livestock Production Systems, Adegbola T. Adesogan, Jose C. B. Dubeux, Lynn E. Sollenberger

IGC Proceedings (1997-2023)

Considerable attention has been paid to reducing nutrient emissions from ruminant livestock in the last few decades. This area will continue to attract considerable research in the future due to increasing farm sizes in some developed countries as well as the increasing demand for meat and dairy products, particularly in developing countries. This paper discusses the deposition and losses of carbon and nitrogen in soils and plants in grazed and harvested forage systems as well as utilization and losses of both nutrients by ruminants in both systems. The paper also outlines several soil, plant, and animal-focused strategies that can be …