Life Sciences Commons^™

Connectivity Of Coastal And Oceanic Ecosystems: Pelagic Habitat Use By Juvenile Reef Fishes In The Gulf Of Mexico, Katie Bowen

HCNSO Student Theses and Dissertations

The assemblage structure, abundance, biomass, and vertical distribution of juvenile reef fishes in the offshore pelagic habitat of the northern Gulf of Mexico are described as part of the NOAA-supported Offshore Nekton Sampling and Analysis Program. The results presented here are from a 3-month, continuous sampling series in 2011 in which discrete depth strata from 0 to 1500 m were sampled using a 10-m² MOCNESS midwater trawl. This is the first study to examine pelagic juvenile reef fish distributions across the entire oceanic northern Gulf of Mexico seaward of the continental shelf break after the Deepwater Horizon Oil Spill. …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Lidar And Machine Learning Estimation Of Hardwood Forest Biomass In Mountainous And Bottomland Environments, Bowei Xue

Graduate Theses and Dissertations

Light detection and ranging (lidar) has been applied in various forest applications, such as to retrieve forest structural information, to build statistical models for identification of tree species, and to monitor forest growth. However, despite significant progress in these areas, the choice of regression approach and parameter tuning remains an ongoing critical question. This study focused on choosing the right spatial generalization level to transform lidar point clouds to 2D images which can be further processed by mature image processing and pattern recognition approaches. It also compared the prediction ability of popular machine learning algorithms applied to aboveground forest biomass …

Enhancing The Sustainability Of Integrated Biofuel Feedstock Production Systems, Amanda Joy Ashworth

Doctoral Dissertations

As use of second-generation biofuel crops increases, so do questions about sustainability, particularly their potential to affect fossil energy consumption and greenhouse gas emissions. Nitrogen (N)-fixing legumes interseeded into switchgrass (Panicum virgatum L.) may be an alternative to inorganic fertilizer in forage-feedstock systems. Research herein is divided into four general experiments: I). N replacement and feedstock impacts from legume intercrops and biochar in switchgrass; II). N-fixation rates in intercrop systems; III). impacts of biofuel systems under enhanced climate change; and, IV). projected sustainability of regional switchgrass production. Approaches included: characterization of feedstock/forage quality traits based on legume, biochar and …

Diallel Analysis Of Biomass And Ethanol Yield In Leaves Versus Stems Of Lowland Switchgrass, Alexandria Christina Desantis

Masters Theses

Switchgrass (Panicum virgatum L.) is a warm season perennial grass used widely as a forage crop. This research seeks to address improving biomass yield and predicted ethanol yield through certain traits by the following objectives: (1) differences in average biomass and predicted ethanol yields from leaves versus stems, (2) genetic variance and heritability estimates of biomass and ethanol yield traits (3) general (GCA) and specific combining ability (SCA) among the five parents for biomass and ethanol yield, and (4) correlations between agronomic and morphological traits. Five parents with varying morphological traits were crossed in a diallel design, excluding selfs. …

Phytoextraction Of Lead From Contaminated Urban Soils By Panicum Virgatum Enhanced With Phytohormone, Edta, Benomyl, And Citric Acid Application, Matthew Aderholt

Master of Science in Integrative Biology Theses

Lead (Pb) contamination in soil represents a threat to human health and cleanup efforts often requires expensive or environmentally disruptive techniques. Phytoextraction has gained attention as a possible alternative to traditional remediation methods because of lower cost and minimal soil disruption. Panicum virgatum L. (switchgrass) was chemically enhanced with applications of the soil-fungicide benomyl, chelates (EDTA and citric acid), and phytohormones for phytoextraction of Pb from contaminated urban soils in Atlanta, GA. EDTA is often regarded as the most effective chelate, but has potential problems associated with its use due to long persistence time in soil and possible Pb mobilization …

Characterization Of Two Biochars Derived From Horse Muck And Their Ability To Reduce Pathogen Transport In Soil, David Griffith

Theses and Dissertations--Biosystems and Agricultural Engineering

Biochars have been created and characterized from a variety livestock manure biomass including poultry, dairy, and swine. However, no research has been conducted on the physical and chemical makeup of biochar pyrolyzed from horse muck. Two horse muck derived biochars containing either straw (HS) or woodchip (HW) bedding were pyrolyzed at 700°C and characterized for their physical and chemical properties. Tests revealed both biochars had high alkalinity, moderate specific conductivity, and low surface area as compared to other biochars in the literature. HS contained more mineral structures than HW. Scanning electron microscopy presented differences in particle shape, size, and presence …